A Long Distance Laser Altimeter for Terrain Relative Navigation and Spacecraft Landing

NASA Technical Reports Server (NTRS)

Pierrottet, Diego F.; Amzajerdian, Farzin; Barnes, Bruce W.

2014-01-01

A high precision laser altimeter was developed under the Autonomous Landing and Hazard Avoidance (ALHAT) project at NASA Langley Research Center. The laser altimeter provides slant-path range measurements from operational ranges exceeding 30 km that will be used to support surface-relative state estimation and navigation during planetary descent and precision landing. The altimeter uses an advanced time-of-arrival receiver, which produces multiple signal-return range measurements from tens of kilometers with 5 cm precision. The transmitter is eye-safe, simplifying operations and testing on earth. The prototype is fully autonomous, and able to withstand the thermal and mechanical stresses experienced during test flights conducted aboard helicopters, fixed-wing aircraft, and Morpheus, a terrestrial rocket-powered vehicle developed by NASA Johnson Space Center. This paper provides an overview of the sensor and presents results obtained during recent field experiments including a helicopter flight test conducted in December 2012 and Morpheus flight tests conducted during March of 2014.

Efficiency Benefits Using the Terminal Area Precision Scheduling and Spacing System

NASA Technical Reports Server (NTRS)

Thipphavong, Jane; Swenson, Harry N.; Lin, Paul; Seo, Anthony Y.; Bagasol, Leonard N.

2011-01-01

NASA has developed a capability for terminal area precision scheduling and spacing (TAPSS) to increase the use of fuel-efficient arrival procedures during periods of traffic congestion at a high-density airport. Sustained use of fuel-efficient procedures throughout the entire arrival phase of flight reduces overall fuel burn, greenhouse gas emissions and noise pollution. The TAPSS system is a 4D trajectory-based strategic planning and control tool that computes schedules and sequences for arrivals to facilitate optimal profile descents. This paper focuses on quantifying the efficiency benefits associated with using the TAPSS system, measured by reduction of level segments during aircraft descent and flight distance and time savings. The TAPSS system was tested in a series of human-in-the-loop simulations and compared to current procedures. Compared to the current use of the TMA system, simulation results indicate a reduction of total level segment distance by 50% and flight distance and time savings by 7% in the arrival portion of flight (200 nm from the airport). The TAPSS system resulted in aircraft maintaining continuous descent operations longer and with more precision, both achieved under heavy traffic demand levels.

COBALT: A GN&C Payload for Testing ALHAT Capabilities in Closed-Loop Terrestrial Rocket Flights

NASA Technical Reports Server (NTRS)

Carson, John M., III; Amzajerdian, Farzin; Hines, Glenn D.; O'Neal, Travis V.; Robertson, Edward A.; Seubert, Carl; Trawny, Nikolas

2016-01-01

The COBALT (CoOperative Blending of Autonomous Landing Technology) payload is being developed within NASA as a risk reduction activity to mature, integrate and test ALHAT (Autonomous precision Landing and Hazard Avoidance Technology) systems targeted for infusion into near-term robotic and future human space flight missions. The initial COBALT payload instantiation is integrating the third-generation ALHAT Navigation Doppler Lidar (NDL) sensor, for ultra high-precision velocity plus range measurements, with the passive-optical Lander Vision System (LVS) that provides Terrain Relative Navigation (TRN) global-position estimates. The COBALT payload will be integrated onboard a rocket-propulsive terrestrial testbed and will provide precise navigation estimates and guidance planning during two flight test campaigns in 2017 (one open-loop and closed- loop). The NDL is targeting performance capabilities desired for future Mars and Moon Entry, Descent and Landing (EDL). The LVS is already baselined for TRN on the Mars 2020 robotic lander mission. The COBALT platform will provide NASA with a new risk-reduction capability to test integrated EDL Guidance, Navigation and Control (GN&C) components in closed-loop flight demonstrations prior to the actual mission EDL.

Evaluation of Aerosol Optical Thickness algorithm for Geostationary Environmental Monitoring Spectrometer (GEMS) Using the OMI Instrument over East Asia

NASA Astrophysics Data System (ADS)

Go, S.; Kim, J.; KIM, M.; Choi, M.; Lim, H.; Torres, O.; Chang, L.; Hong, J.

2016-12-01

Nitrous oxide (N2O) is a powerful greenhouse gas and ozone depleting substance. With high atmospheric backgrounds and small relative signals, N2O emissions have been challenging to observe and understand on regional scales with traditional instrumentation. Fast-response airborne measurements with high precision and accuracy can potentially bridge this observational gap. Here we present flight assessments of a new flight system based on an Aerodyne mini-spectrometer as well as a Los Gatos N2O/CO analyzer during the Fertilizer Emissions Airborne Study (FEAST). With the Scientific Aviation Mooney aircraft, we conducted test flights for both analyzers where a known calibration gas was sampled throughout the flight (`null' tests). Clear altitude/cabin-pressure dependencies were observed for both analyzers if operated in an "off-the-shelf' manner. For the remainder of test flights and the FEAST campaign we used a new flight system based on an Aerodyne mini-spectrometer with the addition of a custom pressure control/calibration system. Instead of using traditional approaches with spectral-zeros and infrequent in-flight calibrations, we employ a high-flow system with stable flow control to enable high frequency (2 minutes), short duration (15 seconds) sampling of a known calibration gas. This approach, supported by the null test, enables correction for spectral drift caused by a variety of factors while maintaining a 90% duty cycle for 1Hz sampling from an aircraft. Preliminary in-flight precisions are estimated at 0.05 ppb, 0.1 ppm, 1 ppb, and 10 ppm for N2O, CO2, CO, and H2O respectively. We also present a further 40 hours of inter-comparison in flight with a Picarro 2301-f ring-down spectrometer demonstrating consistency between CO2 and H2O measurements and no altitude dependent error.

Advances in Telemetry Capability as Demonstrated on an Affordable Precision Mortar

DTIC Science & Technology

2012-06-01

of high rate data and then broadcasting it over the rest of the flight test. Lastly an on-board data storage implementation using a MicroSD card is...broadcasting it over the rest of the flight test. Lastly an on- board data storage implementation using a MicroSD card is presented. KEY WORDS...the flight test. Lastly an on-board data storage implementation using a MicroSD card is presented. 2 GPS INTEGRATION Although ARL has

Three axis electronic flight motion simulator real time control system design and implementation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gao, Zhiyuan; Miao, Zhonghua, E-mail: zhonghua-miao@163.com; Wang, Xiaohua

2014-12-15

A three axis electronic flight motion simulator is reported in this paper including the modelling, the controller design as well as the hardware implementation. This flight motion simulator could be used for inertial navigation test and high precision inertial navigation system with good dynamic and static performances. A real time control system is designed, several control system implementation problems were solved including time unification with parallel port interrupt, high speed finding-zero method of rotary inductosyn, zero-crossing management with continuous rotary, etc. Tests were carried out to show the effectiveness of the proposed real time control system.

Three axis electronic flight motion simulator real time control system design and implementation.

PubMed

Gao, Zhiyuan; Miao, Zhonghua; Wang, Xuyong; Wang, Xiaohua

2014-12-01

A three axis electronic flight motion simulator is reported in this paper including the modelling, the controller design as well as the hardware implementation. This flight motion simulator could be used for inertial navigation test and high precision inertial navigation system with good dynamic and static performances. A real time control system is designed, several control system implementation problems were solved including time unification with parallel port interrupt, high speed finding-zero method of rotary inductosyn, zero-crossing management with continuous rotary, etc. Tests were carried out to show the effectiveness of the proposed real time control system.

Flight test experience with pilot-induced-oscillation suppressor filters

NASA Technical Reports Server (NTRS)

Shafer, M. F.; Smith, R. E.; Stewart, J. F.; Bailey, R. E.

1983-01-01

Digital flight control systems are popular for their flexibility, reliability, and power; however, their use sometimes results in deficient handling qualities, including pilot-induced oscillation (PIO), which can require extensive redesign of the control system. When redesign is not immediately possible, temporary solutions, such as the PIO suppression (PIOS) filter developed for the Space Shuttle, have been proposed. To determine the effectiveness of such PIOS filters on more conventional, high-performance aircraft, three experiments were performed using the NASA F-8 digital fly-by-wire and USAF/Calspan NT-33 variable-stability aircraft. Two types of PIOS filters were evaluated, using high-gain, precision tasks (close formation, probe-and-drogue refueling, and precision touch-and-go landing) with a time delay or a first-order lag added to make the aircraft prone to PIO. Various configurations of the PIOS filter were evaluated in the flight programs, and most of the PIOS filter configurations reduced the occurrence of PIOs and improved the handling qualities of the PIO-prone aircraft. These experiments also confirmed the influence of high-gain tasks and excessive control system time delay in evoking pilot-induced oscillations.

Flight test experience with pilot-induced-oscillation suppression filters

NASA Technical Reports Server (NTRS)

Shafer, M. F.; Smith, R. E.; Stewart, J. F.; Bailey, R. E.

1984-01-01

Digital flight control systems are popular for their flexibility, reliability, and power; however, their use sometimes results in deficient handling qualities, including pilot-induced oscillation (PIO), which can require extensive redesign of the control system. When redesign is not immediately possible, temporary solutions, such as the PIO suppression (PIOS) filter developed for the Space Shuttle, have been proposed. To determine the effectiveness of such PIOS filters on more conventional, high-performance aircraft, three experiments were performed using the NASA F-8 digital fly-by-wire and USAF/Calspan NT-33 variable-stability aircraft. Two types of PIOS filters were evaluated, using high-gain, precision tasks (close formation, probe-and-drogue refueling, and precision touch-and-go landing) with a time delay or a first-order lag added to make the aircraft prone to PIO. Various configurations of the PIOS filter were evaluated in the flight programs, and most of the PIOS filter configurations reduced the occurrence of PIOs and improved the handling qualities of the PIO-prone aircraft. These experiments also confirmed the influence of high-gain tasks and excessive control system time delay in evoking pilot-induced oscillations.

Value of Sample Return and High Precision Analyses: Need for A Resource of Compelling Stories, Metaphors and Examples for Public Speakers

NASA Technical Reports Server (NTRS)

Allton, J. H.

2017-01-01

There is widespread agreement among planetary scientists that much of what we know about the workings of the solar system comes from accurate, high precision measurements on returned samples. Precision is a function of the number of atoms the instrumentation is able to count. Accuracy depends on the calibration or standardization technique. For Genesis, the solar wind sample return mission, acquiring enough atoms to ensure precise SW measurements and then accurately quantifying those measurements were steps known to be non-trivial pre-flight. The difficulty of precise and accurate measurements on returned samples, and why they cannot be made remotely, is not communicated well to the public. In part, this is be-cause "high precision" is abstract and error bars are not very exciting topics. This paper explores ideas for collecting and compiling compelling metaphors and colorful examples as a resource for planetary science public speakers.

Actuated forebody strake controls for the F-18 high alpha research vehicle

NASA Technical Reports Server (NTRS)

Murri, Daniel G.; Shah, Gautam H.; Dicarlo, Daniel J.; Trilling, Todd W.

1993-01-01

A series of ground-based studies have been conducted to develop actuated forebody strake controls for flight test evaluations using the NASA F-18 High-Alpha Research Vehicle. The actuated forebody strake concept has been designed to provide increased levels of yaw control at high angles of attack where conventional rudders become ineffective. Results are presented from tests conducted with the flight-test strake design, including static and dynamic wind-tunnel tests, transonic wind-tunnel tests, full-scale wind-tunnel tests, pressure surveys, and flow visualization tests. Results from these studies show that a pair of conformal actuated forebody strakes applied to the F-18 HARV can provide a powerful and precise yaw control device at high angles of attack. The preparations for flight testing are described, including the fabrication of flight hardware and the development of aircraft flight control laws. The primary objectives of the flight tests are to provide flight validation of the groundbased studies and to evaluate the use of this type of control to enhance fighter aircraft maneuverability.

Time of flight system on a chip

NASA Technical Reports Server (NTRS)

Paschalidis, Nicholas P. (Inventor)

2006-01-01

A CMOS time-of-flight TOF system-on-a-chip SoC for precise time interval measurement with low power consumption and high counting rate has been developed. The analog and digital TOF chip may include two Constant Fraction Discriminators CFDs and a Time-to-Digital Converter TDC. The CFDs can interface to start and stop anodes through two preamplifiers and perform signal processing for time walk compensation (110). The TDC digitizes the time difference with reference to an off-chip precise external clock (114). One TOF output is an 11-bit digital word and a valid event trigger output indicating a valid event on the 11-bit output bus (116).

Proto-Flight Manipulator Arm (P-FMA)

NASA Technical Reports Server (NTRS)

Britton, W. R.

1977-01-01

The technical development of the Proto-Flight Manipulator Arm (P-FMA) which is a seven-degree-of-freedom general-purpose arm capable of being remotely operated in an earth orbital environment is discussed. The P-FMA is a unique manipulator, combining the capabilities of significant dexterity, high tip forces, precise motion control, gear backdriveability, high end effector grip forces and torques, and the quality of flightworthiness. The 2.4-meter (8-foot) arm weighs 52.2 kilograms (115 pounds).

Identification and quantification of nitrofurazone metabolites by ultraperformance liquid chromatography-quadrupole time-of-flight high-resolution mass spectrometry with precolumn derivatization.

PubMed

Zhang, Shuai; Li, PeiPei; Yan, Zhongyong; Long, Ju; Zhang, Xiaojun

2017-03-01

An ultraperformance liquid chromatography-quadrupole time-of-flight high-resolution mass spectrometry method was developed and validated for the determination of nitrofurazone metabolites. Precolumn derivatization with 2,4-dinitrophenylhydrazine and p-dimethylaminobenzaldehyde as an internal standard was used successfully to determine the biomarker 5-nitro-2-furaldehyde. In negative electrospray ionization mode, the precise molecular weights of the derivatives were 320.0372 for the biomarker and 328.1060 for the internal standard (relative error 1.08 ppm). The matrix effect was evaluated and the analytical characteristics of the method and derivatization reaction conditions were validated. For comparison purposes, spiked samples were tested by both internal and external standard methods. The results show high precision can be obtained with p-dimethylaminobenzaldehyde as an internal standard for the identification and quantification of nitrofurazone metabolites in complex biological samples. Graphical Abstract A simplified preparation strategy for biological samples.

Selection and use of TLDS for high precision NERVA shielding measurements

NASA Technical Reports Server (NTRS)

Woodsum, H. C.

1972-01-01

An experimental evaluation of thermoluminescent dosimeters was performed in order to select high precision dosimeters for a study whose purpose is to measure gamma streaming through the coolant passages of a simulated flight type internal NERVA reactor shield. Based on this study, the CaF2 chip TLDs are the most reproducible dosimeters with reproducibility generally within a few percent, but none of the TLDs tested met the reproducibility criterion of plus or minus 2%.

Colloid Microthruster Flight Performance Results from Space Technology 7 Disturbance Reduction System

NASA Technical Reports Server (NTRS)

Ziemer, John; Marrese-Reading, Colleen; Dunn, Charley; Romero-Wolf, Andrew; Cutler, Curt; Javidnia, Shahram; Li, Thanh; Li, Irena; Franklin, Garth; Barela, Phil;

Hard X-ray Detector Calibrations for the FOXSI Sounding Rocket

NASA Astrophysics Data System (ADS)

Lopez, A.; Glesener, L.; Buitrago Casas, J. C.; Han, R.; Ishikawa, S. N.; Christe, S.; Krucker, S.

2015-12-01

In the study of high-energy solar flares, detailed X-ray images and spectra of the Sun are required. The Focusing Optics X-ray Solar Imager (FOXSI) sounding rocket experiment is used to test direct-focusing X-ray telescopes and Double-sided Silicon Strip Detectors (DSSD) for solar flare study and to further understand coronal heating. The measurement of active region differential emission measures, flare temperatures, and possible quiet-Sun emission requires a precisely calibrated spectral response. This poster describes recent updates in the calibration of FOXSI's DSSDs based on new calibration tests that were performed after the second flight. The gain for each strip was recalculated using additional radioactive sources. Additionally, the varying strip sensitivity across the detectors was investigated and based on these measurements, the flight images were flatfielded. These improvements lead to more precise X-ray data for future FOXSI flights and show promise for these new technologies in imaging the Sun.

High precision electric gate for time-of-flight ion mass spectrometers

NASA Technical Reports Server (NTRS)

Sittler, Edward C. (Inventor)

2011-01-01

A time-of-flight mass spectrometer having a chamber with electrodes to generate an electric field in the chamber and electric gating for allowing ions with a predetermined mass and velocity into the electric field. The design uses a row of very thin parallel aligned wires that are pulsed in sequence so the ion can pass through the gap of two parallel plates, which are biased to prevent passage of the ion. This design by itself can provide a high mass resolution capability and a very precise start pulse for an ion mass spectrometer. Furthermore, the ion will only pass through the chamber if it is within a wire diameter of the first wire when it is pulsed and has the right speed so it is near all other wires when they are pulsed.

High-precision cryogenic wheel mechanisms of the JWST/MIRI instrument: performance of the flight models

NASA Astrophysics Data System (ADS)

Krause, O.; Müller, F.; Birkmann, S.; Böhm, A.; Ebert, M.; Grözinger, U.; Henning, Th.; Hofferbert, R.; Huber, A.; Lemke, D.; Rohloff, R.-R.; Scheithauer, S.; Gross, T.; Fischer, T.; Luichtel, G.; Merkle, H.; Übele, M.; Wieland, H.-U.; Amiaux, J.; Jager, R.; Glauser, A.; Parr-Burman, P.; Sykes, J.

2010-07-01

The Mid Infrared Instrument (MIRI) aboard JWST is equipped with one filter wheel and two dichroic-grating wheel mechanisms to reconfigure the instrument between observing modes such as broad/narrow-band imaging, coronagraphy and low/medium resolution spectroscopy. Key requirements for the three mechanisms with up to 18 optical elements on the wheel include: (1) reliable operation at T = 7 K, (2) high positional accuracy of 4 arcsec, (3) low power dissipation, (4) high vibration capability, (5) functionality at 7 K < T < 300 K and (6) long lifetime (5-10 years). To meet these requirements a space-proven wheel concept consisting of a central MoS2-lubricated integrated ball bearing, a central torque motor for actuation, a ratchet system with monolithic CuBe flexural pivots for precise and powerless positioning and a magnetoresistive position sensor has been implemented. We report here the final performance and lessons-learnt from the successful acceptance test program of the MIRI wheel mechanism flight models. The mechanisms have been meanwhile integrated into the flight model of the MIRI instrument, ready for launch in 2014 by an Ariane 5 rocket.

A High-Precision, Fast-Response Airborne CO2 Analyzer for In Situ Sampling From the Surface to the Middle Stratosphere

NASA Technical Reports Server (NTRS)

Daube, B. C., Jr.; Boering, K. A.; Andrews, Arlyn E.; Wofsy, S. C.

2001-01-01

Two in situ CO2 analyzers have been developed for deployment on the NASA ER-2 aircraft and on stratospheric balloons. The ER-2 instrument has had more than 150 flights during 21 deployments from 1992 to 2000, resulting in a dataset with nearly pole-to-pole coverage that includes data from all seasons in both hemispheres except austral summer. In-flight calibrations show that the typical long-term (i.e. flight-to-flight) precision of the instruments is better than plus or minus 0.1 ppmv. The flight standards are traceable to standards held by the Scripps Institute of Oceanography and the National Oceanic and Atmospheric Administration's Climate Monitoring and Diagnostics Laboratory. The balloon instrument has had 8 balloon flights since September 1996, providing the first in situ observations of CO2 above approx. 21 km. In addition, the balloon instrument has been flown onboard a Cessna Citation II aircraft for sampling between the surface and 10 km. In this paper, the instrumentation and calibration procedures for both instruments are described in detail. An intercomparison of the two instruments during the Photochemistry of Ozone Loss in the Arctic Region In Summer (POLARIS) project showed that, on average, the instruments agreed to within 0.05 ppmv.

Airborne 2-Micron Double Pulsed Direct Detection IPDA Lidar for Atmospheric CO2 Measurement

NASA Technical Reports Server (NTRS)

Yu, Jirong; Petros, Mulugeta; Refaat, Tamer F.; Reithmaier, Karl; Remus, Ruben; Singh, Upendra; Johnson, Will; Boyer, Charlie; Fay, James; Johnston, Susan;

Fast in situ airborne measurement of ammonia using a mid-infrared off-axis ICOS spectrometer.

PubMed

Leen, J Brian; Yu, Xiao-Ying; Gupta, Manish; Baer, Douglas S; Hubbe, John M; Kluzek, Celine D; Tomlinson, Jason M; Hubbell, Mike R

2013-09-17

A new ammonia (NH3) analyzer was developed based on off-axis integrated cavity output spectroscopy. Its feasibility was demonstrated by making tropospheric measurements in flights aboard the Department of Energy Gulfstream-1 aircraft. The ammonia analyzer consists of an optical cell, quantum-cascade laser, gas sampling system, control and data acquisition electronics, and analysis software. The NH3 mixing ratio is determined from high-resolution absorption spectra obtained by tuning the laser wavelength over the NH3 fundamental vibration band near 9.67 μm. Excellent linearity is obtained over a wide dynamic range (0-101 ppbv) with a response rate (1/e) of 2 Hz and a precision of ±90 pptv (1σ in 1 s). Two research flights were conducted over the Yakima Valley in Washington State. In the first flight, the ammonia analyzer was used to identify signatures of livestock from local dairy farms with high vertical and spatial resolution under low wind and calm atmospheric conditions. In the second flight, the analyzer captured livestock emission signals under windy conditions. Our results demonstrate that this new ammonia spectrometer is capable of providing fast, precise, and accurate in situ observations of ammonia aboard airborne platforms to advance our understanding of atmospheric compositions and aerosol formation.

Wavefront sensing in space: flight demonstration II of the PICTURE sounding rocket payload

NASA Astrophysics Data System (ADS)

Douglas, Ewan S.; Mendillo, Christopher B.; Cook, Timothy A.; Cahoy, Kerri L.; Chakrabarti, Supriya

2018-01-01

A NASA sounding rocket for high-contrast imaging with a visible nulling coronagraph, the Planet Imaging Concept Testbed Using a Rocket Experiment (PICTURE) payload, has made two suborbital attempts to observe the warm dust disk inferred around Epsilon Eridani. The first flight in 2011 demonstrated a 5 mas fine pointing system in space. The reduced flight data from the second launch, on November 25, 2015, presented herein, demonstrate active sensing of wavefront phase in space. Despite several anomalies in flight, postfacto reduction phase stepping interferometer data provide insight into the wavefront sensing precision and the system stability for a portion of the pupil. These measurements show the actuation of a 32 × 32-actuator microelectromechanical system deformable mirror. The wavefront sensor reached a median precision of 1.4 nm per pixel, with 95% of samples between 0.8 and 12.0 nm per pixel. The median system stability, including telescope and coronagraph wavefront errors other than tip, tilt, and piston, was 3.6 nm per pixel, with 95% of samples between 1.2 and 23.7 nm per pixel.

Using wide area differential GPS to improve total system error for precision flight operations

NASA Astrophysics Data System (ADS)

Alter, Keith Warren

Total System Error (TSE) refers to an aircraft's total deviation from the desired flight path. TSE can be divided into Navigational System Error (NSE), the error attributable to the aircraft's navigation system, and Flight Technical Error (FTE), the error attributable to pilot or autopilot control. Improvement in either NSE or FTE reduces TSE and leads to the capability to fly more precise flight trajectories. The Federal Aviation Administration's Wide Area Augmentation System (WAAS) became operational for non-safety critical applications in 2000 and will become operational for safety critical applications in 2002. This navigation service will provide precise 3-D positioning (demonstrated to better than 5 meters horizontal and vertical accuracy) for civil aircraft in the United States. Perhaps more importantly, this navigation system, which provides continuous operation across large regions, enables new flight instrumentation concepts which allow pilots to fly aircraft significantly more precisely, both for straight and curved flight paths. This research investigates the capabilities of some of these new concepts, including the Highway-In-The Sky (HITS) display, which not only improves FTE but also reduces pilot workload when compared to conventional flight instrumentation. Augmentation to the HITS display, including perspective terrain and terrain alerting, improves pilot situational awareness. Flight test results from demonstrations in Juneau, AK, and Lake Tahoe, CA, provide evidence of the overall feasibility of integrated, low-cost flight navigation systems based on these concepts. These systems, requiring no more computational power than current-generation low-end desktop computers, have immediate applicability to general aviation flight from Cessnas to business jets and can support safer and ultimately more economical flight operations. Commercial airlines may also, over time, benefit from these new technologies.

The flight test of Pi-SAR(L) for the repeat-pass interferometric SAR

NASA Astrophysics Data System (ADS)

Nohmi, Hitoshi; Shimada, Masanobu; Miyawaki, Masanori

2006-09-01

This paper describes the experiment of the repeat pass interferometric SAR using Pi-SAR(L). The air-borne repeat-pass interferometric SAR is expected as an effective method to detect landslide or predict a volcano eruption. To obtain a high-quality interferometric image, it is necessary to make two flights on the same flight pass. In addition, since the antenna of the Pi-SAR(L) is secured to the aircraft, it is necessary to fly at the same drift angle to keep the observation direction same. We built a flight control system using an auto pilot which has been installed in the airplane. This navigation system measures position and altitude precisely with using a differential GPS, and the PC Navigator outputs a difference from the desired course to the auto pilot. Since the air density is thinner and the speed is higher than the landing situation, the gain of the control system is required to be adjusted during the repeat pass flight. The observation direction could be controlled to some extent by adjusting a drift angle with using a flight speed control. The repeat-pass flight was conducted in Japan for three days in late November. The flight was stable and the deviation was within a few meters for both horizontal and vertical direction even in the gusty condition. The SAR data were processed in time domain based on range Doppler algorism to make the complete motion compensation. Thus, the interferometric image processed after precise phase compensation is shown.

Thermospheric temperature measurement technique.

NASA Technical Reports Server (NTRS)

Hueser, J. E.; Fowler, P.

1972-01-01

A method for measurement of temperature in the earth's lower thermosphere from a high-velocity probes is described. An undisturbed atmospheric sample is admitted to the instrument by means of a free molecular flow inlet system of skimmers which avoids surface collisions of the molecules prior to detection. Measurement of the time-of-flight distribution of an initially well-localized group of nitrogen metastable molecular states produced in an open, crossed electron-molecular beam source, yields information on the atmospheric temperature. It is shown that for high vehicle velocities, the time-of-flight distribution of the metastable flux is a sensitive indicator of atmospheric temperature. The temperature measurement precision should be greater than 94% at the 99% confidence level over the range of altitudes from 120-170 km. These precision and altitude range estimates are based on the statistical consideration of the counting rates achieved with a multichannel analyzer using realistic values for system parameters.

Development and flight test of a deployable precision landing system

NASA Technical Reports Server (NTRS)

Sim, Alex G.; Murray, James E.; Neufeld, David C.; Reed, R. Dale

1994-01-01

A joint NASA Dryden Flight Research Facility and Johnson Space Center program was conducted to determine the feasibility of the autonomous recovery of a spacecraft using a ram-air parafoil system for the final stages of entry from space that included a precision landing. The feasibility of this system was studied using a flight model of a spacecraft in the generic shape of a flattened biconic that weighed approximately 150 lb and was flown under a commercially available, ram-air parachute. Key elements of the vehicle included the Global Positioning System guidance for navigation, flight control computer, ultrasonic sensing for terminal altitude, electronic compass, and onboard data recording. A flight test program was used to develop and refine the vehicle. This vehicle completed an autonomous flight from an altitude of 10,000 ft and a lateral offset of 1.7 miles that resulted in a precision flare and landing into the wind at a predetermined location. At times, the autonomous flight was conducted in the presence of winds approximately equal to vehicle airspeed. Several novel techniques for computing the winds postflight were evaluated. Future program objectives are also presented.

Flight control and landing precision in the nocturnal bee Megalopta is robust to large changes in light intensity.

PubMed

Baird, Emily; Fernandez, Diana C; Wcislo, William T; Warrant, Eric J

2015-01-01

Like their diurnal relatives, Megalopta genalis use visual information to control flight. Unlike their diurnal relatives, however, they do this at extremely low light intensities. Although Megalopta has developed optical specializations to increase visual sensitivity, theoretical studies suggest that this enhanced sensitivity does not enable them to capture enough light to use visual information to reliably control flight in the rainforest at night. It has been proposed that Megalopta gain extra sensitivity by summing visual information over time. While enhancing the reliability of vision, this strategy would decrease the accuracy with which they can detect image motion-a crucial cue for flight control. Here, we test this temporal summation hypothesis by investigating how Megalopta's flight control and landing precision is affected by light intensity and compare our findings with the results of similar experiments performed on the diurnal bumblebee Bombus terrestris, to explore the extent to which Megalopta's adaptations to dim light affect their precision. We find that, unlike Bombus, light intensity does not affect flight and landing precision in Megalopta. Overall, we find little evidence that Megalopta uses a temporal summation strategy in dim light, while we find strong support for the use of this strategy in Bombus.

Flight control and landing precision in the nocturnal bee Megalopta is robust to large changes in light intensity

PubMed Central

Baird, Emily; Fernandez, Diana C.; Wcislo, William T.; Warrant, Eric J.

2015-01-01

Like their diurnal relatives, Megalopta genalis use visual information to control flight. Unlike their diurnal relatives, however, they do this at extremely low light intensities. Although Megalopta has developed optical specializations to increase visual sensitivity, theoretical studies suggest that this enhanced sensitivity does not enable them to capture enough light to use visual information to reliably control flight in the rainforest at night. It has been proposed that Megalopta gain extra sensitivity by summing visual information over time. While enhancing the reliability of vision, this strategy would decrease the accuracy with which they can detect image motion—a crucial cue for flight control. Here, we test this temporal summation hypothesis by investigating how Megalopta's flight control and landing precision is affected by light intensity and compare our findings with the results of similar experiments performed on the diurnal bumblebee Bombus terrestris, to explore the extent to which Megalopta's adaptations to dim light affect their precision. We find that, unlike Bombus, light intensity does not affect flight and landing precision in Megalopta. Overall, we find little evidence that Megalopta uses a temporal summation strategy in dim light, while we find strong support for the use of this strategy in Bombus. PMID:26578977

Space Shuttle stability and control flight test techniques

NASA Technical Reports Server (NTRS)

Cooke, D. R.

1980-01-01

A unique approach for obtaining vehicle aerodynamic characteristics during entry has been developed for the Space Shuttle. This is due to the high cost of Shuttle testing, the need to open constraints for operational flights, and the fact that all flight regimes are flown starting with the first flight. Because of uncertainties associated with predicted aerodynamic coefficients, nine flight conditions have been identified at which control problems could occur. A detailed test plan has been developed for testing at these conditions and is presented. Due to limited testing, precise computer initiated maneuvers are implemented. These maneuvers are designed to optimize the vehicle motion for determining aerodynamic coefficients. Special sensors and atmospheric measurements are required to provide stability and control flight data during an entire entry. The techniques employed in data reduction are proven programs developed and used at NASA/DFRC.

CVD diamond detector with interdigitated electrode pattern for time-of-flight energy-loss measurements of low-energy ion bunches

NASA Astrophysics Data System (ADS)

Cayzac, W.; Pomorski, M.; Blažević, A.; Canaud, B.; Deslandes, D.; Fariaut, J.; Gontier, D.; Lescoute, E.; Marmouget, J. G.; Occelli, F.; Oudot, G.; Reverdin, C.; Sauvestre, J. E.; Sollier, A.; Soullié, G.; Varignon, C.; Villette, B.

2018-05-01

Ion stopping experiments in plasma for beam energies of few hundred keV per nucleon are of great interest to benchmark the stopping-power models in the context of inertial confinement fusion and high-energy-density physics research. For this purpose, a specific ion detector on chemical-vapor-deposition diamond basis has been developed for precise time-of-flight measurements of the ion energy loss. The electrode structure is interdigitated for maximizing its sensitivity to low-energy ions, and it has a finger width of 100 μm and a spacing of 500 μm. A short single α-particle response is obtained, with signals as narrow as 700 ps at full width at half maximum. The detector has been tested with α-particle bunches at a 500 keV per nucleon energy, showing an excellent time-of-flight resolution down to 20 ps. In this way, beam energy resolutions from 0.4 keV to a few keV have been obtained in an experimental configuration using a 100 μg/cm2 thick carbon foil as an energy-loss target and a 2 m time-of-flight distance. This allows a highly precise beam energy measurement of δE/E ≈ 0.04%-0.2% and a resolution on the energy loss of 0.6%-2.5% for a fine testing of stopping-power models.

Simulation Results for Airborne Precision Spacing along Continuous Descent Arrivals

NASA Technical Reports Server (NTRS)

Barmore, Bryan E.; Abbott, Terence S.; Capron, William R.; Baxley, Brian T.

2008-01-01

This paper describes the results of a fast-time simulation experiment and a high-fidelity simulator validation with merging streams of aircraft flying Continuous Descent Arrivals through generic airspace to a runway at Dallas-Ft Worth. Aircraft made small speed adjustments based on an airborne-based spacing algorithm, so as to arrive at the threshold exactly at the assigned time interval behind their Traffic-To-Follow. The 40 aircraft were initialized at different altitudes and speeds on one of four different routes, and then merged at different points and altitudes while flying Continuous Descent Arrivals. This merging and spacing using flight deck equipment and procedures to augment or implement Air Traffic Management directives is called Flight Deck-based Merging and Spacing, an important subset of a larger Airborne Precision Spacing functionality. This research indicates that Flight Deck-based Merging and Spacing initiated while at cruise altitude and well prior to the Terminal Radar Approach Control entry can significantly contribute to the delivery of aircraft at a specified interval to the runway threshold with a high degree of accuracy and at a reduced pilot workload. Furthermore, previously documented work has shown that using a Continuous Descent Arrival instead of a traditional step-down descent can save fuel, reduce noise, and reduce emissions. Research into Flight Deck-based Merging and Spacing is a cooperative effort between government and industry partners.

Using simulation to evaluate wildlife survey designs: polar bears and seals in the Chukchi Sea.

PubMed

Conn, Paul B; Moreland, Erin E; Regehr, Eric V; Richmond, Erin L; Cameron, Michael F; Boveng, Peter L

2016-01-01

Logistically demanding and expensive wildlife surveys should ideally yield defensible estimates. Here, we show how simulation can be used to evaluate alternative survey designs for estimating wildlife abundance. Specifically, we evaluate the potential of instrument-based aerial surveys (combining infrared imagery with high-resolution digital photography to detect and identify species) for estimating abundance of polar bears and seals in the Chukchi Sea. We investigate the consequences of different levels of survey effort, flight track allocation and model configuration on bias and precision of abundance estimators. For bearded seals (0.07 animals km(-2)) and ringed seals (1.29 animals km(-2)), we find that eight flights traversing ≈7840 km are sufficient to achieve target precision levels (coefficient of variation (CV)<20%) for a 2.94×10(5) km(2) study area. For polar bears (provisionally, 0.003 animals km(-2)), 12 flights traversing ≈11 760 km resulted in CVs ranging from 28 to 35%. Estimators were relatively unbiased with similar precision over different flight track allocation strategies and estimation models, although some combinations had superior performance. These findings suggest that instrument-based aerial surveys may provide a viable means for monitoring seal and polar bear populations on the surface of the sea ice over large Arctic regions. More broadly, our simulation-based approach to evaluating survey designs can serve as a template for biologists designing their own surveys.

Using simulation to evaluate wildlife survey designs: polar bears and seals in the Chukchi Sea

PubMed Central

Conn, Paul B.; Moreland, Erin E.; Regehr, Eric V.; Richmond, Erin L.; Cameron, Michael F.; Boveng, Peter L.

2016-01-01

Logistically demanding and expensive wildlife surveys should ideally yield defensible estimates. Here, we show how simulation can be used to evaluate alternative survey designs for estimating wildlife abundance. Specifically, we evaluate the potential of instrument-based aerial surveys (combining infrared imagery with high-resolution digital photography to detect and identify species) for estimating abundance of polar bears and seals in the Chukchi Sea. We investigate the consequences of different levels of survey effort, flight track allocation and model configuration on bias and precision of abundance estimators. For bearded seals (0.07 animals km−2) and ringed seals (1.29 animals km−2), we find that eight flights traversing ≈7840 km are sufficient to achieve target precision levels (coefficient of variation (CV)<20%) for a 2.94×105 km2 study area. For polar bears (provisionally, 0.003 animals km−2), 12 flights traversing ≈11 760 km resulted in CVs ranging from 28 to 35%. Estimators were relatively unbiased with similar precision over different flight track allocation strategies and estimation models, although some combinations had superior performance. These findings suggest that instrument-based aerial surveys may provide a viable means for monitoring seal and polar bear populations on the surface of the sea ice over large Arctic regions. More broadly, our simulation-based approach to evaluating survey designs can serve as a template for biologists designing their own surveys. PMID:26909183

The development and flight test of a deployable precision landing system for spacecraft recovery

NASA Technical Reports Server (NTRS)

Sim, Alex G.; Murray, James E.; Neufeld, David C.; Reed, R. Dale

1993-01-01

A joint NASA Dryden Flight Research Facility and Johnson Space Center program was conducted to determine the feasibility of the autonomous recovery of a spacecraft using a ram-air parafoil system for the final stages of entry from space that included a precision landing. The feasibility of this system was studied using a flight model of a spacecraft in the generic shape of a flattened biconic which weighed approximately 150 lb and was flown under a commercially available, ram-air parachute. Key elements of the vehicle included the Global Positioning System guidance for navigation, flight control computer, ultrasonic sensing for terminal altitude, electronic compass, and onboard data recording. A flight test program was used to develop and refine the vehicle. This vehicle completed an autonomous flight from an altitude of 10,000 ft and a lateral offset of 1.7 miles which resulted in a precision flare and landing into the wind at a predetermined location. At times, the autonomous flight was conducted in the presence of winds approximately equal to vehicle airspeed. Several techniques for computing the winds postflight were evaluated. Future program objectives are also presented.

A source of antihydrogen for in-flight hyperfine spectroscopy

PubMed Central

Kuroda, N.; Ulmer, S.; Murtagh, D. J.; Van Gorp, S.; Nagata, Y.; Diermaier, M.; Federmann, S.; Leali, M.; Malbrunot, C.; Mascagna, V.; Massiczek, O.; Michishio, K.; Mizutani, T.; Mohri, A.; Nagahama, H.; Ohtsuka, M.; Radics, B.; Sakurai, S.; Sauerzopf, C.; Suzuki, K.; Tajima, M.; Torii, H. A.; Venturelli, L.; Wu¨nschek, B.; Zmeskal, J.; Zurlo, N.; Higaki, H.; Kanai, Y.; Lodi Rizzini, E.; Nagashima, Y.; Matsuda, Y.; Widmann, E.; Yamazaki, Y.

2014-01-01

Antihydrogen, a positron bound to an antiproton, is the simplest antiatom. Its counterpart—hydrogen—is one of the most precisely investigated and best understood systems in physics research. High-resolution comparisons of both systems provide sensitive tests of CPT symmetry, which is the most fundamental symmetry in the Standard Model of elementary particle physics. Any measured difference would point to CPT violation and thus to new physics. Here we report the development of an antihydrogen source using a cusp trap for in-flight spectroscopy. A total of 80 antihydrogen atoms are unambiguously detected 2.7 m downstream of the production region, where perturbing residual magnetic fields are small. This is a major step towards precision spectroscopy of the ground-state hyperfine splitting of antihydrogen using Rabi-like beam spectroscopy. PMID:24448273

Development and flight test of a helicopter compact, portable, precision landing system concept

NASA Technical Reports Server (NTRS)

Clary, G. R.; Bull, J. S.; Davis, T. J.; Chisholm, J. P.

1984-01-01

An airborne, radar-based, precision approach concept is being developed and flight tested as a part of NASA's Rotorcraft All-Weather Operations Research Program. A transponder-based beacon landing system (BLS) applying state-of-the-art X-band radar technology and digital processing techniques, was built and is being flight tested to demonstrate the concept feasibility. The BLS airborne hardware consists of an add-on microprocessor, installed in conjunction with the aircraft weather/mapping radar, which analyzes the radar beacon receiver returns and determines range, localizer deviation, and glide-slope deviation. The ground station is an inexpensive, portable unit which can be quickly deployed at a landing site. Results from the flight test program show that the BLS concept has a significant potential for providing rotorcraft with low-cost, precision instrument approach capability in remote areas.

Fabrication and Metrology of High-Precision Foil Mirror Mounting Elements

NASA Technical Reports Server (NTRS)

Schattenburg, Mark L.

2002-01-01

During the period of this Cooperative Agreement, MIT (Massachusetts Institute of Technology) developed advanced methods for applying silicon microstructures for the precision assembly of foil x-ray optics in support of the Constellation-X Spectroscopy X-ray Telescope (SXT) development effort at Goddard Space Flight Center (GSFC). MIT developed improved methods for fabricating and characterizing the precision silicon micro-combs. MIT also developed and characterized assembly tools and several types of metrology tools in order to characterize and reduce the errors associated with precision assembly of foil optics. Results of this effort were published and presented to the scientific community and the GSFC SXT team. A bibliography of papers and presentations is offered.

Abdicating power for control: a precision timing strategy to modulate function of flight power muscles.

PubMed

Sponberg, S; Daniel, T L

2012-10-07

Muscles driving rhythmic locomotion typically show strong dependence of power on the timing or phase of activation. This is particularly true in insects' main flight muscles, canonical examples of muscles thought to have a dedicated power function. However, in the moth (Manduca sexta), these muscles normally activate at a phase where the instantaneous slope of the power-phase curve is steep and well below maximum power. We provide four lines of evidence demonstrating that, contrary to the current paradigm, the moth's nervous system establishes significant control authority in these muscles through precise timing modulation: (i) left-right pairs of flight muscles normally fire precisely, within 0.5-0.6 ms of each other; (ii) during a yawing optomotor response, left-right muscle timing differences shift throughout a wider 8 ms timing window, enabling at least a 50 per cent left-right power differential; (iii) timing differences correlate with turning torque; and (iv) the downstroke power muscles alone causally account for 47 per cent of turning torque. To establish (iv), we altered muscle activation during intact behaviour by stimulating individual muscle potentials to impose left-right timing differences. Because many organisms also have muscles operating with high power-phase gains (Δ(power)/Δ(phase)), this motor control strategy may be ubiquitous in locomotor systems.

Abdicating power for control: a precision timing strategy to modulate function of flight power muscles

PubMed Central

Sponberg, S.; Daniel, T. L.

2012-01-01

Muscles driving rhythmic locomotion typically show strong dependence of power on the timing or phase of activation. This is particularly true in insects' main flight muscles, canonical examples of muscles thought to have a dedicated power function. However, in the moth (Manduca sexta), these muscles normally activate at a phase where the instantaneous slope of the power–phase curve is steep and well below maximum power. We provide four lines of evidence demonstrating that, contrary to the current paradigm, the moth's nervous system establishes significant control authority in these muscles through precise timing modulation: (i) left–right pairs of flight muscles normally fire precisely, within 0.5–0.6 ms of each other; (ii) during a yawing optomotor response, left—right muscle timing differences shift throughout a wider 8 ms timing window, enabling at least a 50 per cent left–right power differential; (iii) timing differences correlate with turning torque; and (iv) the downstroke power muscles alone causally account for 47 per cent of turning torque. To establish (iv), we altered muscle activation during intact behaviour by stimulating individual muscle potentials to impose left—right timing differences. Because many organisms also have muscles operating with high power–phase gains (Δpower/Δphase), this motor control strategy may be ubiquitous in locomotor systems. PMID:22833272

Manual flying of curved precision approaches to landing with electromechanical instrumentation. A piloted simulation study

NASA Technical Reports Server (NTRS)

Knox, Charles E.

1993-01-01

A piloted simulation study was conducted to examine the requirements for using electromechanical flight instrumentation to provide situation information and flight guidance for manually controlled flight along curved precision approach paths to a landing. Six pilots were used as test subjects. The data from these tests indicated that flight director guidance is required for the manually controlled flight of a jet transport airplane on curved approach paths. Acceptable path tracking performance was attained with each of the three situation information algorithms tested. Approach paths with both multiple sequential turns and short final path segments were evaluated. Pilot comments indicated that all the approach paths tested could be used in normal airline operations.

GPS-based precision orbit determination - A Topex flight experiment

NASA Technical Reports Server (NTRS)

Melbourne, William G.; Davis, Edgar S.

1988-01-01

Plans for a Topex/Poseiden flight experiment to test the accuracy of using GPS data for precision orbit determination of earth satellites are presented. It is expected that the GPS-based precision orbit determination will provide subdecimeter accuracies in the radial component of the Topex orbit when the extant gravity model is tuned for wavelengths longer than about 1000 kms. The concept, design, flight receiver, antenna system, ground processing, and data processing of GPS are examined. Also, an accurate quasi-geometric orbit determination approach called nondynamic or reduced dynamic tracking which relies on the use of the pseudorange and the carrier phase measurements to reduce orbit errors arising from mismodeled dynamics is discussed.

CLASP2: High-Precision Spectro-Polarimetery in Mg II h & k

NASA Technical Reports Server (NTRS)

Ishikawa, R.; McKenzie, D.; Trujillo Bueno, J.; Auchere, F.; Rachmeler, L.; Okamoto, T. J.; Kano, R.; Song, D.; Kubo, M.; Narukage, N.;

Achieving sub-millimetre precision with a solid-state full-field heterodyning range imaging camera

NASA Astrophysics Data System (ADS)

Dorrington, A. A.; Cree, M. J.; Payne, A. D.; Conroy, R. M.; Carnegie, D. A.

2007-09-01

We have developed a full-field solid-state range imaging system capable of capturing range and intensity data simultaneously for every pixel in a scene with sub-millimetre range precision. The system is based on indirect time-of-flight measurements by heterodyning intensity-modulated illumination with a gain modulation intensified digital video camera. Sub-millimetre precision to beyond 5 m and 2 mm precision out to 12 m has been achieved. In this paper, we describe the new sub-millimetre class range imaging system in detail, and review the important aspects that have been instrumental in achieving high precision ranging. We also present the results of performance characterization experiments and a method of resolving the range ambiguity problem associated with homodyne and heterodyne ranging systems.

Cable Tensiometer for Aircraft

NASA Technical Reports Server (NTRS)

Nunnelee, Mark (Inventor)

2008-01-01

The invention is a cable tensiometer that can be used on aircraft for real-time, in-flight cable tension measurements. The invention can be used on any aircraft cables with high precision. The invention is extremely light-weight, hangs on the cable being tested and uses a dual bending beam design with a high mill-volt output to determine tension.

Status and outlook of CHIP-TRAP: The Central Michigan University high precision Penning trap

NASA Astrophysics Data System (ADS)

Redshaw, M.; Bryce, R. A.; Hawks, P.; Gamage, N. D.; Hunt, C.; Kandegedara, R. M. E. B.; Ratnayake, I. S.; Sharp, L.

2016-06-01

At Central Michigan University we are developing a high-precision Penning trap mass spectrometer (CHIP-TRAP) that will focus on measurements with long-lived radioactive isotopes. CHIP-TRAP will consist of a pair of hyperbolic precision-measurement Penning traps, and a cylindrical capture/filter trap in a 12 T magnetic field. Ions will be produced by external ion sources, including a laser ablation source, and transported to the capture trap at low energies enabling ions of a given m / q ratio to be selected via their time-of-flight. In the capture trap, contaminant ions will be removed with a mass-selective rf dipole excitation and the ion of interest will be transported to the measurement traps. A phase-sensitive image charge detection technique will be used for simultaneous cyclotron frequency measurements on single ions in the two precision traps, resulting in a reduction in statistical uncertainty due to magnetic field fluctuations.

Precise measurement of the neutron magnetic form factor G(M)n in the few-GeV2 region.

PubMed

Lachniet, J; Afanasev, A; Arenhövel, H; Brooks, W K; Gilfoyle, G P; Higinbotham, D; Jeschonnek, S; Quinn, B; Vineyard, M F; Adams, G; Adhikari, K P; Amaryan, M J; Anghinolfi, M; Asavapibhop, B; Asryan, G; Avakian, H; Bagdasaryan, H; Baillie, N; Ball, J P; Baltzell, N A; Barrow, S; Batourine, V; Battaglieri, M; Beard, K; Bedlinskiy, I; Bektasoglu, M; Bellis, M; Benmouna, N; Berman, B L; Biselli, A S; Bonner, B E; Bookwalter, C; Bouchigny, S; Boiarinov, S; Bradford, R; Branford, D; Briscoe, W J; Bültmann, S; Burkert, V D; Calarco, J R; Careccia, S L; Carman, D S; Casey, L; Cheng, L; Cole, P L; Coleman, A; Collins, P; Cords, D; Corvisiero, P; Crabb, D; Crede, V; Cummings, J P; Dale, D; Daniel, A; Dashyan, N; De Masi, R; De Vita, R; De Sanctis, E; Degtyarenko, P V; Denizli, H; Dennis, L; Deur, A; Dhamija, S; Dharmawardane, K V; Dhuga, K S; Dickson, R; Djalali, C; Dodge, G E; Doughty, D; Dragovitsch, P; Dugger, M; Dytman, S; Dzyubak, O P; Egiyan, H; Egiyan, K S; El Fassi, L; Elouadrhiri, L; Empl, A; Eugenio, P; Fatemi, R; Fedotov, G; Fersch, R; Feuerbach, R J; Forest, T A; Fradi, A; Gabrielyan, M Y; Garçon, M; Gavalian, G; Gevorgyan, N; Giovanetti, K L; Girod, F X; Goetz, J T; Gohn, W; Golovatch, E; Gothe, R W; Graham, L; Griffioen, K A; Guidal, M; Guillo, M; Guler, N; Guo, L; Gyurjyan, V; Hadjidakis, C; Hafidi, K; Hakobyan, H; Hanretty, C; Hardie, J; Hassall, N; Heddle, D; Hersman, F W; Hicks, K; Hleiqawi, I; Holtrop, M; Hu, J; Huertas, M; Hyde-Wright, C E; Ilieva, Y; Ireland, D G; Ishkhanov, B S; Isupov, E L; Ito, M M; Jenkins, D; Jo, H S; Johnstone, J R; Joo, K; Juengst, H G; Kageya, T; Kalantarians, N; Keller, D; Kellie, J D; Khandaker, M; Khetarpal, P; Kim, K Y; Kim, K; Kim, W; Klein, A; Klein, F J; Klusman, M; Konczykowski, P; Kossov, M; Kramer, L H; Kubarovsky, V; Kuhn, J; Kuhn, S E; Kuleshov, S V; Kuznetsov, V; Laget, J M; Langheinrich, J; Lawrence, D; Lima, A C S; Livingston, K; Lowry, M; Lu, H Y; Lukashin, K; Maccormick, M; Malace, S; Manak, J J; Markov, N; Mattione, P; McAleer, S; McCracken, M E; McKinnon, B; McNabb, J W C; Mecking, B A; Mestayer, M D; Meyer, C A; Mibe, T; Mikhailov, K; Mineeva, T; Minehart, R; Mirazita, M; Miskimen, R; Mokeev, V; Moreno, B; Moriya, K; Morrow, S A; Moteabbed, M; Mueller, J; Munevar, E; Mutchler, G S; Nadel-Turonski, P; Nasseripour, R; Niccolai, S; Niculescu, G; Niculescu, I; Niczyporuk, B B; Niroula, M R; Niyazov, R A; Nozar, M; O'Rielly, G V; Osipenko, M; Ostrovidov, A I; Park, K; Park, S; Pasyuk, E; Paterson, C; Pereira, S Anefalos; Philips, S A; Pierce, J; Pivnyuk, N; Pocanic, D; Pogorelko, O; Polli, E; Popa, I; Pozdniakov, S; Preedom, B M; Price, J W; Prok, Y; Protopopescu, D; Qin, L M; Raue, B A; Riccardi, G; Ricco, G; Ripani, M; Ritchie, B G; Rosner, G; Rossi, P; Rowntree, D; Rubin, P D; Sabatié, F; Saini, M S; Salamanca, J; Salgado, C; Sandorfi, A; Santoro, J P; Sapunenko, V; Schott, D; Schumacher, R A; Serov, V S; Sharabian, Y G; Sharov, D; Shaw, J; Shvedunov, N V; Skabelin, A V; Smith, E S; Smith, L C; Sober, D I; Sokhan, D; Starostin, A; Stavinsky, A; Stepanyan, S; Stepanyan, S S; Stokes, B E; Stoler, P; Stopani, K A; Strakovsky, I I; Strauch, S; Suleiman, R; Taiuti, M; Taylor, S; Tedeschi, D J; Thompson, R; Tkabladze, A; Tkachenko, S; Ungaro, M; Vlassov, A V; Watts, D P; Wei, X; Weinstein, L B; Weygand, D P; Williams, M; Wolin, E; Wood, M H; Yegneswaran, A; Yun, J; Yurov, M; Zana, L; Zhang, J; Zhao, B; Zhao, Z W

2009-05-15

The neutron elastic magnetic form factor was extracted from quasielastic electron scattering on deuterium over the range Q;{2}=1.0-4.8 GeV2 with the CLAS detector at Jefferson Lab. High precision was achieved with a ratio technique and a simultaneous in situ calibration of the neutron detection efficiency. Neutrons were detected with electromagnetic calorimeters and time-of-flight scintillators at two beam energies. The dipole parametrization gives a good description of the data.

X-43A Flight Controls

NASA Technical Reports Server (NTRS)

Baumann, Ethan

2006-01-01

A viewgraph presentation detailing X-43A Flight controls at NASA Dryden Flight Research Center is shown. The topics include: 1) NASA Dryden, Overview and current and recent flight test programs; 2) Unmanned Aerial Vehicle Synthetic Aperture Radar (UAVSAR) Program, Program Overview and Platform Precision Autopilot; and 3) Hyper-X Program, Program Overview, X-43A Flight Controls and Flight Results.

A novel laser ranging system for measurement of ground-to-satellite distances

NASA Technical Reports Server (NTRS)

Golden, K. E.; Kind, D. E.; Leonard, S. L.; Ward, R. C.

1973-01-01

A technique was developed for improving the precision of laser ranging measurements of ground-to-satellite distances. The method employs a mode-locked laser transmitter and utilizes an image converter tube equipped with deflection plates in measuring the time of flight of the laser pulse to a distant retroreflector and back. Samples of the outgoing and returning light pulses are focussed on the photocathode of the image converter tube, whose deflection plates are driven by a high-voltage 120 MHz sine wave derived from a very stable oscillator. From the relative positions of the images produced at the output phosphor by the two light pulses, it is possible to make a precise determination of the fractional amount by which the time of flight exceeds some large integral multiple of the period of the deflection sinusoid.

Non-contact Measurement of Creep in Ultra-High-Temperature Materials

DTIC Science & Technology

2009-11-04

Task 1: Process UHTC materials at the relevant temperatures in Electrostatic Levitation for extended periods. 5 3.5 Task 2: Prepare the required high...Electrostatic Levitation ITI Industrial Tectonics, Inc. MSFC NASA George C. Marshall Space Flight Center NASA National Aeronautics and Space...was divided into certain research questions: Can high-precision UHTC spheres be processed in Electrostatic Levitation (ESL) at the relevant

An Overview of Flight Test Results for a Formation Flight Autopilot

NASA Technical Reports Server (NTRS)

Hanson, Curtis E.; Ryan, Jack; Allen, Michael J.; Jacobson, Steven R.

2002-01-01

The first flight test phase of the NASA Dryden Flight Research Center Autonomous Formation Flight project has successfully demonstrated precision autonomous station-keeping of an F/A-18 research airplane with a second F/A-18 airplane. Blended inertial navigation system (INS) and global positioning system (GPS) measurements have been communicated across an air-to-air telemetry link and used to compute relative-position estimates. A precision research formation autopilot onboard the trailing airplane controls lateral and vertical spacing while the leading airplane operates under production autopilot control. Four research autopilot gain sets have been designed and flight-tested, and each exceeds the project design requirement of steady-state tracking accuracy within 1 standard deviation of 10 ft. Performance also has been demonstrated using single- and multiple-axis inputs such as step commands and frequency sweeps. This report briefly describes the experimental formation flight systems employed and discusses the navigation, guidance, and control algorithms that have been flight-tested. An overview of the flight test results of the formation autopilot during steady-state tracking and maneuvering flight is presented.

TITAN's multiple-reflection time-of-flight isobar separator

NASA Astrophysics Data System (ADS)

Reiter, Moritz Pascal; Titan Collaboration

2016-09-01

At the ISAC facility located at TRIUMF exotic nuclei are produced by the ISOL method. Exotic nuclei are separated by a magnetic separator and transported to TRIUMF's Ion Trap for Atomic and Nuclear science (TITAN). TITAN is a system of multiple ion traps for high precision mass measurements and in-trap decay spectroscopy. Although ISAC can deliver some of the highest yields for even many of the most exotic species many measurements suffer from a strong isobaric background. This background often prevents the high precision measurement of the species of interest. To overcome this limitation an additional isobar separator based on the Multiple-Reflection Time-Of-Flight Mass Spectrometry (MR-TOF-MS) technique has been developed for TITAN. Mass selection is achieved using dynamic re-trapping of the species of interest after a time-of-flight analysis in an electrostatic isochronous reflector system. Additionally the MR-TOF-MS will, on its own, enable mass measurements of very short-lived nuclides that are weakly produced. Being able to measure all isobars of a given mass number at the same time the MR-TOF-MS can be used for beam diagnostics or determination of beam compositions. Results from the offline commissioning showing mass resolving power and separation power will be presented.

Diving-flight aerodynamics of a peregrine falcon (Falco peregrinus).

PubMed

Ponitz, Benjamin; Schmitz, Anke; Fischer, Dominik; Bleckmann, Horst; Brücker, Christoph

2014-01-01

This study investigates the aerodynamics of the falcon Falco peregrinus while diving. During a dive peregrines can reach velocities of more than 320 km h⁻¹. Unfortunately, in freely roaming falcons, these high velocities prohibit a precise determination of flight parameters such as velocity and acceleration as well as body shape and wing contour. Therefore, individual F. peregrinus were trained to dive in front of a vertical dam with a height of 60 m. The presence of a well-defined background allowed us to reconstruct the flight path and the body shape of the falcon during certain flight phases. Flight trajectories were obtained with a stereo high-speed camera system. In addition, body images of the falcon were taken from two perspectives with a high-resolution digital camera. The dam allowed us to match the high-resolution images obtained from the digital camera with the corresponding images taken with the high-speed cameras. Using these data we built a life-size model of F. peregrinus and used it to measure the drag and lift forces in a wind-tunnel. We compared these forces acting on the model with the data obtained from the 3-D flight path trajectory of the diving F. peregrinus. Visualizations of the flow in the wind-tunnel uncovered details of the flow structure around the falcon's body, which suggests local regions with separation of flow. High-resolution pictures of the diving peregrine indicate that feathers pop-up in the equivalent regions, where flow separation in the model falcon occurred.

Laser-based sensors on UAVs for quantifying local emissions of greenhouse gases

NASA Astrophysics Data System (ADS)

Zondlo, Mark; Tao, Lei; O'Brien, Anthony; Ross, Kevin; Khan, Amir; Pan, Da; Golston, Levi; Sun, Kang; DiGangi, Josh

2015-04-01

Small unmanned aerial systems (UAS) provide an ideal platform to sample both locally near an emission source as well as within the atmospheric boundary layer. However, small UAS (those with wingspans or rotors on the order of a meter) place severe constraints on sensor size (~ liter volume), mass (~ kg), and power (10s W). Laser-based sensors employing absorption techniques are ideally suited for such platforms due to their high sensitivity, high selectivity, and compact footprint. We have developed and flown compact sensors for water vapor, carbon dioxide and methane using new advances in open-path, laser-based spectroscopy on a variety of platforms ranging from remote control helicopters to long-duration UAS. Open-path spectroscopy allows for high frequency sampling (10-25 Hz) while avoiding the size/mass/power of sample delays, inlet lines, and pumps. To address the challenges of in-flight stability in changing environmental conditions and any associated flight artifacts on the measurement itself (e.g. vibrations), we use an in-line reference cell at a reduced pressure (10 hPa) to account for systematic drift continuously while in flight. Wavelength modulation spectroscopy is used at different harmonics to isolate the narrow linewidth of the in-line reference signal from the ambient, pressure-broadened absorption lineshape of the trace gas of interest. As a result, a metric of in-flight performance is achieved in real-time on the same optical pathlength as the ambient signal. To demonstrate the great potential of laser-based sensors on UAS, we deployed a 1.65 micron-based methane sensor (4 kg, 50 W, 100 ppbv precision at 10 Hz) on a UT-Dallas remote control aircraft for two weeks around gas/oil extraction activities as part of the EDF Barnett Coordinated Campaign in October 2013. We conducted thirty-four flights around a compressor station to examine the spatial and temporal characteristics of its emissions. Leaks of methane were typically lofted to altitudes well above the surface (up to 100 m). In addition, plumes were very narrow horizontally (10-30 m width) within 200 m of the emission origin. By using a mass balance approach of upwind versus downwind CH4 concentrations, coupled to meteorological wind data, the CH4 emission rate from the compressor station averaged 13 ± 5 g CH4 s-1, consistent with individual, leak surveys measured within the compressor station itself. More recently, we developed a mid-infrared version of the same sensor using an antimonide laser at 3.3 microns. This sensor has a precision of 2 ppbv CH4 at 10 Hz, a mass of 1.3 kg, and consumes 10 W of power. Flight tests show the improved precision is capable of detecting methane leaks from landfills and cattle feedlots at higher altitudes (500 m) and greater distances downwind (several km) than the near infrared CH4 sensor. Sampling strategy is particularly important for not only UAS-based flight patterns but also sensor design. Many tradeoffs exist between the sampling density of the flight pattern, sensor precision, accuracy of wind data, and geographic isolation of the source of interest, and these will be discussed in the context of airborne-based CH4 measurements in the field. The development of compact yet robust trace gas sensors to be deployed on small UAS opens new capabilities for atmospheric sensing such as quantifying local source emissions (e.g. farms, well pads), vertical profiling of trace gases in a forest canopy, and trace gas distributions in complex areas (mountains, urban canyons).

Advancing Lidar Sensors Technologies for Next Generation Landing Missions

NASA Technical Reports Server (NTRS)

Amzajerdian, Farzin; Hines, Glenn D.; Roback, Vincent E.; Petway, Larry B.; Barnes, Bruce W.; Brewster, Paul F.; Pierrottet, Diego F.; Bulyshev, Alexander

2015-01-01

Missions to solar systems bodies must meet increasingly ambitious objectives requiring highly reliable "precision landing", and "hazard avoidance" capabilities. Robotic missions to the Moon and Mars demand landing at pre-designated sites of high scientific value near hazardous terrain features, such as escarpments, craters, slopes, and rocks. Missions aimed at paving the path for colonization of the Moon and human landing on Mars need to execute onboard hazard detection and precision maneuvering to ensure safe landing near previously deployed assets. Asteroid missions require precision rendezvous, identification of the landing or sampling site location, and navigation to the highly dynamic object that may be tumbling at a fast rate. To meet these needs, NASA Langley Research Center (LaRC) has developed a set of advanced lidar sensors under the Autonomous Landing and Hazard Avoidance Technology (ALHAT) project. These lidar sensors can provide precision measurement of vehicle relative proximity, velocity, and orientation, and high resolution elevation maps of the surface during the descent to the targeted body. Recent flights onboard Morpheus free-flyer vehicle have demonstrated the viability of ALHAT lidar sensors for future landing missions to solar system bodies.

Adaptive Neural Star Tracker Calibration for Precision Spacecraft Pointing and Tracking

NASA Technical Reports Server (NTRS)

Bayard, David S.

1996-01-01

The Star Tracker is an essential sensor for precision pointing and tracking in most 3-axis stabilized spacecraft. In the interest (of) improving pointing performance by taking advantage of dramatic increases in flight computer power and memory anticipated over the next decade, this paper investigates the use of a neural net for adaptive in-flight calibration of the Star Tracker.

Temperature-Dependent Refractive Index of Cleartran® ZnS to Cryogenic Temperatures

NASA Technical Reports Server (NTRS)

Leviton, Doug; Frey, Brad

2013-01-01

First, let's talk about the CHARMS facility at NASA's Goddard Space Flight Center: Cryogenic, High-Accuracy Refraction Measuring System (CHARMS); design features for highest accuracy and precision; technologies we rely on; data products and examples; optical materials for which we've measured cryogenic refractive index.

Design of a cusped field thruster for drag-free flight

NASA Astrophysics Data System (ADS)

Liu, H.; Chen, P. B.; Sun, Q. Q.; Hu, P.; Meng, Y. C.; Mao, W.; Yu, D. R.

2016-09-01

Drag-free flight has played a more and more important role in many space missions. The thrust control system is the key unit to achieve drag-free flight by providing a precise compensation for the disturbing force except gravity. The cusped field thruster has shown a significant potential to be capable of the function due to its long life, high efficiency, and simplicity. This paper demonstrates a cusped field thruster's feasibility in drag-free flight based on its instinctive characteristics and describes a detailed design of a cusped field thruster made by Harbin Institute of Technology (HIT). Furthermore, the performance test is conducted, which shows that the cusped field thruster can achieve a continuously variable thrust from 1 to 20 mN with a low noise and high resolution below 650 W, and the specific impulse can achieve 1800 s under a thrust of 18 mN and discharge voltage of 1000 V. The thruster's overall performance indicates that the cusped field thruster is quite capable of achieving drag-free flight. With the further optimization, the cusped field thruster will exhibit a more extensive application value.

Ion microscopy with resonant ionization mass spectrometry : time-of-flight depth profiling with improved isotopic precision.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pellin, M. J.; Veryovkin, I. V.; Levine, J.

2010-01-01

There are four generally mutually exclusive requirements that plague many mass spectrometric measurements of trace constituents: (1) the small size (limited by the depth probed) of many interesting materials requires high useful yields to simply detect some trace elements, (2) the low concentrations of interesting elements require efficient discrimination from isobaric interferences, (3) it is often necessary to measure the depth distribution of elements with high surface and low bulk contributions, and (4) many applications require precise isotopic analysis. Resonant ionization mass spectrometry has made dramatic progress in addressing these difficulties over the past five years.

Aircraft as Research Tools

NASA Technical Reports Server (NTRS)

1999-01-01

Aeronautical research usually begins with computers, wind tunnels, and flight simulators, but eventually the theories must fly. This is when flight research begins, and aircraft are the primary tools of the trade. Flight research involves doing precision maneuvers in either a specially built experimental aircraft or an existing production airplane that has been modified. For example, the AD-1 was a unique airplane made only for flight research, while the NASA F-18 High Alpha Research Vehicle (HARV) was a standard fighter aircraft that was transformed into a one-of-a-kind aircraft as it was fitted with new propulsion systems, flight controls, and scientific equipment. All research aircraft are able to perform scientific experiments because of the onboard instruments that record data about its systems, aerodynamics, and the outside environment. Since the 1970's, NASA flight research has become more comprehensive, with flights involving everything form Space Shuttles to ultralights. NASA now flies not only the fastest airplanes, but some of the slowest. Flying machines continue to evolve with new wing designs, propulsion systems, and flight controls. As always, a look at today's experimental research aircraft is a preview of the future.

Further development and flight test of an autonomous precision landing system using a parafoil

NASA Technical Reports Server (NTRS)

Murray, James E.; Sim, Alex G.; Neufeld, David C.; Rennich, Patrick K.; Norris, Stephen R.; Hughes, Wesley S.

1994-01-01

NASA Dryden Flight Research Center and NASA Johnson Space Center are jointly conducting a phased program to determine the feasibility of the autonomous recovery of a spacecraft using a ram-air parafoil system for the final stages of entry from space to a precision landing. The feasibility is being studied using a flight model of a spacecraft in the generic shape of a flattened biconic that weighs approximately 120 lb and is flown under a commercially available ram-air parafoil. Key components of the vehicle include the global positioning system (GPS) guidance for navigation, a flight control computer, an electronic compass, a yaw rate gyro, and an onboard data recorder. A flight test program is being used to develop and refine the vehicle. The primary flight goal is to demonstrate autonomous flight from an altitude of 3,000 m (10,000 ft) with a lateral offset of 1.6 km (1.0 mi) to a precision soft landing. This paper summarizes the progress to date. Much of the navigation system has been tested, including a heading tracker that was developed using parameter estimation techniques and a complementary filter. The autoland portion of the autopilot is still in development. The feasibility of conducting the flare maneuver without servoactuators was investigated as a means of significantly reducing the servoactuator rate and load requirements.

Interfacing and Verifying ALHAT Safe Precision Landing Systems with the Morpheus Vehicle

NASA Technical Reports Server (NTRS)

Carson, John M., III; Hirsh, Robert L.; Roback, Vincent E.; Villalpando, Carlos; Busa, Joseph L.; Pierrottet, Diego F.; Trawny, Nikolas; Martin, Keith E.; Hines, Glenn D.

2015-01-01

The NASA Autonomous precision Landing and Hazard Avoidance Technology (ALHAT) project developed a suite of prototype sensors to enable autonomous and safe precision landing of robotic or crewed vehicles under any terrain lighting conditions. Development of the ALHAT sensor suite was a cross-NASA effort, culminating in integration and testing on-board a variety of terrestrial vehicles toward infusion into future spaceflight applications. Terrestrial tests were conducted on specialized test gantries, moving trucks, helicopter flights, and a flight test onboard the NASA Morpheus free-flying, rocket-propulsive flight-test vehicle. To accomplish these tests, a tedious integration process was developed and followed, which included both command and telemetry interfacing, as well as sensor alignment and calibration verification to ensure valid test data to analyze ALHAT and Guidance, Navigation and Control (GNC) performance. This was especially true for the flight test campaign of ALHAT onboard Morpheus. For interfacing of ALHAT sensors to the Morpheus flight system, an adaptable command and telemetry architecture was developed to allow for the evolution of per-sensor Interface Control Design/Documents (ICDs). Additionally, individual-sensor and on-vehicle verification testing was developed to ensure functional operation of the ALHAT sensors onboard the vehicle, as well as precision-measurement validity for each ALHAT sensor when integrated within the Morpheus GNC system. This paper provides some insight into the interface development and the integrated-systems verification that were a part of the build-up toward success of the ALHAT and Morpheus flight test campaigns in 2014. These campaigns provided valuable performance data that is refining the path toward spaceflight infusion of the ALHAT sensor suite.

Integrated control and display research for transition and vertical flight on the NASA V/STOL Research Aircraft (VSRA)

NASA Technical Reports Server (NTRS)

Foster, John D.; Moralez, Ernesto, III; Franklin, James A.; Schroeder, Jeffery A.

1987-01-01

Results of a substantial body of ground-based simulation experiments indicate that a high degree of precision of operation for recovery aboard small ships in heavy seas and low visibility with acceptable levels of effort by the pilot can be achieved by integrating the aircraft flight and propulsion controls. The availability of digital fly-by-wire controls makes it feasible to implement an integrated control design to achieve and demonstrate in flight the operational benefits promised by the simulation experience. It remains to validate these systems concepts in flight to establish their value for advanced short takeoff vertical landing (STOVL) aircraft designs. This paper summarizes analytical studies and simulation experiments which provide a basis for the flight research program that will develop and validate critical technologies for advanced STOVL aircraft through the development and evaluation of advanced, integrated control and display concepts, and lays out the plan for the flight program that will be conducted on NASA's V/STOL Research Aircraft (VSRA).

High precision laser ranging by time-of-flight measurement of femtosecond pulses

NASA Astrophysics Data System (ADS)

Lee, Joohyung; Lee, Keunwoo; Lee, Sanghyun; Kim, Seung-Woo; Kim, Young-Jin

2012-06-01

Time-of-flight (TOF) measurement of femtosecond light pulses was investigated for laser ranging of long distances with sub-micrometer precision in the air. The bandwidth limitation of the photo-detection electronics used in timing femtosecond pulses was overcome by adopting a type-II nonlinear second-harmonic crystal that permits the production of a balanced optical cross-correlation signal between two overlapping light pulses. This method offered a sub-femtosecond timing resolution in determining the temporal offset between two pulses through lock-in control of the pulse repetition rate with reference to the atomic clock. The exceptional ranging capability was verified by measuring various distances of 1.5, 60 and 700 m. This method is found well suited for future space missions based on formation-flying satellites as well as large-scale industrial applications for land surveying, aircraft manufacturing and shipbuilding.

Precision Neutron Time-of-Flight Detectors Provide Insight into NIF Implosion Dynamics

NASA Astrophysics Data System (ADS)

Schlossberg, David; Eckart, M. J.; Grim, G. P.; Hartouni, E. P.; Hatarik, R.; Moore, A. S.; Waltz, C. S.

2017-10-01

During inertial confinement fusion, higher-order moments of neutron time-of-flight (nToF) spectra can provide essential information for optimizing implosions. The nToF diagnostic suite at the National Ignition Facility (NIF) was recently upgraded to include novel, quartz Cherenkov detectors. These detectors exploit the rapid Cherenkov radiation process, in contrast with conventional scintillator decay times, to provide high temporal-precision measurements that support higher-order moment analyses. Preliminary measurements have been made on the NIF during several implosions and initial results are presented here. Measured line-of-sight asymmetries, for example in ion temperatures, will be discussed. Finally, advanced detector optimization is shown to advance accessible physics, with possibilities for energy discrimination, gamma source identification, and further reduction in quartz response times. Work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344.

Robotic Lunar Lander Development Status

NASA Technical Reports Server (NTRS)

Ballard, Benjamin; Cohen, Barbara A.; McGee, Timothy; Reed, Cheryl

2012-01-01

NASA Marshall Space Flight Center and John Hopkins University Applied Physics Laboratory have developed several mission concepts to place scientific and exploration payloads ranging from 10 kg to more than 200 kg on the surface of the moon. The mission concepts all use a small versatile lander that is capable of precision landing. The results to date of the lunar lander development risk reduction activities including high pressure propulsion system testing, structure and mechanism development and testing, and long cycle time battery testing will be addressed. The most visible elements of the risk reduction program are two fully autonomous lander flight test vehicles. The first utilized a high pressure cold gas system (Cold Gas Test Article) with limited flight durations while the subsequent test vehicle, known as the Warm Gas Test Article, utilizes hydrogen peroxide propellant resulting in significantly longer flight times and the ability to more fully exercise flight sensors and algorithms. The development of the Warm Gas Test Article is a system demonstration and was designed with similarity to an actual lunar lander including energy absorbing landing legs, pulsing thrusters, and flight-like software implementation. A set of outdoor flight tests to demonstrate the initial objectives of the WGTA program was completed in Nov. 2011, and will be discussed.

NASA's Robotic Lunar Lander Development Program

NASA Technical Reports Server (NTRS)

Ballard, Benjamin W.; Reed, Cheryl L. B.; Artis, David; Cole, Tim; Eng, Doug S.; Kubota, Sanae; Lafferty, Paul; McGee, Timothy; Morese, Brian J.; Chavers, Gregory;

Precision controllability of the F-15 airplane

NASA Technical Reports Server (NTRS)

Sisk, T. R.; Matheny, N. W.

1979-01-01

A flying qualities evaluation conducted on a preproduction F-15 airplane permitted an assessment to be made of its precision controllability in the high subsonic and low transonic flight regime over the allowable angle of attack range. Precision controllability, or gunsight tracking, studies were conducted in windup turn maneuvers with the gunsight in the caged pipper mode and depressed 70 mils. This evaluation showed the F-15 airplane to experience severe buffet and mild-to-moderate wing rock at the higher angles of attack. It showed the F-15 airplane radial tracking precision to vary from approximately 6 to 20 mils over the load factor range tested. Tracking in the presence of wing rock essentially doubled the radial tracking error generated at the lower angles of attack. The stability augmentation system affected the tracking precision of the F-15 airplane more than it did that of previous aircraft studied.

Kinematic compensation for wing loss in flying damselflies.

PubMed

Kassner, Ziv; Dafni, Eyal; Ribak, Gal

2016-02-01

Flying insects can tolerate substantial wing wear before their ability to fly is entirely compromised. In order to keep flying with damaged wings, the entire flight apparatus needs to adjust its action to compensate for the reduced aerodynamic force and to balance the asymmetries in area and shape of the damaged wings. While several studies have shown that damaged wings change their flapping kinematics in response to partial loss of wing area, it is unclear how, in insects with four separate wings, the remaining three wings compensate for the loss of a fourth wing. We used high-speed video of flying blue-tailed damselflies (Ischnura elegans) to identify the wingbeat kinematics of the two wing pairs and compared it to the flapping kinematics after one of the hindwings was artificially removed. The insects remained capable of flying and precise maneuvering using only three wings. To compensate for the reduction in lift, they increased flapping frequency by 18±15.4% on average. To achieve steady straight flight, the remaining intact hindwing reduced its flapping amplitude while the forewings changed their stroke plane angle so that the forewing of the manipulated side flapped at a shallower stroke plane angle. In addition, the angular position of the stroke reversal points became asymmetrical. When the wingbeat amplitude and frequency of the three wings were used as input in a simple aerodynamic model, the estimation of total aerodynamic force was not significantly different (paired t-test, p=0.73) from the force produced by the four wings during normal flight. Thus, the removal of one wing resulted in adjustments of the motions of the remaining three wings, exemplifying the precision and plasticity of coordination between the operational wings. Such coordination is vital for precise maneuvering during normal flight but it also provides the means to maintain flight when some of the wings are severely damaged. Copyright © 2015 Elsevier Ltd. All rights reserved.

Aircraft Configuration and Flight Crew Compliance with Procedures While Conducting Flight Deck Based Interval Management (FIM) Operations

NASA Technical Reports Server (NTRS)

Shay, Rick; Swieringa, Kurt A.; Baxley, Brian T.

2012-01-01

Flight deck based Interval Management (FIM) applications using ADS-B are being developed to improve both the safety and capacity of the National Airspace System (NAS). FIM is expected to improve the safety and efficiency of the NAS by giving pilots the technology and procedures to precisely achieve an interval behind the preceding aircraft by a specific point. Concurrently but independently, Optimized Profile Descents (OPD) are being developed to help reduce fuel consumption and noise, however, the range of speeds available when flying an OPD results in a decrease in the delivery precision of aircraft to the runway. This requires the addition of a spacing buffer between aircraft, reducing system throughput. FIM addresses this problem by providing pilots with speed guidance to achieve a precise interval behind another aircraft, even while flying optimized descents. The Interval Management with Spacing to Parallel Dependent Runways (IMSPiDR) human-in-the-loop experiment employed 24 commercial pilots to explore the use of FIM equipment to conduct spacing operations behind two aircraft arriving to parallel runways, while flying an OPD during high-density operations. This paper describes the impact of variations in pilot operations; in particular configuring the aircraft, their compliance with FIM operating procedures, and their response to changes of the FIM speed. An example of the displayed FIM speeds used incorrectly by a pilot is also discussed. Finally, this paper examines the relationship between achieving airline operational goals for individual aircraft and the need for ATC to deliver aircraft to the runway with greater precision. The results show that aircraft can fly an OPD and conduct FIM operations to dependent parallel runways, enabling operational goals to be achieved efficiently while maintaining system throughput.

Comparative Study on a Solving Model and Algorithm for a Flush Air Data Sensing System

PubMed Central

Liu, Yanbin; Xiao, Dibo; Lu, Yuping

2014-01-01

With the development of high-performance aircraft, precise air data are necessary to complete challenging tasks such as flight maneuvering with large angles of attack and high speed. As a result, the flush air data sensing system (FADS) was developed to satisfy the stricter control demands. In this paper, comparative stuides on the solving model and algorithm for FADS are conducted. First, the basic principles of FADS are given to elucidate the nonlinear relations between the inputs and the outputs. Then, several different solving models and algorithms of FADS are provided to compute the air data, including the angle of attck, sideslip angle, dynamic pressure and static pressure. Afterwards, the evaluation criteria of the resulting models and algorithms are discussed to satisfy the real design demands. Futhermore, a simulation using these algorithms is performed to identify the properites of the distinct models and algorithms such as the measuring precision and real-time features. The advantages of these models and algorithms corresponding to the different flight conditions are also analyzed, furthermore, some suggestions on their engineering applications are proposed to help future research. PMID:24859025

Comparative study on a solving model and algorithm for a flush air data sensing system.

PubMed

Liu, Yanbin; Xiao, Dibo; Lu, Yuping

2014-05-23

With the development of high-performance aircraft, precise air data are necessary to complete challenging tasks such as flight maneuvering with large angles of attack and high speed. As a result, the flush air data sensing system (FADS) was developed to satisfy the stricter control demands. In this paper, comparative stuides on the solving model and algorithm for FADS are conducted. First, the basic principles of FADS are given to elucidate the nonlinear relations between the inputs and the outputs. Then, several different solving models and algorithms of FADS are provided to compute the air data, including the angle of attck, sideslip angle, dynamic pressure and static pressure. Afterwards, the evaluation criteria of the resulting models and algorithms are discussed to satisfy the real design demands. Futhermore, a simulation using these algorithms is performed to identify the properites of the distinct models and algorithms such as the measuring precision and real-time features. The advantages of these models and algorithms corresponding to the different flight conditions are also analyzed, furthermore, some suggestions on their engineering applications are proposed to help future research.

Diving-Flight Aerodynamics of a Peregrine Falcon (Falco peregrinus)

PubMed Central

Ponitz, Benjamin; Schmitz, Anke; Fischer, Dominik; Bleckmann, Horst; Brücker, Christoph

2014-01-01

This study investigates the aerodynamics of the falcon Falco peregrinus while diving. During a dive peregrines can reach velocities of more than 320 km h−1. Unfortunately, in freely roaming falcons, these high velocities prohibit a precise determination of flight parameters such as velocity and acceleration as well as body shape and wing contour. Therefore, individual F. peregrinus were trained to dive in front of a vertical dam with a height of 60 m. The presence of a well-defined background allowed us to reconstruct the flight path and the body shape of the falcon during certain flight phases. Flight trajectories were obtained with a stereo high-speed camera system. In addition, body images of the falcon were taken from two perspectives with a high-resolution digital camera. The dam allowed us to match the high-resolution images obtained from the digital camera with the corresponding images taken with the high-speed cameras. Using these data we built a life-size model of F. peregrinus and used it to measure the drag and lift forces in a wind-tunnel. We compared these forces acting on the model with the data obtained from the 3-D flight path trajectory of the diving F. peregrinus. Visualizations of the flow in the wind-tunnel uncovered details of the flow structure around the falcon’s body, which suggests local regions with separation of flow. High-resolution pictures of the diving peregrine indicate that feathers pop-up in the equivalent regions, where flow separation in the model falcon occurred. PMID:24505258

Encoding properties of haltere neurons enable motion feature detection in a biological gyroscope

PubMed Central

Fox, Jessica L.; Fairhall, Adrienne L.; Daniel, Thomas L.

2010-01-01

The halteres of dipteran insects are essential sensory organs for flight control. They are believed to detect Coriolis and other inertial forces associated with body rotation during flight. Flies use this information for rapid flight control. We show that the primary afferent neurons of the haltere’s mechanoreceptors respond selectively with high temporal precision to multiple stimulus features. Although we are able to identify many stimulus features contributing to the response using principal component analysis, predictive models using only two features, common across the cell population, capture most of the cells’ encoding activity. However, different sensitivity to these two features permits each cell to respond to sinusoidal stimuli with a different preferred phase. This feature similarity, combined with diverse phase encoding, allows the haltere to transmit information at a high rate about numerous inertial forces, including Coriolis forces. PMID:20133721

NASA Precision Landing Technologies Completes Initial Flight Tests on Vertical Testbed Rocket

NASA Image and Video Library

2017-04-19

This 2-minute, 40-second video shows how over the past 5 weeks, NASA and Masten Space Systems teams have prepared for and conducted sub-orbital rocket flight tests of next-generation lander navigation technology through the CoOperative Blending of Autonomous Landing Technologies (COBALT) project. The COBALT payload was integrated onto Masten’s rocket, Xodiac. The Xodiac vehicle used the Global Positioning System (GPS) for navigation during this first campaign, which was intentional to verify and refine COBALT system performance. The joint teams conducted numerous ground verification tests, made modifications in the process, practiced and refined operations’ procedures, conducted three tether tests, and have now flown two successful free flights. This successful, collaborative campaign has provided the COBALT and Xodiac teams with the valuable performance data needed to refine the systems and prepare them for the second flight test campaign this summer when the COBALT system will navigate the Xodiac rocket to a precision landing. The technologies within COBALT provide a spacecraft with knowledge during entry, descent, and landing that enables it to precisely navigate and softly land close to surface locations that have been previously too risky to target with current capabilities. The technologies will enable future exploration destinations on Mars, the moon, Europa, and other planets and moons. The two primary navigation components within COBALT include the Langley Research Center’s Navigation Doppler Lidar, which provides ultra-precise velocity and line-of-sight range measurements, and Jet Propulsion Laboratory’s Lander Vision System (LVS), which provides navigation estimates relative to an existing surface map. The integrated system is being flight tested onboard a Masten suborbital rocket vehicle called Xodiac. The COBALT project is led by the Johnson Space Center, with funding provided through the Game Changing Development, Flight Opportunities program, and Advanced Exploration Systems programs. Based at NASA’s Armstrong Flight Research Center in Edwards, CA, the Flight Opportunities program funds technology development flight tests on commercial suborbital space providers of which Masten is a vendor. The program has previously tested the LVS on the Masten rocket and validated the technology for the Mars 2020 rover.

The Estimation of Precisions in the Planning of Uas Photogrammetric Surveys

NASA Astrophysics Data System (ADS)

Passoni, D.; Federici, B.; Ferrando, I.; Gagliolo, S.; Sguerso, D.

2018-05-01

The Unmanned Aerial System (UAS) is widely used in the photogrammetric surveys both of structures and of small areas. Geomatics focuses the attention on the metric quality of the final products of the survey, creating several 3D modelling applications from UAS images. As widely known, the quality of results derives from the quality of images acquisition phase, which needs an a priori estimation of the expected precisions. The planning phase is typically managed using dedicated tools, adapted from the traditional aerial-photogrammetric flight plan. But UAS flight has features completely different from the traditional one. Hence, the use of UAS for photogrammetric applications today requires a growth in knowledge in planning. The basic idea of this research is to provide a drone photogrammetric flight planning tools considering the required metric precisions, given a priori the classical parameters of a photogrammetric planning: flight altitude, overlaps and geometric parameters of the camera. The created "office suite" allows a realistic planning of a photogrammetric survey, starting from an approximate knowledge of the Digital Surface Model (DSM), and the effective attitude parameters, changing along the route. The planning products are the overlapping of the images, the Ground Sample Distance (GSD) and the precision on each pixel taking into account the real geometry. The different tested procedures, the obtained results and the solution proposed for the a priori estimates of the precisions in the particular case of UAS surveys are here reported.

Using reflection time-of-flight mass spectrometer techniques to investigate cluster dynamics and bonding

NASA Astrophysics Data System (ADS)

Wei, Shiqing; Castleman, A. W., Jr.

1994-02-01

Lase based time-of-flight mass spectrometer systems affixed with reflectrons are valuable tools for investigating cluster dynamics and reactions, spectroscopy and structures. Utilizing the reflectron time-of-flight mass spectrometer techniques, both decay fractions and kinetic energy releases of metastable cluster ions can be measured with high precision. By applying related theoretical models, the desired thermochemical values of metastable species can be deduced, which are otherwise very difficult to obtain. Several examples are discussed with attention focused on ammonia as a test case for hydrogen bond systems, and xenon for weaker van der Waals clusters. A brief overview of applications to investigating solvation effects on reactions and structures, delayed electron transfer and ionization through intracluster Penning ionization is also given.

Study of ultrasonic thermometry based on ultrasonic time-of-flight measurement

NASA Astrophysics Data System (ADS)

Jia, Ruixi; Xiong, Qingyu; Wang, Lijie; Wang, Kai; Shen, Xuehua; Liang, Shan; Shi, Xin

2016-03-01

Ultrasonic thermometry is a kind of acoustic pyrometry and it has been evolving as a new temperature measurement technology for various environment. However, the accurate measurement of the ultrasonic time-of-flight is the key for ultrasonic thermometry. In this paper, we study the ultrasonic thermometry technique based on ultrasonic time-of-flight measurement with a pair of ultrasonic transducers for transmitting and receiving signal. The ultrasonic transducers are installed in a single path which ultrasonic travels. In order to validate the performance of ultrasonic thermometry, we make a contrast about the absolute error between the measured temperature value and the practical one. With and without heater source, the experimental results indicate ultrasonic thermometry has high precision of temperature measurement.

HAI: A novel airborne multi-channel hygrometer for fast multi-phase H2O quantification: Performance of the HAI instrument during the first flights on the German HALO aircraft

NASA Astrophysics Data System (ADS)

Buchholz, B.; Ebert, V.; Kraemer, M.; Afchine, A.

2014-12-01

Common gas phase H2O measurements on fast airborne platforms e.g. using backward facing or "Rosemount"-inlets can lead to a high risk of ice and droplets contamination. In addition, currently no single hygrometer exists that allows a simultaneous, high-speed measurement of all phases (gas, liquid, ice) with the same detection principle. In the rare occasions multi-phase measurements are realized, gas-and condensed-phase observations rely on different methods, instruments and calibration strategies so that precision and accuracy levels are quite difficult to quantify. This is effectively avoided by the novel TDLAS instrument, HAI, Hygrometer for Atmospheric Investigation, which allows a simultaneous, high speed, multi-phase detection without any sensor calibration in a unique "2+2" channel concept. Hai combines two independent wavelength channels, at 1.4 µm and at 2.6 µm, for a wide dynamic range from 1 to 30 000 ppmv, with a simultaneous closed path (extractive) and open path detection. Thus, "Total", i.e. gas-phase plus condensed-phase water is measured by sampling via a forward facing inlet into "closed-path" extractive cells. A selective, sampling-free, high speed gas phase detection is realized via a dual-wavelength "open-path" cell placed outside of the aircraft fuselage. All channels can be sampled with 120 Hz (measurement cycle time Dt=1.6 ms) allowing an unprecedented spatial resolution of 30 cm at 900 km/h. The evaluation of the individual multi-channel raw-data is done post flight, without any channel interdependencies, in calibration-free mode, thus allowing fast, accurate and precise multi-phase water detection in flight. The performance could be shown in more than 200 net flights hours in three scientific flight campaigns (TACTS, ESMVal, ML-CIRRUS) on the new German HALO aircraft. In addition the level of the accuracy of the calibration free evaluation was evaluated at the German national primary water vapor standard.

Structural health monitoring ultrasonic thickness measurement accuracy and reliability of various time-of-flight calculation methods

NASA Astrophysics Data System (ADS)

Eason, Thomas J.; Bond, Leonard J.; Lozev, Mark G.

2016-02-01

The accuracy, precision, and reliability of ultrasonic thickness structural health monitoring systems are discussed in-cluding the influence of systematic and environmental factors. To quantify some of these factors, a compression wave ultrasonic thickness structural health monitoring experiment is conducted on a flat calibration block at ambient temperature with forty four thin-film sol-gel transducers and various time-of-flight thickness calculation methods. As an initial calibration, the voltage response signals from each sensor are used to determine the common material velocity as well as the signal offset unique to each calculation method. Next, the measurement precision of the thickness error of each method is determined with a proposed weighted censored relative maximum likelihood analysis technique incorporating the propagation of asymmetric measurement uncertainty. The results are presented as upper and lower confidence limits analogous to the a90/95 terminology used in industry recognized Probability-of-Detection assessments. Future work is proposed to apply the statistical analysis technique to quantify measurement precision of various thickness calculation methods under different environmental conditions such as high temperature, rough back-wall surface, and system degradation with an intended application to monitor naphthenic acid corrosion in oil refineries.

A compact, fast ozone UV photometer and sampling inlet for research aircraft

NASA Astrophysics Data System (ADS)

Gao, R. S.; Ballard, J.; Watts, L. A.; Thornberry, T. D.; Ciciora, S. J.; McLaughlin, R. J.; Fahey, D. W.

2012-05-01

In situ measurements of atmospheric ozone (O3) are performed routinely from many research aircraft platforms. The most common technique depends on the strong absorption of ultraviolet (UV) light by ozone. As atmospheric science advances to the widespread use of unmanned aircraft systems (UASs), there is an increasing requirement for minimizing instrument space, weight, and power while maintaining instrument accuracy, precision and time response. The design and use of a new, dual-beam, polarized, UV photometer instrument for in situ O3 measurements is described. The instrument has a fast sampling rate (2 Hz), high accuracy (3%), and precision (1.1 × 1010 O3 molecules cm-3). The size (36 l), weight (18 kg), and power (50-200 W) make the instrument suitable for many UAS and other airborne platforms. Inlet and exhaust configurations are also described for ambient sampling in the troposphere and lower stratosphere (1000-50 mb) that optimize the sample flow rate to increase time response while minimizing loss of precision due to induced turbulence in the sample cell. In-flight and laboratory intercomparisons with existing O3 instruments show that measurement accuracy is maintained in flight.

2-Micron Pulsed Direct Detection IPDA Lidar for Atmospheric CO2 Measurement

NASA Technical Reports Server (NTRS)

Yu, Jirong; Petros, Mulugeta; Refaat, Tamer; Reithmaier, Karl; Remus, Ruben; Singh, Upendra; Johnson, Will; Boyer, Charlie; Fay, James; Johnston, Susan;

COBALT Flight Demonstrations Fuse Technologies

NASA Image and Video Library

2017-06-07

This 5-minute, 50-second video shows how the CoOperative Blending of Autonomous Landing Technologies (COBALT) system pairs new landing sensor technologies that promise to yield the highest precision navigation solution ever tested for NASA space landing applications. The technologies included a navigation doppler lidar (NDL), which provides ultra-precise velocity and line-of-sight range measurements, and the Lander Vision System (LVS), which provides terrain-relative navigation. Through flight campaigns conducted in March and April 2017 aboard Masten Space Systems' Xodiac, a rocket-powered vertical takeoff, vertical landing (VTVL) platform, the COBALT system was flight tested to collect sensor performance data for NDL and LVS and to check the integration and communication between COBALT and the rocket. The flight tests provided excellent performance data for both sensors, as well as valuable information on the integrated performance with the rocket that will be used for subsequent COBALT modifications prior to follow-on flight tests. Based at NASA’s Armstrong Flight Research Center in Edwards, CA, the Flight Opportunities program funds technology development flight tests on commercial suborbital space providers of which Masten is a vendor. The program has previously tested the LVS on the Masten rocket and validated the technology for the Mars 2020 rover.

Control integration concept for hypersonic cruise-turn maneuvers

NASA Technical Reports Server (NTRS)

Raney, David L.; Lallman, Frederick J.

1992-01-01

Piloting difficulties associated with conducting aircraft maneuvers in hypersonic flight are caused in part by the nonintuitive nature of the aircraft response and the stringent constraints anticipated on allowable angle of attack and dynamic pressure variations. An approach is documented that provides precise, coordinated maneuver control during excursions from a hypersonic cruise flight path and the necessary flight condition constraints. The approach is to achieve specified guidance commands by resolving altitude and cross range errors into a load factor and bank angle command by using a coordinate transformation that acts as an interface between outer and inner loop flight controls. This interface, referred to as a 'resolver', applies constraints on angle of attack and dynamic pressure perturbations while prioritizing altitude regulation over cross range. An unpiloted test simulation, in which the resolver was used to drive inner loop flight controls, produced time histories of responses to guidance commands and atmospheric disturbances at Mach numbers of 6, 10, 15, and 20. Angle of attack and throttle perturbation constraints, combined with high speed flight effects and the desire to maintain constant dynamic pressure, significantly impact the maneuver envelope for a hypersonic vehicle.

Coding, testing and documentation of processors for the flight design system

NASA Technical Reports Server (NTRS)

1980-01-01

The general functional design and implementation of processors for a space flight design system are briefly described. Discussions of a basetime initialization processor; conic, analytical, and precision coasting flight processors; and an orbit lifetime processor are included. The functions of several utility routines are also discussed.

Performance of the Chicago Water Isotope Spectrometer in the UTLS during the Asian Monsoon

NASA Astrophysics Data System (ADS)

Gaeta, D. C.; Clouser, B.; Sarkozy, L.; Singer, C. E.; Moyer, E. J.

2017-12-01

The preferential condensation of water vapor isotopologues makes the isotopic composition of water vapor a useful tracer of the processes responsible for the distribution of water in the UTLS, but the UTLS also offers particular challenges for its measurement. We report here on the field performance of a new instrument designed for measurement of HDO and H2O in the UTLS region: the Chicago Water Isotope Spectrometer (Chi-WIS). Chi-WIS is a laser-based infrared absorption spectrometer at 2.65 μm that uses a high-reflectivity optical cavity to obtain 6 km of effective path length, allowing sensitive measurements of scarce molecules. During the 2017 StratoClim aircraft campaign in Kathmandu, Nepal, Chi-WIS flew aboard the M-55 Geophysica high-altitude research aircraft in a series of flights to probe the Asian Monsoon. Preliminary results show in-flight performance consistent with laboratory performance and the achievement of design targets necessary to reach UTLS science goals. Residual noise on spectra is stable across flights at 4-5x10-4 with 1 second averaging (i.e. absorption depth of .04-.05%); the instrument is robust in terms of alignment and shows no evidence of optical resonances. The resulting measurement precision is as expected from these characteristics. Because we use a relatively strong water line, the water vapor measurement is extremely precise: constant-altitude flight legs in the stratosphere at 4 ppm H2O show 1 s standard deviation 0.03 ppmv for 1 s averaging, and 0.08 ppbv for HDO with 10 s averaging. We show comparisons with other StratoClim instruments and examples of how these measurements resolve scientifically relevant atmospheric features.

Project Morpheus: Morpheus 1.5A Lander Failure Investigation Results

NASA Technical Reports Server (NTRS)

Devolites, Jennifer L.; Olansen, Jon B.; Munday, Stephen R.

2013-01-01

On August 9, 2012 the Morpheus 1.5A vehicle crashed shortly after lift off from the Kennedy Space Center. The loss was limited to the vehicle itself which was pre-declared to be a test failure and not a mishap. The Morpheus project is demonstrating advanced technologies for in space and planetary surface vehicles including: autonomous flight control, landing site hazard identification and safe site selection, relative surface and hazard navigation, precision landing, modular reusable flight software, and high performance, non-toxic, cryogenic liquid Oxygen and liquid Methane integrated main engine and attitude control propulsion system. A comprehensive failure investigation isolated the fault to the Inertial Measurement Unit (IMU) data path to the flight computer. Several improvements have been identified and implemented for the 1.5B and 1.5C vehicles.

Heavy rainfall triggers increased nocturnal flight in desert populations of the Pacific black duck (Anas superciliosa).

PubMed

McEvoy, J F; Ribot, R F H; Wingfield, J C; Bennett, A T D

2017-12-14

Understanding of avian nocturnal flight comes mainly from northern hemisphere species in seasonal temperate ecosystems where nocturnal flight is often precisely timed and entrained by annual photoperiod. Here we investigate patterns of nocturnal flight in waterbirds of Australian desert ecosystems that fly considerable distances to find temporary water bodies formed from rainfall which is highly unpredictable seasonally and spatially, and when there is sufficient water, they then breed. How they perform these feats of navigation and physiology remain poorly known. Using GPS tracking of 38 satellite tagged Pacific black ducks (Anas superciliosa) in two contrasting ecosystems, before and after heavy rainfall we revealed a key role for facultative nocturnal flight in the movement ecology of this species. After large rainfall events, birds rapidly increased nocturnal flight activity in the arid aseasonal ecosystem, but not in the mesic seasonal one. Nocturnal flights occurred throughout the night in both ecosystems. Long range flights (>50 km in 2 hours) occurred almost exclusively at night; at night the distance flown was higher than during the day, birds visited more locations, and the locations were more widely dispersed. Our work reveals that heavy rainfall triggers increased nocturnal flight activity in desert populations of waterbirds.

Estimating chlorophyll with thermal and broadband multispectral high resolution imagery from an unmanned aerial system using relevance vector machines for precision agriculture

NASA Astrophysics Data System (ADS)

Elarab, Manal; Ticlavilca, Andres M.; Torres-Rua, Alfonso F.; Maslova, Inga; McKee, Mac

2015-12-01

Precision agriculture requires high-resolution information to enable greater precision in the management of inputs to production. Actionable information about crop and field status must be acquired at high spatial resolution and at a temporal frequency appropriate for timely responses. In this study, high spatial resolution imagery was obtained through the use of a small, unmanned aerial system called AggieAirTM. Simultaneously with the AggieAir flights, intensive ground sampling for plant chlorophyll was conducted at precisely determined locations. This study reports the application of a relevance vector machine coupled with cross validation and backward elimination to a dataset composed of reflectance from high-resolution multi-spectral imagery (VIS-NIR), thermal infrared imagery, and vegetative indices, in conjunction with in situ SPAD measurements from which chlorophyll concentrations were derived, to estimate chlorophyll concentration from remotely sensed data at 15-cm resolution. The results indicate that a relevance vector machine with a thin plate spline kernel type and kernel width of 5.4, having LAI, NDVI, thermal and red bands as the selected set of inputs, can be used to spatially estimate chlorophyll concentration with a root-mean-squared-error of 5.31 μg cm-2, efficiency of 0.76, and 9 relevance vectors.

Speed and path control for conflict-free flight in high air traffic demand in terminal airspace

NASA Astrophysics Data System (ADS)

Rezaei, Ali

To accommodate the growing air traffic demand, flights will need to be planned and navigated with a much higher level of precision than today's aircraft flight path. The Next Generation Air Transportation System (NextGen) stands to benefit significantly in safety and efficiency from such movement of aircraft along precisely defined paths. Air Traffic Operations (ATO) relying on such precision--the Precision Air Traffic Operations or PATO--are the foundation of high throughput capacity envisioned for the future airports. In PATO, the preferred method is to manage the air traffic by assigning a speed profile to each aircraft in a given fleet in a given airspace (in practice known as (speed control). In this research, an algorithm has been developed, set in the context of a Hybrid Control System (HCS) model, that determines whether a speed control solution exists for a given fleet of aircraft in a given airspace and if so, computes this solution as a collective speed profile that assures separation if executed without deviation. Uncertainties such as weather are not considered but the algorithm can be modified to include uncertainties. The algorithm first computes all feasible sequences (i.e., all sequences that allow the given fleet of aircraft to reach destinations without violating the FAA's separation requirement) by looking at all pairs of aircraft. Then, the most likely sequence is determined and the speed control solution is constructed by a backward trajectory generation, starting with the aircraft last out and proceeds to the first out. This computation can be done for different sequences in parallel which helps to reduce the computation time. If such a solution does not exist, then the algorithm calculates a minimal path modification (known as path control) that will allow separation-compliance speed control. We will also prove that the algorithm will modify the path without creating a new separation violation. The new path will be generated by adding new waypoints in the airspace. As a byproduct, instead of minimal path modification, one can use the aircraft arrival time schedule to generate the sequence in which the aircraft reach their destinations.

Flight Software Development for the CHEOPS Instrument with the CORDET Framework

NASA Astrophysics Data System (ADS)

Cechticky, V.; Ottensamer, R.; Pasetti, A.

2015-09-01

CHEOPS is an ESA S-class mission dedicated to the precise measurement of radii of already known exoplanets using ultra-high precision photometry. The instrument flight software controlling the instrument and handling the science data is developed by the University of Vienna using the CORDET Framework offered by P&P Software GmbH. The CORDET Framework provides a generic software infrastructure for PUS-based applications. This paper describes how the framework is used for the CHEOPS application software to provide a consistent solution for to the communication and control services, event handling and FDIR procedures. This approach is innovative in four respects: (a) it is a true third-party reuse; (b) re-use is done at specification, validation and code level; (c) the re-usable assets and their qualification data package are entirely open-source; (d) re-use is based on call-back with the application developer providing functions which are called by the reusable architecture. File names missing from here on out (I tried to mimic the files names from before.)

LandingNav: a precision autonomous landing sensor for robotic platforms on planetary bodies

NASA Astrophysics Data System (ADS)

Katake, Anup; Bruccoleri, Chrisitian; Singla, Puneet; Junkins, John L.

2010-01-01

Increased interest in the exploration of extra terrestrial planetary bodies calls for an increase in the number of spacecraft landing on remote planetary surfaces. Currently, imaging and radar based surveys are used to determine regions of interest and a safe landing zone. The purpose of this paper is to introduce LandingNav, a sensor system solution for autonomous landing on planetary bodies that enables landing on unknown terrain. LandingNav is based on a novel multiple field of view imaging system that leverages the integration of different state of the art technologies for feature detection, tracking, and 3D dense stereo map creation. In this paper we present the test flight results of the LandingNav system prototype. Sources of errors due to hardware limitations and processing algorithms were identified and will be discussed. This paper also shows that addressing the issues identified during the post-flight test data analysis will reduce the error down to 1-2%, thus providing for a high precision 3D range map sensor system.

Optimized merging of search coil and fluxgate data for MMS

NASA Astrophysics Data System (ADS)

Fischer, David; Magnes, Werner; Hagen, Christian; Dors, Ivan; Chutter, Mark W.; Needell, Jerry; Torbert, Roy B.; Le Contel, Olivier; Strangeway, Robert J.; Kubin, Gernot; Valavanoglou, Aris; Plaschke, Ferdinand; Nakamura, Rumi; Mirioni, Laurent; Russell, Christopher T.; Leinweber, Hannes K.; Bromund, Kenneth R.; Le, Guan; Kepko, Lawrence; Anderson, Brian J.; Slavin, James A.; Baumjohann, Wolfgang

2016-11-01

The Magnetospheric Multiscale mission (MMS) targets the characterization of fine-scale current structures in the Earth's tail and magnetopause. The high speed of these structures, when traversing one of the MMS spacecraft, creates magnetic field signatures that cross the sensitive frequency bands of both search coil and fluxgate magnetometers. Higher data quality for analysis of these events can be achieved by combining data from both instrument types and using the frequency bands with best sensitivity and signal-to-noise ratio from both sensors. This can be achieved by a model-based frequency compensation approach which requires the precise knowledge of instrument gain and phase properties. We discuss relevant aspects of the instrument design and the ground calibration activities, describe the model development and explain the application on in-flight data. Finally, we show the precision of this method by comparison of in-flight data. It confirms unity gain and a time difference of less than 100 µs between the different magnetometer instruments.

Precision Cleaning and Verification Processes Used at Marshall Space Flight Center for Critical Hardware Applications

NASA Technical Reports Server (NTRS)

Caruso, Salvadore V.; Cox, Jack A.; McGee, Kathleen A.

1999-01-01

This presentation discuss the Marshall Space Flight Center Operations and Responsibilities. These are propulsion, microgravity experiments, international space station, space transportation systems, and advance vehicle research.

Robust Flight Path Determination for Mars Precision Landing Using Genetic Algorithms

NASA Technical Reports Server (NTRS)

Bayard, David S.; Kohen, Hamid

1997-01-01

This paper documents the application of genetic algorithms (GAs) to the problem of robust flight path determination for Mars precision landing. The robust flight path problem is defined here as the determination of the flight path which delivers a low-lift open-loop controlled vehicle to its desired final landing location while minimizing the effect of perturbations due to uncertainty in the atmospheric model and entry conditions. The genetic algorithm was capable of finding solutions which reduced the landing error from 111 km RMS radial (open-loop optimal) to 43 km RMS radial (optimized with respect to perturbations) using 200 hours of computation on an Ultra-SPARC workstation. Further reduction in the landing error is possible by going to closed-loop control which can utilize the GA optimized paths as nominal trajectories for linearization.

Summary of the effects of engine throttle response on airplane formation-flying qualities

NASA Technical Reports Server (NTRS)

Walsh, Kevin R.

1992-01-01

A flight evaluation as conducted to determine the effect of engine throttle response characteristics on precision formation-flying qualities. A variable electronic throttle control system was developed and flight-tested on a TF-104G airplane with a J79-11B engine at the NASA Dryden Flight Research Facility. Ten research flights were flown to evaluate the effects of throttle gain, time delay, and fuel control rate limiting on engine handling qualities during a demanding precision wing formation task. Handling quality effects of lag filters and lead compensation time delays were also evaluated. Data from pilot ratings and comments indicate that throttle control system time delays and rate limits cause significant degradations in handling qualities. Threshold values for satisfactory (level 1) and adequate (level 2) handling qualities of these key variables are presented.

The Role of X-Rays in Future Space Navigation and Communication

NASA Technical Reports Server (NTRS)

Winternitz, Luke M. B.; Gendreau, Keith C.; Hasouneh, Monther A.; Mitchell, Jason W.; Fong, Wai H.; Lee, Wing-Tsz; Gavriil, Fotis; Arzoumanian, Zaven

2013-01-01

In the near future, applications using X-rays will enable autonomous navigation and time distribution throughout the solar system, high capacity and low-power space data links, highly accurate attitude sensing, and extremely high-precision formation flying capabilities. Each of these applications alone has the potential to revolutionize mission capabilities, particularly beyond Earth orbit. This paper will outline the NASA Goddard Space Flight Center vision and efforts toward realizing the full potential of X-ray navigation and communications.

Bumblebee flight performance in environments of different proximity.

PubMed

Linander, Nellie; Baird, Emily; Dacke, Marie

2016-02-01

Flying animals are capable of navigating through environments of different complexity with high precision. To control their flight when negotiating narrow tunnels, bees and birds use the magnitude of apparent image motion (known as optic flow) generated by the walls. In their natural habitat, however, these animals would encounter both cluttered and open environments. Here, we investigate how large changes in the proximity of nearby surfaces affect optic flow-based flight control strategies. We trained bumblebees to fly along a flight and recorded how the distance between the walls--from 60 cm to 240 cm--affected their flight control. Our results reveal that, as tunnel width increases, both lateral position and ground speed become increasingly variable. We also find that optic flow information from the ground has an increasing influence on flight control, suggesting that bumblebees measure optic flow flexibly over a large lateral and ventral field of view, depending on where the highest magnitude of optic flow occurs. A consequence of this strategy is that, when flying in narrow spaces, bumblebees use optic flow information from the nearby obstacles to control flight, while in more open spaces they rely primarily on optic flow cues from the ground.

Development of the fast and efficient gamma detector using Cherenkov light for TOF-PET

NASA Astrophysics Data System (ADS)

Canot, C.; Alokhina, M.; Abbon, P.; Bard, J. P.; Tauzin, G.; Yvon, D.; Sharyy, V.

2017-12-01

In this paper we present two configurations of innovative gamma detectors using Cherenkov light for time-of-flight—Positron Emission Tomography (PET). The first uses heavy crystals as a Cherenkov radiator to develop a demonstrator for a whole body PET scanner with high detection efficiency. We demonstrated a 30% detection efficiency and a 180 ps (FWHM) time resolution, mainly limited by the time transit spread of the photomultiplier. The second configuration uses an innovative liquid, the TriMethyl Bismuth, to develop a high precision brain-scanning PET device with time-of-flight capability. According to Geant4 simulation, we expect to reach a precision of 150 ps (FWHM) and an efficiency of about 25%.

Precision controllability of the YF-17 airplane

NASA Technical Reports Server (NTRS)

Sisk, T. R.; Mataeny, N. W.

1980-01-01

A flying qualities evaluation conducted on the YF-17 airplane permitted assessment of its precision controllability in the transonic flight regime over the allowable angle of attack range. The precision controllability (tailchase tracking) study was conducted in constant-g and windup turn tracking maneuvers with the command augmentation system (CAS) on, automatic maneuver flaps, and the caged pipper gunsight depressed 70 mils. This study showed that the YF-17 airplane tracks essentially as well at 7 g's to 8 g's as earlier fighters did at 4 g's to 5 g's before they encountered wing rock. The pilots considered the YF-17 airplane one of the best tracking airplanes they had flown. Wing rock at the higher angles of attack degraded tracking precision, and lack of control harmony made precision controllability more difficult. The revised automatic maneuver flap schedule incorporated in the airplane at the time of the tests did not appear to be optimum. The largest tracking errors and greatest pilot workload occurred at high normal load factors at low angles of attack. The pilots reported that the high-g maneuvers caused some tunnel vision and that they found it difficult to think clearly after repeated maneuvers.

Perception of silent and motionless prey on vegetation by echolocation in the gleaning bat Micronycteris microtis.

PubMed

Geipel, Inga; Jung, Kirsten; Kalko, Elisabeth K V

2013-03-07

Gleaning insectivorous bats that forage by using echolocation within dense forest vegetation face the sensorial challenge of acoustic masking effects. Active perception of silent and motionless prey in acoustically cluttered environments by echolocation alone has thus been regarded impossible. The gleaning insectivorous bat Micronycteris microtis however, forages in dense understory vegetation and preys on insects, including dragonflies, which rest silent and motionless on vegetation. From behavioural experiments, we show that M. microtis uses echolocation as the sole sensorial modality for successful prey perception within a complex acoustic environment. All individuals performed a stereotypical three-dimensional hovering flight in front of prey items, while continuously emitting short, multi-harmonic, broadband echolocation calls. We observed a high precision in target localization which suggests that M. microtis perceives a detailed acoustic image of the prey based on shape, surface structure and material. Our experiments provide, to our knowledge, the first evidence that a gleaning bat uses echolocation alone for successful detection, classification and precise localization of silent and motionless prey in acoustic clutter. Overall, we conclude that the three-dimensional hovering flight of M. microtis in combination with a frequent emission of short, high-frequency echolocation calls is the key for active prey perception in acoustically highly cluttered environments.

Perception of silent and motionless prey on vegetation by echolocation in the gleaning bat Micronycteris microtis

PubMed Central

Geipel, Inga; Jung, Kirsten; Kalko, Elisabeth K. V.

2013-01-01

Gleaning insectivorous bats that forage by using echolocation within dense forest vegetation face the sensorial challenge of acoustic masking effects. Active perception of silent and motionless prey in acoustically cluttered environments by echolocation alone has thus been regarded impossible. The gleaning insectivorous bat Micronycteris microtis however, forages in dense understory vegetation and preys on insects, including dragonflies, which rest silent and motionless on vegetation. From behavioural experiments, we show that M. microtis uses echolocation as the sole sensorial modality for successful prey perception within a complex acoustic environment. All individuals performed a stereotypical three-dimensional hovering flight in front of prey items, while continuously emitting short, multi-harmonic, broadband echolocation calls. We observed a high precision in target localization which suggests that M. microtis perceives a detailed acoustic image of the prey based on shape, surface structure and material. Our experiments provide, to our knowledge, the first evidence that a gleaning bat uses echolocation alone for successful detection, classification and precise localization of silent and motionless prey in acoustic clutter. Overall, we conclude that the three-dimensional hovering flight of M. microtis in combination with a frequent emission of short, high-frequency echolocation calls is the key for active prey perception in acoustically highly cluttered environments. PMID:23325775

Flying Boresight for Advanced Testing and Calibration of Tracking Antennas and Flight Path Simulations

NASA Astrophysics Data System (ADS)

Hafner, D.

2015-09-01

The application of ground-based boresight sources for calibration and testing of tracking antennas usually entails various difficulties, mostly due to unwanted ground effects. To avoid this problem, DLR MORABA developed a small, lightweight, frequency-adjustable S-band boresight source, mounted on a small remote-controlled multirotor aircraft. Highly accurate GPS-supported, position and altitude control functions allow both, very steady positioning of the aircraft in mid-air, and precise waypoint-based, semi-autonomous flights. In contrast to fixed near-ground boresight sources this flying setup enables to avoid obstructions in the Fresnel zone between source and antenna. Further, it minimizes ground reflections and other multipath effects which can affect antenna calibration. In addition, the large operating range of a flying boresight simplifies measurements in the far field of the antenna and permits undisturbed antenna pattern tests. A unique application is the realistic simulation of sophisticated flight paths, including overhead tracking and demanding trajectories of fast objects such as sounding rockets. Likewise, dynamic tracking tests are feasible which provide crucial information about the antenna pedestal performance — particularly at high elevations — and reveal weaknesses in the autotrack control loop of tracking antenna systems. During acceptance tests of MORABA's new tracking antennas, a manned aircraft was never used, since the Flying Boresight surpassed all expectations regarding usability, efficiency, and precision. Hence, it became an integral part of MORABA's standard antenna setup and calibration procedures.

Preliminary results from a subsonic high angle-of-attack flush airdata sensing (HI-FADS) system: Design, calibration, and flight test evaluation

NASA Technical Reports Server (NTRS)

Whitmore, Stephen A.; Moes, Timothy R.; Larson, Terry J.

1990-01-01

A nonintrusive high angle-of-attack flush airdata sensing (HI-FADS) system was installed and flight-tested on the F-18 high alpha research flight vehicle. The system is a matrix of 25 pressure orifices in concentric circles on the nose of the vehicle. The orifices determine angles of attack and sideslip, Mach number, and pressure altitude. Pressure was transmitted from the orifices to an electronically scanned pressure module by lines of pneumatic tubing. The HI-FADS system was calibrated and demonstrated using dutch roll flight maneuvers covering large Mach, angle-of-attack, and sideslip ranges. Reference airdata for system calibration were generated by a minimum variance estimation technique blending measurements from two wingtip airdata booms with inertial velocities, aircraft angular rates and attitudes, precision radar tracking, and meteorological analyses. The pressure orifice calibration was based on identifying empirical adjustments to modified Newtonian flow on a hemisphere. Calibration results are presented. Flight test results used all 25 orifices or used a subset of 9 orifices. Under moderate maneuvering conditions, the HI-FADS system gave excellent results over the entire subsonic Mach number range up to 55 deg angle of attack. The internal pneumatic frequency response of the system is accurate to beyond 10 Hz. Aerodynamic lags in the aircraft flow field caused some performance degradation during heavy maneuvering.

KSC-2012-6430

NASA Image and Video Library

2012-12-05

CAPE CANAVERAL, Fla. – Technicians prepare to lift a special fixture inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6447

NASA Image and Video Library

2012-12-06

CAPE CANAVERAL, Fla. – Technicians lift a special fixture inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6428

NASA Image and Video Library

2012-12-05

CAPE CANAVERAL, Fla. – Technicians prepare to lift a special fixture inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6429

NASA Image and Video Library

2012-12-05

CAPE CANAVERAL, Fla. – Technicians prepare to lift a special fixture inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6446

NASA Image and Video Library

2012-12-06

CAPE CANAVERAL, Fla. – Technicians lift a special fixture inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6445

NASA Image and Video Library

2012-12-05

CAPE CANAVERAL, Fla. – Technicians lift a special fixture inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

Correction of static pressure on a research aircraft in accelerated flight using differential pressure measurements

NASA Astrophysics Data System (ADS)

Rodi, A. R.; Leon, D. C.

2012-05-01

Geometric altitude data from a combined Global Navigation Satellite System (GNSS) and inertial measurement unit (IMU) system on the University of Wyoming King Air research aircraft are used to estimate acceleration effects on static pressure measurement. Using data collected during periods of accelerated flight, comparison of measured pressure with that derived from GNSS/IMU geometric altitude show that errors exceeding 150 Pa can occur which is significant in airspeed and atmospheric air motion determination. A method is developed to predict static pressure errors from analysis of differential pressure measurements from a Rosemount model 858 differential pressure air velocity probe. The method was evaluated with a carefully designed probe towed on connecting tubing behind the aircraft - a "trailing cone" - in steady flight, and shown to have a precision of about ±10 Pa over a wide range of conditions including various altitudes, power settings, and gear and flap extensions. Under accelerated flight conditions, compared to the GNSS/IMU data, this algorithm predicts corrections to a precision of better than ±20 Pa. Some limiting factors affecting the precision of static pressure measurement on a research aircraft are examined.

Evaluation of High-Speed Civil Transport Handling Qualities Criteria with Supersonic Flight Data

NASA Technical Reports Server (NTRS)

Cox, Timothy H.; Jackson, Dante W.

1997-01-01

Most flying qualities criteria have been developed from data in the subsonic flight regime. Unique characteristics of supersonic flight raise questions about whether these criteria successfully extend into the supersonic flight regime. Approximately 25 years ago NASA Dryden Flight Research Center addressed this issue with handling qualities evaluations of the XB-70 and YF-12. Good correlations between some of the classical handling qualities parameters, such as the control anticipation parameter as a function of damping, were discovered. More criteria have been developed since these studies. Some of these more recent criteria are being used in designing the High-Speed Civil Transport (HSCT). A second research study recently addressed this issue through flying qualities evaluations of the SR-71 at Mach 3. The research goal was to extend the high-speed flying qualities experience of large airplanes and to evaluate more recent MIL-STD-1797 criteria against pilot comments and ratings. Emphasis was placed on evaluating the criteria used for designing the HSCT. XB-70 and YF-12 data from the previous research supplemented the SR-71 data. The results indicate that the criteria used in the HSCT design are conservative and should provide good flying qualities for typical high-speed maneuvering. Additional results show correlation between the ratings and comments and criteria for gradual maneuvering with precision control. Correlation is shown between ratings and comments and an extension of the Neal/Smith criterion using normal acceleration instead of pitch rate.

KSC-2009-1896

NASA Image and Video Library

2009-02-26

CAPE CANAVERAL, Fla. – In high bay 4 of the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida, a large overhead crane lowers the Ares I-X service module onto the service adapter. Workers check the precision of the connection. Ares I-X is the test flight for the Ares I. The I-X flight will provide NASA an early opportunity to test and prove hardware, facilities and ground operations associated with Ares I. The launch of the 327-foot-tall, full-scale Ares I-X, targeted for July 2009, will be the first in a series of unpiloted rocket launches from Kennedy. Photo credit: NASA/Tim Jacobs

Soliton microcomb range measurement

NASA Astrophysics Data System (ADS)

Suh, Myoung-Gyun; Vahala, Kerry J.

2018-02-01

Laser-based range measurement systems are important in many application areas, including autonomous vehicles, robotics, manufacturing, formation flying of satellites, and basic science. Coherent laser ranging systems using dual-frequency combs provide an unprecedented combination of long range, high precision, and fast update rate. We report dual-comb distance measurement using chip-based soliton microcombs. A single pump laser was used to generate dual-frequency combs within a single microresonator as counterpropagating solitons. We demonstrated time-of-flight measurement with 200-nanometer precision at an averaging time of 500 milliseconds within a range ambiguity of 16 millimeters. Measurements at distances up to 25 meters with much lower precision were also performed. Our chip-based source is an important step toward miniature dual-comb laser ranging systems that are suitable for photonic integration.

Virtual decoupling flight control via real-time trajectory synthesis and tracking

NASA Astrophysics Data System (ADS)

Zhang, Xuefu

The production of the General Aviation industry has declined in the past 25 years. Ironically, however, the increasing demand for air travel as a fast, safe, and high-quality mode of transportation has been far from satisfied. Addressing this demand shortfall with personal air transportation necessitates advanced systems for navigation, guidance, control, flight management, and flight traffic control. Among them, an effective decoupling flight control system will not only improve flight quality, safety, and simplicity, and increase air space usage, but also reduce expenses on pilot initial and current training, and thus expand the current market and explore new markets. Because of the formidable difficulties encountered in the actual decoupling of non-linear, time-variant, and highly coupled flight control systems through traditional approaches, a new approach, which essentially converts the decoupling problem into a real-time trajectory synthesis and tracking problem, is employed. Then, the converted problem is solved and a virtual decoupling effect is achieved. In this approach, a trajectory in inertial space can be predefined and dynamically modified based on the flight mission and the pilot's commands. A feedforward-feedback control architecture is constructed to guide the airplane along the trajectory as precisely as possible. Through this approach, the pilot has much simpler, virtually decoupled control of the airplane in terms of speed, flight path angle and horizontal radius of curvature. To verify and evaluate this approach, extensive computer simulation is performed. A great deal of test cases are designed for the flight control under different flight conditions. The simulation results show that our decoupling strategy is satisfactory and promising, and therefore the research can serve as a consolidated foundation for future practical applications.

A linear refractive photovoltaic concentrator solar array flight experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, P.A.; Murphy, D.M.; Piszczor, M.F.

1995-12-31

Concentrator arrays deliver a number of generic benefits for space including high array efficiency, protection from space radiation effects, and minimized plasma interactions. The line focus concentrator concept delivers two added advantages: (1) low-cost mass production of the lens material and, (2) relaxation of precise array tracking requirements to only a single axis. New array designs emphasize lightweight, high stiffness, stow-ability and ease of manufacture and assembly. The linear refractive concentrator can be designed to provide an essentially flat response over a wide range of longitudinal pointing errors for satellites having only single-axis tracking capability. In this paper the authorsmore » address the current status of the SCARLET linear concentrator program with special emphasis on hardware development of an array-level linear refractive concentrator flight experiment. An aggressive, 6-month development and flight validation program, sponsored by the Ballistic Missile Defense Organization (BMDO) and NASA Lewis Research Center, will quantify and verify SCARLET benefits with in-orbit performance measurements.« less

Solid state neutron dosimeter for space applications

NASA Technical Reports Server (NTRS)

Entine, Gerald; Nagargar, Vivek; Sharif, Daud

1990-01-01

Personnel engaged in space flight are exposed to significant flux of high energy neutrons arising from both primary and secondary sources of ionizing radiation. Presently, there exist no compact neutron sensor capable of being integrated in a flight instrument to provide real time measurement of this radiation flux. A proposal was made to construct such an instrument using special PIN silicon diode which has the property of being insensitive to the other forms of ionizing radiation. Studies were performed to determine the design and construction of a better reading system to allow the PIN diode to be read with high precision. The physics of the device was studied, especially with respect to those factors which affect the sensitivity and reproducibility of the neutron response. This information was then used to develop methods to achieve high sensitivity at low neutron doses. The feasibility was shown of enhancing the PIN diode sensitivity to make possible the measurement of the low doses of neutrons encountered in space flights. The new PIN diode will make possible the development of a very compact, accurate, personal neutron dosimeter.

NASA’s Improved Supersonic Cockpit Display Shows Precise Locations of Sonic Booms

NASA Image and Video Library

2016-10-15

Flight Test Engineer Jacob Schaefer inspects the Cockpit Interactive Sonic Boom Display Avionics, or CISBoomDA, from the cockpit of his F-18 at NASA’s Armstrong Flight Research Center in Edwards, California.

Evaluation of Flight Deck-Based Interval Management Crew Procedure Feasibility

NASA Technical Reports Server (NTRS)

Wilson, Sara R.; Murdoch, Jennifer L.; Hubbs, Clay E.; Swieringa, Kurt A.

2013-01-01

Air traffic demand is predicted to increase over the next 20 years, creating a need for new technologies and procedures to support this growth in a safe and efficient manner. The National Aeronautics and Space Administration's (NASA) Air Traffic Management Technology Demonstration - 1 (ATD-1) will operationally demonstrate the feasibility of efficient arrival operations combining ground-based and airborne NASA technologies. The integration of these technologies will increase throughput, reduce delay, conserve fuel, and minimize environmental impacts. The ground-based tools include Traffic Management Advisor with Terminal Metering for precise time-based scheduling and Controller Managed Spacing decision support tools for better managing aircraft delay with speed control. The core airborne technology in ATD-1 is Flight deck-based Interval Management (FIM). FIM tools provide pilots with speed commands calculated using information from Automatic Dependent Surveillance - Broadcast. The precise merging and spacing enabled by FIM avionics and flight crew procedures will reduce excess spacing buffers and result in higher terminal throughput. This paper describes a human-in-the-loop experiment designed to assess the acceptability and feasibility of the ATD-1 procedures used in a voice communications environment. This experiment utilized the ATD-1 integrated system of ground-based and airborne technologies. Pilot participants flew a high-fidelity fixed base simulator equipped with an airborne spacing algorithm and a FIM crew interface. Experiment scenarios involved multiple air traffic flows into the Dallas-Fort Worth Terminal Radar Control airspace. Results indicate that the proposed procedures were feasible for use by flight crews in a voice communications environment. The delivery accuracy at the achieve-by point was within +/- five seconds and the delivery precision was less than five seconds. Furthermore, FIM speed commands occurred at a rate of less than one per minute, and pilots found the frequency of the speed commands to be acceptable at all times throughout the experiment scenarios.

Thruster Limitation Consideration for Formation Flight Control

NASA Technical Reports Server (NTRS)

Xu, Yunjun; Fitz-Coy, Norman; Mason, Paul

2003-01-01

Physical constraints of any real system can have a drastic effect on its performance. Some of the more recognized constraints are actuator and sensor saturation and bandwidth, power consumption, sampling rate (sensor and control-loop) and computation limits. These constraints can degrade system s performance, such as settling time, overshoot, rising time, and stability margins. In order to address these issues, researchers have investigated the use of robust and nonlinear controllers that can incorporate uncertainty and constraints into a controller design. For instance, uncertainties can be addressed in the synthesis model used in such algorithms as H(sub infinity), or mu. There is a significant amount of literature addressing this type of problem. However, there is one constraint that has not often been considered; that is, actuator authority resolution. In this work, thruster resolution and controller schemes to compensate for this effect are investigated for position and attitude control of a Low Earth Orbit formation flight system In many academic problems, actuators are assumed to have infinite resolution. In real system applications, such as formation flight systems, the system actuators will not have infinite resolution. High-precision formation flying requires the relative position and the relative attitude to be controlled on the order of millimeters and arc-seconds, respectively. Therefore, the minimum force resolution is a significant concern in this application. Without the sufficient actuator resolution, the system may be unable to attain the required pointing and position precision control. Furthermore, fuel may be wasted due to high-frequency chattering phenomena when attempting to provide a fine control with inadequate actuators. To address this issue, a Sliding Mode Controller is developed along with the boundary Layer Control to provide the best control resolution constraints. A Genetic algorithm is used to optimize the controller parameters according to the states error and fuel consumption criterion. The tradeoffs and effects of the minimum force limitation on performance are studied and compared to the case without the limitation. Furthermore, two methods are proposed to reduce chattering and improve precision.

Real-time synthetic vision cockpit display for general aviation

NASA Astrophysics Data System (ADS)

Hansen, Andrew J.; Smith, W. Garth; Rybacki, Richard M.

1999-07-01

Low cost, high performance graphics solutions based on PC hardware platforms are now capable of rendering synthetic vision of a pilot's out-the-window view during all phases of flight. When coupled to a GPS navigation payload the virtual image can be fully correlated to the physical world. In particular, differential GPS services such as the Wide Area Augmentation System WAAS will provide all aviation users with highly accurate 3D navigation. As well, short baseline GPS attitude systems are becoming a viable and inexpensive solution. A glass cockpit display rendering geographically specific imagery draped terrain in real-time can be coupled with high accuracy (7m 95% positioning, sub degree pointing), high integrity (99.99999% position error bound) differential GPS navigation/attitude solutions to provide both situational awareness and 3D guidance to (auto) pilots throughout en route, terminal area, and precision approach phases of flight. This paper describes the technical issues addressed when coupling GPS and glass cockpit displays including the navigation/display interface, real-time 60 Hz rendering of terrain with multiple levels of detail under demand paging, and construction of verified terrain databases draped with geographically specific satellite imagery. Further, on-board recordings of the navigation solution and the cockpit display provide a replay facility for post-flight simulation based on live landings as well as synchronized multiple display channels with different views from the same flight. PC-based solutions which integrate GPS navigation and attitude determination with 3D visualization provide the aviation community, and general aviation in particular, with low cost high performance guidance and situational awareness in all phases of flight.

Platform Precision Autopilot Overview and Flight Test Results

NASA Technical Reports Server (NTRS)

Lin, V.; Strovers, B.; Lee, J.; Beck, R.

2008-01-01

The Platform Precision Autopilot is an instrument landing system interfaced autopilot system, developed to enable an aircraft to repeatedly fly nearly the same trajectory hours, days, or weeks later. The Platform Precision Autopilot uses a novel design to interface with a NASA Gulfstream III jet by imitating the output of an instrument landing system approach. This technique minimizes, as much as possible, modifications to the baseline Gulfstream III jet and retains the safety features of the aircraft autopilot. The Platform Precision Autopilot requirement is to fly within a 5-m (16.4-ft) radius tube for distances to 200 km (108 nmi) in the presence of light turbulence for at least 90 percent of the time. This capability allows precise repeat-pass interferometry for the Uninhabited Aerial Vehicle Synthetic Aperture Radar program, whose primary objective is to develop a miniaturized, polarimetric, L-band synthetic aperture radar. Precise navigation is achieved using an accurate differential global positioning system developed by the Jet Propulsion Laboratory. Flight-testing has demonstrated the ability of the Platform Precision Autopilot to control the aircraft within the specified tolerance greater than 90 percent of the time in the presence of aircraft system noise and nonlinearities, constant pilot throttle adjustments, and light turbulence.

NASA Webb Mirror is 'CIAF' and Sound

NASA Image and Video Library

2017-12-08

A James Webb Space Telescope flight spare primary mirror segment is loaded onto the CMM (Configuration Measurement Machine) at the CIAF (Calibration, Integration and Alignment Facility) at NASA's Goddard Space Flight Center in Greenbelt, Md. The CMM is used for precision measurements of the mirrors. These precision measurements must be accurate to 0.1 microns or 1/400th the thickness of a human hair. Image credit: NASA/Goddard/Chris Gunn NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Autonomous Precision Landing and Hazard Avoidance Technology (ALHAT) Project Status as of May 2010

NASA Technical Reports Server (NTRS)

Striepe, Scott A.; Epp, Chirold D.; Robertson, Edward A.

2010-01-01

This paper includes the current status of NASA s Autonomous precision Landing and Hazard Avoidance Technology (ALHAT) Project. The ALHAT team has completed several flight tests and two major design analysis cycles. These tests and analyses examine terrain relative navigation sensors, hazard detection and avoidance sensors and algorithms, and hazard relative navigation algorithms, and the guidance and navigation system using these ALHAT functions. The next flight test is scheduled for July 2010. The paper contains results from completed flight tests and analysis cycles. ALHAT system status, upcoming tests and analyses is also addressed. The current ALHAT plans as of May 2010 are discussed. Application of the ALHAT system to landing on bodies other than the Moon is included

Flight tests of the 4D flight guidance display

NASA Astrophysics Data System (ADS)

Below, Christian; von Viebahn, Harro; Purpus, Matthias

1997-06-01

A perspective primary flight and a navigation display format were evaluated in a flying testbed. The flight tests comprised ILS- and standard approaches as well as low level operations utilizing the depiction of a spatial channel, and demonstrations of the inherent ground proximity warning function. In the cockpit of the VFW614, the left seat was equipped with a sidestick and a flat panel display, which showed both the 4D-display an the Navigation Display format. Airline and airforce pilots flew several missions each. Although most of the pilots criticizes that a typical flight director commanding the aircraft's attitude was missing, they could follow the channel precisely. However, some airline pilots stated a lack of vertical guidance information during the final approach. Leaving and re- entering the channel could be easily accomplished form any direction. In summary pilots' assessment of the display concept yielded an overall improvement of SA. In particular it was stated that displays are an appropriate means to avoid CFIT accidents. With the fist prototypes of 3D- graphics generators designed for avionics available the flight evaluation will continue including feasibility demonstrations of high-performance graphics for civil and military aircraft applications.

Demonstration of Helicopter Multi-Towed Array Detection System (MTADS) Magnetometry Technology at Pueblo Precision Bombing Range #2, Colorado

DTIC Science & Technology

2008-08-28

for aircraft pitch measurement Fluxgate magnetometer 10 RS232- ASCII SerialDevice.fluxgate Provides redundant aircraft attitude measurement...Figure 28. Filtered, ’final’ magnetometer data taken at high altitude. ......................................................... 43 LIST OF TABLES...flight. The magnetometer data can be analyzed to extract either distributions of magnetic anomalies (which can be further used to locate and bound

KSC-2012-6433

NASA Image and Video Library

2012-12-05

CAPE CANAVERAL, Fla. – Technicians prepare to fit a special fixture around an Orion capsule inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6444

NASA Image and Video Library

2012-12-05

CAPE CANAVERAL, Fla. – Technicians prepare to fit a special fixture around an Orion capsule inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6434

NASA Image and Video Library

2012-12-05

CAPE CANAVERAL, Fla. – Technicians prepare to fit a special fixture around an Orion capsule inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6442

NASA Image and Video Library

2012-12-05

CAPE CANAVERAL, Fla. – Technicians prepare to fit a special fixture around an Orion capsule inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6441

NASA Image and Video Library

2012-12-05

CAPE CANAVERAL, Fla. – Technicians prepare to fit a special fixture around an Orion capsule inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6440

NASA Image and Video Library

2012-12-05

CAPE CANAVERAL, Fla. – Technicians prepare to fit a special fixture around an Orion capsule inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6432

NASA Image and Video Library

2012-12-05

CAPE CANAVERAL, Fla. – Technicians prepare to fit a special fixture around an Orion capsule inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6443

NASA Image and Video Library

2012-12-05

CAPE CANAVERAL, Fla. – Technicians prepare to fit a special fixture around an Orion capsule inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6431

NASA Image and Video Library

2012-12-05

CAPE CANAVERAL, Fla. – Technicians prepare to fit a special fixture around an Orion capsule inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6437

NASA Image and Video Library

2012-12-05

CAPE CANAVERAL, Fla. – Technicians prepare to fit a special fixture around an Orion capsule inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6435

NASA Image and Video Library

2012-12-05

CAPE CANAVERAL, Fla. – Technicians prepare to fit a special fixture around an Orion capsule inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6436

NASA Image and Video Library

2012-12-05

CAPE CANAVERAL, Fla. – Technicians prepare to fit a special fixture around an Orion capsule inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6448

NASA Image and Video Library

2012-12-06

CAPE CANAVERAL, Fla. – Technicians lower a special fixture around an Orion spacecraft inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6449

NASA Image and Video Library

2012-12-06

CAPE CANAVERAL, Fla. – Technicians lower a special fixture around an Orion spacecraft inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6450

NASA Image and Video Library

2012-12-06

CAPE CANAVERAL, Fla. – A special fixture stands in place around an Orion spacecraft inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6439

NASA Image and Video Library

2012-12-05

CAPE CANAVERAL, Fla. – Technicians prepare to fit a special fixture around an Orion capsule inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

KSC-2012-6438

NASA Image and Video Library

2012-12-05

CAPE CANAVERAL, Fla. – Technicians prepare to fit a special fixture around an Orion capsule inside the high bay of the Operations & Checkout Building at NASA's Kennedy Space Center in Florida. The fixture is designed to enable precise pre-launch processing of the Orion spacecraft. An Orion capsule is being prepared to make a flight test in 2014 on a mission that will not carry any astronauts. Photo by Tim Jacobs

Simple Refractometers for Index Measurements by Minimum Deviation Method from Far-ultraviolet to Near Infrared

NASA Technical Reports Server (NTRS)

Leviton, Douglas B.; Madison, Timothy J.; Petrone, Peter

1998-01-01

The focal shift of an optical filter used in non-collimated light depends directly on substrate thickness and index of refraction. The HST Advanced Camera for Surveys (ACS) requires a set of filters whose focal shifts are tightly matched. Knowing the index of refraction for substrate glasses allows precise substrate thicknesses to be specified. Two refractometers have been developed at the Goddard Space Flight Center (GSFC) to determine the indices of refraction of materials from which ACS filters are made. Modem imaging detectors for the near infrared, visible, and far ultraviolet spectral regions make these simple yet sophisticated refractometers possible. A new technology, high accuracy, angular encoder also developed at GSFC makes high precision index measurement possible in the vacuum ultraviolet.

Investigation of Space Interferometer Control Using Imaging Sensor Output Feedback

NASA Technical Reports Server (NTRS)

Leitner, Jesse A.; Cheng, Victor H. L.

2003-01-01

Numerous space interferometry missions are planned for the next decade to verify different enabling technologies towards very-long-baseline interferometry to achieve high-resolution imaging and high-precision measurements. These objectives will require coordinated formations of spacecraft separately carrying optical elements comprising the interferometer. High-precision sensing and control of the spacecraft and the interferometer-component payloads are necessary to deliver sub-wavelength accuracy to achieve the scientific objectives. For these missions, the primary scientific product of interferometer measurements may be the only source of data available at the precision required to maintain the spacecraft and interferometer-component formation. A concept is studied for detecting the interferometer's optical configuration errors based on information extracted from the interferometer sensor output. It enables precision control of the optical components, and, in cases of space interferometers requiring formation flight of spacecraft that comprise the elements of a distributed instrument, it enables the control of the formation-flying vehicles because independent navigation or ranging sensors cannot deliver the high-precision metrology over the entire required geometry. Since the concept can act on the quality of the interferometer output directly, it can detect errors outside the capability of traditional metrology instruments, and provide the means needed to augment the traditional instrumentation to enable enhanced performance. Specific analyses performed in this study include the application of signal-processing and image-processing techniques to solve the problems of interferometer aperture baseline control, interferometer pointing, and orientation of multiple interferometer aperture pairs.

Innovative use of global navigation satellite systems for flight inspection

NASA Astrophysics Data System (ADS)

Kim, Eui-Ho

The International Civil Aviation Organization (ICAO) mandates flight inspection in every country to provide safety during flight operations. Among many criteria of flight inspection, airborne inspection of Instrument Landing Systems (ILS) is very important because the ILS is the primary landing guidance system worldwide. During flight inspection of the ILS, accuracy in ILS landing guidance is checked by using a Flight Inspection System (FIS). Therefore, a flight inspection system must have high accuracy in its positioning capability to detect any deviation so that accurate guidance of the ILS can be maintained. Currently, there are two Automated Flight Inspection Systems (AFIS). One is called Inertial-based AFIS, and the other one is called Differential GPS-based (DGPS-based) AFIS. The Inertial-based AFIS enables efficient flight inspection procedures, but its drawback is high cost because it requires a navigation-grade Inertial Navigation System (INS). On the other hand, the DGPS-based AFIS has relatively low cost, but flight inspection procedures require landing and setting up a reference receiver. Most countries use either one of the systems based on their own preferences. There are around 1200 ILS in the U.S., and each ILS must be inspected every 6 to 9 months. Therefore, it is important to manage the airborne inspection of the ILS in a very efficient manner. For this reason, the Federal Aviation Administration (FAA) mainly uses the Inertial-based AFIS, which has better efficiency than the DGPS-based AFIS in spite of its high cost. Obviously, the FAA spends tremendous resources on flight inspection. This thesis investigates the value of GPS and the FAA's augmentation to GPS for civil aviation called the Wide Area Augmentation System (or WAAS) for flight inspection. Because standard GPS or WAAS position outputs cannot meet the required accuracy for flight inspection, in this thesis, various algorithms are developed to improve the positioning ability of Flight Inspection Systems (FIS) by using GPS and WAAS in novel manners. The algorithms include Adaptive Carrier Smoothing (ACS), optimizing WAAS accuracy and stability, and reference point-based precise relative positioning for real-time and near-real-time applications. The developed systems are WAAS-aided FIS, WAAS-based FIS, and stand-alone GPS-based FIS. These systems offer both high efficiency and low cost, and they have different advantages over one another in terms of accuracy, integrity, and worldwide availability. The performance of each system is tested with experimental flight test data and shown to have accuracy that is sufficient for flight inspection and superior to the current Inertial-based AFIS.

Precise mapping of annual river bed changes based on airborne laser bathymetry

NASA Astrophysics Data System (ADS)

Mandlburger, Gottfried; Wieser, Martin; Pfeifer, Norbert; Pfennigbauer, Martin; Steinbacher, Frank; Aufleger, Markus

2014-05-01

Airborne Laser Bathymtery (ALB) is a method for capturing relatively shallow water bodies from the air using a pulsed green laser (wavelength=532nm). While this technique was first used for mapping coastal waters only, recent progress in sensor technology has opened the field to apply ALB to running inland waters. Especially for alpine rivers the precise mapping of the channel topography is a challenging task as the flow velocities are often high and the area is difficult and/or dangerous to access by boat or by feet. Traditional mapping techniques like tachymetry or echo sounding fail in such situations while ALB provides, both, high spot position accuracy in the cm range and high spatial resolution in the dm range. Furthermore, state-of-the-art ALB systems allow simultaneous mapping of the river bed and the riparian area and, therefore, represent a comprehensive and efficient technology for mapping the entire floodplain area. The maximum penetration depth depends on, both, water turbidity and bottom reflectivity. Consequently, ALB provides the highest accuracy and resolution over bright gravel rivers with relatively clear water. We demonstrate the capability of ALB for precise mapping of river bed changes based on three flight campaigns in April, May and October 2013 at the River Pielach (Lower Austria) carried out with Riegl's VQ-820-G topo-bathymetric laser scanner. Operated at a flight height of 600m above ground with a pulse repetition rate of 510kHz (effective measurement rate 200kHz) this yielded a mean point spacing within the river bed of 20cm (i.e. point density: 25 points/m2). The positioning accuracy of the river bed points is approx. 2-5cm and depends on the overall ranging precision (20mm), the quality of the water surface model (derived from the ALB point cloud), and the signal intensity (decreasing with water depth). All in all, the obtained point cloud allowed the derivation of a dense grid model of the channel topography (0.25m cell size) for all three epochs constituting an excellent basis for, both, the visual and quantitative estimation of the changes over the year. It turned out that even between the April and May flight remarkable differences could be detected although there was no major precipitation event in-between and the flow conditions were entirely below mean flow. In contrast to the moderate changes between April and May, the flood event in June 2013 (HQ1) resulted in a radical change of the river bed topography documented by the October flight. Since the study site (Neubacher Au) is a Natura2000 conservation area, space for a meandering flow is allowed. Entire gravel bars have been removed and new bars were deposited down-stream. Furthermore, the river axis was locally shifted by more than 1m during the flood event. The results demonstrate the high potential of laser bathymetry for precise mapping of river bed changes. This opens new perspectives for the validation of sediment transport models models and a much better understanding of the river morphology (e.g. formation and changes of sand and gravel banks). The traditional approach in sediment transport modelling based on a limited number of cross sections can be completed respectively replaced by a more comprehensive and more reliable concept on the basis of spatial distributed river bed data. Valuable calibration data in a new quality will be available.

NASA’s Improved Supersonic Cockpit Display Shows Precise Locations of Sonic Booms

NASA Image and Video Library

2016-10-06

Engineers and researchers at NASA’s Armstrong Flight Research Center monitored the flights, and were able to observe the mapping of the sonic boom carpet from the F-18, from the center’s Mission Control Center.

Open-Loop Flight Testing of COBALT GN&C Technologies for Precise Soft Landing

NASA Technical Reports Server (NTRS)

Carson, John M., III; Amzajerdian, Farzin; Seubert, Carl R.; Restrepo, Carolina I.

2017-01-01

A terrestrial, open-loop (OL) flight test campaign of the NASA COBALT (CoOperative Blending of Autonomous Landing Technologies) platform was conducted onboard the Masten Xodiac suborbital rocket testbed, with support through the NASA Advanced Exploration Systems (AES), Game Changing Development (GCD), and Flight Opportunities (FO) Programs. The COBALT platform integrates NASA Guidance, Navigation and Control (GN&C) sensing technologies for autonomous, precise soft landing, including the Navigation Doppler Lidar (NDL) velocity and range sensor and the Lander Vision System (LVS) Terrain Relative Navigation (TRN) system. A specialized navigation filter running onboard COBALT fuzes the NDL and LVS data in real time to produce a precise navigation solution that is independent of the Global Positioning System (GPS) and suitable for future, autonomous planetary landing systems. The OL campaign tested COBALT as a passive payload, with COBALT data collection and filter execution, but with the Xodiac vehicle Guidance and Control (G&C) loops closed on a Masten GPS-based navigation solution. The OL test was performed as a risk reduction activity in preparation for an upcoming 2017 closed-loop (CL) flight campaign in which Xodiac G&C will act on the COBALT navigation solution and the GPS-based navigation will serve only as a backup monitor.

Estimating maneuvers for precise relative orbit determination using GPS

NASA Astrophysics Data System (ADS)

Allende-Alba, Gerardo; Montenbruck, Oliver; Ardaens, Jean-Sébastien; Wermuth, Martin; Hugentobler, Urs

2017-01-01

Precise relative orbit determination is an essential element for the generation of science products from distributed instrumentation of formation flying satellites in low Earth orbit. According to the mission profile, the required formation is typically maintained and/or controlled by executing maneuvers. In order to generate consistent and precise orbit products, a strategy for maneuver handling is mandatory in order to avoid discontinuities or precision degradation before, after and during maneuver execution. Precise orbit determination offers the possibility of maneuver estimation in an adjustment of single-satellite trajectories using GPS measurements. However, a consistent formulation of a precise relative orbit determination scheme requires the implementation of a maneuver estimation strategy which can be used, in addition, to improve the precision of maneuver estimates by drawing upon the use of differential GPS measurements. The present study introduces a method for precise relative orbit determination based on a reduced-dynamic batch processing of differential GPS pseudorange and carrier phase measurements, which includes maneuver estimation as part of the relative orbit adjustment. The proposed method has been validated using flight data from space missions with different rates of maneuvering activity, including the GRACE, TanDEM-X and PRISMA missions. The results show the feasibility of obtaining precise relative orbits without degradation in the vicinity of maneuvers as well as improved maneuver estimates that can be used for better maneuver planning in flight dynamics operations.

Flight evaluation of differential GPS aided inertial navigation systems

NASA Technical Reports Server (NTRS)

Mcnally, B. David; Paielli, Russell A.; Bach, Ralph E., Jr.; Warner, David N., Jr.

1992-01-01

Algorithms are described for integration of Differential Global Positioning System (DGPS) data with Inertial Navigation System (INS) data to provide an integrated DGPS/INS navigation system. The objective is to establish the benefits that can be achieved through various levels of integration of DGPS with INS for precision navigation. An eight state Kalman filter integration was implemented in real-time on a twin turbo-prop transport aircraft to evaluate system performance during terminal approach and landing operations. A fully integrated DGPS/INS system is also presented which models accelerometer and rate-gyro measurement errors plus position, velocity, and attitude errors. The fully integrated system was implemented off-line using range-domain (seventeen-state) and position domain (fifteen-state) Kalman filters. Both filter integration approaches were evaluated using data collected during the flight test. Flight-test data consisted of measurements from a 5 channel Precision Code GPS receiver, a strap-down Inertial Navigation Unit (INU), and GPS satellite differential range corrections from a ground reference station. The aircraft was laser tracked to determine its true position. Results indicate that there is no significant improvement in positioning accuracy with the higher levels of DGPS/INS integration. All three systems provided high-frequency (e.g., 20 Hz) estimates of position and velocity. The fully integrated system provided estimates of inertial sensor errors which may be used to improve INS navigation accuracy should GPS become unavailable, and improved estimates of acceleration, attitude, and body rates which can be used for guidance and control. Precision Code DGPS/INS positioning accuracy (root-mean-square) was 1.0 m cross-track and 3.0 m vertical. (This AGARDograph was sponsored by the Guidance and Control Panel.)

Helicopter flight test of 3D imaging flash LIDAR technology for safe, autonomous, and precise planetary landing

NASA Astrophysics Data System (ADS)

Roback, Vincent; Bulyshev, Alexander; Amzajerdian, Farzin; Reisse, Robert

2013-05-01

Two flash lidars, integrated from a number of cutting-edge components from industry and NASA, are lab characterized and flight tested for determination of maximum operational range under the Autonomous Landing and Hazard Avoidance Technology (ALHAT) project (in its fourth development and field test cycle) which is seeking to develop a guidance, navigation, and control (GNC) and sensing system based on lidar technology capable of enabling safe, precise crewed or robotic landings in challenging terrain on planetary bodies under any ambient lighting conditions. The flash lidars incorporate pioneering 3-D imaging cameras based on Indium-Gallium-Arsenide Avalanche Photo Diode (InGaAs APD) and novel micro-electronic technology for a 128 x 128 pixel array operating at 30 Hz, high pulse-energy 1.06 μm Nd:YAG lasers, and high performance transmitter and receiver fixed and zoom optics. The two flash lidars are characterized on the NASA-Langley Research Center (LaRC) Sensor Test Range, integrated with other portions of the ALHAT GNC system from partner organizations into an instrument pod at NASA-JPL, integrated onto an Erickson Aircrane Helicopter at NASA-Dryden, and flight tested at the Edwards AFB Rogers dry lakebed over a field of humanmade geometric hazards during the summer of 2010. Results show that the maximum operational range goal of 1 km is met and exceeded up to a value of 1.2 km. In addition, calibrated 3-D images of several hazards are acquired in realtime for later reconstruction into Digital Elevation Maps (DEM's).

Helicopter Flight Test of 3-D Imaging Flash LIDAR Technology for Safe, Autonomous, and Precise Planetary Landing

NASA Technical Reports Server (NTRS)

Roback, Vincent; Bulyshev, Alexander; Amzajerdian, Farzin; Reisse, Robert

2013-01-01

Two flash lidars, integrated from a number of cutting-edge components from industry and NASA, are lab characterized and flight tested for determination of maximum operational range under the Autonomous Landing and Hazard Avoidance Technology (ALHAT) project (in its fourth development and field test cycle) which is seeking to develop a guidance, navigation, and control (GN&C) and sensing system based on lidar technology capable of enabling safe, precise crewed or robotic landings in challenging terrain on planetary bodies under any ambient lighting conditions. The flash lidars incorporate pioneering 3-D imaging cameras based on Indium-Gallium-Arsenide Avalanche Photo Diode (InGaAs APD) and novel micro-electronic technology for a 128 x 128 pixel array operating at 30 Hz, high pulse-energy 1.06 micrometer Nd:YAG lasers, and high performance transmitter and receiver fixed and zoom optics. The two flash lidars are characterized on the NASA-Langley Research Center (LaRC) Sensor Test Range, integrated with other portions of the ALHAT GN&C system from partner organizations into an instrument pod at NASA-JPL, integrated onto an Erickson Aircrane Helicopter at NASA-Dryden, and flight tested at the Edwards AFB Rogers dry lakebed over a field of human-made geometric hazards during the summer of 2010. Results show that the maximum operational range goal of 1 km is met and exceeded up to a value of 1.2 km. In addition, calibrated 3-D images of several hazards are acquired in real-time for later reconstruction into Digital Elevation Maps (DEM's).

A rocket telescope spectrometer with high precision pointing control.

PubMed

Bottema, M; Fastie, W G; Moos, H W

1969-09-01

One second of arc pointing accuracy has been achieved by servocontrolling the secondary mirror of a Dall-Kirkham telescope flown in an Aerobee 150 rocket. The primary mirror is weight-relieved, mounted at its nodal line and can resolve 2 arc sec. An objective LiF prism mounted near the focal plane provides a lowresolution far uv spectrum suitable for studying planetary atmospheres. Solar blind photomultiplier tubes with pulse counting electronics provide a dark current background of less than 1 count/sec. Spectra of Venus, Jupiter and eta Ursa Majoris (U Ma) were obtained in a flight from White Sands, New Mexico, on 5 December 1967. Further flights are planned with the recovered package.

Hypoxia and flight performance of military instructor pilots in a flight simulator.

PubMed

Temme, Leonard A; Still, David L; Acromite, Michael T

2010-07-01

Military aircrew and other operational personnel frequently perform their duties at altitudes posing a significant hypoxia risk, often with limited access to supplemental oxygen. Despite the significant risk hypoxia poses, there are few studies relating it to primary flight performance, which is the purpose of the present study. Objective, quantitative measures of aircraft control were collected from 14 experienced, active duty instructor pilot volunteers as they breathed an air/nitrogen mix that provided an oxygen partial pressure equivalent to the atmosphere at 18,000 ft (5486.4 m) above mean sea level. The flight task required holding a constant airspeed, altitude, and heading at an airspeed significantly slower than the aircraft's minimum drag speed. The simulated aircraft's inherent instability at the target speed challenged the pilot to maintain constant control of the aircraft in order to minimize deviations from the assigned flight parameters. Each pilot's flight performance was evaluated by measuring all deviations from assigned target values. Hypoxia degraded the pilot's precision of altitude and airspeed control by 53%, a statistically significant decrease in flight performance. The effect on heading control effects was not statistically significant. There was no evidence of performance differences when breathing room air pre- and post-hypoxia. Moderate levels of hypoxia degraded the ability of military instructor pilots to perform a precision slow flight task. This is one of a small number of studies to quantify an effect of hypoxia on primary flight performance.

Simulation of Attitude and Trajectory Dynamics and Control of Multiple Spacecraft

NASA Technical Reports Server (NTRS)

Stoneking, Eric T.

2009-01-01

Agora software is a simulation of spacecraft attitude and orbit dynamics. It supports spacecraft models composed of multiple rigid bodies or flexible structural models. Agora simulates multiple spacecraft simultaneously, supporting rendezvous, proximity operations, and precision formation flying studies. The Agora environment includes ephemerides for all planets and major moons in the solar system, supporting design studies for deep space as well as geocentric missions. The environment also contains standard models for gravity, atmospheric density, and magnetic fields. Disturbance force and torque models include aerodynamic, gravity-gradient, solar radiation pressure, and third-body gravitation. In addition to the dynamic and environmental models, Agora supports geometrical visualization through an OpenGL interface. Prototype models are provided for common sensors, actuators, and control laws. A clean interface accommodates linking in actual flight code in place of the prototype control laws. The same simulation may be used for rapid feasibility studies, and then used for flight software validation as the design matures. Agora is open-source and portable across computing platforms, making it customizable and extensible. It is written to support the entire GNC (guidance, navigation, and control) design cycle, from rapid prototyping and design analysis, to high-fidelity flight code verification. As a top-down design, Agora is intended to accommodate a large range of missions, anywhere in the solar system. Both two-body and three-body flight regimes are supported, as well as seamless transition between them. Multiple spacecraft may be simultaneously simulated, enabling simulation of rendezvous scenarios, as well as formation flying. Built-in reference frames and orbit perturbation dynamics provide accurate modeling of precision formation control.

Flying at no mechanical energy cost: disclosing the secret of wandering albatrosses.

PubMed

Sachs, Gottfried; Traugott, Johannes; Nesterova, Anna P; Dell'Omo, Giacomo; Kümmeth, Franz; Heidrich, Wolfgang; Vyssotski, Alexei L; Bonadonna, Francesco

2012-01-01

Albatrosses do something that no other birds are able to do: fly thousands of kilometres at no mechanical cost. This is possible because they use dynamic soaring, a flight mode that enables them to gain the energy required for flying from wind. Until now, the physical mechanisms of the energy gain in terms of the energy transfer from the wind to the bird were mostly unknown. Here we show that the energy gain is achieved by a dynamic flight manoeuvre consisting of a continually repeated up-down curve with optimal adjustment to the wind. We determined the energy obtained from the wind by analysing the measured trajectories of free flying birds using a new GPS-signal tracking method yielding a high precision. Our results reveal an evolutionary adaptation to an extreme environment, and may support recent biologically inspired research on robotic aircraft that might utilize albatrosses' flight technique for engineless propulsion.

Flying at No Mechanical Energy Cost: Disclosing the Secret of Wandering Albatrosses

PubMed Central

Sachs, Gottfried; Traugott, Johannes; Nesterova, Anna P.; Dell'Omo, Giacomo; Kümmeth, Franz; Heidrich, Wolfgang

2012-01-01

Albatrosses do something that no other birds are able to do: fly thousands of kilometres at no mechanical cost. This is possible because they use dynamic soaring, a flight mode that enables them to gain the energy required for flying from wind. Until now, the physical mechanisms of the energy gain in terms of the energy transfer from the wind to the bird were mostly unknown. Here we show that the energy gain is achieved by a dynamic flight manoeuvre consisting of a continually repeated up-down curve with optimal adjustment to the wind. We determined the energy obtained from the wind by analysing the measured trajectories of free flying birds using a new GPS-signal tracking method yielding a high precision. Our results reveal an evolutionary adaptation to an extreme environment, and may support recent biologically inspired research on robotic aircraft that might utilize albatrosses' flight technique for engineless propulsion. PMID:22957014

Mapping the Active Vents of Stromboli Volcano with an Unmanned Aerial Vehicle

NASA Astrophysics Data System (ADS)

Turner, N.; Houghton, B. F.; von der Lieth, J.; Hort, M. K.; Taddeucci, J.; Kueppers, U.; Ricci, T.; Gaudin, D.

2016-12-01

We present a new detailed map of the active vents of Stromboli volcano obtained from UAV flights in May 2016, when the active NE and SW craters were repeatedly mapped. Due to high levels of gas emissions and frequent explosions, fine-scale measurements of vent geometry from single flights were challenging. However, the compilation of data acquired over 12 flights used with Structure from Motion software allowed us to create a 10 cm Digital Elevation Model (DEM) offering a non-obstructed view into the active craters. Such direct observations permits us to constrain parameters such as vent geometry and depth with an unprecedented precision, thus potentially reducing the uncertainty of models depending on such inputs (e.g. conduit and acoustic models). Furthermore, the low-cost and safety of UAVs allows mapping changes at small temporal and spatial resolutions, making this technique complementary to monitoring efforts at active volcanoes.

Goddard Space Flight Center Spacecraft Magnetic Test Facility Restoration Project

NASA Technical Reports Server (NTRS)

Vernier, Robert; Bonalksy, Todd; Slavin, James

2004-01-01

The Goddard Space Flight Center Spacecraft Magnetic Test Facility (SMTF) was constructed in the 1960's for the purpose of simulating geomagnetic and interplanetary magnetic field environments. The facility includes a three axis Braunbek coil system consisting of 12 loops, 4 loops on each of the three orthogonal axes; a remote Earth field sensing magnetometer and servo controller; and a remote power control and instrumentation building. The inner coils of the Braunbek system are 42-foot in diameter with a 10-foot by 10-foot opening through the outer coils to accommodate spacecraft access into the test volume. The physical size and precision of the facility are matched by only two other such facilities in the world. The facility was used extensively from the late 1960's until the early 1990's when the requirement for spacecraft level testing diminished. New NASA missions planned under the Living with a Star, Solar Terrestrial Probes, Explorer, and New Millennium Programs include precision, high-resolution magnetometers to obtain magnetic field data that is critical to fulfilling their scientific mission. It is highly likely that future Lunar and Martian exploration missions will also use precision magnetometers to conduct geophysical magnetic surveys. To ensure the success of these missions, ground-testing using a magnetic test facility such as the GSFC SMTF will be required. This paper describes the history of the facility, the future mission requirements that have renewed the need for spacecraft level magnetic testing, and the plans for restoring the facility to be capable of performing to its original design specifications.

Goddard Space Flight Center Spacecraft Magnetic Test Facility Restoration Project

NASA Technical Reports Server (NTRS)

Vernier, Robert; Bonalosky, Todd; Slavin, James

2004-01-01

The Goddard Space Flight Center Spacecraft Magnetic Test Facility (SMTF) was constructed in the 1960's for the purpose of simulating geomagnetic and interplanetary magnetic field environments. The facility includes a three axis Braunbek coil system consisting of 12 loops, 4 loops on each of the three orthogonal axes; a remote Earth field sensing magnetometer and servo controller; and a remote power control and instrumentation building. The inner coils of the Braunbek system are 42-foot in diameter with a 10-foot by 10-foot opening through the outer coils to accommodate spacecraft access into the test volume. The physical size and precision of the facility are matched by only two other such facilities in the world. The facility was used extensively from the late 1960's until the early 1990's when the requirement for spacecraft level testing diminished. New NASA missions planned under the Living with a Star, Solar Terrestrial Probes, Explorer, and New Millennium Programs include precision, high-resolution magnetometers to obtain magnetic field data that is critical to fulfilling their scientific mission. It is highly likely that future Lunar and Martian exploration missions will also use precision magnetometers to conduct geophysical magnetic surveys. To ensure the success of these missions, ground testing using a magnetic test facility such as the GSFC SMTF will be required. This paper describes the history of the facility, the future mission requirements that have renewed the need for spacecraft level magnetic testing, and the plans for restoring the facility to be capable of performing to its original design specifications.

Update on Piloted and Un-Piloted Aircraft at NASA Dryden

NASA Technical Reports Server (NTRS)

DelFrate, John H.

2007-01-01

This viewgraph presentation reviews the NASA Dryden Flight Research Center's (DFRC) environment for testing of experimental aircraft. Included are a satellite view of the Dryden locale, and a summary of the capabilities at DFRC. It reviews the capabilites of High Altitude Platform (HAP) testing; Gulfstream III (1.)Unmanned Aerial Vehicle (UAV) synthetic aperture radar (SAR) (2) Precision Trajectory Capability Global Hawk (ACTD); ER-2; Ikhana (Predator B);

Preliminary investigation of electrothermal vaporization sample introduction for inductively coupled plasma time-of-flight mass spectrometry.

PubMed

Mahoney, P P; Ray, S J; Li, G; Hieftje, G M

1999-04-01

The coupling of an electrothermal vaporization (ETV) apparatus to an inductively coupled plasma time-of-flight mass spectrometer (ICP-TOFMS) is described. The ability of the ICP-TOFMS to produce complete elemental mass spectra at high repetition rates is experimentally demonstrated. A signal-averaging data acquisition board is employed to rapidly record complete elemental spectra throughout the vaporization stage of the ETV temperature cycle; a solution containing 34 elements is analyzed. The reduction of both molecular and atomic isobaric interferences through the temperature program of the furnace is demonstrated. Isobaric overlaps among the isotopes of cadmium, tin, and indium are resolved by exploiting differences in the vaporization characteristics of the elements. Figures of merit for the system are defined with several different data acquisition schemes capable of operating at the high repetition rate of the TOF instrument. With the use of both ion counting and a boxcar averager, the dynamic range is shown to be linear over a range of at least 6 orders of magnitude. A pair of boxcar averagers are used to measure the isotope ratio for silver with a precision of 1.9% RSD, despite a cycle-to-cycle precision of 19% RSD. Detection limits of 10-80 fg are calculated for seven elements, based upon a 10-microL injection.

These two NASA F/A-18 aircraft are flying a test point for the Autonomous Formation Flight project o

NASA Technical Reports Server (NTRS)

2001-01-01

Two NASA F/A-18 aircraft are flying a test point for the Autonomous Formation Flight project over California's Mojave Desert. This second flight phase is mapping the wingtip vortex of the lead aircraft, the Systems Research Aircraft (tail number 847), on the trailing F/A-18 tail number 847. Wingtip vortex is a spiraling wind flowing from the wing during flight. The project is studying the drag and fuel reduction of precision formation flying.

Familiar route loyalty implies visual pilotage in the homing pigeon

PubMed Central

Biro, Dora; Meade, Jessica; Guilford, Tim

2004-01-01

Wide-ranging animals, such as birds, regularly traverse large areas of the landscape efficiently in the course of their local movement patterns, which raises fundamental questions about the cognitive mechanisms involved. By using precision global-positioning-system loggers, we show that homing pigeons (Columba livia) not only come to rely on highly stereotyped yet surprisingly inefficient routes within the local area but are attracted directly back to their individually preferred routes even when released from novel sites off-route. This precise route loyalty demonstrates a reliance on familiar landmarks throughout the flight, which was unexpected under current models of avian navigation. We discuss how visual landmarks may be encoded as waypoints within familiar route maps. PMID:15572457

Flight test evaluation of the Stanford University/United Airlines differential GPS Category 3 automatic landing system

NASA Technical Reports Server (NTRS)

Kaufmann, David N.; Ncnally, B. David

1995-01-01

Test flights were conducted to evaluate the capability of Differential Global Positioning System (DGPS) to provide the accuracy and integrity required for International Civil Aviation Organization (ICAO) Category (CAT) 3 precision approach and landings. These test flights were part of a Federal Aviation Administration (FAA) program to evaluate the technical feasibility of using DGPS based technology for CAT 3 precision approach and landing applications. A United Airlines Boeing 737-300 (N304UA) was equipped with DGPS receiving equipment and additional computing capability provided by Stanford University. The test flights were conducted at NASA Ames Research Center's Crows Landing Flight Facility, Crows Landing, California. The flight test evaluation was based on completing 100 approaches and autolandings; 90 touch and go, and 10 terminating with a full stop. Two types of accuracy requirements were evaluated: 1) Total system error, based on the Required Navigation Performance (RNP), and 2) Navigation sensor error, based on ICAO requirements for the Microwave Landing System (MLS). All of the approaches and autolandings were evaluated against ground truth reference data provided by a laser tracker. Analysis of these approaches and autolandings shows that the Stanford University/United Airlines system met the requirements for a successful approach and autolanding 98 out of 100 approaches and autolandings, based on the total system error requirements as specified in the FAA CAT 3 Level 2 Flight Test Plan.

Adaptive structures flight experiments

NASA Astrophysics Data System (ADS)

Martin, Maurice

The topics are presented in viewgraph form and include the following: adaptive structures flight experiments; enhanced resolution using active vibration suppression; Advanced Controls Technology Experiment (ACTEX); ACTEX program status; ACTEX-2; ACTEX-2 program status; modular control patch; STRV-1b Cryocooler Vibration Suppression Experiment; STRV-1b program status; Precision Optical Bench Experiment (PROBE); Clementine Spacecraft Configuration; TECHSAT all-composite spacecraft; Inexpensive Structures and Materials Flight Experiment (INFLEX); and INFLEX program status.

Adaptive Structures Flight Experiments

NASA Technical Reports Server (NTRS)

Martin, Maurice

1992-01-01

The topics are presented in viewgraph form and include the following: adaptive structures flight experiments; enhanced resolution using active vibration suppression; Advanced Controls Technology Experiment (ACTEX); ACTEX program status; ACTEX-2; ACTEX-2 program status; modular control patch; STRV-1b Cryocooler Vibration Suppression Experiment; STRV-1b program status; Precision Optical Bench Experiment (PROBE); Clementine Spacecraft Configuration; TECHSAT all-composite spacecraft; Inexpensive Structures and Materials Flight Experiment (INFLEX); and INFLEX program status.

Flight test evaluation of the E-systems Differential GPS category 3 automatic landing system

NASA Technical Reports Server (NTRS)

Kaufmann, David N.; Mcnally, B. David

1995-01-01

Test flights were conducted to evaluate the capability of Differential Global Positioning System (DGPS) to provide the accuracy and integrity required for International Civil Aviation Organization (ICAO) Category (CAT) III precision approach and landings. These test flights were part of a Federal Aviation Administration (FAA) program to evaluate the technical feasibility of using DGPS based technology for CAT III precision approach and landing applications. An IAI Westwind 1124 aircraft (N24RH) was equipped with DGPS receiving equipment and additional computing capability provided by E-Systems. The test flights were conducted at NASA Ames Research Center's Crows Landing Flight Facility, Crows Landing, California. The flight test evaluation was based on completing 100 approaches and landings. The navigation sensor error accuracy requirements were based on ICAO requirements for the Microwave Landing System (MLS). All of the approaches and landings were evaluated against ground truth reference data provided by a laser tracker. Analysis of these approaches and landings shows that the E-Systems DGPS system met the navigation sensor error requirements for a successful approach and landing 98 out of 100 approaches and landings, based on the requirements specified in the FAA CAT III Level 2 Flight Test Plan. In addition, the E-Systems DGPS system met the integrity requirements for a successful approach and landing or stationary trial for all 100 approaches and landings and all ten stationary trials, based on the requirements specified in the FAA CAT III Level 2 Flight Test Plan.

Calcium signalling indicates bilateral power balancing in the Drosophila flight muscle during manoeuvring flight

PubMed Central

Lehmann, Fritz-Olaf; Skandalis, Dimitri A.; Berthé, Ruben

2013-01-01

Manoeuvring flight in animals requires precise adjustments of mechanical power output produced by the flight musculature. In many insects such as fruit flies, power generation is most likely varied by altering stretch-activated tension, that is set by sarcoplasmic calcium levels. The muscles reside in a thoracic shell that simultaneously drives both wings during wing flapping. Using a genetically expressed muscle calcium indicator, we here demonstrate in vivo the ability of this animal to bilaterally adjust its calcium activation to the mechanical power output required to sustain aerodynamic costs during flight. Motoneuron-specific comparisons of calcium activation during lift modulation and yaw turning behaviour suggest slightly higher calcium activation for dorso-longitudinal than for dorsoventral muscle fibres, which corroborates the elevated need for muscle mechanical power during the wings’ downstroke. During turning flight, calcium activation explains only up to 54 per cent of the required changes in mechanical power, suggesting substantial power transmission between both sides of the thoracic shell. The bilateral control of muscle calcium runs counter to the hypothesis that the thorax of flies acts as a single, equally proportional source for mechanical power production for both flapping wings. Collectively, power balancing highlights the precision with which insects adjust their flight motor to changing energetic requirements during aerial steering. This potentially enhances flight efficiency and is thus of interest for the development of technical vehicles that employ bioinspired strategies of power delivery to flapping wings. PMID:23486171

Flared landing approach flying qualities. Volume 2: Appendices

NASA Technical Reports Server (NTRS)

Weingarten, Norman C.; Berthe, Charles J., Jr.; Rynaski, Edmund G.; Sarrafian, Shahan K.

1986-01-01

An in-flight research study was conducted utilizing the USAF/Total In-Flight Simulator (TIFS) to investigate longitudinal flying qualities for the flared landing approach phase of flight. A consistent set of data were generated for: determining what kind of command response the pilot prefers/requires in order to flare and land an aircraft with precision, and refining a time history criterion that took into account all the necessary variables and the characteristics that would accurately predict flying qualities. Seven evaluation pilots participated representing NASA Langley, NASA Dryden, Calspan, Boeing, Lockheed, and DFVLR (Braunschweig, Germany). The results of the first part of the study provide guidelines to the flight control system designer, using MIL-F-8785-(C) as a guide, that yield the dynamic behavior pilots prefer in flared landings. The results of the second part provide the flying qualities engineer with a derived flying qualities predictive tool which appears to be highly accurate. This time-domain predictive flying qualities criterion was applied to the flight data as well as six previous flying qualities studies, and the results indicate that the criterion predicted the flying qualities level 81% of the time and the Cooper-Harper pilot rating, within + or - 1%, 60% of the time.

Soliton microcomb range measurement.

PubMed

Suh, Myoung-Gyun; Vahala, Kerry J

2018-02-23

Laser-based range measurement systems are important in many application areas, including autonomous vehicles, robotics, manufacturing, formation flying of satellites, and basic science. Coherent laser ranging systems using dual-frequency combs provide an unprecedented combination of long range, high precision, and fast update rate. We report dual-comb distance measurement using chip-based soliton microcombs. A single pump laser was used to generate dual-frequency combs within a single microresonator as counterpropagating solitons. We demonstrated time-of-flight measurement with 200-nanometer precision at an averaging time of 500 milliseconds within a range ambiguity of 16 millimeters. Measurements at distances up to 25 meters with much lower precision were also performed. Our chip-based source is an important step toward miniature dual-comb laser ranging systems that are suitable for photonic integration. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Flight tests, laboratory studies, and intercomparisons of the NSF/NCAR Gulfstream-V VCSEL hygrometer

NASA Astrophysics Data System (ADS)

Zondlo, M. A.; Paige, M. E.; Silver, J. A.; Curry, M. D.

2007-12-01

New observation platforms and state-of-the-art science requirements place challenging demands on the development of new instrumentation. Instruments are desired be faster, smaller, lighter while still maintaining excellent accuracy, precision, and even offering new observational capabilities. New measurements understandably require a large body of evidence documenting their performance before much acceptance in the community. In this context, we will discuss the performance of our recently-developed water vapor sensor designed for the NSF/NCAR Gulfstream-V aircraft by showing results from the first flight tests, laboratory experiments, flow modeling studies of the pylon design, and intercomparison campaigns. Water vapor plays critical roles in atmospheric dynamics, radiative properties, and chemistry throughout the troposphere and lower stratosphere, but there are many measurement challenges due to the large dynamic range in concentration, extreme heterogeneity, presence of cloud particles, and efficient adsorption to instrument surfaces. The Gulfstream-V water vapor instrument uses a fiberized vertical cavity surface emitting laser (VCSEL) operating near a wavelength of 1854 nm to measure water vapor at 25 Hz with <3% precision and 5% accuracy over a range from 1 ppmv (-92 C frost point at 50 hPa) to 40,000 ppmv (+30 C dew point at sea level). The instrument operates unattended, has a mass of 5 kg, and consumes 5 W power. Extensive flight testing of the instrument was performed in spring and summer of 2007 as part of the NSF Pacific Dust Experiment (PACDEX) and HIAPER Experimental Flight Tests. The instrument showed excellent response in clouds ranging from stratocumulus to cirrus. Detailed cloud structure was observed in both cases at 25 Hz that can increase the understanding of cloud entrainment/detrainment processes. In addition, a relatively homogeneous flight segment near the tropopause at 14.8 km (135 hPa) allowed for in-flight checks of the instrument precision (as opposed to laboratory conditions). Under flight conditions of ~ 3 ppmv water vapor, 25 Hz measurements had a standard deviation of 2.1%, thereby placing an upper limit on the precision of the system as some of the variability originated from the real atmosphere. Allan deviation experiments in the laboratory at similar concentrations show about 1% precision, but more importantly, suggest that long-term drift for experiments lasting several days is negligible. Determination of the accuracy of the sensor is being conducted by three methods: calibrations using standard dilution of flows, immersion of the sensor at ice saturated conditions in constant-temperature ice/organic baths, and through studies at the upcoming AIDA International Water Vapor Intercomparison campaign (October 2007). In combination, these results will be used to assess the overall performance of the VCSEL hygrometer and identify where outstanding issues remain.

A new ball launching system with controlled flight parameters for catching experiments.

PubMed

d'Avella, A; Cesqui, B; Portone, A; Lacquaniti, F

2011-03-30

Systematic investigations of sensorimotor control of interceptive actions in naturalistic conditions, such as catching or hitting a ball moving in three-dimensional space, requires precise control of the projectile flight parameters and of the associated visual stimuli. Such control is challenging when air drag cannot be neglected because the mapping of launch parameters into flight parameters cannot be computed analytically. We designed, calibrated, and experimentally validated an actuated launching apparatus that can control the average spatial position and flight duration of a ball at a given distance from a fixed launch location. The apparatus was constructed by mounting a ball launching machine with adjustable delivery speed on an actuated structure capable of changing the spatial orientation of the launch axis while projecting balls through a hole in a screen hiding the apparatus. The calibration procedure relied on tracking the balls with a motion capture system and on approximating the mapping of launch parameters into flight parameters by means of polynomials functions. Polynomials were also used to estimate the variability of the flight parameters. The coefficients of these polynomials were obtained using the launch and flight parameters of 660 launches with 65 different initial conditions. The relative accuracy and precision of the apparatus were larger than 98% for flight times and larger than 96% for ball heights at a distance of 6m from the screen. Such novel apparatus, by reliably and automatically controlling desired ball flight characteristics without neglecting air drag, allows for a systematic investigation of naturalistic interceptive tasks. Copyright © 2011 Elsevier B.V. All rights reserved.

3D reconstruction optimization using imagery captured by unmanned aerial vehicles

NASA Astrophysics Data System (ADS)

Bassie, Abby L.; Meacham, Sean; Young, David; Turnage, Gray; Moorhead, Robert J.

2017-05-01

Because unmanned air vehicles (UAVs) are emerging as an indispensable image acquisition platform in precision agriculture, it is vitally important that researchers understand how to optimize UAV camera payloads for analysis of surveyed areas. In this study, imagery captured by a Nikon RGB camera attached to a Precision Hawk Lancaster was used to survey an agricultural field from six different altitudes ranging from 45.72 m (150 ft.) to 121.92 m (400 ft.). After collecting imagery, two different software packages (MeshLab and AgiSoft) were used to measure predetermined reference objects within six three-dimensional (3-D) point clouds (one per altitude scenario). In-silico measurements were then compared to actual reference object measurements, as recorded with a tape measure. Deviations of in-silico measurements from actual measurements were recorded as Δx, Δy, and Δz. The average measurement deviation in each coordinate direction was then calculated for each of the six flight scenarios. Results from MeshLab vs. AgiSoft offered insight into the effectiveness of GPS-defined point cloud scaling in comparison to user-defined point cloud scaling. In three of the six flight scenarios flown, MeshLab's 3D imaging software (user-defined scale) was able to measure object dimensions from 50.8 to 76.2 cm (20-30 inches) with greater than 93% accuracy. The largest average deviation in any flight scenario from actual measurements was 14.77 cm (5.82 in.). Analysis of the point clouds in AgiSoft (GPS-defined scale) yielded even smaller Δx, Δy, and Δz than the MeshLab measurements in over 75% of the flight scenarios. The precisions of these results are satisfactory in a wide variety of precision agriculture applications focused on differentiating and identifying objects using remote imagery.

Flight Performance of the HEROES Solar Aspect System

NASA Astrophysics Data System (ADS)

Shih, Albert Y.; Christe, Steven; Rodriguez, Marcello; Gregory, Kyle; Cramer, Alexander; Edgerton, Melissa; Gaskin, Jessica; O'Connor, Brian; Sobey, Alexander

2014-06-01

Hard X-ray (HXR) observations of solar flares reveal the signatures of energetic electrons, and HXR images with high dynamic range and high sensitivity can distinguish between where electrons are accelerated and where they stop. Furthermore, high-sensitivity HXR measurements may be able to detect the presence of electron acceleration in the non-flaring corona. The High Energy Replicated Optics to Explore the Sun (HEROES) balloon mission added the capability of solar observations to an existing astrophysics balloon payload, HERO, which used grazing-incidence optics for direct HXR imaging. The HEROES Solar Aspect System (SAS) was developed and built to provide pointing knowledge during solar observations to better than the ~20 arcsec FWHM angular resolution of the HXR instrument. The SAS consists of two separate systems: the Pitch-Yaw aspect System (PYAS) and the Roll Aspect System (RAS). The PYAS compares the position of an optical image of the Sun relative to precise fiducials to determine the pitch and yaw pointing offsets from the desired solar target. The RAS images the Earth's horizon in opposite directions simultaneously to determine the roll of the gondola. HEROES launched in September 2013 from Fort Sumner, New Mexico, and had a successful one-day flight. We present the detailed analysis of the performance of the SAS for that flight.

Flight evaluations of several hover control and display combinations for precise blind vertical landings

NASA Technical Reports Server (NTRS)

Schroeder, J. A.; Merrick, V. K.

1990-01-01

Several control and display concepts were evaluated on a variable-stability helicopter prior to future evaluations on a modified Harrier. The control and display concepts had been developed to enable precise hover maneuvers, station keeping, and vertical landings in simulated zero-visibility conditions and had been evaluated extensively in previous piloted simulations. Flight evaluations early in the program revealed several inadequacies in the display drive laws that were later corrected using an alternative design approach that integrated the control and display characteristics with the desired guidance law. While hooded, three pilots performed landing-pad captures followed by vertical landings with attitude-rate, attitude, and translation-velocity-command control systems. The latter control system incorporated a modified version of state-rate-feedback implicit-model following. Precise landing within 2 ft of the desired touchdown point were achieved.

Custom 3D Printers Revolutionize Space Supply Chain

NASA Technical Reports Server (NTRS)

2015-01-01

Under a series of SBIR contracts with Marshall Space Flight Center, start-up company Made In Space, located on the center's campus, developed a high-precision 3D printer capable of manufacturing items in microgravity. The company will soon have a printer installed on the International Space Station, altering the space supply chain. It will print supplies and tools for NASA, as well as nanosatellite shells and other items for public and private entities.

Why pilots are least likely to get good decision making precisely when they need it most

NASA Technical Reports Server (NTRS)

Maher, John W.

1991-01-01

Studies of commercial aircraft incidents and accidents indicate that, in flight conditions not covered by standard operating procedures, as well as when the environment is saturated with information or unmanaged stress, cognitive shortcuts dominate aircrews' decisionmaking processes. Multidisciplinary research on such situations with high-fidelity simulators becomes critically important, as do psychometric tools which examine vigilance, personality resiliency before stressful conditions, and decisional and interpersonal mind-sets.

Development of the functional simulator for the Galileo attitude and articulation control system

NASA Technical Reports Server (NTRS)

Namiri, M. K.

1983-01-01

A simulation program for verifying and checking the performance of the Galileo Spacecraft's Attitude and Articulation Control Subsystem's (AACS) flight software is discussed. The program, which is called Functional Simulator (FUNSIM), provides a simple method of interfacing user-supplied mathematical models coded in FORTRAN which describes spacecraft dynamics, sensors, and actuators; this is done with the AACS flight software, coded in HAL/S (High-level Advanced Language/Shuttle). It is thus able to simulate the AACS flight software accurately to the HAL/S statement level in the environment of a mainframe computer system. FUNSIM also has a command and data subsystem (CDS) simulator. It is noted that the input/output data and timing are simulated with the same precision as the flight microprocessor. FUNSIM uses a variable stepsize numerical integration algorithm complete with individual error bound control on the state variable to solve the equations of motion. The program has been designed to provide both line printer and matrix dot plotting of the variables requested in the run section and to provide error diagnostics.

Cryogenic Optical Position Encoders for Mechanisms in the JWST Optical Telescope Element Simulator (OSIM)

NASA Technical Reports Server (NTRS)

Leviton, Douglas B.; Anderjaska, Thomas; Badger, James (Inventor); Capon, Tom; Davis, CLinton; Dicks, Brent (Inventor); Eichhorn, William; Garza, Mario; Guishard, Corina; Haghani, Shadan;

In-Flight Performance of the Polarization Modulator in the CLASP Rocket Experiment

NASA Technical Reports Server (NTRS)

Ishikawa, S.; Shimizu, T.; Kano, R.; Bando, T.; Ishikawa, R.; Giono, G.; Beabout, D.; Beabout, B.; Nakayama, S.; Tajima, T.

2016-01-01

We developed a polarization modulation unit (PMU), a motor system to rotate a waveplate continuously. We applied this PMU for the Chromospheric Lyman-alpha SpectroPolarimeter (CLASP), a sounding rocket experiment to observe the linear polarization of the Lyman-alpha emission (121.6 nm vacuum ultraviolet) from the upper chromosphere and transition region of the Sun with a high polarization sensitivity of 0.1% for the first time and investigate the vector magnetic field. Rotation non-uniformity of the waveplate causes error in the polarization degree (i.e. scale error) and crosstalk between Stokes components. In the ground tests, we confirmed that PMU has superior rotation uniformity. CLASP was successfully launched on September 3, 2015, and PMU functioned well as designed. PMU achieved a good rotation uniformity during the flight and the high precision polarization measurement of CLASP was successfully achieved.

Direct detection of antiprotons with the Timepix3 in a new electrostatic selection beamline

NASA Astrophysics Data System (ADS)

Pacifico, N.; Aghion, S.; Alozy, J.; Amsler, C.; Ariga, A.; Ariga, T.; Bonomi, G.; Bräunig, P.; Bremer, J.; Brusa, R. S.; Cabaret, L.; Caccia, M.; Campbell, M.; Caravita, R.; Castelli, F.; Cerchiari, G.; Chlouba, K.; Cialdi, S.; Comparat, D.; Consolati, G.; Demetrio, A.; Di Noto, L.; Doser, M.; Dudarev, A.; Ereditato, A.; Evans, C.; Ferragut, R.; Fesel, J.; Fontana, A.; Gerber, S.; Giammarchi, M.; Gligorova, A.; Guatieri, F.; Haider, S.; Holmestad, H.; Huse, T.; Jordan, E.; Kellerbauer, A.; Kimura, M.; Krasnický, D.; Lagomarsino, V.; Lansonneur, P.; Lawler, G.; Lebrun, P.; Llopart, X.; Malbrunot, C.; Mariazzi, S.; Marx, L.; Matveev, V.; Mazzotta, Z.; Nebbia, G.; Nedelec, P.; Oberthaler, M.; Pagano, D.; Penasa, L.; Petracek, V.; Pistillo, C.; Prelz, F.; Prevedelli, M.; Ravelli, L.; Resch, L.; Røhne, O. M.; Rotondi, A.; Sacerdoti, M.; Sandaker, H.; Santoro, R.; Scampoli, P.; Smestad, L.; Sorrentino, F.; Spacek, M.; Storey, J.; Strojek, I. M.; Testera, G.; Tietje, I.; Tlustos, L.; Widmann, E.; Yzombard, P.; Zavatarelli, S.; Zmeskal, J.; Zurlo, N.

2016-09-01

We present here the first results obtained employing the Timepix3 for the detection and tagging of annihilations of low energy antiprotons. The Timepix3 is a recently developed hybrid pixel detector with advanced Time-of-Arrival and Time-over-Threshold capabilities and has the potential of allowing precise kinetic energy measurements of low energy charged particles from their time of flight. The tagging of the characteristic antiproton annihilation signature, already studied by our group, is enabled by the high spatial and energy resolution of this detector. In this study we have used a new, dedicated, energy selection beamline (GRACE). The line is symbiotic to the AEgIS experiment at the CERN Antiproton Decelerator and is dedicated to detector tests and possibly antiproton physics experiments. We show how the high resolution of the Timepix3 on the Time-of-Arrival and Time-over-Threshold information allows for a precise 3D reconstruction of the annihilation prongs. The presented results point at the potential use of the Timepix3 in antimatter-research experiments where a precise and unambiguous tagging of antiproton annihilations is required.

Measurement and Characterization of Helicopter Noise in Steady-State and Maneuvering Flight

NASA Technical Reports Server (NTRS)

Schmitz, Fredric H.; Greenwood, Eric; Sickenberger, Richard D.; Gopalan, Gaurav; Sim, Ben Well-C; Conner, David; Moralez, Ernesto; Decker, William A.

2007-01-01

A special acoustic flight test program was performed on the Bell 206B helicopter outfitted with an in-flight microphone boom/array attached to the helicopter while simultaneous acoustic measurements were made using a linear ground array of microphones arranged to be perpendicular to the flight path. Air and ground noise measurements were made in steady-state longitudinal and steady turning flight, and during selected dynamic maneuvers. Special instrumentation, including direct measurement of the helicopter s longitudinal tip-path-plane (TPP) angle, Differential Global Positioning System (DGPS) and Inertial Navigation Unit (INU) measurements, and a pursuit guidance display were used to measure important noise controlling parameters and to make the task of flying precise operating conditions and flight track easier for the pilot. Special care was also made to test only in very low winds. The resulting acoustic data is of relatively high quality and shows the value of carefully monitoring and controlling the helicopter s performance state. This paper has shown experimentally, that microphones close to the helicopter can be used to estimate the specific noise sources that radiate to the far field, if the microphones are positioned correctly relative to the noise source. Directivity patterns for steady, turning flight were also developed, for the first time, and connected to the turning performance of the helicopter. Some of the acoustic benefits of combining normally separated flight segments (i.e. an accelerated segment and a descending segment) were also demonstrated.

Auto-Coding UML Statecharts for Flight Software

NASA Technical Reports Server (NTRS)

Benowitz, Edward G; Clark, Ken; Watney, Garth J.

2006-01-01

Statecharts have been used as a means to communicate behaviors in a precise manner between system engineers and software engineers. Hand-translating a statechart to code, as done on some previous space missions, introduces the possibility of errors in the transformation from chart to code. To improve auto-coding, we have developed a process that generates flight code from UML statecharts. Our process is being used for the flight software on the Space Interferometer Mission (SIM).

Optical Fiber Array Assemblies for Space Flight on the Lunar Reconnaissance Orbiter

NASA Technical Reports Server (NTRS)

Ott, Jelanie; Matuszeski, Adam

2011-01-01

Custom fiber optic bundle array assemblies developed by the Photonics Group at NASA Goddard Space Flight Center were an enabling technology for both the Lunar Orbiter Laser Altimeter (LOLA) and the Laser Ranging (LR) Investigation on the Lunar Reconnaissance Orbiter (LRO) currently in operation. The unique assembly array designs provided considerable decrease in size and weight and met stringent system level requirements. This is the first time optical fiber array bundle assemblies were used in a high performance space flight application. This innovation was achieved using customized Diamond Switzerland AVIM optical connectors. For LOLA, a five fiber array was developed for the receiver telescope to maintain precise alignment for each of the 200/220 micron optical fibers collecting 1,064 nm wavelength light being reflected back from the moon. The array splits to five separate detectors replacing the need for multiple telescopes. An image illustration of the LOLA instrument can be found at the top of the figure. For the laser ranging, a seven-optical-fiber array of 400/440 micron fibers was developed to transmit light from behind the LR receiver telescope located on the end of the high gain antenna system (HGAS). The bundle was routed across two moving gimbals, down the HGAS boom arm, over a deployable mandrel and across the spacecraft to a detector on the LOLA instrument. The routing of the optical fiber bundle and its end locations is identified in the figure. The Laser Ranging array and bundle is currently accepting light at a wavelength of 532 nm sent to the moon from laser stations at Greenbelt MD and other stations around the world to gather precision ranging information from the Earth to the LRO spacecraft. The LR bundle assembly is capable of withstanding temperatures down to -55 C at the connectors, and 20,000 mechanical gimbal cycles at temperatures as cold as -20 C along the length of the seven-fiber bundle (that is packaged into the gimbals). The total bundle assembly is 10 meters long with two interconnections requiring precise clocking of the seven-fiber array pattern.

Comparison of TOPEX/Poseidon orbit determination solutions obtained by the Goddard Space Flight Center Flight Dynamics Division and Precision Orbit Determination Teams

NASA Technical Reports Server (NTRS)

Doll, C.; Mistretta, G.; Hart, R.; Oza, D.; Cox, C.; Nemesure, M.; Bolvin, D.; Samii, Mina V.

1993-01-01

Orbit determination results are obtained by the Goddard Space Flight Center (GSFC) Flight Dynamics Division (FDD) using the Goddard Trajectory Determination System (GTDS) and a real-time extended Kalman filter estimation system to process Tracking Data and Relay Satellite (TDRS) System (TDRSS) measurements in support of the Ocean Topography Experiment (TOPEX)/Poseidon spacecraft navigation and health and safety operations. GTDS is the operational orbit determination system used by the FDD, and the extended Kalman fliter was implemented in an analysis prototype system, the Real-Time Orbit Determination System/Enhanced (RTOD/E). The Precision Orbit Determination (POD) team within the GSFC Space Geodesy Branch generates an independent set of high-accuracy trajectories to support the TOPEX/Poseidon scientific data. These latter solutions use the Geodynamics (GEODYN) orbit determination system with laser ranging tracking data. The TOPEX/Poseidon trajectories were estimated for the October 22 - November 1, 1992, timeframe, for which the latest preliminary POD results were available. Independent assessments were made of the consistencies of solutions produced by the batch and sequential methods. The batch cases were assessed using overlap comparisons, while the sequential cases were assessed with covariances and the first measurement residuals. The batch least-squares and forward-filtered RTOD/E orbit solutions were compared with the definitive POD orbit solutions. The solution differences were generally less than 10 meters (m) for the batch least squares and less than 18 m for the sequential estimation solutions. The differences among the POD, GTDS, and RTOD/E solutions can be traced to differences in modeling and tracking data types, which are being analyzed in detail.

Flight Technical Error for Category B Non-Precision Approaches and Missed Approaches Using Non-Differential GPS for Course Guidance

DOT National Transportation Integrated Search

1993-11-01

Twelve general aviation pilots flew a Beechcraft Baron on 93 non-precision instrument approaches using a nondifferential : GPS receiver nodifled to satisfy selected functional requirements specified in TS0-C129. : The purposes of the effort were to d...

Development of Navigation Doppler Lidar for Future Landing Mission

NASA Technical Reports Server (NTRS)

Amzajerdian, Farzin; Hines, Glenn D.; Petway, Larry B.; Barnes, Bruce W.; Pierrottet, Diego F.; Carson, John M., III

2016-01-01

A coherent Navigation Doppler Lidar (NDL) sensor has been developed under the Autonomous precision Landing and Hazard Avoidance Technology (ALHAT) project to support future NASA missions to planetary bodies. This lidar sensor provides accurate surface-relative altitude and vector velocity data during the descent phase that can be used by an autonomous Guidance, Navigation, and Control (GN&C) system to precisely navigate the vehicle from a few kilometers above the ground to a designated location and execute a controlled soft touchdown. The operation and performance of the NDL was demonstrated through closed-loop flights onboard the rocket-propelled Morpheus vehicle in 2014. In Morpheus flights, conducted at the NASA Kennedy Space Center, the NDL data was used by an autonomous GN&C system to navigate and land the vehicle precisely at the selected location surrounded by hazardous rocks and craters. Since then, development efforts for the NDL have shifted toward enhancing performance, optimizing design, and addressing spaceflight size and mass constraints and environmental and reliability requirements. The next generation NDL, with expanded operational envelope and significantly reduced size, will be demonstrated in 2017 through a new flight test campaign onboard a commercial rocketpropelled test vehicle.

UAV-based L-band SAR with precision flight path control

NASA Astrophysics Data System (ADS)

Madsen, Soren N.; Hensley, Scott; Wheeler, Kevin; Sadowy, Gregory A.; Miller, Tim; Muellerschoen, Ron; Lou, Yunling; Rosen, Paul A.

2005-01-01

NASA's Jet Propulsion Laboratory is currently implementing a reconfigurable polarimetric L-band synthetic aperture radar (SAR), specifically designed to acquire airborne repeat track interferometric (RTI) SAR data, also know as differential interferometric measurements. Differential interferometry can provide key displacement measurements, important for the scientific studies of Earthquakes and volcanoes1. Using precision real-time GPS and a sensor controlled flight management system, the system will be able to fly predefined paths with great precision. The radar will be designed to operate on a UAV (Unmanned Arial Vehicle) but will initially be demonstrated on a minimally piloted vehicle (MPV), such as the Proteus build by Scaled Composites. The application requires control of the flight path to within a 10 m tube to support repeat track and formation flying measurements. The design is fully polarimetric with an 80 MHz bandwidth (2 m range resolution) and 16 km range swath. The antenna is an electronically steered array to assure that the actual antenna pointing can be controlled independent of the wind direction and speed. The system will nominally operate at 45,000 ft. The program started out as a Instrument Incubator Project (IIP) funded by NASA Earth Science and Technology Office (ESTO).

UAV-Based L-Band SAR with Precision Flight Path Control

NASA Technical Reports Server (NTRS)

Madsen, Soren N.; Hensley, Scott; Wheeler, Kevin; Sadowy, Greg; Miller, Tim; Muellerschoen, Ron; Lou, Yunling; Rosen, Paul

2004-01-01

NASA's Jet Propulsion Laboratory is currently implementing a reconfigurable polarimetric L-band synthetic aperture radar (SAR), specifically designed to acquire airborne repeat track interferometric (RTI) SAR data, also know as differential interferometric measurements. Differential interferometry can provide key displacement measurements, important for the scientific studies of Earthquakes and volcanoes. Using precision real-time GPS and a sensor controlled flight management system, the system will be able to fly predefined paths with great precision. The radar will be designed to operate on a UAV (Unmanned Arial Vehicle) but will initially be demonstrated on a minimally piloted vehicle (MPV), such as the Proteus build by Scaled Composites. The application requires control of the flight path to within a 10 meter tube to support repeat track and formation flying measurements. The design is fully polarimetric with an 80 MHz bandwidth (2 meter range resolution) and 16 kilometer range swath. The antenna is an electronically steered array to assure that the actual antenna pointing can be controlled independent of the wind direction and speed. The system will nominally operate at 45,000 ft. The program started out as a Instrument Incubator Project (IIP) funded by NASA Earth Science and Technology Office (ESTO).

A technique for the assessment of fighter aircraft precision controllability

NASA Technical Reports Server (NTRS)

Sisk, T. R.

1978-01-01

Today's emerging fighter aircraft are maneuvering as well at normal accelerations of 7 to 8 g's as their predecessors did at 4 to 5 g's. This improved maneuvering capability has significantly expanded their operating envelope and made the task of evaluating handling qualities more difficult. This paper describes a technique for assessing the precision controllability of highly maneuverable aircraft, a technique that was developed to evaluate the effects of buffet intensity on gunsight tracking capability and found to be a useful tool for the general assessment of fighter aircraft handling qualities. It has also demonstrated its usefulness for evaluating configuration and advanced flight control system refinements. This technique is believed to have application to future aircraft dynamics and pilot-vehicle interface studies.

Modeling pilot interaction with automated digital avionics systems: Guidance and control algorithms for contour and nap-of-the-Earth flight

NASA Technical Reports Server (NTRS)

Hess, Ronald A.

1990-01-01

A collection of technical papers are presented that cover modeling pilot interaction with automated digital avionics systems and guidance and control algorithms for contour and nap-of-the-earth flight. The titles of the papers presented are as follows: (1) Automation effects in a multiloop manual control system; (2) A qualitative model of human interaction with complex dynamic systems; (3) Generalized predictive control of dynamic systems; (4) An application of generalized predictive control to rotorcraft terrain-following flight; (5) Self-tuning generalized predictive control applied to terrain-following flight; and (6) Precise flight path control using a predictive algorithm.

Generation and Assessment of High Resolution Digital Surface Model by Using Unmanned Air Vehicle Based Multicopter

NASA Astrophysics Data System (ADS)

Gülci, S.; Dindaroğlu, T.; Gündoğan, R.

2017-11-01

Unmanned air vehicle systems (UAVSs), which are presently defined as effective measuring instruments, can be used for measurements and evaluation studies in fields. Furthermore, UAVs are effective tools that can produce high-precision and resolution data for use in geographic information system-based work. This study examined a multicopter (hexacopter) as an air platform to seek opportunity in generating DSM with high resolution. Flights were performed in Kahramanmaras Sutcu Imam University Campus area in Turkey. Pre-assessment of field works, mission, tests and installation were prepared by using a Laptop with an adaptive ground control station. Hand remote controller unit was also linked and activated during flight to interfere with emergency situations. Canon model IXSUS 160 was preferred as sensor. As a result of this study, as mentioned previous studies, .The orthophotos can be produced by RGB (Red-green-blue) images obtained with UAV, herewith information on terrain topography, land cover and soil erosion can be evaluated.

Design of an air traffic computer simulation system to support investigation of civil tiltrotor aircraft operations

NASA Technical Reports Server (NTRS)

Rogers, Ralph V.

1993-01-01

The TATSS Project's goal was to develop a design for computer software that would support the attainment of the following objectives for the air traffic simulation model: (1) Full freedom of movement for each aircraft object in the simulation model. Each aircraft object may follow any designated flight plan or flight path necessary as required by the experiment under consideration. (2) Object position precision up to +/- 3 meters vertically and +/- 15 meters horizontally. (3) Aircraft maneuvering in three space with the object position precision identified above. (4) Air traffic control operations and procedures. (5) Radar, communication, navaid, and landing aid performance. (6) Weather. (7) Ground obstructions and terrain. (8) Detection and recording of separation violations. (9) Measures of performance including deviations from flight plans, air space violations, air traffic control messages per aircraft, and traditional temporal based measures.

Proposed definition of the term en route in en route aircraft noise

NASA Technical Reports Server (NTRS)

Garbell, Maurice A.

1990-01-01

The problem of en route aircraft noise was examined in a formal, dedicated, setting. Whereas the general meaning of the term en route might be intuitively understood, it is suggested that a precise formal definition of the term en route would be opportune from the outset, especially since the scientific and technical investigation of the problem of noise immissions on the ground from aircraft in flight away from the airspace of an airport may conceivably lead to administrative, regulatory, and legal consequences that would mandatorily require a precise definition of the term en route. Five flight segments, with their differing airframe configurations, engine thrusts, and airspeed management, should form the basis for the differential consideration of the noise immissions perceived on the ground underneath or near the defined segments of the flightpath in en route flight, from the end of the initial climb from an airport after takeoff until the final approach to an airport.

Aquacells — Flagellates under long-term microgravity and potential usage for life support systems

NASA Astrophysics Data System (ADS)

Häder, Donat-P.; Richter, Peter R.; Strauch, S. M.; Schuster, M.

2006-09-01

The motile behavior of the unicellular photosynthetic flagellate Euglena gracilis was studied during a two-week mission on the Russian satellite Foton M2. The precision of gravitactic orientation was high before launch and, as expected, the cells were unoriented during microgravity. While after previous short-term TEXUS flights the precision of orientation was as high as before launch, it took several hours for the organisms to regain their gravitaxis. Also the percentage of motile cells and the swimming velocity of the remaining motile cells were considerably lower than in the ground control. In preparatory experiments the flagellate Euglena was shown to produce considerable amounts of photosynthetically generated oxygen. In a coupling experiment in a prototype for a planned space mission on Foton M3, the photosynthetic producers were shown to supply sufficient amounts of oxygen to a fish compartment with 35 larval cichlids, Oreochromis mossambicus.

Flight behavior of the rhinoceros beetle Trypoxylus dichotomus during electrical nerve stimulation.

PubMed

Van Truong, Tien; Byun, Doyoung; Lavine, Laura Corley; Emlen, Douglas J; Park, Hoon Cheol; Kim, Min Jun

2012-09-01

Neuronal stimulation is an intricate part of understanding insect flight behavior and control insect itself. In this study, we investigated the effects of electrical pulses applied to the brain and basalar muscle of the rhinoceros beetle (Trypoxylus dichotomus). To understand specific neuronal stimulation mechanisms, responses and flight behavior of the beetle, four electrodes were implanted into the two optic lobes, the brain's central complex and the ventral nerve cord in the posterior pronotum. We demonstrated flight initiation, turning and cessation by stimulating the brain. The change undergone by the wing flapping in response to the electrical signal was analyzed from a sequence of images captured by a high-speed camera. Here, we provide evidence to distinguish the important differences between neuronal and muscular flight stimulations in beetles. We found that in the neural potential stimulation, both the hind wing and the elytron were suppressed. Interestingly, the beetle stopped flying whenever a stimulus potential was applied between the pronotum and one side of the optic lobe, or between the ventral nerve cord in the posterior pronotum and the central complex. In-depth experimentation demonstrated the effective of neural stimulation over muscle stimulation for flight control. During electrical stimulation of the optic lobes, the beetle performed unstable flight, resulting in alternating left and right turns. By applying the electrical signal into both the optic lobes and the central complex of the brain, we could precisely control the direction of the beetle flight. This work provides an insight into insect flight behavior for future development of insect-micro air vehicle.

The Pamela experiment ready for flight

NASA Astrophysics Data System (ADS)

Adriani, O.; Albi, M.; Altamura, F.; Ambriola, M.; Bakaldin, A.; Barbarino, G. C.; Basili, A.; Bazilevskaja, G.; Bellotti, R.; Bencardino, R.; Boezio, M.; Bogomolov, E.; Bonechi, L.; Bongi, M.; Bongiorno, L.; Bonvicini, V.; Boscherini, M.; Bottai, S.; Cafagna, F.; Campana, D.; Carlson, P.; Casolino, M.; Castellini, G.; Circella, M.; De Marzo, C.; De Pascale, M. P.; Fedele, D.; Galper, A. M.; Grigorjeva, A.; Grandi, M.; Hofverberg, P.; Koldashov, S. V.; Korotkov, M. G.; Krutkov, S.; Lund, J.; Lundquist, J.; Malvezzi, V.; Marcelli, L.; Menn, W.; Mikhailov, V. V.; Minori, M.; Mitchell, J. W.; Mocchiutti, E.; Morselli, A.; Mukhametshin, R.; Nagni, M.; Orsi, S.; Osteria, G.; Papini, P.; Pearce, M.; Picozza, P.; Ricci, M.; Ricciarini, S.; Russo, S.; Schiavon, P.; Simon, M.; Spillantini, P.; Sparvoli, R.; Stephens, S. A.; Stochaj, S. J.; Stozhkov, R. Y.; Streitmatter, E.; Taddei, E.; Vacchi, A.; Vannuccini, E.; Vasiljev, G.; Voronov, S. A.; Yurkin, Y.; Zampa, G.; Zampa, N.

2007-03-01

The Pamela apparatus will allow precise measurements of cosmic rays in Low Earth Orbit, mainly focusing on the antiparticles component. The apparatus is now ready for flight, and the launch is foreseen during June 2006. The paper briefly reports the status of the experiment, and the performances of the various components as measured before the launch.

Summary of the effects of engine throttle response on airplane formation-flying qualities

NASA Technical Reports Server (NTRS)

Walsh, Kevin R.

1993-01-01

A flight evaluation was conducted to determine the effect of engine throttle response characteristics on precision formation-flying qualities. A variable electronic throttle control system was developed and flight-tested on a TF-104G airplane with a J79-11B engine at the NASA Dryden Flight Research Facility. This airplane was chosen because of its known, very favorable thrust response characteristics. Ten research flights were flown to evaluate the effects of throttle gain, time delay, and fuel control rate limiting on engine handling qualities during a demanding precision wing formation task. Handling quality effects of lag filters and lead compensation time delays were also evaluated. The Cooper and Harper Pilot Rating Scale was used to assign levels of handling quality. Data from pilot ratings and comments indicate that throttle control system time delays and rate limits cause significant degradations in handling qualities. Threshold values for satisfactory (level 1) and adequate (level 2) handling qualities of these key variables are presented. These results may provide engine manufacturers with guidelines to assure satisfactory handling qualities in future engine designs.

First aircraft experiment results with the wide-angle airborne laser ranging system

NASA Astrophysics Data System (ADS)

Bock, Olivier; Thom, Christian; Kasser, Michel

1999-12-01

The first aircraft experiment with the Wide-Angle Airborne Laser Ranging System has been conducted in May 1998 over an air base in France equipped with a network of 64 cub-corner retroreflectors. The ranging system was operated from the Avion de Recherche Atmospherique et de Teledetection of CNES/IGN/INSU. Data have been collected during two 4-hour flights. The paper describes the data processing methods and presents the first experimental results. The precision is of 2 cm on the difference of vertical coordinates from two sets of 3 X 103 distance measurements, which is consistent with simulations and a posteriori covariance. The precision is mainly limited by the smallness of the number of efficient measurements remaining after a drastic data sorting for outliers. Higher precision is expected for future experiments after some instrumental improvements (achieving higher link budget) and measurement of aircraft attitude during the flight.

Airborne Laser Altimetric Monitoring of the Rapid Evolution of Topography in the Long Valley, CA, Caldera

NASA Technical Reports Server (NTRS)

Rundle, John

1998-01-01

A consortium of investigators from several universities and Government agencies have conducted a series of aircraft topographic surveys over the Long Valley caldera, California. The region has a geologic history of extensive volcanism, and its central dome has recently been undergoing resurgent uplift episodes of up to 4 cm per year, a deformation rate that is still continuing. These surveys were conducted from the NASA WFF T39 jet aircraft, outfitted with a nadir-profiling altimetric laser (ATLAS), a GPS guidance system for in-flight precision navigation, two P-code GPS receivers, a Litton LTN92 inertial unit for attitude determination, and both video and still-frame aerial cameras. In addition, two base-station GPS receivers were deployed for post-flight differential navigation, complementing the permanent GPS station operated on the resurgent dome by JPL, and a kinematic automobile survey of roads crossing the area was conducted, thereby complementing the JPL kinematic GPS surveys of some of the same roads. Precision flying yielded multiple profiles along nearly identical paths, including crossing profiles over selected locations within the caidera and calibration flights over Mono Lake, and Lake Crowley. Data from the most recent survey in 1995 are at this time still being reduced, but the standard error of the mean is very low (< 3 mm), due to the high number of crossover points. We thus intend to evaluate the technique for measuring systematic changes in the dome height over time.

Motion of a Moving Object

NASA Technical Reports Server (NTRS)

1998-01-01

SpaceAge Control, Inc., was established in 1968 to design, develop and manufacture pilot protection devices in support of space-based and high-performance test aircraft programs. In 1970, the company was awarded a NASA contract to produce precision, small-format position transducers for aircraft flight control testing. The successful completion of this contract led to the development and production of a complete line of position transducers. Today the company has over 600 customers in 20 industries and over 30 countries.

The flight robotics laboratory

NASA Technical Reports Server (NTRS)

Tobbe, Patrick A.; Williamson, Marlin J.; Glaese, John R.

1988-01-01

The Flight Robotics Laboratory of the Marshall Space Flight Center is described in detail. This facility, containing an eight degree of freedom manipulator, precision air bearing floor, teleoperated motion base, reconfigurable operator's console, and VAX 11/750 computer system, provides simulation capability to study human/system interactions of remote systems. The facility hardware, software and subsequent integration of these components into a real time man-in-the-loop simulation for the evaluation of spacecraft contact proximity and dynamics are described.

Analysis of inflight sleep, experiment M008

NASA Technical Reports Server (NTRS)

Kellaway, P.

1971-01-01

The feasibility of recording the electroencephalogram during space flight is demonstrated. The precise information that is collected with the electroencephalograph regarding the duration, depth, and number of sleep periods implies that electroencephalogram monitoring should be considered for routine use in the long-duration space flights that are contemplated for the Apollo Program and other programs. The importance of such information in the direction and execution of the flight, both to the medical monitors and to the crewmembers, is obvious.

Capitalizing Resolving Power of Density Gradient Ultracentrifugation by Freezing and Precisely Slicing Centrifuged Solution: Enabling Identification of Complex Proteins from Mitochondria by Matrix Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry

PubMed Central

Yu, Haiqing; Lu, Joann J.; Rao, Wei

2016-01-01

Density gradient centrifugation is widely utilized for various high purity sample preparations, and density gradient ultracentrifugation (DGU) is often used for more resolution-demanding purification of organelles and protein complexes. Accurately locating different isopycnic layers and precisely extracting solutions from these layers play a critical role in achieving high-resolution DGU separations. In this technique note, we develop a DGU procedure by freezing the solution rapidly (but gently) after centrifugation to fix the resolved layers and by slicing the frozen solution to fractionate the sample. Because the thickness of each slice can be controlled to be as thin as 10 micrometers, we retain virtually all the resolution produced by DGU. To demonstrate the effectiveness of this method, we fractionate complex V from HeLa mitochondria using a conventional technique and this freezing-slicing (F-S) method. The comparison indicates that our F-S method can reduce complex V layer thicknesses by ~40%. After fractionation, we analyze complex V proteins directly on a matrix assisted laser desorption/ionization, time-of-flight mass spectrometer. Twelve out of fifteen subunits of complex V are positively identified. Our method provides a practical protocol to identify proteins from complexes, which is useful to investigate biomolecular complexes and pathways in various conditions and cell types. PMID:27668122

Deuterium-tritium neutron yield measurements with the 4.5 m neutron-time-of-flight detectors at NIF.

PubMed

Moran, M J; Bond, E J; Clancy, T J; Eckart, M J; Khater, H Y; Glebov, V Yu

2012-10-01

The first several campaigns of laser fusion experiments at the National Ignition Facility (NIF) included a family of high-sensitivity scintillator∕photodetector neutron-time-of-flight (nTOF) detectors for measuring deuterium-deuterium (DD) and DT neutron yields. The detectors provided consistent neutron yield (Y(n)) measurements from below 10(9) (DD) to nearly 10(15) (DT). The detectors initially demonstrated detector-to-detector Y(n) precisions better than 5%, but lacked in situ absolute calibrations. Recent experiments at NIF now have provided in situ DT yield calibration data that establish the absolute sensitivity of the 4.5 m differential tissue harmonic imaging (DTHI) detector with an accuracy of ± 10% and precision of ± 1%. The 4.5 m nTOF calibration measurements also have helped to establish improved detector impulse response functions and data analysis methods, which have contributed to improving the accuracy of the Y(n) measurements. These advances have also helped to extend the usefulness of nTOF measurements of ion temperature and downscattered neutron ratio (neutron yield 10-12 MeV divided by yield 13-15 MeV) with other nTOF detectors.

Movable Ground Based Recovery System for Reuseable Space Flight Hardware

NASA Technical Reports Server (NTRS)

Sarver, George L. (Inventor)

2013-01-01

A reusable space flight launch system is configured to eliminate complex descent and landing systems from the space flight hardware and move them to maneuverable ground based systems. Precision landing of the reusable space flight hardware is enabled using a simple, light weight aerodynamic device on board the flight hardware such as a parachute, and one or more translating ground based vehicles such as a hovercraft that include active speed, orientation and directional control. The ground based vehicle maneuvers itself into position beneath the descending flight hardware, matching its speed and direction and captures the flight hardware. The ground based vehicle will contain propulsion, command and GN&C functionality as well as space flight hardware landing cushioning and retaining hardware. The ground based vehicle propulsion system enables longitudinal and transverse maneuverability independent of its physical heading.

Single photon ranging system using two wavelengths laser and analysis of precision

NASA Astrophysics Data System (ADS)

Chen, Yunfei; He, Weiji; Miao, Zhuang; Gu, Guohua; Chen, Qian

2013-09-01

The laser ranging system based on time correlation single photon counting technology and single photon detector has the feature of high precision and low emergent energy etc. In this paper, we established a single photon laser ranging system that use the supercontinuum laser as light source, and two wavelengths (532nm and 830nm) of echo signal as the stop signal. We propose a new method that is capable to improve the single photon ranging system performance. The method is implemented by using two single-photon detectors to receive respectively the two different wavelength signals at the same time. We extracted the firings of the two detectors triggered by the same laser pulse at the same time and then took mean time of the two firings as the combined detection time-of-flight. The detection by two channels using two wavelengths will effectively improve the detection precision and decrease the false alarm probability. Finally, an experimental single photon ranging system was established. Through a lot of experiments, we got the system precision using both single and two wavelengths and verified the effectiveness of the method.

Biosonar navigation above water I: estimating flight height.

PubMed

Hoffmann, Susanne; Genzel, Daria; Prosch, Selina; Baier, Leonie; Weser, Sabrina; Wiegrebe, Lutz; Firzlaff, Uwe

2015-02-15

Locomotion and foraging on the wing require precise navigation in more than just the horizontal plane. Navigation in three dimensions and, specifically, precise adjustment of flight height are essential for flying animals. Echolocating bats drink from water surfaces in flight, which requires an exceptionally precise vertical navigation. Here, we exploit this behavior in the bat, Phyllostomus discolor, to understand the biophysical and neural mechanisms that allow for sonar-guided navigation in the vertical plane. In a set of behavioral experiments, we show that for echolocating bats, adjustment of flight height depends on the tragus in their outer ears. Specifically, the tragus imposes elevation-specific spectral interference patterns on the echoes of the bats' sonar emissions. Head-related transfer functions of our bats show that these interference patterns are most conspicuous in the frequency range ∼55 kHz. This conspicuousness is faithfully preserved in the frequency tuning and spatial receptive fields of cortical single and multiunits recorded from anesthetized animals. In addition, we recorded vertical spatiotemporal response maps that describe neural tuning in elevation over time. One class of units that were very sharply tuned to frequencies ∼55 kHz showed unusual spatiotemporal response characteristics with a preference for paired echoes where especially the first echo originates from very low elevations. These behavioral and neural data provide the first insight into biosonar-based processing and perception of acoustic elevation cues that are essential for bats to navigate in three-dimensional space. Copyright © 2015 the American Physiological Society.

Future ultra-speed tube-flight

NASA Astrophysics Data System (ADS)

Salter, Robert M.

1994-05-01

Future long-link, ultra-speed, surface transport systems will require electromagnetically (EM) driven and restrained vehicles operating under reduced-atmosphere in very straight tubes. Such tube-flight trains will be safe, energy conservative, pollution-free, and in a protected environment. Hypersonic (and even hyperballistic) speeds are theoretically achievable. Ultimate system choices will represent tradeoffs between amoritized capital costs (ACC) and operating costs. For example, long coasting links might employ aerodynamic lift coupled with EM restraint and drag make-up. Optimized, combined EM lift, and thrust vectors could reduce energy costs but at increased ACC. (Repulsive levitation can produce lift-over-drag l/d ratios a decade greater than aerodynamic), Alternatively, vehicle-emanated, induced-mirror fields in a conducting (aluminum sheet) road bed could reduce ACC but at substantial energy costs. Ultra-speed tube flight will demand fast-acting, high-precision sensors and computerized magnetic shimming. This same control system can maintain a magnetic 'guide way' invariant in inertial space with inertial detectors imbedded in tube structures to sense and correct for earth tremors. Ultra-speed tube flight can complete with aircraft for transit time and can provide even greater passenger convenience by single-model connections with local subways and feeder lines. Although cargo transport generally will not need to be performed at ultra speeds, such speeds may well be desirable for high throughput to optimize channel costs. Thus, a large and expensive pipeline might be replaced with small EM-driven pallets at high speeds.

Future ultra-speed tube-flight

NASA Technical Reports Server (NTRS)

Salter, Robert M.

1994-01-01

Future long-link, ultra-speed, surface transport systems will require electromagnetically (EM) driven and restrained vehicles operating under reduced-atmosphere in very straight tubes. Such tube-flight trains will be safe, energy conservative, pollution-free, and in a protected environment. Hypersonic (and even hyperballistic) speeds are theoretically achievable. Ultimate system choices will represent tradeoffs between amoritized capital costs (ACC) and operating costs. For example, long coasting links might employ aerodynamic lift coupled with EM restraint and drag make-up. Optimized, combined EM lift, and thrust vectors could reduce energy costs but at increased ACC. (Repulsive levitation can produce lift-over-drag l/d ratios a decade greater than aerodynamic), Alternatively, vehicle-emanated, induced-mirror fields in a conducting (aluminum sheet) road bed could reduce ACC but at substantial energy costs. Ultra-speed tube flight will demand fast-acting, high-precision sensors and computerized magnetic shimming. This same control system can maintain a magnetic 'guide way' invariant in inertial space with inertial detectors imbedded in tube structures to sense and correct for earth tremors. Ultra-speed tube flight can complete with aircraft for transit time and can provide even greater passenger convenience by single-model connections with local subways and feeder lines. Although cargo transport generally will not need to be performed at ultra speeds, such speeds may well be desirable for high throughput to optimize channel costs. Thus, a large and expensive pipeline might be replaced with small EM-driven pallets at high speeds.

Flight test evaluation of drag effects on surface coatings on the NASA Boeing 737 TCV airplane

NASA Technical Reports Server (NTRS)

George-Falvy, D.; Sikavi, D. A.

1981-01-01

A flight test program was conducted in which the effects of various surface coatings on aerodynamic drag were investigated; results of this program are described in this report. The tests were conducted at NASA-Langley Research Center on the terminal configured vehicle (TCV) Boeing 737 research airplane. The Boeing Company, as contractor with NASA under the Energy Efficient Transport (EET) program, planned and evaluated the experiment. The NASA-TCV Program Office coordinated the experiment and performed the flight tests. The principal objective of the test was to evaluate the drag reduction potential of an elastomeric polyurethane surface coating, CAAPCO B-274, which also has been considered for application on transport airplanes to protect leading edges from erosion. The smooth surface achievable with this type of coating held some promise of reducing the skin friction drag as compared to conventional production type aircraft surfaces, which are usually anodized bare metal or coated with corrosion protective paint. Requirements for high precision measurements were the principal considerations in the experiment.

Experimental study of the flight envelope and research of safety requirements for hang-gliders

NASA Technical Reports Server (NTRS)

Laburthe, C.

1979-01-01

The flight mechanic computations were computed, providing both the flight envelopes with all sorts of limits and a fairly precise idea of the influence of several parameters, such as pilot's weight, wing settings, aeroelasticity, etc... The particular problem of luffing dives was thoroughly analyzed, and two kinds of causes were exhibited in both the rules of luffing and aeroelastic effects. The general analysis of longitudinal stability showed a strong link with fabric tension, as expected through Nielsen's and Twaites' theory. Fabric tension strongly depending upon aeroelasticity, that parameter was found to be the most effective design one for positive stability. Lateral stability was found to be very similar in all gliders except perhaps the cylindro-conical. The loss of stability happens in roll at low angle of attack, whereas it happens in yaw at high angle. Turning performance was a bit suprising, with a common maximum value of approximately 55 deg of bank angle for a steady turn.

Integration and Test Flight Validation Plans for the Pulsed Plasma Thruster Experiment on EO- 1

NASA Technical Reports Server (NTRS)

Zakrzwski, Charles; Benson, Scott; Sanneman, Paul; Hoskins, Andy; Bauer, Frank H. (Technical Monitor)

2002-01-01

The Pulsed Plasma Thruster (PPT) Experiment on the Earth Observing One (EO-1) spacecraft has been designed to demonstrate the capability of a new generation PPT to perform spacecraft attitude control. The PPT is a small, self-contained pulsed electromagnetic propulsion system capable of delivering high specific impulse (900-1200 s), very small impulse bits (10-1000 uN-s) at low average power (less than 1 to 100 W). Teflon fuel is ablated and slightly ionized by means of a capacitative discharge. The discharge also generates electromagnetic fields that accelerate the plasma by means of the Lorentz Force. EO-1 has a single PPT that can produce thrust in either the positive or negative pitch direction. The flight validation has been designed to demonstrate of the ability of the PPT to provide precision pointing accuracy, response and stability, and confirmation of benign plume and EMI effects. This paper will document the success of the flight validation.

Flight Test Evaluation of an Unmanned Aircraft System Traffic Management (UTM) Concept for Multiple Beyond-Visual-Line-of-Sight (BVLOS) Operations

NASA Technical Reports Server (NTRS)

Johnson, Marcus; Jung, Jaewoo; Rios, Joseph; Mercer, Joey; Homola, Jeffrey; Prevot, Thomas; Mulfinger, Daniel; Kopardekar, Parimal

2017-01-01

Many applications of small Unmanned Aircraft System (UAS) have been envisioned. These include surveillance of key assets such as pipelines, rail, or electric wires, deliveries, search and rescue, traffic monitoring, videography, and precision agriculture. These operations are likely to occur in the same airspace in the presence of many static and dynamic constraints such as airports, and high wind areas. Therefore, operations of small UAS need to be managed to ensure safety and operation efficiency is maintained. NASA has advanced a concept for UAS Traffic Management (UTM) and has initiated a research effort to refine that concept and develop operational and system requirements. A UTM research platform is in development and flight test activities to evaluate core functions and key assumptions focusing exclusively on UAS operations in different environments are underway. This seminar will present lessons learned from a recent flight test focused on enabling operations of multiple UAS in lower-risk environments within and beyond visual line of sight (BVLOS).

Integration of radar altimeter, precision navigation, and digital terrain data for low-altitude flight

NASA Technical Reports Server (NTRS)

Zelenka, Richard E.

1992-01-01

Avionic systems that depend on digitized terrain elevation data for guidance generation or navigational reference require accurate absolute and relative distance measurements to the terrain, especially as they approach lower altitudes. This is particularly exacting in low-altitude helicopter missions, where aggressive terrain hugging maneuvers create minimal horizontal and vertical clearances and demand precise terrain positioning. Sole reliance on airborne precision navigation and stored terrain elevation data for above-ground-level (AGL) positioning severely limits the operational altitude of such systems. A Kalman filter is presented which blends radar altimeter returns, precision navigation, and stored terrain elevation data for AGL positioning. The filter is evaluated using low-altitude helicopter flight test data acquired over moderately rugged terrain. The proposed Kalman filter is found to remove large disparities in predicted AGL altitude (i.e., from airborne navigation and terrain elevation data) in the presence of measurement anomalies and dropouts. Previous work suggested a minimum clearance altitude of 220 ft AGL for a near-terrain guidance system; integration of a radar altimeter allows for operation of that system below 50 ft, subject to obstacle-avoidance limitations.

An overview of the flight campaign for the GAUGE project: airborne greenhouse gas (and other complementary trace gas) measurements around and over the UK between April 2014 and May 2015

NASA Astrophysics Data System (ADS)

Allen, Grant; Pitt, Joseph; Le Breton, Michael; Percival, Carl; Bannan, Thomas; O'Doherty, Simon; Manning, Alistair; Rigby, Matt; Gannesan, Anita; Mead, Mohammed; Bauguitte, Stephane; Lee, James; Wenger, Angelina; Palmer, Paul

2016-04-01

This work highlights data measured during flights by the UK Facility for Airborne Atmospheric Measurement (FAAM) as part of the Greenhouse gAs UK and Global Emissions (GAUGE) campaign. A total of 17 flights (85 flight-hours) have been conducted so far around the UK mainland and Ireland to sample precision in situ CH4, CO2, N2O (and other trace gas) concentrations and meteorological parameters at altitudes up to 9500m throughout the period April 2014 to May 2015. Airborne remote sensing retrievals of greenhouse gas total columns have also been calculated using the Manchester Airborne Retrieval Scheme for the UK Met Office ARIES high resolution FTIR instrument. This airborne dataset represents a mapped climatology and a series of case studies from which to assess top-down bulk-net-flux snapshots for regions of the UK, and provides for evaluation of inverse modelling approaches that challenge bottom-up inventories, satellite remote sensing measurements, and assessment of model transport uncertainty. In this paper, we shall describe the instrumentation on the FAAM aircraft and provide a diary of GAUGE FAAM flights (and data highlights) to date; and discuss selected flights of interest to studies such as those above with a focus of net mass flux evaluation.

Progress in the Fabrication and Testing of Telescope Mirrors for The James Webb Space Telescope

NASA Astrophysics Data System (ADS)

Bowers, Charles W.; Clampin, M.; Feinberg, L.; Keski-Kuha, R.; McKay, A.; Chaney, D.; Gallagher, B.; Ha, K.

2012-01-01

The telescope of the James Webb Space Telescope (JWST) is an f/20, three mirror anastigmat design, passively cooled (40K) in an L2 orbit. The design provides diffraction limited performance (Strehl ≥ 0.8) at λ=2μm. To fit within the launch vehicle envelope (Arianne V), the 6.6 meter primary mirror and the secondary mirror support structure are folded for launch, then deployed and aligned in space. The primary mirror is composed of 18 individual, 1.3 meter (flat:flat) hexagonal segments, each adjustable in seven degrees of freedom (six rigid body + radius of curvature) provided by a set of high precision actuators. The actuated secondary mirror ( 0.74m) is similarly positioned in six degrees of rigid body motion. The .70x.51m, fixed tertiary and 0.17m, flat fine steering mirror complete the telescope mirror complement. The telescope is supported by a composite structure optimized for performance at cryogenic temperatures. All telescope mirrors are made of Be with substantial lightweighting (21kg for each 1.3M primary segment). Additional Be mounting and supporting structure for the high precision ( 10nm steps) actuators are attached to the primary segments and secondary mirror. All mirrors undergo a process of thermal stabilization to reduce stress. An extensive series of interferometric measurements guide each step of the polishing process. Final polishing must account for any deformation between the ambient temperature of polishing and the cryogenic, operational temperature. This is accomplished by producing highly precise, cryo deformation target maps of each surface which are incorporated into the final polishing cycle. All flight mirrors have now completed polishing, coating with protected Au and final cryo testing, and the telescope is on track to meet all system requirements. We here review the measured performance of the component mirrors and the predicted performance of the flight telescope.

Knowledge-based processing for aircraft flight control

NASA Technical Reports Server (NTRS)

Painter, John H.

1991-01-01

The purpose is to develop algorithms and architectures for embedding artificial intelligence in aircraft guidance and control systems. With the approach adopted, AI-computing is used to create an outer guidance loop for driving the usual aircraft autopilot. That is, a symbolic processor monitors the operation and performance of the aircraft. Then, based on rules and other stored knowledge, commands are automatically formulated for driving the autopilot so as to accomplish desired flight operations. The focus is on developing a software system which can respond to linguistic instructions, input in a standard format, so as to formulate a sequence of simple commands to the autopilot. The instructions might be a fairly complex flight clearance, input either manually or by data-link. Emphasis is on a software system which responds much like a pilot would, employing not only precise computations, but, also, knowledge which is less precise, but more like common-sense. The approach is based on prior work to develop a generic 'shell' architecture for an AI-processor, which may be tailored to many applications by describing the application in appropriate processor data bases (libraries). Such descriptions include numerical models of the aircraft and flight control system, as well as symbolic (linguistic) descriptions of flight operations, rules, and tactics.

Aircraft automatic-flight-control system with inversion of the model in the feed-forward path using a Newton-Raphson technique for the inversion

NASA Technical Reports Server (NTRS)

Smith, G. A.; Meyer, G.; Nordstrom, M.

1986-01-01

A new automatic flight control system concept suitable for aircraft with highly nonlinear aerodynamic and propulsion characteristics and which must operate over a wide flight envelope was investigated. This exact model follower inverts a complete nonlinear model of the aircraft as part of the feed-forward path. The inversion is accomplished by a Newton-Raphson trim of the model at each digital computer cycle time of 0.05 seconds. The combination of the inverse model and the actual aircraft in the feed-forward path alloys the translational and rotational regulators in the feedback path to be easily designed by linear methods. An explanation of the model inversion procedure is presented. An extensive set of simulation data for essentially the full flight envelope for a vertical attitude takeoff and landing aircraft (VATOL) is presented. These data demonstrate the successful, smooth, and precise control that can be achieved with this concept. The trajectory includes conventional flight from 200 to 900 ft/sec with path accelerations and decelerations, altitude changes of over 6000 ft and 2g and 3g turns. Vertical attitude maneuvering as a tail sitter along all axes is demonstrated. A transition trajectory from 200 ft/sec in conventional flight to stationary hover in the vertical attitude includes satisfactory operation through lift-cure slope reversal as attitude goes from horizontal to vertical at constant altitude. A vertical attitude takeoff from stationary hover to conventional flight is also demonstrated.

The ISOMAX Magnetic Rigidity Spectrometer

NASA Astrophysics Data System (ADS)

Hams, Thomas

1999-08-01

The Isotope Magnet Experiment, (ISOMAX), is a balloon-borne superconducting magnetic spectrometer with a time-of-flight system and aerogel Cherenkov counters. Its purpose is to measure the isotopic composition of the light elements (3 < Z < 8) in the cosmic radiation. Particle mass is derived from a velocity vs. magnetic rigidity (momentum/charge) technique. The experiment had its first flight in August 1998. The precision magnetic spectrometer uses advanced drift-chamber tracking and a large, high-field, superconducting magnet. The drift-chamber system consists of three chambers with 24 layers of hexagonal drift cells (16 bending, 8 non-bending) and a vertical extent of 1.4 m. Pure CO2 gas is used. The magnet is a split-pair design with 79 cm diameter coils and a separation of 80 cm. During the 1998 flight, the central field was 0.8 T (60% of the full design field). Presented are results from flight data, for a range of incident particle Z, on the spatial resolution and efficiency of the tracking system, and on the maximum detectable rigidity (MDR) of the spectrometer. For in-flight data, spatial resolutions of 54 mm for Z=2 and 45 mm for Z=4 are obtained. An MDR of 970 GV/c is achieved for Z=2.

SEXTANT X-Ray Pulsar Navigation Demonstration: Flight System and Test Results

NASA Technical Reports Server (NTRS)

Winternitz, Luke; Mitchell, Jason W.; Hassouneh, Munther A.; Valdez, Jennifer E.; Price, Samuel R.; Semper, Sean R.; Yu, Wayne H.; Ray, Paul S.; Wood, Kent S.; Arzoumanian, Zaven;

Air ambulance nurses as expert supplement to local emergency services.

PubMed

Wisborg, Torben; Bjerkan, Bjørn

2014-01-01

Flight nurses in the Norwegian National Air Ambulance Service are specialist nurse anesthetists or intensive care nursing specialists. For air ambulance bases far from hospitals, these nurses present otherwise unavailable competencies. This study reports a 6-year experience with flight nurse participation in local emergencies beyond the transportation phase. The fixed-wing air ambulance base in Alta, Northern Norway (20,000 inhabitants), with 2 aircraft and 2 on-call teams is 150 km by road from the nearest hospital. We did a prospective registration of all emergency nonflight missions near the air ambulance base from January 1, 2005, to December 31, 2010. The 217 completed missions corresponded to 3 missions per month, half during daytime. Twenty-three percent of patients were under age 18, injury rate was high (36%), 63% had potentially or manifest life-threatening conditions, and 11% died during treatment. One third of all missions (67/217) resulted in an air ambulance flight to the hospital. Mission frequency did not significantly reduce flight availability, and precision in case selection for this special service was good. The use of flight nurses in the local community promotes equal access to advanced medical services for populations far from hospitals. Copyright © 2014 Air Medical Journal Associates. Published by Elsevier Inc. All rights reserved.

Sensitive far uv spectrograph with a multispectral element microchannel plate detector for rocket-borne astronomy.

PubMed

Weiser, H; Vitz, R C; Moos, H W; Weinstein, A

1976-12-01

An evacuated high transmission prism spectrograph using a microchannel plate detection system with resistive strip readout was flown behind a precision pointing telescope on a sounding rocket. The construction, preparation, flight performance, and calibration stability of the system are discussed. Despite the adverse environmental conditions associated with sounding rocket flights, the microchannel detector system performed well. Far uv spectra (1160-1750 A) of stellar and planetary objects were obtained; spectral features with fluxes as low as 0.06 photons cm(-2) sec(-1) were detectable. This was achieved by operating the plates at lower than normal gains, using sensitive pulse counting electronics with both upper and lower limit discriminators, and maintaining the spectrograph and detector at a pressure of ~10(-6) Torr until reaching altitude.

Nutrition and Musculoskeletal Function: Skylab Experiment Series Number M070

NASA Technical Reports Server (NTRS)

Raumbaut, P. C.

1972-01-01

The M070 experiments are expected to give medical investigators precise information on a variety of biochemical changes occurring during exposure to space flight. Sufficient control data are being generated by baseline studies to differentiate those effects that are caused by weightless flight and those that are caused by other abnormal conditions that normally accompany spaceflight.

The three-dimensional flight of red-footed boobies: adaptations to foraging in a tropical environment?

PubMed Central

Weimerskirch, H.; Le Corre, M.; Ropert-Coudert, Y.; Kato, A.; Marsac, F.

2005-01-01

In seabirds a broad variety of morphologies, flight styles and feeding methods exist as an adaptation to optimal foraging in contrasted marine environments for a wide variety of prey types. Because of the low productivity of tropical waters it is expected that specific flight and foraging techniques have been selected there, but very few data are available. By using five different types of high-precision miniaturized logger (global positioning systems, accelerometers, time depth recorders, activity recorders, altimeters) we studied the way a seabird is foraging over tropical waters. Red-footed boobies are foraging in the day, never foraging at night, probably as a result of predation risks. They make extensive use of wind conditions, flying preferentially with crosswinds at median speed of 38 km h−1, reaching highest speeds with tail winds. They spent 66% of the foraging trip in flight, using a flap–glide flight, and gliding 68% of the flight. Travelling at low costs was regularly interrupted by extremely active foraging periods where birds are very frequently touching water for landing, plunge diving or surface diving (30 landings h−1). Dives were shallow (maximum 2.4 m) but frequent (4.5 dives h−1), most being plunge dives. While chasing for very mobile prey like flying fishes, boobies have adopted a very active and specific hunting behaviour, but the use of wind allows them to reduce travelling cost by their extensive use of gliding. During the foraging and travelling phases birds climb regularly to altitudes of 20–50 m to spot prey or congeners. During the final phase of the flight, they climb to high altitudes, up to 500 m, probably to avoid attacks by frigatebirds along the coasts. This study demonstrates the use by boobies of a series of very specific flight and activity patterns that have probably been selected as adaptations to the conditions of tropical waters. PMID:15875570

The three-dimensional flight of red-footed boobies: adaptations to foraging in a tropical environment?

PubMed

Weimerskirch, H; Le Corre, M; Ropert-Coudert, Y; Kato, A; Marsac, F

2005-01-07

In seabirds a broad variety of morphologies, flight styles and feeding methods exist as an adaptation to optimal foraging in contrasted marine environments for a wide variety of prey types. Because of the low productivity of tropical waters it is expected that specific flight and foraging techniques have been selected there, but very few data are available. By using five different types of high-precision miniaturized logger (global positioning systems, accelerometers, time depth recorders, activity recorders, altimeters) we studied the way a seabird is foraging over tropical waters. Red-footed boobies are foraging in the day, never foraging at night, probably as a result of predation risks. They make extensive use of wind conditions, flying preferentially with crosswinds at median speed of 38 km h(-1), reaching highest speeds with tail winds. They spent 66% of the foraging trip in flight, using a flap-glide flight, and gliding 68% of the flight. Travelling at low costs was regularly interrupted by extremely active foraging periods where birds are very frequently touching water for landing, plunge diving or surface diving (30 landings h(-1)). Dives were shallow (maximum 2.4 m) but frequent (4.5 dives h(-1)), most being plunge dives. While chasing for very mobile prey like flying fishes, boobies have adopted a very active and specific hunting behaviour, but the use of wind allows them to reduce travelling cost by their extensive use of gliding. During the foraging and travelling phases birds climb regularly to altitudes of 20-50 m to spot prey or congeners. During the final phase of the flight, they climb to high altitudes, up to 500 m, probably to avoid attacks by frigatebirds along the coasts. This study demonstrates the use by boobies of a series of very specific flight and activity patterns that have probably been selected as adaptations to the conditions of tropical waters.

Flight test techniques for the X-29A aircraft

NASA Technical Reports Server (NTRS)

Hicks, John W.; Cooper, James M., Jr.; Sefic, Walter J.

1987-01-01

The X-29A advanced technology demonstrator is a single-seat, single-engine aircraft with a forward-swept wing. The aircraft incorporates many advanced technologies being considered for this country's next generation of aircraft. This unusual aircraft configuration, which had never been flown before, required a precise approach to flight envelope expansion. This paper describes the real-time analysis methods and flight test techniques used during the envelope expansion of the x-29A aircraft, including new and innovative approaches.

Improved measurement linearity and precision for AMCW time-of-flight range imaging cameras.

PubMed

Payne, Andrew D; Dorrington, Adrian A; Cree, Michael J; Carnegie, Dale A

2010-08-10

Time-of-flight range imaging systems utilizing the amplitude modulated continuous wave (AMCW) technique often suffer from measurement nonlinearity due to the presence of aliased harmonics within the amplitude modulation signals. Typically a calibration is performed to correct these errors. We demonstrate an alternative phase encoding approach that attenuates the harmonics during the sampling process, thereby improving measurement linearity in the raw measurements. This mitigates the need to measure the system's response or calibrate for environmental changes. In conjunction with improved linearity, we demonstrate that measurement precision can also be increased by reducing the duty cycle of the amplitude modulated illumination source (while maintaining overall illumination power).

A Spaceflight Magnetic Bearing Equipped Optical Chopper with Six-Axis Active Control

NASA Technical Reports Server (NTRS)

Blumenstock, Kenneth A.; Lee, Kenneth Y.; Schepis, Joseph P.

1998-01-01

This paper describes the development of an ETU (Engineering Test Unit) rotary optical chopper with magnetic bearings. An ETU is required to be both flight-like, nearly identical to a flight unit without the need for material certifications, and demonstrate structural and performance integrity. A prototype breadboard design previously demonstrated the feasibility of meeting flight performance requirements using magnetic bearings. The chopper mechanism is a critical component of the High Resolution Dynamics Limb Sounder (HIRDLS) which will be flown on EOS-CHEM (Earth Observing System-Chemistry). Particularly noteworthy are the science requirements which demand high precision positioning and minimal power consumption along with full redundancy of coils and sensors in a miniature, lightweight package. The magnetic bearings are unique in their pole design to minimize parasitic losses and utilize collocated optical sensing. The motor is of an unusual disk-type ironless stator design. The ETU design has evolved from the breadboard design. A number of improvements have been incorporated into the ETU design. Active thrust control has been added along with changes to improve sensor stability, motor efficiency, and touchdown and launch survivability. It was necessary to do all this while simultaneously reducing the mechanism volume. Flight-like electronics utilize a DSP (Digital Signal Processor) and contain all sensor electronics and drivers on a single five inch by nine inch circuit board. Performance test results are reported including magnetic bearing and motor rotational losses.

Imaging Analysis of the Hard X-Ray Telescope ProtoEXIST2 and New Techniques for High-Resolution Coded-Aperture Telescopes

NASA Technical Reports Server (NTRS)

Hong, Jaesub; Allen, Branden; Grindlay, Jonathan; Barthelmy, Scott D.

2016-01-01

Wide-field (greater than or approximately equal to 100 degrees squared) hard X-ray coded-aperture telescopes with high angular resolution (greater than or approximately equal to 2 minutes) will enable a wide range of time domain astrophysics. For instance, transient sources such as gamma-ray bursts can be precisely localized without the assistance of secondary focusing X-ray telescopes to enable rapid followup studies. On the other hand, high angular resolution in coded-aperture imaging introduces a new challenge in handling the systematic uncertainty: the average photon count per pixel is often too small to establish a proper background pattern or model the systematic uncertainty in a timescale where the model remains invariant. We introduce two new techniques to improve detection sensitivity, which are designed for, but not limited to, a high-resolution coded-aperture system: a self-background modeling scheme which utilizes continuous scan or dithering operations, and a Poisson-statistics based probabilistic approach to evaluate the significance of source detection without subtraction in handling the background. We illustrate these new imaging analysis techniques in high resolution coded-aperture telescope using the data acquired by the wide-field hard X-ray telescope ProtoEXIST2 during a high-altitude balloon flight in fall 2012. We review the imaging sensitivity of ProtoEXIST2 during the flight, and demonstrate the performance of the new techniques using our balloon flight data in comparison with a simulated ideal Poisson background.

Photometer Performance Assessment in Kepler Science Data Processing

NASA Technical Reports Server (NTRS)

Li, Jie; Allen, Christopher; Bryson, Stephen T.; Caldwell, Douglas A.; Chandrasekaran, Hema; Clarke, Bruce D.; Gunter, Jay P.; Jenkins, Jon M.; Klaus, Todd C.; Quintana, Elisa V.;

Precision Thickness Variation Mapping Via One-Transducer Ultrasonic High Resolution Profilometry for Sample With Irregular or Rough Surface

NASA Technical Reports Server (NTRS)

Roth, Don J. (Inventor)

1996-01-01

An apparatus and method for determination of sample thickness and surface depression utilizing ultrasonic pulses is discussed. The sample is held in a predetermined position by a support member having a reference surface. Ultrasonic pulses travel through a medium of known velocity propagation and reflect off the reference surface and a sample surface. Time of flight data of surface echoes are converted to distances between sample surfaces to obtain computer-generated thickness profiles and surface mappings.

Delivery of Colloid Micro-Newton Thrusters for the Space Technology 7 Mission

NASA Technical Reports Server (NTRS)

Ziemer, John K.; Randolph, Thomas M.; Franklin, Garth W.; Hruby, Vlad; Spence, Douglas; Demmons, Nathaniel; Roy, Thomas; Ehrbar, Eric; Zwahlen, Jurg; Martin, Roy;

Accuracy Assessment of Professional Grade Unmanned Systems for High Precision Airborne Mapping

NASA Astrophysics Data System (ADS)

Mostafa, M. M. R.

2017-08-01

Recently, sophisticated multi-sensor systems have been implemented on-board modern Unmanned Aerial Systems. This allows for producing a variety of mapping products for different mapping applications. The resulting accuracies match the traditional well engineered manned systems. This paper presents the results of a geometric accuracy assessment project for unmanned systems equipped with multi-sensor systems for direct georeferencing purposes. There are a number of parameters that either individually or collectively affect the quality and accuracy of a final airborne mapping product. This paper focuses on identifying and explaining these parameters and their mutual interaction and correlation. Accuracy Assessment of the final ground object positioning accuracy is presented through real-world 8 flight missions that were flown in Quebec, Canada. The achievable precision of map production is addressed in some detail.

Ultra-Light Precision Membrane Optics

NASA Technical Reports Server (NTRS)

Moore, Jim; Gunter, Kent; Patrick, Brian; Marty, Dave; Bates, Kevin; Gatlin, Romona; Clayton, Bill; Rood, Bob; Brantley, Whitt (Technical Monitor)

2001-01-01

SRS Technologies and NASA Marshall Space Flight Center have conducted a research effort to explore the possibility of developing ultra-lightweight membrane optics for future imaging applications. High precision optical flats and spherical mirrors were produced under this research effort. The thin film mirrors were manufactured using surface replication casting of CPI(Trademark), a polyimide material developed specifically for UV hardness and thermal stability. In the course of this program, numerous polyimide films were cast with surface finishes better than 1.5 nanometers rms and thickness variation of less than 63 nanometers. Precision membrane optical flats were manufactured demonstrating better than 1/13 wave figure error when measured at 633 nanometers. The aerial density of these films is 0.037 kilograms per square meter. Several 0.5-meter spherical mirrors were also manufactured. These mirrors had excellent surface finish (1.5 nanometers rms) and figure error on the order of tens of microns. This places their figure error within the demonstrated correctability of advanced wavefront correction technologies such as real time holography.

Precise Lamb Shift Measurements in Hydrogen-Like Heavy Ions—Status and Perspectives

NASA Astrophysics Data System (ADS)

Andrianov, V.; Beckert, K.; Bleile, A.; Chatterjee, Ch.; Echler, A.; Egelhof, P.; Gumberidze, A.; Ilieva, S.; Kiselev, O.; Kilbourne, C.; Kluge, H.-J.; Kraft-Bermuth, S.; McCammon, D.; Meier, J. P.; Reuschl, R.; Stöhlker, T.; Trassinelli, M.

2009-12-01

The precise determination of the energy of the Lyman α1 and α2 lines in hydrogen-like heavy ions provides a sensitive test of quantum electrodynamics in very strong Coulomb fields. For the first time, a calorimetric low-temperature detector was applied in an experiment to precisely determine the transition energy of the Lyman lines of lead ions 207Pb81+ at the Experimental Storage Ring (ESR) at GSI. The detectors consist of silicon thermistors, provided by the NASA/Goddard Space Flight Center, and Pb or Sn absorbers to obtain high quantum efficiency in the energy range of 40-80 keV, where the Doppler-shifted Lyman lines are located. The measured energy of the Lyman α1 line, E(Ly-α1, 207Pb81+) = (77937±12stat±23syst) eV, agrees within errors with theoretical predictions. The systematic error is mainly due to uncertainties in the non-linear energy calibration of the detectors as well as the relative position of detector and gas-jet target.

Estimating short-period dynamics using an extended Kalman filter

NASA Technical Reports Server (NTRS)

Bauer, Jeffrey E.; Andrisani, Dominick

1990-01-01

An extended Kalman filter (EKF) is used to estimate the parameters of a low-order model from aircraft transient response data. The low-order model is a state space model derived from the short-period approximation of the longitudinal aircraft dynamics. The model corresponds to the pitch rate to stick force transfer function currently used in flying qualities analysis. Because of the model chosen, handling qualities information is also obtained. The parameters are estimated from flight data as well as from a six-degree-of-freedom, nonlinear simulation of the aircraft. These two estimates are then compared and the discrepancies noted. The low-order model is able to satisfactorily match both flight data and simulation data from a high-order computer simulation. The parameters obtained from the EKF analysis of flight data are compared to those obtained using frequency response analysis of the flight data. Time delays and damping ratios are compared and are in agreement. This technique demonstrates the potential to determine, in near real time, the extent of differences between computer models and the actual aircraft. Precise knowledge of these differences can help to determine the flying qualities of a test aircraft and lead to more efficient envelope expansion.

Flight Synchrony among the Major Moth Pests of Cranberries in the Upper Midwest, USA.

PubMed

Steffan, Shawn A; Singleton, Merritt E; Sojka, Jayne; Chasen, Elissa M; Deutsch, Annie E; Zalapa, Juan E; Guédot, Christelle

2017-02-26

The cranberry fruitworm ( Acrobasis vaccinii Riley), sparganothis fruitworm ( Sparganothis sulfureana Clemens), and blackheaded fireworm ( Rhopobota naevana Hübner) are historically significant pests of cranberries ( Vaccinium macrocarpon Aiton) in the Upper Midwest (Wisconsin), USA. Their respective natural histories are well documented but correlations between developmental benchmarks (e.g., larval eclosion) and degree-day accruals are not yet known. Treatment timings are critical to the optimization of any given control tactic, and degree-day accrual facilitates optimization by quantifying the developmental status of pest populations. When key developmental benchmarks in the pest life cycle are linked to degree-days, real-time weather data can be used to predict precise treatment timings. Here, we provide the degree-day accumulations associated with discrete biological events (i.e., initiation of flight and peak flight) for the three most consistent moth pests of cranberries in Wisconsin. Moths were trapped each spring and summer from 2003 to 2011. To characterize flight dynamics and average timing of flight initiation, pheromone-baited trap-catch data were tallied for all three pest species within each of seven growing seasons. These flight dynamics were then associated with the corresponding degree-day accumulations generated using the cranberry plant's developmental thresholds. Finally, models were fit to the data in order to determine the peak flight of each species. The initiation of the spring flight among all three moth species was highly synchronous, aiding in the timing of control tactics; however, there were substantial differences in the timing of peak flight among the moth species. Characterization of the relationship between temperature and pest development allows pest management professionals to target specific life stages, improving the efficacy of any given pest control tactic.

Study on UKF based federal integrated navigation for high dynamic aviation

NASA Astrophysics Data System (ADS)

Zhao, Gang; Shao, Wei; Chen, Kai; Yan, Jie

2011-08-01

High dynamic aircraft is a very attractive new generation vehicles, in which provides near space aviation with large flight envelope both speed and altitude, for example the hypersonic vehicles. The complex flight environments for high dynamic vehicles require high accuracy and stability navigation scheme. Since the conventional Strapdown Inertial Navigation System (SINS) and Global Position System (GPS) federal integrated scheme based on EKF (Extended Kalman Filter) is invalidation in GPS single blackout situation because of high speed flight, a new high precision and stability integrated navigation approach is presented in this paper, in which the SINS, GPS and Celestial Navigation System (CNS) is combined as a federal information fusion configuration based on nonlinear Unscented Kalman Filter (UKF) algorithm. Firstly, the new integrated system state error is modeled. According to this error model, the SINS system is used as the navigation solution mathematic platform. The SINS combine with GPS constitute one error estimation filter subsystem based on UKF to obtain local optimal estimation, and the SINS combine with CNS constitute another error estimation subsystem. A non-reset federated configuration filter based on partial information is proposed to fuse two local optimal estimations to get global optimal error estimation, and the global optimal estimation is used to correct the SINS navigation solution. The χ 2 fault detection method is used to detect the subsystem fault, and the fault subsystem is isolation through fault interval to protect system away from the divergence. The integrated system takes advantages of SINS, GPS and CNS to an immense improvement for high accuracy and reliably high dynamic navigation application. Simulation result shows that federated fusion of using GPS and CNS to revise SINS solution is reasonable and availably with good estimation performance, which are satisfied with the demands of high dynamic flight navigation. The UKF is superior than EKF based integrated scheme, in which has smaller estimation error and quickly convergence rate.

High-precision measurement of the light response of BC-418 plastic scintillator to protons with energies from 100 keV to 10 MeV

NASA Astrophysics Data System (ADS)

Henzl, Vladimir; Daub, Brian; French, Jennifer; Matthews, June; Kovash, Michael; Wender, Stephen; Famiano, Michael; Koehler, Katrina; Yuly, Mark

2010-11-01

The determination of the light response of many organic scintillators to various types of radiation has been a subject of numerous experimental as well as theoretical studies in the past. But while the data on light response to particles with energies above 1 MeV are precise and abundant, the information on light response to very low energy particles (i.e. below 1 MeV) is scarce or completely missing. In this study we measured the light response of a BC-418 scintillator to protons with energies from 100 keV to 10 MeV. The experiment was performed at Weapons Neutron Research Facility at LANSCE, Los Alamos. The neutron beam from a spallation source is used to irradiate the active target made from BC-418 plastic scintillator. The recoiled protons detected in the active target are measured in coincidence with elastically scattered incident neutrons detected by and adjacent liquid scintillator. Time of flight of the incident neutron and the knowledge of scattering geometry allow for a kinematically complete and high-precision measurement of the light response as a function of the proton energy.

Post-Flight Analysis of the Guidance, Navigation, and Control Performance During Orion Exploration Flight Test 1

NASA Technical Reports Server (NTRS)

Barth, Andrew; Mamich, Harvey; Hoelscher, Brian

2015-01-01

The first test flight of the Orion Multi-Purpose Crew Vehicle presented additional challenges for guidance, navigation and control as compared to a typical re-entry from the International Space Station or other Low Earth Orbit. An elevated re-entry velocity and steeper flight path angle were chosen to achieve aero-thermal flight test objectives. New IMU's, a GPS receiver, and baro altimeters were flight qualified to provide the redundant navigation needed for human space flight. The guidance and control systems must manage the vehicle lift vector in order to deliver the vehicle to a precision, coastal, water landing, while operating within aerodynamic load, reaction control system, and propellant constraints. Extensive pre-flight six degree-of-freedom analysis was performed that showed mission success for the nominal mission as well as in the presence of sensor and effector failures. Post-flight reconstruction analysis of the test flight is presented in this paper to show whether that all performance metrics were met and establish how well the pre-flight analysis predicted the in-flight performance.

Russian Countermeasure Systems for Adverse Effects of Microgravity on Long-Duration ISS Flights.

PubMed

Kozlovskaya, Inessa B; Yarmanova, E N; Yegorov, A D; Stepantsov, V I; Fomina, E V; Tomilovaskaya, E S

2015-12-01

The system of countermeasures for the adverse effects of microgravity developed in the USSR supported the successful implementation of long-duration spaceflight (LDS) programs on the Salyut and Mir orbital stations and was subsequently adapted for flights on the International Space Station (ISS). From 2000 through 2010, crews completed 26 ISS flight increments ranging in duration from 140 to 216 d, with the participation of 27 Russian cosmonauts. These flights have made it possible to more precisely determine a crew-member's level of conditioning, better assess the advantages and disadvantages of training processes, and determine prospects for future developments.

The development and testing of the Lens Antenna Deployment Demonstration (LADD) test article

NASA Technical Reports Server (NTRS)

Pugh, Mark L.; Denton, Robert J., Jr.; Strange, Timothy J.

1993-01-01

The USAF Rome Laboratory and NASA Marshall Space Flight Center, through contract to Grumman Corporation, have developed a space-qualifiable test article for the Strategic Defense Initiative Organization to demonstrate the critical structural and mechanical elements of single-axis roll-out membrane deployment for Space Based Radar (SBR) applications. The Lens Antenna Deployment Demonstration (LADD) test article, originally designed as a shuttle-attached flight experiment, is a large precision space structure which is representative of operational designs for space-fed lens antennas. Although the flight experiment was cancelled due to funding constraints and major revisions in the Strategic Defense System (SDS) architecture, development of this test article was completed in June 1989. To take full advantage of the existence of this unique structure, a series of ground tests are proposed which include static, dynamic, and thermal measurements in a simulated space environment. An equally important objective of these tests is the verification of the analytical tools used to design and develop large precision space structures.

Impact of GPS antenna phase center and code residual variation maps on orbit and baseline determination of GRACE

NASA Astrophysics Data System (ADS)

Mao, X.; Visser, P. N. A. M.; van den IJssel, J.

2017-06-01

Precision Orbit Determination (POD) is a prerequisite for the success of many Low Earth Orbiting (LEO) satellite missions. With high-quality, dual-frequency Global Positioning System (GPS) receivers, typically precisions of the order of a few cm are possible for single-satellite POD, and of a few mm for relative POD of formation flying spacecraft with baselines up to hundreds of km. To achieve the best precision, the use of Phase Center Variation (PCV) maps is indispensable. For LEO GPS receivers, often a-priori PCV maps are obtained by a pre-launch ground campaign, which is not able to represent the real space-borne environment of satellites. Therefore, in-flight calibration of the GPS antenna is more widely conducted. This paper shows that a further improvement is possible by including the so-called Code Residual Variation (CRV) maps in absolute/undifferenced and relative/Double-differenced (DD) POD schemes. Orbit solutions are produced for the GRACE satellite formation for a four months test period (August-November, 2014), demonstrating enhanced orbit precision after first using the in-flight PCV maps and a further improvement after including the CRV maps. The application of antenna maps leads to a better consistency with independent Satellite Laser Ranging (SLR) and K-band Ranging (KBR) low-low Satellite-to-Satellite Tracking (ll-SST) observations. The inclusion of the CRV maps results also in a much better consistency between reduced-dynamic and kinematic orbit solutions for especially the cross-track direction. The improvements are largest for GRACE-B, where a cross-talk between the GPS main antenna and the occultation antenna yields higher systematic observation residuals. For high-precision relative POD which necessitates DD carrier-phase ambiguity fixing, in principle frequency-dependent PCV maps would be required. To this aim, use is made of an Extended Kalman Filter (EKF) that is capable of optimizing relative spacecraft dynamics and iteratively fixing the DD carrier-phase ambiguities. It is found that PCV maps significantly improve the baseline solution. CRV maps slightly enhance the baseline precision, more significantly they lead to a much better initialization of the ambiguity fixing. The GRACE single-satellite orbit solutions compare to within a few cm 3-dimensionally with state-of-the-art external orbit solutions and SLR observations, whereas for the baseline a consistency of better than 0.7 mm with KBR observations is achieved.

Highly accurate analytic formulae for projectile motion subjected to quadratic drag

NASA Astrophysics Data System (ADS)

Turkyilmazoglu, Mustafa

2016-05-01

The classical phenomenon of motion of a projectile fired (thrown) into the horizon through resistive air charging a quadratic drag onto the object is revisited in this paper. No exact solution is known that describes the full physical event under such an exerted resistance force. Finding elegant analytical approximations for the most interesting engineering features of dynamical behavior of the projectile is the principal target. Within this purpose, some analytical explicit expressions are derived that accurately predict the maximum height, its arrival time as well as the flight range of the projectile at the highest ascent. The most significant property of the proposed formulas is that they are not restricted to the initial speed and firing angle of the object, nor to the drag coefficient of the medium. In combination with the available approximations in the literature, it is possible to gain information about the flight and complete the picture of a trajectory with high precision, without having to numerically simulate the full governing equations of motion.

Magnetic fingerprints of rolling cells for quantitative flow cytometry in whole blood

NASA Astrophysics Data System (ADS)

Reisbeck, Mathias; Helou, Michael Johannes; Richter, Lukas; Kappes, Barbara; Friedrich, Oliver; Hayden, Oliver

2016-09-01

Over the past 50 years, flow cytometry has had a profound impact on preclinical and clinical applications requiring single cell function information for counting, sub-typing and quantification of epitope expression. At the same time, the workflow complexity and high costs of such optical systems still limit flow cytometry applications to specialized laboratories. Here, we present a quantitative magnetic flow cytometer that incorporates in situ magnetophoretic cell focusing for highly accurate and reproducible rolling of the cellular targets over giant magnetoresistance sensing elements. Time-of-flight analysis is used to unveil quantitative single cell information contained in its magnetic fingerprint. Furthermore, we used erythrocytes as a biological model to validate our methodology with respect to precise analysis of the hydrodynamic cell diameter, quantification of binding capacity of immunomagnetic labels, and discrimination of cell morphology. The extracted time-of-flight information should enable point-of-care quantitative flow cytometry in whole blood for clinical applications, such as immunology and primary hemostasis.

Effet de l'encombrement visuel de l'ecran primaire de vol sur la performance du pilote, la charge de travail et le parcours visuel

NASA Astrophysics Data System (ADS)

Doyon-Poulin, Philippe

Flight deck of 21st century commercial aircrafts does not look like the one the Wright brothers used for their first flight. The rapid growth of civilian aviation resulted in an increase in the number of flight deck instruments and of their complexity, in order to complete a safe and ontime flight. However, presenting an abundance of visual information using visually cluttered flight instruments might reduce the pilot's flight performance. Visual clutter has received an increased interest by the aerospace community to understand the effects of visual density and information overload on pilots' performance. Aerospace regulations demand to minimize visual clutter of flight deck displays. Past studies found a mixed effect of visual clutter of the primary flight display on pilots' technical flight performance. More research is needed to better understand this subject. In this thesis, we did an experimental study in a flight simulator to test the effects of visual clutter of the primary flight display on the pilot's technical flight performance, mental workload and gaze pattern. First, we identified a gap in existing definitions of visual clutter and we proposed a new definition relevant to the aerospace community that takes into account the context of use of the display. Then, we showed that past research on the effects of visual clutter of the primary flight display on pilots' performance did not manipulate the variable of visual clutter in a similar manner. Past research changed visual clutter at the same time than the flight guidance function. Using a different flight guidance function between displays might have masked the effect of visual clutter on pilots' performance. To solve this issue, we proposed three requirements that all tested displays must satisfy to assure that only the variable of visual clutter is changed during study while leaving other variables unaffected. Then, we designed three primary flight displays with a different visual clutter level (low, medium, high) but with the same flight guidance function, by respecting the previous requirements. Twelve pilots, with a mean experience of over 4000 total flight hours, completed an instrument landing in a flight simulator using all three displays for a total of nine repetitions. Our results showed that pilots reported lower workload level and had better lateral precision during the approach using the medium-clutter display compared to the low- and high-clutter displays. Also, pilots reported that the medium-clutter display was the most useful for the flight task compared to the two other displays. Eye tracker results showed that pilots' gaze pattern was less efficient for the high-clutter display compared to the low- and medium-clutter displays. Overall, these new experimental results emphasize the importance of optimizing visual clutter of flight displays as it affects both objective and subjective performance of experienced pilots in their flying task. This thesis ends with practical recommendations to help designers optimize visual clutter of displays used for man-machine interface.

Helicopter flight investigation to determine the effects of a closed-circuit TV on performance of a precision sling-load handling task

NASA Technical Reports Server (NTRS)

Dicarlo, D. J.; Kelley, H. L.; Spivey, D. L.

1974-01-01

Helicopter sling-load operations have been limited during hover and low-speed flight by the degree of precision achieved by the pilot/helicopter/sling-load combination. Previous attempts to improve precision have included stabilization of the load and helicopter and the addition of a pilot station directly facing the load. In these tests, use of a closed-circuit TV as a display that would permit sling-load delivery and placement by the forward-facing pilot was evaluated using a CH-54B helicopter. In all, three test cases were documented, which included the following: (1) forward-facing pilot using the TV display, (2) forward-facing pilot using verbal commands from a load-facing observer, and (3) aft-facing pilot using direct visual cues. The results indicate that a comparable level of performance was achieved for each test case; however, an increase in pilot workload was noted when the TV system was used.

A Stainless-Steel Mandrel for Slumping Glass X-ray Mirrors

NASA Technical Reports Server (NTRS)

Gubarev, Mikhail V.; O'Dell, Stephen L.; Jones, William D.; Kester, Thomas J.; Griffith, Charles W.; Zhang, William W.; Saha, Timo T.; Chan, Kai-Wing

2009-01-01

We have fabricated a precision full-cylinder stainless-steel mandrel at Marshall Space Flight Center. The mandrel is figured for a 30-cm diameter primary (paraboloid) mirror of an 840-cm focal-length Wolter-1 telescope. We have developed this mandrel for experiments in slumping.thermal forming at about 600 C.of glass mirror segments at Goddard Space Flight Center, in support of NASA's participation in the International X-ray Observatory (IXO). Precision turning of stainless-steel mandrels may offer a low-cost alternative to conventional figuring of fused-silica or other glassy forming mandrels. We report on the fabrication, metrology, and performance of this first mandrel; then we discuss plans and goals for stainless-steel mandrel technology.

A Stainless-Steel Mandrel for Slumping Glass X-Ray Mirrors

NASA Technical Reports Server (NTRS)

ODell, Stephen L.; Gubarev, Mikhail V.; Jones, William D.; Kester, Thomas J.; Griffith, Charles W.; Zhang, William W.; Saha, Timo T.; Chan, Kai-Wing

2008-01-01

We have fabricated a precision full -cylinder stainless-steel mandrel at Marshall Space Flight Center. The mandrel is figured for a 30-cm-diameter primary (paraboloid) mirror of an 840-cm focal-lengthWolter-1 telescope. We have developed this mandrel for experiments in slumping.thermal forming at about 600 C-of glass mirror segments at Goddard Space Flight Center, in support of NASA fs participation in the International X -ray Observatory (IXO). Precision turning of stainless ]steel mandrels may offer a lowcost alternative to conventional figuring of fused -silica or other glassy forming mandrels. We report on the fabrication, metrology, and performance of this first mandrel; then we discuss plans and goals for stainless-steel mandrel technology.

Guidance and control 1991; Proceedings of the Annual Rocky Mountain Guidance and Control Conference, Keystone, CO, Feb. 2-6, 1991

NASA Astrophysics Data System (ADS)

Culp, Robert D.; McQuerry, James P.

1991-07-01

The present conference on guidance and control encompasses advances in guidance, navigation, and control, storyboard displays, approaches to space-borne pointing control, international space programs, recent experiences with systems, and issues regarding navigation in the low-earth-orbit space environment. Specific issues addressed include a scalable architecture for an operational spaceborne autonavigation system, the mitigation of multipath error in GPS-based attitude determination, microgravity flight testing of a laboratory robot, and the application of neural networks. Other issues addressed include image navigation with second-generation Meteosat, Magellan star-scanner experiences, high-precision control systems for telescopes and interferometers, gravitational effects on low-earth orbiters, experimental verification of nanometer-level optical pathlengths, and a flight telerobotic servicer prototype simulator. (For individual items see A93-15577 to A93-15613)

Plasma arc welding repair of space flight hardware

NASA Technical Reports Server (NTRS)

Hoffman, David S.

1993-01-01

Repair and refurbishment of flight and test hardware can extend the useful life of very expensive components. A technique to weld repair the main combustion chamber of space shuttle main engines has been developed. The technique uses the plasma arc welding process and active cooling to seal cracks and pinholes in the hot-gas wall of the main combustion chamber liner. The liner hot-gas wall is made of NARloyZ, a copper alloy previously thought to be unweldable using conventional arc welding processes. The process must provide extensive heat input to melt the high conductivity NARloyZ while protecting the delicate structure of the surrounding material. The higher energy density of the plasma arc process provides the necessary heat input while active water cooling protects the surrounding structure. The welding process is precisely controlled using a computerized robotic welding system.

Concepts and effects of damping in isolators

NASA Technical Reports Server (NTRS)

Kerley, J.

1984-01-01

A series of innovative designs and inventions which led to the solution of many aerospace vibration and shock problems through damping techniques is presented. The design of damped airborne structures has presented a need for such creative innovation. The primary concern was to discover what concepts were necessary for good structural damping. Once these concepts are determined and converted into basic principles, the design of hardware follows. The following hardware and techniques were developed in support of aerospace program requirements: shipping containers, alignment cables for precision mechanisms, isolation of small components such as relays and flight instruments, isolation for heavy flight equipment, coupling devices, universal joints, use of wire mesh to replace cable, isolation of 16-dB, 5000 lb horn, and compound damping devices to get better isolation from shock and vibration in a high steady environment.

Cryogenic thermal conductivity measurements on candidate materials for space missions

NASA Astrophysics Data System (ADS)

Tuttle, James; Canavan, Edgar; Jahromi, Amir

2017-12-01

Spacecraft and instruments on space missions are built using a wide variety of carefully-chosen materials. It is common for NASA engineers to propose new candidate materials which have not been totally characterized at cryogenic temperatures. In many cases a material's cryogenic thermal conductivity must be known before selecting it for a specific space-flight application. We developed a test facility in 2004 at NASA's Goddard Space Flight Center to measure the longitudinal thermal conductivity of materials at temperatures between 4 and 300 K, and we have characterized many candidate materials since then. The measurement technique is not extremely complex, but proper care to details of the setup, data acquisition and data reduction is necessary for high precision and accuracy. We describe the thermal conductivity measurement process and present results for ten engineered materials, including alloys, polymers, composites, and a ceramic.

Vectorcardiographic changes during extended space flight (M093): Observations at rest and during exercise

NASA Technical Reports Server (NTRS)

Smith, R. F.; Stanton, K.; Stoop, D.; Brown, D.; Janusz, W.; King, P.

1977-01-01

The objectives of Skylab Experiment M093 were to measure electrocardiographic signals during space flight, to elucidate the electrophysiological basis for the changes observed, and to assess the effect of the change on the human cardiovascular system. Vectorcardiographic methods were used to quantitate changes, standardize data collection, and to facilitate reduction and statistical analysis of data. Since the Skylab missions provided a unique opportunity to study the effects of prolonged weightlessness on human subjects, an effort was made to construct a data base that contained measurements taken with precision and in adequate number to enable conclusions to be made with a high degree of confidence. Standardized exercise loads were incorporated into the experiment protocol to increase the sensitivity of the electrocardiogram for effects of deconditioning and to detect susceptability for arrhythmias.

Space Science

NASA Image and Video Library

1999-04-21

NASA's Space Optics Manufacturing Center has been working to expand our view of the universe via sophisticated new telescopes. The Optics Center's goal is to develop low-cost, advanced space optics technologies for the NASA program in the 21st century - including the long-term goal of imaging Earth-like planets in distant solar systems. To reduce the cost of mirror fabrication, Marshall Space Flight Center (MSFC) has developed replication techniques, the machinery, and materials to replicate electro-formed nickel mirrors. The process allows fabricating precisely shaped mandrels to be used and reused as masters for replicating high-quality mirrors. Dr. Joe Ritter examines a replicated electro-formed nickel-alloy mirror which exemplifies the improvements in mirror fabrication techniques, with benefits such as dramtic weight reduction that have been achieved at the Marshall Space Flight Center's Space Optics Manufacturing Technology Center (SOMTC).

Precision Cleaning and Verification Processes Used at Marshall Space Flight Center for Critical Hardware Applications

NASA Technical Reports Server (NTRS)

Caruso, Salvadore V.; Cox, Jack A.; McGee, Kathleen A.

1998-01-01

Marshall Space Flight Center (MSFC) of the National Aeronautics and Space Administration performs many research and development programs that require hardware and assemblies to be cleaned to levels that are compatible with fuels and oxidizers (liquid oxygen, solid propellants, etc.). Also, MSFC is responsible for developing large telescope satellites which require a variety of optical systems to be cleaned. A precision cleaning shop is operated within MSFC by the Fabrication Services Division of the Materials & Processes Laboratory. Verification of cleanliness is performed for all precision cleaned articles in the Environmental and Analytical Chemistry Branch. Since the Montreal Protocol was instituted, MSFC had to find substitutes for many materials that have been in use for many years, including cleaning agents and organic solvents. As MSFC is a research center, there is a great variety of hardware that is processed in the Precision Cleaning Shop. This entails the use of many different chemicals and solvents, depending on the nature and configuration of the hardware and softgoods being cleaned. A review of the manufacturing cleaning and verification processes, cleaning materials and solvents used at MSFC and changes that resulted from the Montreal Protocol will be presented.

Precision Cleaning and Verification Processes Used at Marshall Space Flight Center for Critical Hardware Applications

NASA Technical Reports Server (NTRS)

Caruso, Salvadore V.

1999-01-01

Marshall Space Flight Center (MSFC) of the National Aeronautics and Space Administration (NASA) performs many research and development programs that require hardware and assemblies to be cleaned to levels that are compatible with fuels and oxidizers (liquid oxygen, solid propellants, etc.). Also, the Center is responsible for developing large telescope satellites which requires a variety of optical systems to be cleaned. A precision cleaning shop is operated with-in MSFC by the Fabrication Services Division of the Materials & Processes Division. Verification of cleanliness is performed for all precision cleaned articles in the Analytical Chemistry Branch. Since the Montreal Protocol was instituted, MSFC had to find substitutes for many materials that has been in use for many years, including cleaning agents and organic solvents. As MSFC is a research Center, there is a great variety of hardware that is processed in the Precision Cleaning Shop. This entails the use of many different chemicals and solvents, depending on the nature and configuration of the hardware and softgoods being cleaned. A review of the manufacturing cleaning and verification processes, cleaning materials and solvents used at MSFC and changes that resulted from the Montreal Protocol will be presented.

Flight evaluation of stabilization and command augmentation system concepts and cockpit displays during approach and landing of powered-lift STOL aircraft

NASA Technical Reports Server (NTRS)

Franklin, J. A.; Innis, R. C.; Hardy, G. H.

1980-01-01

A flight research program was conducted to assess the effectiveness of manual control concepts and various cockpit displays in improving altitude (pitch, roll, and yaw) and longitudinal path control during short takeoff aircraft approaches and landings. Satisfactory flying qualities were demonstrared to minimum decision heights of 30 m (100 ft) for selected stabilization and command augmentation systems and flight director combinations. Precise landings at low touchdown sink rates were achieved with a gentle flare maneuver.

Coronas-F Orbit Monitoring and Re-Entry Prediction

NASA Technical Reports Server (NTRS)

Ivanov, N. M.; Kolyuka, Yu. F.; Afanasieva, T. I.; Gridchina, T. A.

2007-01-01

Russian scientific satellite CORONAS-F was launched on July, 31, 2001. The object was inserted in near-circular orbit with the inclination 82.5deg and a mean altitude approx. 520 km. Due to the upper atmosphere drag CORONAS-F was permanently descended and as a result on December, 6, 2005 it has finished the earth-orbital flight, having lifetime in space approx. 4.5 years. The satellite structural features and its flight attitude control led to the significant variations of its ballistic coefficient during the flight. It was a cause of some specific difficulties in the fulfillment of the ballistic and navigation support of this space vehicle flight. Besides the main mission objective CORONAS-F also has been selected by the Inter-Agency Space Debris Coordination Committee (IADC) as a target object for the next regular international re-entry test campaign on a program of surveillance and re-entry prediction for the hazard space objects within their de-orbiting phases. Spacecraft (S/C) CORONAS-F kept its working state right up to the end of the flight - down to the atmosphere entry. This fact enabled to realization of the additional research experiments, concerning with an estimation of the atmospheric density within the low earth orbits (LEO) of the artificial satellites, and made possible to continue track the S/C during final phase of its flight by means of Russian regular command & tracking system, used for it control. Thus there appeared a unique possibility of using for tracking S/C at its de-orbiting phase not only passive radar facilities, belonging to the space surveillance systems and traditionally used for support of the IADC re-entry test campaigns, but also more precise active trajectory radio-tracking facilities from the ground control complex (GCC) applied for this object. Under the corresponding decision of the Russian side such capability of additional high-precise tracking control of the CORONAS-F flight in this period of time has been implemented. The organizing of the CORONAS-F ballistic and navigational support (BNS) and solving its main tasks (such as S/C orbit determination (OD) and its motion prediction and connected with them) both for regular mission stage and for additional flight program were realized by the group of specialists from the Mission Control Center (MCC). MCC was also assigned as a principal organization from the Russian side for participation in the 7th IADC re-entry test campaign on CORONAS-F. The CORONAS-F flight features and space environments circumstances during its flight as well as a methodology and technology of spacecraft ballistic and navigational support are given below. The BNS results for different phases of S/C flight, including the results of its re-entry predictions, obtained during the realization of the 7th IADC test campaign are submitted. The accuracy of space vehicle re-entry prediction and its dependence on various factors are analyzed in more details.

Implementation and flight-test of a multi-mode rotorcraft flight-control system for single-pilot use in poor visibility

NASA Technical Reports Server (NTRS)

Hindson, William S.

1987-01-01

A flight investigation was conducted to evaluate a multi-mode flight control system designed according to the most recent recommendations for handling qualities criteria for new military helicopters. The modes and capabilities that were included in the system are those considered necessary to permit divided-attention (single-pilot) lowspeed and hover operations near the ground in poor visibility conditions. Design features included mode-selection and mode-blending logic, the use of an automatic position-hold mode that employed precision measurements of aircraft position, and a hover display which permitted manually-controlled hover flight tasks in simulated instrument conditions. Pilot evaluations of the system were conducted using a multi-segment evaluation task. Pilot comments concerning the use of the system are provided, and flight-test data are presented to show system performance.

Space Shuttle Main Engine - The Relentless Pursuit of Improvement

NASA Technical Reports Server (NTRS)

VanHooser, Katherine P.; Bradley, Douglas P.

2011-01-01

The Space Shuttle Main Engine (SSME) is the only reusable large liquid rocket engine ever developed. The specific impulse delivered by the staged combustion cycle, substantially higher than previous rocket engines, minimized volume and weight for the integrated vehicle. The dual pre-burner configuration permitted precise mixture ratio and thrust control while the fully redundant controller and avionics provided a very high degree of system reliability and health diagnosis. The main engine controller design was the first rocket engine application to incorporate digital processing. The engine was required to operate at a high chamber pressure to minimize engine volume and weight. Power level throttling was required to minimize structural loads on the vehicle early in flight and acceleration levels on the crew late in ascent. Fatigue capability, strength, ease of assembly and disassembly, inspectability, and materials compatibility were all major considerations in achieving a fully reusable design. During the multi-decade program the design evolved substantially using a series of block upgrades. A number of materials and manufacturing challenges were encountered throughout SSME s history. Significant development was required for the final configuration of the high pressure turbopumps. Fracture control was implemented to assess life limits of critical materials and components. Survival in the hydrogen environment required assessment of hydrogen embrittlement. Instrumentation systems were a challenge due to the harsh thermal and dynamic environments within the engine. Extensive inspection procedures were developed to assess the engine components between flights. The Space Shuttle Main Engine achieved a remarkable flight performance record. All flights were successful with only one mission requiring an ascent abort condition, which still resulted in an acceptable orbit and mission. This was achieved in large part via extensive ground testing to fully characterize performance and to establish acceptable life limits. During the program over a million seconds of accumulated test and flight time was achieved. Post flight inspection and assessment was a key part of assuring proper performance of the flight hardware. By the end of the program the predicted reliability had improved by a factor of four. These unique challenges, evolution of the design, and the resulting reliability will be discussed in this paper.

Atom Interferometry with Ultracold Quantum Gases in a Microgravity Environment

NASA Astrophysics Data System (ADS)

Williams, Jason; D'Incao, Jose; Chiow, Sheng-Wey; Yu, Nan

2015-05-01

Precision atom interferometers (AI) in space promise exciting technical capabilities for fundamental physics research, with proposals including unprecedented tests of the weak equivalence principle, precision measurements of the fine structure and gravitational constants, and detection of gravity waves and dark energy. Consequently, multiple AI-based missions have been proposed to NASA, including a dual-atomic-species interferometer that is to be integrated into the Cold Atom Laboratory (CAL) onboard the International Space Station. In this talk, I will discuss our plans and preparation at JPL for the proposed flight experiments to use the CAL facility to study the leading-order systematics expected to corrupt future high-precision measurements of fundamental physics with AIs in microgravity. The project centers on the physics of pairwise interactions and molecular dynamics in these quantum systems as a means to overcome uncontrolled shifts associated with the gravity gradient and few-particle collisions. We will further utilize the CAL AI for proof-of-principle tests of systematic mitigation and phase-readout techniques for use in the next-generation of precision metrology experiments based on AIs in microgravity. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

Influence of Time-Pickoff Circuit Parameters on LiDAR Range Precision

PubMed Central

Wang, Hongming; Yang, Bingwei; Huyan, Jiayue; Xu, Lijun

2017-01-01

A pulsed time-of-flight (TOF) measurement-based Light Detection and Ranging (LiDAR) system is more effective for medium-long range distances. As a key ranging unit, a time-pickoff circuit based on automatic gain control (AGC) and constant fraction discriminator (CFD) is designed to reduce the walk error and the timing jitter for obtaining the accurate time interval. Compared with Cramer–Rao lower bound (CRLB) and the estimation of the timing jitter, four parameters-based Monte Carlo simulations are established to show how the range precision is influenced by the parameters, including pulse amplitude, pulse width, attenuation fraction and delay time of the CFD. Experiments were carried out to verify the relationship between the range precision and three of the parameters, exclusing pulse width. It can be concluded that two parameters of the ranging circuit (attenuation fraction and delay time) were selected according to the ranging performance of the minimum pulse amplitude. The attenuation fraction should be selected in the range from 0.2 to 0.6 to achieve high range precision. The selection criterion of the time-pickoff circuit parameters is helpful for the ranging circuit design of TOF LiDAR system. PMID:29039772

Basic Geometric Support of Systems for Earth Observation from Geostationary and Highly Elliptical Orbits

NASA Astrophysics Data System (ADS)

Gektin, Yu. M.; Egoshkin, N. A.; Eremeev, V. V.; Kuznecov, A. E.; Moskatinyev, I. V.; Smelyanskiy, M. B.

2017-12-01

A set of standardized models and algorithms for geometric normalization and georeferencing images from geostationary and highly elliptical Earth observation systems is considered. The algorithms can process information from modern scanning multispectral sensors with two-coordinate scanning and represent normalized images in optimal projection. Problems of the high-precision ground calibration of the imaging equipment using reference objects, as well as issues of the flight calibration and refinement of geometric models using the absolute and relative reference points, are considered. Practical testing of the models, algorithms, and technologies is performed in the calibration of sensors for spacecrafts of the Electro-L series and during the simulation of the Arktika prospective system.

MS Hadfield aims a laser range finder through a window on the aft flight deck of Endeavour

NASA Image and Video Library

2001-04-21

S100-E-5141 (21 April 2001) --- Astronaut Chris A. Hadfield of the Canadian Space Agency (CSA) uses a laser ranging device to keep up with the precise location of the International Space Station (ISS) from his post on the aft flight deck of the Space Shuttle Endeavour. The image was recorded with a digital still camera.

Comparison of Three Wind Measuring Systems for Flight Test

NASA Technical Reports Server (NTRS)

Teets, Edward H., Jr.; Harvey, Philip O.

2000-01-01

A preliminary field test of the accuracy of wind velocity measurements obtained using global positioning system-tracked rawinsonde balloons has been performed. Wind comparisons have been conducted using global positioning system (GPS) and radio automatic theodolite sounder (RATS) rawinsondes and a high-precision range instrumentation radar-tracked reflector. Wind velocity differences between the GPS rawinsondes and the radar were significantly less than between the RATS rawinsondes and the radar. These limited test results indicate a root-mean-square wind velocity difference from 4.98 kn (2.56 m/sec) for the radar and RATS to 1.09 kn (0.56 m/sec) for the radar and GPS. Differences are influenced by user reporting requirements, data processing techniques, and the inherent tracking accuracies of the system. This brief field test indicates that the GPS sounding system tracking data are more precise than the RATS system. When high-resolution wind data are needed, use of GPS rawinsonde systems can reduce the burden on range radar operations.

Flight test integration and evaluation of the LANTIRN system on the F-15E

NASA Astrophysics Data System (ADS)

Presuhn, Gary G.; Zeis, Joseph E.

1991-08-01

In today's high threat arena of air combat, the need to fly low, penetrate enemy defenses, strike effectively, and safely return to base is more valid than ever. The F-15E is designed to accomplish just that type of mission scenario, regardless of weather and time of day. In order to accomplish this demanding profile, any such aircraft requires terrain-following equipment and precision target designation. The LANTIRN system on the F-15E is designed to fulfill that role. This paper examines the two major aspects of the LANTIRN system found on the F-15E: the Navigation Pod and the Targeting Pod, and investigates flight test issues during F-15E integration testing. The Navigation Pod consists of two major subsystems, the Fixed Imaging Navigation Sensor (FINS) and the terrain following radar (TFR). Discussion of the FINS centers around the integration issues of the system and its utility in the night low level environment, as determined through flight test. In providing a 'window on the world,' this aspect of the LANTIRN system provides unique capabilities in navigation as well as weapons delivery. The TFR, the other major subsystem, is a continuation of the F-111 and RF-4 terrain following systems. While an effective system, integration of the TFR into the F-15E has been a challenge to the flight test community, with many lessons to be learned. The Targeting Pod is the second component of the LANTIRN system. Its purpose is to acquire and designate a target through use of its selectable dual field of view infrared sensor and laser ranger/designator. The laser also provides terminal guidance capability for precision guided weapons. Integration of the Targeting Pod into the avionics suite of the F-15E has provided classic examples of systems flight testing, evaluating both the technical and performance aspects of the pod, as well as the key human factors interface. The overall intent of this paper is to describe avionics testing, as applied to low level navigation and targeting systems, and to discuss lessons learned in that process, both of a specific and a general nature.

Adaptive control of a millimeter-scale flapping-wing robot.

PubMed

Chirarattananon, Pakpong; Ma, Kevin Y; Wood, Robert J

2014-06-01

Challenges for the controlled flight of a robotic insect are due to the inherent instability of the system, complex fluid-structure interactions, and the general lack of a complete system model. In this paper, we propose theoretical models of the system based on the limited information available from previous work and a comprehensive flight controller. The modular flight controller is derived from Lyapunov function candidates with proven stability over a large region of attraction. Moreover, it comprises adaptive components that are capable of coping with uncertainties in the system that arise from manufacturing imperfections. We have demonstrated that the proposed methods enable the robot to achieve sustained hovering flights with relatively small errors compared to a non-adaptive approach. Simple lateral maneuvers and vertical takeoff and landing flights are also shown to illustrate the fidelity of the flight controller. The analysis suggests that the adaptive scheme is crucial in order to achieve millimeter-scale precision in flight control as observed in natural insect flight.

Flight Test Evaluation of the ATD-1 Interval Management Application

NASA Technical Reports Server (NTRS)

Swieringa, Kurt A.; Wilson, Sara R.; Baxley, Brian T.; Roper, Roy D.; Abbott, Terence S.; Levitt, Ian; Scharl, Julien

2017-01-01

Interval Management (IM) is a concept designed to be used by air traffic controllers and flight crews to more efficiently and precisely manage inter-aircraft spacing. Both government and industry have been working together to develop the IM concept and standards for both ground automation and supporting avionics. NASA contracted with Boeing, Honeywell, and United Airlines to build and flight test an avionics prototype based on NASA's spacing algorithm and conduct a flight test. The flight test investigated four different types of IM operations over the course of nineteen days, and included en route, arrival, and final approach phases of flight. This paper examines the spacing accuracy achieved during the flight test and the rate of speed commands provided to the flight crew. Many of the time-based IM operations met or exceeded the operational design goals set out in the standards for the maintain operations and a subset of the achieve operations. Those operations which did not meet the goals were due to issues that are identified and will be further analyzed.

Flight-Determined, Subsonic, Lateral-Directional Stability and Control Derivatives of the Thrust-Vectoring F-18 High Angle of Attack Research Vehicle (HARV), and Comparisons to the Basic F-18 and Predicted Derivatives

NASA Technical Reports Server (NTRS)

Iliff, Kenneth W.; Wang, Kon-Sheng Charles

1999-01-01

The subsonic, lateral-directional, stability and control derivatives of the thrust-vectoring F-1 8 High Angle of Attack Research Vehicle (HARV) are extracted from flight data using a maximum likelihood parameter identification technique. State noise is accounted for in the identification formulation and is used to model the uncommanded forcing functions caused by unsteady aerodynamics. Preprogrammed maneuvers provided independent control surface inputs, eliminating problems of identifiability related to correlations between the aircraft controls and states. The HARV derivatives are plotted as functions of angles of attack between 10deg and 70deg and compared to flight estimates from the basic F-18 aircraft and to predictions from ground and wind tunnel tests. Unlike maneuvers of the basic F-18 aircraft, the HARV maneuvers were very precise and repeatable, resulting in tightly clustered estimates with small uncertainty levels. Significant differences were found between flight and prediction; however, some of these differences may be attributed to differences in the range of sideslip or input amplitude over which a given derivative was evaluated, and to differences between the HARV external configuration and that of the basic F-18 aircraft, upon which most of the prediction was based. Some HARV derivative fairings have been adjusted using basic F-18 derivatives (with low uncertainties) to help account for differences in variable ranges and the lack of HARV maneuvers at certain angles of attack.

Test Flight Results of the New Airborne CH4 and CO2 Lidar CHARM-F

NASA Astrophysics Data System (ADS)

Kiemle, Christoph; Amediek, Axel; Fix, Andreas; Wirth, Martin; Quatrevalet, Mathieu; Büdenbender, Christian; Ehret, Gerhard

2017-04-01

Installed onboard the German research aircraft HALO the integrated-path differential-absorption (IPDA) lidar CHARM-F measures weighted vertical columns of the greenhouse gases CO2 and CH4 below the aircraft and along its flight track aiming at high accuracy and precision. CHARM-F was designed and built as an airborne demonstrator for the space lidar MERLIN, the "Methane Remote Lidar Mission", conducted by the German and French space agencies DLR and CNES with launch foreseen in 2021. It provides excellent opportunities for targeted measurements of regional fluxes and hot spots. We present exemplary measurements from several flights performed in spring 2015 over Central Europe. Our analyses reveal a measurement precision of below 0.5% for 20-km averages. A methane plume from a coal mine ventilation shaft was overflown, as well as a carbon dioxide plume from a large coal-fired power plant. The method to estimate fluxes from the lidar signals will be explained. The results show good agreement with reported emission rates. The airborne measurements are expected to improve the retrieval of future space-borne IPDA lidar systems such as MERLIN. CHARM-F measurements over mountains, water and clouds help assess the strength and variability of backscatter from such challenging surfaces. The IPDA weighting function, or measurement sensitivity, is dependent on atmospheric pressure and temperature. We use ECMWF analyses interpolated in space and time to the aircraft track that provide these auxiliary data. The relatively coarse model representation of orography, with respect to the lidar, causes uncertainties that we assess. CHARM-F will be a key instrument in the upcoming CoMet field experiment, where active and passive remote sensing, as well as in-situ instruments will be installed onboard HALO. The flights are scheduled in April and May 2017 over Central Europe and will focus on point sources such as power plants, coal mines, and landfills, as well as on urban gradients and more extended sources such as agriculture and wetlands.

Technology-enabled Airborne Spacing and Merging

NASA Technical Reports Server (NTRS)

Hull, James; Barmore, Bryan; Abbott, Tetence

2005-01-01

Over the last several decades, advances in airborne and groundside technologies have allowed the Air Traffic Service Provider (ATSP) to give safer and more efficient service, reduce workload and frequency congestion, and help accommodate a critically escalating traffic volume. These new technologies have included advanced radar displays, and data and communication automation to name a few. In step with such advances, NASA Langley is developing a precision spacing concept designed to increase runway throughput by enabling the flight crews to manage their inter-arrival spacing from TRACON entry to the runway threshold. This concept is being developed as part of NASA s Distributed Air/Ground Traffic Management (DAG-TM) project under the Advanced Air Transportation Technologies Program. Precision spacing is enabled by Automatic Dependent Surveillance-Broadcast (ADS-B), which provides air-to-air data exchange including position and velocity reports; real-time wind information and other necessary data. On the flight deck, a research prototype system called Airborne Merging and Spacing for Terminal Arrivals (AMSTAR) processes this information and provides speed guidance to the flight crew to achieve the desired inter-arrival spacing. AMSTAR is designed to support current ATC operations, provide operationally acceptable system-wide increases in approach spacing performance and increase runway throughput through system stability, predictability and precision spacing. This paper describes problems and costs associated with an imprecise arrival flow. It also discusses methods by which Air Traffic Controllers achieve and maintain an optimum interarrival interval, and explores means by which AMSTAR can assist in this pursuit. AMSTAR is an extension of NASA s previous work on in-trail spacing that was successfully demonstrated in a flight evaluation at Chicago O Hare International Airport in September 2002. In addition to providing for precision inter-arrival spacing, AMSTAR provides speed guidance for aircraft on converging routes to safely and smoothly merge onto a common approach. Much consideration has been given to working with operational conditions such as imperfect ADS-B data, wind prediction errors, changing winds, differing aircraft types and wake vortex separation requirements. A series of Monte Carlo simulations are planned for the spring and summer of 2004 at NASA Langley to further study the system behavior and performance under more operationally extreme and varying conditions. This will coincide with a human-in-the-loop study to investigate the flight crew interface, workload and acceptability.

Benefit Assessment of the Precision Departure Release Capability Concept

NASA Technical Reports Server (NTRS)

Palopo, Kee; Chatterji, Gano B.; Lee, Hak-Tae

2011-01-01

A Precision Departure Release Capability concept is being evaluated by both the National Aeronautics and Space Administration and the Federal Aviation Administration as part of a larger goal of improving throughput, efficiency and capacity in integrated departure, arrival and surface operations. The concept is believed to have the potential of increasing flight efficiency and throughput by avoiding missing assigned slots and minimizing speed increase or path stretch to recover the slot. The main thrust of the paper is determining the impact of early and late departures from the departure runway when an aircraft has a slot assigned either at a meter fix or at the arrival airport. Results reported in the paper are for two scenarios. The first scenario considers flights out of Dallas/Fort Worth destined for Hartsfield-Jackson International Airport in Atlanta flying through the Meridian meter-fix in the Memphis Center with miles-in-trail constraints. The second scenario considers flights destined to George Bush Intercontinental/Houston Airport with specified airport arrival rate constraint. Results show that delay reduction can be achieved by allowing reasonable speed changes in scheduling. It was determined that the traffic volume between Dallas/Fort Worth and Atlanta via the Meridian fix is low and the departures times are spread enough that large departure schedule uncertainty can be tolerated. Flights can depart early or late within 90 minutes without accruing much more delay due to miles-in-trail constraint at the Meridian fix. In the Houston scenario, 808 arrivals from 174 airports were considered. Results show that delay experienced by the 16 Dallas/Fort Worth departures is higher if initial schedules of the remaining 792 flights are kept unaltered while they are rescheduled. Analysis shows that the probability of getting the initially assigned slot back after perturbation and rescheduling decreases with increasing standard deviation of the departure delay distributions. Results show that most Houston arrivals can be expected to be on time based on the assumed zero-mean Normal departure delay distributions achievable by Precision Departure Release Capability. In the current system, airport-departure delay, which is the sum of gate-departure delay and taxi-out delay, is observed at the airports. This delay acts as a bias, which can be reduced by Precision Departure Release Capability.

Proceedings from the 2nd International Symposium on Formation Flying Missions and Technologies

NASA Technical Reports Server (NTRS)

2004-01-01

Topics discussed include: The Stellar Imager (SI) "Vision Mission"; First Formation Flying Demonstration Mission Including on Flight Nulling; Formation Flying X-ray Telescope in L2 Orbit; SPECS: The Kilometer-baseline Far-IR Interferometer in NASA's Space Science Roadmap Presentation; A Tight Formation for Along-track SAR Interferometry; Realization of the Solar Power Satellite using the Formation Flying Solar Reflector; SIMBOL-X : Formation Flying for High-Energy Astrophysics; High Precision Optical Metrology for DARWIN; Close Formation Flight of Micro-Satellites for SAR Interferometry; Station-Keeping Requirements for Astronomical Imaging with Constellations of Free-Flying Collectors; Closed-Loop Control of Formation Flying Satellites; Formation Control for the MAXIM Mission; Precision Formation Keeping at L2 Using the Autonomous Formation Flying Sensor; Robust Control of Multiple Spacecraft Formation Flying; Virtual Rigid Body (VRB) Satellite Formation Control: Stable Mode-Switching and Cross-Coupling; Electromagnetic Formation Flight (EMFF) System Design, Mission Capabilities, and Testbed Development; Navigation Algorithms for Formation Flying Missions; Use of Formation Flying Small Satellites Incorporating OISL's in a Tandem Cluster Mission; Semimajor Axis Estimation Strategies; Relative Attitude Determination of Earth Orbiting Formations Using GPS Receivers; Analysis of Formation Flying in Eccentric Orbits Using Linearized Equations of Relative Motion; Conservative Analytical Collision Probabilities for Orbital Formation Flying; Equations of Motion and Stability of Two Spacecraft in Formation at the Earth/Moon Triangular Libration Points; Formations Near the Libration Points: Design Strategies Using Natural and Non-Natural Ares; An Overview of the Formation and Attitude Control System for the Terrestrial Planet Finder Formation Flying Interferometer; GVE-Based Dynamics and Control for Formation Flying Spacecraft; GNC System Design for a New Concept of X-Ray Distributed Telescope; GNC System for the Deployment and Fine Control of the DARWIN Free-Flying Interferometer; Formation Algorithm and Simulation Testbed; and PLATFORM: A Formation Flying, RvD and Robotic Validation Test-bench.

Wakeshield WSF-02 GPS Experiment

NASA Technical Reports Server (NTRS)

Schutz, B. E.; Abusali, P. A. M.; Schroeder, Christine; Tapley, Byron; Exner, Michael; Mccloskey, rick; Carpenter, Russell; Cooke, Michael; Mcdonald, samantha; Combs, Nick;

Completely optical orientation determination for an unstabilized aerial three-line camera

NASA Astrophysics Data System (ADS)

Wohlfeil, Jürgen

2010-10-01

Aerial line cameras allow the fast acquisition of high-resolution images at low costs. Unfortunately the measurement of the camera's orientation with the necessary rate and precision is related with large effort, unless extensive camera stabilization is used. But also stabilization implicates high costs, weight, and power consumption. This contribution shows that it is possible to completely derive the absolute exterior orientation of an unstabilized line camera from its images and global position measurements. The presented approach is based on previous work on the determination of the relative orientation of subsequent lines using optical information from the remote sensing system. The relative orientation is used to pre-correct the line images, in which homologous points can reliably be determined using the SURF operator. Together with the position measurements these points are used to determine the absolute orientation from the relative orientations via bundle adjustment of a block of overlapping line images. The approach was tested at a flight with the DLR's RGB three-line camera MFC. To evaluate the precision of the resulting orientation the measurements of a high-end navigation system and ground control points are used.

On the Shoulders of Titans: A History of Project Gemini

NASA Technical Reports Server (NTRS)

Hacker, B. C.

1977-01-01

Gemini was the intermediate manned space flight program between America's first steps into space with Mercury and the manned lunar expeditions of Apollo. Because of its position between these two other efforts, Gemini is probably less remembered. Still, it more than had its place in man's progress into this new frontier. Gemini accomplishments were manyfold. They included many firsts: first astronaut-controlled maneuvering in space; first rendezvous in space of one spacecraft with another; first docking of one spacecraft with a propulsive stage and use of that stage to transfer man to high altitude; first traverse of man into the earth's radiation belts; first extended manned flights of a week or more in duration; first extended stays of man outside his spacecraft; first controlled reentry and precision landing; and many more. These achievements were significant in ways one cannot truly evaluate even today, but two things stand out: (1) it was the time when America caught up and surpassed the Soviet Union in manned space flight, and (2) these demonstrations of capability were an absolute prerequisite to the phenomenal Apollo accomplishments then yet to come.

Utility of an airframe referenced spatial auditory display for general aviation operations

NASA Astrophysics Data System (ADS)

Naqvi, M. Hassan; Wigdahl, Alan J.; Ranaudo, Richard J.

2009-05-01

The University of Tennessee Space Institute (UTSI) completed flight testing with an airframe-referenced localized audio cueing display. The purpose was to assess its affect on pilot performance, workload, and situational awareness in two scenarios simulating single-pilot general aviation operations under instrument meteorological conditions. Each scenario consisted of 12 test procedures conducted under simulated instrument meteorological conditions, half with the cue off, and half with the cue on. Simulated aircraft malfunctions were strategically inserted at critical times during each test procedure. Ten pilots participated in the study; half flew a moderate workload scenario consisting of point to point navigation and holding pattern operations and half flew a high workload scenario consisting of non precision approaches and missed approach procedures. Flight data consisted of aircraft and navigation state parameters, NASA Task Load Index (TLX) assessments, and post-flight questionnaires. With localized cues there was slightly better pilot technical performance, a reduction in workload, and a perceived improvement in situational awareness. Results indicate that an airframe-referenced auditory display has utility and pilot acceptance in general aviation operations.

LH2 Tank Composite Coverplate Development and Flight Qualification for the X-33

NASA Technical Reports Server (NTRS)

Wright, Richard J.; Roule, Gerard M.

2000-01-01

In this paper, the development history for the first cryogenic pressurized fuel tank coverplates is presented along with a synopsis of the development strategy and technologies which led to success on this program. Coverplates are the large access panels used to access launch vehicle fuel tanks. These structures incorporate all of the requirements for a pressure vessel as well as the added requirement to mount all of the miscellaneous access points required for a fuel management system. The first composite coverplates to meet the requirements for flight qualification were developed on the X-33 program. The X-33 composite coverplates went from an open requirement to successful finished flight hardware with multiple unique configurations, complete with verification testing, in less than eighteen months. Besides the rapid development schedule, these components introduced several new technologies previously unseen in cryogenic composites including solutions to cryogenic shrinkage, self-supporting sealing surfaces, and highly loaded composite bosses with precision sealing interfaces. These components were proven to seal liquid hydrogen at cryogenic temperatures under maximum loading and pressure conditions.

Adaptive Controller Effects on Pilot Behavior

NASA Technical Reports Server (NTRS)

Trujillo, Anna C.; Gregory, Irene M.; Hempley, Lucas E.

2014-01-01

Adaptive control provides robustness and resilience for highly uncertain, and potentially unpredictable, flight dynamics characteristic. Some of the recent flight experiences of pilot-in-the-loop with an adaptive controller have exhibited unpredicted interactions. In retrospect, this is not surprising once it is realized that there are now two adaptive controllers interacting, the software adaptive control system and the pilot. An experiment was conducted to categorize these interactions on the pilot with an adaptive controller during control surface failures. One of the objectives of this experiment was to determine how the adaptation time of the controller affects pilots. The pitch and roll errors, and stick input increased for increasing adaptation time and during the segment when the adaptive controller was adapting. Not surprisingly, altitude, cross track and angle deviations, and vertical velocity also increase during the failure and then slowly return to pre-failure levels. Subjects may change their behavior even as an adaptive controller is adapting with additional stick inputs. Therefore, the adaptive controller should adapt as fast as possible to minimize flight track errors. This will minimize undesirable interactions between the pilot and the adaptive controller and maintain maneuvering precision.

High Resolution Airborne Digital Imagery for Precision Agriculture

NASA Technical Reports Server (NTRS)

Herwitz, Stanley R.

1998-01-01

The Environmental Research Aircraft and Sensor Technology (ERAST) program is a NASA initiative that seeks to demonstrate the application of cost-effective aircraft and sensor technology to private commercial ventures. In 1997-98, a series of flight-demonstrations and image acquisition efforts were conducted over the Hawaiian Islands using a remotely-piloted solar- powered platform (Pathfinder) and a fixed-wing piloted aircraft (Navajo) equipped with a Kodak DCS450 CIR (color infrared) digital camera. As an ERAST Science Team Member, I defined a set of flight lines over the largest coffee plantation in Hawaii: the Kauai Coffee Company's 4,000 acre Koloa Estate. Past studies have demonstrated the applications of airborne digital imaging to agricultural management. Few studies have examined the usefulness of high resolution airborne multispectral imagery with 10 cm pixel sizes. The Kodak digital camera integrated with ERAST's Airborne Real Time Imaging System (ARTIS) which generated multiband CCD images consisting of 6 x 106 pixel elements. At the designated flight altitude of 1,000 feet over the coffee plantation, pixel size was 10 cm. The study involved the analysis of imagery acquired on 5 March 1998 for the detection of anomalous reflectance values and for the definition of spectral signatures as indicators of tree vigor and treatment effectiveness (e.g., drip irrigation; fertilizer application).

An Inertial Dual-State State Estimator for Precision Planetary Landing with Hazard Detection and Avoidance

NASA Technical Reports Server (NTRS)

Bishop, Robert H.; DeMars, Kyle; Trawny, Nikolas; Crain, Tim; Hanak, Chad; Carson, John M.; Christian, John

2016-01-01

The navigation filter architecture successfully deployed on the Morpheus flight vehicle is presented. The filter was developed as a key element of the NASA Autonomous Landing and Hazard Avoidance Technology (ALHAT) project and over the course of 15 free fights was integrated into the Morpheus vehicle, operations, and flight control loop. Flight testing completed by demonstrating autonomous hazard detection and avoidance, integration of an altimeter, surface relative velocity (velocimeter) and hazard relative navigation (HRN) measurements into the onboard dual-state inertial estimator Kalman flter software, and landing within 2 meters of the vertical testbed GPS-based navigation solution at the safe landing site target. Morpheus followed a trajectory that included an ascent phase followed by a partial descent-to-landing, although the proposed filter architecture is applicable to more general planetary precision entry, descent, and landings. The main new contribution is the incorporation of a sophisticated hazard relative navigation sensor-originally intended to locate safe landing sites-into the navigation system and employed as a navigation sensor. The formulation of a dual-state inertial extended Kalman filter was designed to address the precision planetary landing problem when viewed as a rendezvous problem with an intended landing site. For the required precision navigation system that is capable of navigating along a descent-to-landing trajectory to a precise landing, the impact of attitude errors on the translational state estimation are included in a fully integrated navigation structure in which translation state estimation is combined with attitude state estimation. The map tie errors are estimated as part of the process, thereby creating a dual-state filter implementation. Also, the filter is implemented using inertial states rather than states relative to the target. External measurements include altimeter, velocimeter, star camera, terrain relative navigation sensor, and a hazard relative navigation sensor providing information regarding hazards on a map generated on-the-fly.

The MAGSAT vector magnetometer: A precision fluxgate magnetometer for the measurement of the geomagnetic field

NASA Technical Reports Server (NTRS)

Acuna, M. H.; Scearce, C. S.; Seek, J.; Scheifele, J.

1978-01-01

A description of the precision triaxial fluxgate magnetometer to be flown aboard the MAGSAT spacecraft is presented. The instrument covers the range of + or - 64,000 nT with a resolution of + or - 0.5 nT, an intrinsic accuracy of + or - 0.001% of full scale and an angular alignment stability of the order of 2 seconds of arc. It was developed at NASA's Goddard Space Flight Center and represents the state-of-the-art in precision vector magnetometers developed for spaceflight use.

Helicopter precision approach capability using the Global Positioning System

NASA Technical Reports Server (NTRS)

Kaufmann, David N.

1992-01-01

The period between 1 July and 31 December, 1992, was spent developing a research plan as well as a navigation system document and flight test plan to investigate helicopter precision approach capability using the Global Positioning System (GPS). In addition, all hardware and software required for the research was acquired, developed, installed, and verified on both the test aircraft and the ground-based reference station.

The role of national regulations in RPAS-based mapping projects in the monitoring of natural hazards that could involve infrastructures: the example of the Val Venosta Railway (Northern Italy - Bolzano).

NASA Astrophysics Data System (ADS)

Gandolfo, Luca; Busnardo, Enrico; Castellarin, Nicola; Canella, Claudio; Canella, Federico; Stabile, Marco; Curci, Francesco; Petrillo, Giovanni

2016-04-01

Italy has adopted National Regulations for the use of RPAS in its country's airspace in December 2013, issued by the Italian Civil Aviation Authority (ENAC). Despite the issued regulations, over the past months an increasing number of unauthorized and unsafe operations have been performed and the attention to safety is growing quickly in the public opinion. For this reason "Critical Operations" is permitted only to those RPAS Operators which have received special authorization by ENAC after a very demanding Aeronautical procedure. According to the Regulations, the flight close to-over urban areas, industrial plants, highways and railways, implies that only authorized RPAS Operators may perform such activities. An example of a "Critical" operation were the RPAS flights performed along the Venosta railway line to evaluate the current situation of two areas affected by geological instability and laid the basis for a future high accurate monitoring. The Venosta Valley is located in the western part of South Tyrol (Norhtern Italy). The valley possesses some unique features compared to the entire Alps, the particularly dry climate and the presence of huge alluvional fans, which give rise to different levels of altitude in the valley. From geological point of view, the Venosta Valley is characterized by the presence of the Austroalpine domain. In particular, there are two different geological units in this area: (i) the crystalline schists of the basement, which includes paragneiss, gneiss, granitoid pegmatites, garnet micaschists, quartzites and phyllites. (ii) The Mesozoic coverage divided into various complexes with successions of phyllites, volcanics and magmatiti. The railway line that runs through the Venosta Valley (Merano - Malles) unfolds along a path of 59,8 kilometers and covers an altitude difference of about 700 meters. In particular, three tunnels characterized the first section, including the M. Giuseppe tunnel, which required extensive consolidations both inside and outside. The mission's scope was to achieve high precision photogrammetry data to reconstruct sub-centimetric 3D models of the retaining wall and the unstable rock mass. Flights have been performed with two different RPAS, a multicopter and an helicopter, controlled by a crew composed by three members: two pilots (Command and Backup Pilot) operating redundant data links for flight control and a payload operator and Aeronautical Flight procedures have been applied. The payload operated the camera to achieve the best images for the data acquisition and 3D model reconstruction. The flights have been conducted with manual piloting flight procedures because of the RPAS on board GPS is significantly affected by the mountain slope proximity. For this reason, for the georeferencing procedure, ground control points have been acquired by using an high precision GPS. Finally, using RPAS data it has been possible to assess the lateral earth pressure on the retaining wall of the railway embankment, while in the second case the aim was to accurately reconstruct the volumes of an unstable rock mass.

3D flash lidar performance in flight testing on the Morpheus autonomous, rocket-propelled lander to a lunar-like hazard field

NASA Astrophysics Data System (ADS)

Roback, Vincent E.; Amzajerdian, Farzin; Bulyshev, Alexander E.; Brewster, Paul F.; Barnes, Bruce W.

2016-05-01

For the first time, a 3-D imaging Flash Lidar instrument has been used in flight to scan a lunar-like hazard field, build a 3-D Digital Elevation Map (DEM), identify a safe landing site, and, in concert with an experimental Guidance, Navigation, and Control system, help to guide the Morpheus autonomous, rocket-propelled, free-flying lander to that safe site on the hazard field. The flight tests served as the TRL 6 demo of the Autonomous Precision Landing and Hazard Detection and Avoidance Technology (ALHAT) system and included launch from NASA-Kennedy, a lunar-like descent trajectory from an altitude of 250m, and landing on a lunar-like hazard field of rocks, craters, hazardous slopes, and safe sites 400m down-range. The ALHAT project developed a system capable of enabling safe, precise crewed or robotic landings in challenging terrain on planetary bodies under any ambient lighting conditions. The Flash Lidar is a second generation, compact, real-time, air-cooled instrument. Based upon extensive on-ground characterization at flight ranges, the Flash Lidar was shown to be capable of imaging hazards from a slant range of 1 km with an 8 cm range precision and a range accuracy better than 35 cm, both at 1-σ. The Flash Lidar identified landing hazards as small as 30 cm from the maximum slant range which Morpheus could achieve (450 m); however, under certain wind conditions it was susceptible to scintillation arising from air heated by the rocket engine and to pre-triggering on a dust cloud created during launch and transported down-range by wind.

Fully automatic and precise data analysis developed for time-of-flight mass spectrometry.

PubMed

Meyer, Stefan; Riedo, Andreas; Neuland, Maike B; Tulej, Marek; Wurz, Peter

2017-09-01

Scientific objectives of current and future space missions are focused on the investigation of the origin and evolution of the solar system with the particular emphasis on habitability and signatures of past and present life. For in situ measurements of the chemical composition of solid samples on planetary surfaces, the neutral atmospheric gas and the thermal plasma of planetary atmospheres, the application of mass spectrometers making use of time-of-flight mass analysers is a technique widely used. However, such investigations imply measurements with good statistics and, thus, a large amount of data to be analysed. Therefore, faster and especially robust automated data analysis with enhanced accuracy is required. In this contribution, an automatic data analysis software, which allows fast and precise quantitative data analysis of time-of-flight mass spectrometric data, is presented and discussed in detail. A crucial part of this software is a robust and fast peak finding algorithm with a consecutive numerical integration method allowing precise data analysis. We tested our analysis software with data from different time-of-flight mass spectrometers and different measurement campaigns thereof. The quantitative analysis of isotopes, using automatic data analysis, yields results with an accuracy of isotope ratios up to 100 ppm for a signal-to-noise ratio (SNR) of 10 4 . We show that the accuracy of isotope ratios is in fact proportional to SNR -1 . Furthermore, we observe that the accuracy of isotope ratios is inversely proportional to the mass resolution. Additionally, we show that the accuracy of isotope ratios is depending on the sample width T s by T s 0.5 . Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

3-D Flash Lidar Performance in Flight Testing on the Morpheus Autonomous, Rocket-Propelled Lander to a Lunar-Like Hazard Field

NASA Technical Reports Server (NTRS)

Roback, Vincent E.; Amzajerdian, Farzin; Bulyshev, Alexander E.; Brewster, Paul F.; Barnes, Bruce W.

2016-01-01

For the first time, a 3-D imaging Flash Lidar instrument has been used in flight to scan a lunar-like hazard field, build a 3-D Digital Elevation Map (DEM), identify a safe landing site, and, in concert with an experimental Guidance, Navigation, and Control (GN&C) system, help to guide the Morpheus autonomous, rocket-propelled, free-flying lander to that safe site on the hazard field. The flight tests served as the TRL 6 demo of the Autonomous Precision Landing and Hazard Detection and Avoidance Technology (ALHAT) system and included launch from NASA-Kennedy, a lunar-like descent trajectory from an altitude of 250m, and landing on a lunar-like hazard field of rocks, craters, hazardous slopes, and safe sites 400m down-range. The ALHAT project developed a system capable of enabling safe, precise crewed or robotic landings in challenging terrain on planetary bodies under any ambient lighting conditions. The Flash Lidar is a second generation, compact, real-time, air-cooled instrument. Based upon extensive on-ground characterization at flight ranges, the Flash Lidar was shown to be capable of imaging hazards from a slant range of 1 km with an 8 cm range precision and a range accuracy better than 35 cm, both at 1-delta. The Flash Lidar identified landing hazards as small as 30 cm from the maximum slant range which Morpheus could achieve (450 m); however, under certain wind conditions it was susceptible to scintillation arising from air heated by the rocket engine and to pre-triggering on a dust cloud created during launch and transported down-range by wind.

MoonBEAM: Gamma-Ray Burst Detectors on SmallSAT

NASA Technical Reports Server (NTRS)

Hui, C. M.; Briggs, M. S.; Goldstein, A. M.; Jenke, P. A.; Kocevski, D.; Wilson-Hodge, C. A.

2018-01-01

Moon Burst Energetics All-sky Monitor (MoonBEAM) is a CubeSat concept of deploying gamma-ray detectors in cislunar space to improve localization precision for gamma-ray bursts by utilizing the light travel time difference between a spacecraft in Earth and cislunar orbit. MoonBEAM is designed with high TRL components to be flight ready. This instrument would probe the extreme processes in cosmic collision of compact objects and facilitate multi-messenger time-domain astronomy to explore the end of stellar life cycles and black hole formations.

A summary of wind tunnel research on tilt rotors from hover to cruise flight

NASA Technical Reports Server (NTRS)

Poisson-Quinton, PH.; Cook, W. L.

1972-01-01

An experimental research program has been conducted on a series of tilt rotors designed for a range of blade twist in various wind tunnel facilities. The objective was to obtain precise results on the influence of blade twist and aeroelasticity on tilt rotor performance, from hover to high speed cruise Mach number of about 0.7. global forces on the rotor, local loads and blade torsional deflection measurements were compared with theoretical predictions inside a large Reynolds-Mach envelope. Testing techniques developed during the program are described.

Sensor fault diagnosis of aero-engine based on divided flight status.

PubMed

Zhao, Zhen; Zhang, Jun; Sun, Yigang; Liu, Zhexu

2017-11-01

Fault diagnosis and safety analysis of an aero-engine have attracted more and more attention in modern society, whose safety directly affects the flight safety of an aircraft. In this paper, the problem concerning sensor fault diagnosis is investigated for an aero-engine during the whole flight process. Considering that the aero-engine is always working in different status through the whole flight process, a flight status division-based sensor fault diagnosis method is presented to improve fault diagnosis precision for the aero-engine. First, aero-engine status is partitioned according to normal sensor data during the whole flight process through the clustering algorithm. Based on that, a diagnosis model is built for each status using the principal component analysis algorithm. Finally, the sensors are monitored using the built diagnosis models by identifying the aero-engine status. The simulation result illustrates the effectiveness of the proposed method.

Sensor fault diagnosis of aero-engine based on divided flight status

NASA Astrophysics Data System (ADS)

Zhao, Zhen; Zhang, Jun; Sun, Yigang; Liu, Zhexu

2017-11-01

Fault diagnosis and safety analysis of an aero-engine have attracted more and more attention in modern society, whose safety directly affects the flight safety of an aircraft. In this paper, the problem concerning sensor fault diagnosis is investigated for an aero-engine during the whole flight process. Considering that the aero-engine is always working in different status through the whole flight process, a flight status division-based sensor fault diagnosis method is presented to improve fault diagnosis precision for the aero-engine. First, aero-engine status is partitioned according to normal sensor data during the whole flight process through the clustering algorithm. Based on that, a diagnosis model is built for each status using the principal component analysis algorithm. Finally, the sensors are monitored using the built diagnosis models by identifying the aero-engine status. The simulation result illustrates the effectiveness of the proposed method.

Differential GPS for air transport: Status

NASA Technical Reports Server (NTRS)

Hueschen, Richard M.

1993-01-01

The presentation presents background on what the Global Navigation Satellite System (GNSS) is, desired target dates for initial GNSS capabilities for aircraft operations, and a description of differential GPS (Global Positioning System). The presentation also presents an overview of joint flight tests conducted by LaRC and Honeywell on an integrated differential GPS/inertial reference unit (IRU) navigation system. The overview describes the system tested and the results of the flight tests. The last item presented is an overview of a current grant with Ohio University from LaRC which has the goal of developing a precision DGPS navigation system based on interferometry techniques. The fundamentals of GPS interferometry are presented and its application to determine attitude and heading and precision positioning are shown. The presentation concludes with the current status of the grant.

In flight image processing on multi-rotor aircraft for autonomous landing

NASA Astrophysics Data System (ADS)

Henry, Richard, Jr.

An estimated $6.4 billion was spent during the year 2013 on developing drone technology around the world and is expected to double in the next decade. However, drone applications typically require strong pilot skills, safety, responsibilities and adherence to regulations during flight. If the flight control process could be safer and more reliable in terms of landing, it would be possible to further develop a wider range of applications. The objective of this research effort is to describe the design and evaluation of a fully autonomous Unmanned Aerial system (UAS), specifically a four rotor aircraft, commonly known as quad copter for precise landing applications. The full landing autonomy is achieved by image processing capabilities during flight for target recognition by employing the open source library OpenCV. In addition, all imaging data is processed by a single embedded computer that estimates a relative position with respect to the target landing pad. Results shows a reduction on the average offset error by 67.88% in comparison to the current return to lunch (RTL) method which only relies on GPS positioning. The present work validates the need for relying on image processing for precise landing applications instead of the inexact method of a commercial low cost GPS dependency.

Determination of enantiomeric vigabatrin by derivatization with diacetyl-l-tartaric anhydride followed by ultra-high performance liquid chromatography-quadrupole-time-of-flight mass spectrometry.

PubMed

Zhao, Jing; Shin, Yujin; Jin, Yan; Jeong, Kyung Min; Lee, Jeongmi

2017-01-01

Vigabatrin, one of the most widely used antiepileptic drugs, is marketed and administered as a racemic mixture, while only S-enantiomer is therapeutically effective. In the present study, diacetyl-l-tartaric acid anhydride was used as an inexpensive and effective chiral derivatization reagent to produce tartaric acid monoester derivatives of vigabatrin enantiomers that could be readily resolved by reversed phase chromatography. Derivatization conditions were statistically optimized by response surface methodology, resulting in an optimal reaction temperature of 44°C and an optimal reaction time of 30min. The derivatized diastereomers of vigabatrin and internal standard (gabapentin) were analyzed using ultra-high performance liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry. For this analysis, an Agilent ZORBAX Rapid Resolution High Definition Eclipse Plus C18 column (100mm×2.1mm, 1.8μm) was employed for chromatographic separation using 10mM ammonium formate (pH 3.0) and methanol as mobile phase at a flow rate of 0.2mLmin -1 . The established method was validated in terms of specificity, linearity, precision, accuracy, dilution integrity, recovery, matrix effect, stability, and incurred sample reanalysis. It was linear over a range of 0.25-100.0mgL -1 for both S- and R-enantiomers (R 2 ≥0.9987 for both). Intra- and inter-day precisions and accuracies were within acceptable ranges. The method was successfully applied to determine the levels of vigabatrin enantiomers in mouse serum after administration of vigabatrin racemate. Copyright © 2016 Elsevier B.V. All rights reserved.

Apollo 16 photographic standards documentation

NASA Technical Reports Server (NTRS)

Bourque, P. F.

1972-01-01

The activities of the Photographic Technology Division, and particularly the Photo Science Office, the Precision Processing Laboratory, and the Motion Picture Laboratory, in connection with the scientific photography of the Apollo 16 manned space mission are documented. Described are the preflight activities involved in establishing a standard process for each of the flight films, the manned in which flight films were handled upon arrival at the Manned Spacecraft Center in Houston, Texas, and how the flight films were processed and duplicated. The tone reproduction method of duplication is described. The specific sensitometric and chemical process controls are not included.

Initial Results of Instrument-Flying Trials Conducted In A Single-Rotor Helicopter

NASA Technical Reports Server (NTRS)

Crim, Almer D; Reeder, John P; Whitten, James B

1953-01-01

Instrument-flying trials have been conducted in a single-rotor helicopter, the maneuver stability of which could be changed from satisfactory to unsatisfactory. The results indicated that existing longitudinal flying-qualities requirements based on contact flight were adequate for instrument flight at speeds above that for minimum power. However, lateral-directional problems were encountered at low speeds and during precision maneuvers. The adequacy, for helicopter use, of standard airplane instruments was also investigated, and the conclusion was reached that special instruments would be desirable under all conditions, and necessary for sustained low-speed instrument flight.

Identification and quantification of flavonoids and chromes in Baeckea frutescens by using HPLC coupled with diode-array detection and quadruple time-of-flight mass spectrometry.

PubMed

Jia, Bei-Xi; Huangfu, Qian-Qian; Ren, Feng-Xiao; Jia, Lu; Zhang, Yan-Bing; Liu, Hong-Min; Yang, Jie; Wang, Qiang

2015-01-01

This article marks the first report on high-performance liquid chromatography (HPLC) coupled with diode-array detection (DAD) and quadruple time-of-flight mass spectrometry (Q-TOF/MS) for the identification and quantification of main bioactive constituents in Baeckea frutescens. In total, 24 compounds were identified or tentatively characterised based on their retention behaviours, UV profiles and MS fragment information. Furthermore, a validated method with good linearity, sensitivity, precision, stability, repeatability and accuracy was successfully applied for simultaneous determination of five flavonoids and one chromone in different plant parts of B. frutescens collected at different harvest times, and their dynamic contents revealed the appropriate harvest times. The established HPLC-DAD-Q-TOF/MS using multi-bioactive markers was proved to be a validated strategy for the quality evaluation on both raw materials and related products of B. frutescens.

Orbit control of a stratospheric satellite with parameter uncertainties

NASA Astrophysics Data System (ADS)

Xu, Ming; Huo, Wei

2016-12-01

When a stratospheric satellite travels by prevailing winds in the stratosphere, its cross-track displacement needs to be controlled to keep a constant latitude orbital flight. To design the orbit control system, a 6 degree-of-freedom (DOF) model of the satellite is established based on the second Lagrangian formulation, it is proven that the input/output feedback linearization theory cannot be directly implemented for the orbit control with this model, thus three subsystem models are deduced from the 6-DOF model to develop a sequential nonlinear control strategy. The control strategy includes an adaptive controller for the balloon-tether subsystem with uncertain balloon parameters, a PD controller based on feedback linearization for the tether-sail subsystem, and a sliding mode controller for the sail-rudder subsystem with uncertain sail parameters. Simulation studies demonstrate that the proposed control strategy is robust to uncertainties and satisfies high precision requirements for the orbit flight of the satellite.

Design of Cherenkov bars for the optical part of the time-of-flight detector in Geant4.

PubMed

Nozka, L; Brandt, A; Rijssenbeek, M; Sykora, T; Hoffman, T; Griffiths, J; Steffens, J; Hamal, P; Chytka, L; Hrabovsky, M

2014-11-17

We present the results of studies devoted to the development and optimization of the optical part of a high precision time-of-flight (TOF) detector for the Large Hadron Collider (LHC). This work was motivated by a proposal to use such a detector in conjunction with a silicon detector to tag and measure protons from interactions of the type p + p → p + X + p, where the two outgoing protons are scattered in the very forward directions. The fast timing detector uses fused silica (quartz) bars that emit Cherenkov radiation as a relativistic particle passes through and the emitted Cherenkov photons are detected by, for instance, a micro-channel plate multi-anode Photomultiplier Tube (MCP-PMT). Several possible designs are implemented in Geant4 and studied for timing optimization as a function of the arrival time, and the number of Cherenkov photons reaching the photo-sensor.

Advanced Chemical Propulsion for Science Missions

NASA Technical Reports Server (NTRS)

Liou, Larry

2008-01-01

The advanced chemical propulsion technology area of NASA's In-Space Technology Project is investing in systems and components for increased performance and reduced cost of chemical propulsion technologies applicable to near-term science missions. Presently the primary investment in the advanced chemical propulsion technology area is in the AMBR high temperature storable bipropellant rocket engine. Scheduled to be available for flight development starting in year 2008, AMBR engine shows a 60 kg payload gain in an analysis for the Titan-Enceladus orbiter mission and a 33 percent manufacturing cost reduction over its baseline, state-of-the-art counterpart. Other technologies invested include the reliable lightweight tanks for propellant and the precision propellant management and mixture ratio control. Both technologies show significant mission benefit, can be applied to any liquid propulsion system, and upon completion of the efforts described in this paper, are at least in parts ready for flight infusion. Details of the technologies are discussed.

Design, fabrication and delivery of a prototype saturator for ACPL

NASA Technical Reports Server (NTRS)

Keyser, G.; Rogers, C. F.; Squires, P.

1979-01-01

The design configuration and performance characteristics of a saturator developed to provide ground-based simulation for some of the experiments for ACPL-1 first flights of Spacelab are described, some difficulties encountered with the apparatus are discussed, and recommendations concerning testing of this type of instrument are presented. The saturators provide a means of accurately fixing the water vapor mixing ratio of an aerosol sample. Dew point temperatures from almost freezing to ambient room temperatures can be attained with high precision. The instruments can accommodate aerosol flow rates approaching 1000 cc/s. Provisions were made to inject aerosols upstream of these saturators, although downstream injection can be accomplished as well. A device of this type will be used in the ACPL-1 to condition various aerosols delivered concurrently to a CFD, expansion chamber, and static diffusion chamber used in zero gravity cloud-forming experiments. The saturator was designed to meet the requirements projected for the flight instrument.

Lidar Sensors for Autonomous Landing and Hazard Avoidance

NASA Technical Reports Server (NTRS)

Amzajerdian, Farzin; Petway, Larry B.; Hines, Glenn D.; Roback, Vincent E.; Reisse, Robert A.; Pierrottet, Diego F.

2013-01-01

Lidar technology will play an important role in enabling highly ambitious missions being envisioned for exploration of solar system bodies. Currently, NASA is developing a set of advanced lidar sensors, under the Autonomous Landing and Hazard Avoidance (ALHAT) project, aimed at safe landing of robotic and manned vehicles at designated sites with a high degree of precision. These lidar sensors are an Imaging Flash Lidar capable of generating high resolution three-dimensional elevation maps of the terrain, a Doppler Lidar for providing precision vehicle velocity and altitude, and a Laser Altimeter for measuring distance to the ground and ground contours from high altitudes. The capabilities of these lidar sensors have been demonstrated through four helicopter and one fixed-wing aircraft flight test campaigns conducted from 2008 through 2012 during different phases of their development. Recently, prototype versions of these landing lidars have been completed for integration into a rocket-powered terrestrial free-flyer vehicle (Morpheus) being built by NASA Johnson Space Center. Operating in closed-loop with other ALHAT avionics, the viability of the lidars for future landing missions will be demonstrated. This paper describes the ALHAT lidar sensors and assesses their capabilities and impacts on future landing missions.

Flight evaluation of a computer aided low-altitude helicopter flight guidance system

NASA Technical Reports Server (NTRS)

Swenson, Harry N.; Jones, Raymond D.; Clark, Raymond

1993-01-01

The Flight Systems Development branch of the U.S. Army's Avionics Research and Development Activity (AVRADA) and NASA Ames Research Center developed for flight testing a Computer Aided Low-Altitude Helicopter Flight (CALAHF) guidance system. The system includes a trajectory-generation algorithm which uses dynamic programming and a helmet-mounted display (HMD) presentation of a pathway-in-the-sky, a phantom aircraft, and flight-path vector/predictor guidance symbology. The trajectory-generation algorithm uses knowledge of the global mission requirements, a digital terrain map, aircraft performance capabilities, and precision navigation information to determine a trajectory between mission waypoints that seeks valleys to minimize threat exposure. This system was developed and evaluated through extensive use of piloted simulation and has demonstrated a 'pilot centered' concept of automated and integrated navigation and terrain mission planning flight guidance. This system has shown a significant improvement in pilot situational awareness, and mission effectiveness as well as a decrease in training and proficiency time required for a near terrain, nighttime, adverse weather system.

Atom Interferometer Technologies in Space for Gravity Mapping and Gravity Science

NASA Astrophysics Data System (ADS)

Williams, Jason; Chiow, Sheng-Wey; Kellogg, James; Kohel, James; Yu, Nan

2015-05-01

Atom interferometers utilize the wave-nature of atomic gases for precision measurements of inertial forces, with potential applications ranging from gravity mapping for planetary science to unprecedented tests of fundamental physics with quantum gases. The high stability and sensitivity intrinsic to these devices already place them among the best terrestrial sensors available for measurements of gravitational accelerations, rotations, and gravity gradients, with the promise of several orders of magnitude improvement in their detection sensitivity in microgravity. Consequently, multiple precision atom-interferometer-based projects are under development at the Jet Propulsion Laboratory, including a dual-atomic-species interferometer that is to be integrated into the Cold Atom Laboratory onboard the International Space Station and a highly stable gravity gradiometer in a transportable design relevant for earth science measurements. We will present JPL's activities in the use of precision atom interferometry for gravity mapping and gravitational wave detection in space. Our recent progresses bringing the transportable JPL atom interferometer instrument to be competitive with the state of the art and simulations of the expected capabilities of a proposed flight project will also be discussed. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

A Solar Aspect System for the HEROES Mission

NASA Technical Reports Server (NTRS)

Christe, Steven; Shih, Albert; Rodriguez, Marcello; Gregory, Kyle; Cramer, Alexander; Edgerton, Melissa; Gaskin, Jessica; O'Connor, Brian; Sobey, Alexander

2014-01-01

A new Solar Aspect System (SAS) has been developed to provide the ability to observe the Sun on an existing balloon payload HERO (short for High Energy Replicated Optics). Developed under the HEROES program (High Energy Replicated Optics to Explore the Sun), the SAS aspect system provides solar pointing knowledge in pitch, yaw, and roll. The required precision of these measurements must be better than the HEROES X-ray resolution of approximately 20 arcsec Full Width at Half Maximum (FWHM) so as to not degrade the image resolution. The SAS consists of two separate systems: the Pitch-Yaw Aspect System (PYAS) and the Roll Aspect System (RAS). The PYAS functions by projecting an image of the Sun onto a screen with precision fiducials. A CCD camera takes an image of these fiducials, and an automated algorithm determines the location of the Sun as well as the location of the fiducials. The spacing between fiducials is unique and allows each to be identified so that the location of the Sun on the screen can be precisely determined. The RAS functions by imaging the Earth's horizon in opposite directions using a silvered prism imaged by a CCD camera. The design and first results of the performance of these systems during the HEROES flight which occurred in September 2013 are presented here.

Terrain changes from images acquired on opportunistic flights by SfM photogrammetry

NASA Astrophysics Data System (ADS)

Girod, Luc; Nuth, Christopher; Kääb, Andreas; Etzelmüller, Bernd; Kohler, Jack

2017-03-01

Acquiring data to analyse change in topography is often a costly endeavour requiring either extensive, potentially risky, fieldwork and/or expensive equipment or commercial data. Bringing the cost down while keeping the precision and accuracy has been a focus in geoscience in recent years. Structure from motion (SfM) photogrammetric techniques are emerging as powerful tools for surveying, with modern algorithm and large computing power allowing for the production of accurate and detailed data from low-cost, informal surveys. The high spatial and temporal resolution permits the monitoring of geomorphological features undergoing relatively rapid change, such as glaciers, moraines, or landslides. We present a method that takes advantage of light-transport flights conducting other missions to opportunistically collect imagery for geomorphological analysis. We test and validate an approach in which we attach a consumer-grade camera and a simple code-based Global Navigation Satellite System (GNSS) receiver to a helicopter to collect data when the flight path covers an area of interest. Our method is based and builds upon Welty et al. (2013), showing the ability to link GNSS data to images without a complex physical or electronic link, even with imprecise camera clocks and irregular time lapses. As a proof of concept, we conducted two test surveys, in September 2014 and 2015, over the glacier Midtre Lovénbreen and its forefield, in northwestern Svalbard. We were able to derive elevation change estimates comparable to in situ mass balance stake measurements. The accuracy and precision of our DEMs allow detection and analysis of a number of processes in the proglacial area, including the presence of thermokarst and the evolution of water channels.

Uncertainty in LiDAR derived Canopy Height Models in three unique forest ecosystems

NASA Astrophysics Data System (ADS)

Goulden, T.; Leisso, N.; Scholl, V.; Hass, B.

2016-12-01

The National Ecological Observatory Network (NEON) is a continental-scale ecological observation platform designed to collect and disseminate data that contributes to understanding and forecasting the impacts of climate change, land use change, and invasive species on ecology. NEON will collect in-situ and airborne data over 81 sites across the US, including Alaska, Hawaii, and Puerto Rico. The Airborne Observation Platform (AOP) group within the NEON project operates a payload suite that includes a waveform / discrete LiDAR, imaging spectrometer (NIS) and high resolution RGB camera. One of the products derived from the discrete LiDAR is a canopy height model (CHM) raster developed at 1 m spatial resolution. Currently, it is hypothesized that differencing annually acquired CHM products allows identification of tree growth at in-situ distributed plots throughout the NEON sites. To test this hypothesis, the precision of the CHM product was determined through a specialized flight plan that independently repeated up to 20 observations of the same area with varying view geometries. The flight plan was acquired at three NEON sites, each with a unique forest types including 1) San Joaquin Experimental Range (SJER, open woodland dominated by oaks), 2) Soaproot Saddle (SOAP, mixed conifer deciduous forest), and 3) Oak Ridge National Laboratory (ORNL, oak hickory and pine forest). A CHM was developed for each flight line at each site and the overlap area was used to empirically estimate a site-specific precision of the CHM. The average cell-by-cell CHM precision at SJER, SOAP and ORNL was 1.34 m, 4.24 m and 0.72 m respectively. Given the average growth rate of the dominant species at each site and the average CHM uncertainty, the minimum time interval required between LiDAR acquisitions to confidently conclude growth had occurred at the plot scale was estimated to be between one and four years. The minimum interval time was shown to be primarily dependent on the CHM uncertainty and number of cells within a plot which contained vegetation. This indicates that users of NEON data should not expect that changes in canopy height can be confidently identified between annual AOP acquisitions for all areas of NEON sites.

Hardware-In-The-Loop Testing of Continuous Control Algorithms for a Precision Formation Flying Demonstration Mission

NASA Technical Reports Server (NTRS)

Naasz, Bo J.; Burns, Richard D.; Gaylor, David; Higinbotham, John

2004-01-01

A sample mission sequence is defined for a low earth orbit demonstration of Precision Formation Flying (PFF). Various guidance navigation and control strategies are discussed for use in the PFF experiment phases. A sample PFF experiment is implemented and tested in a realistic Hardware-in-the-Loop (HWIL) simulation using the Formation Flying Test Bed (FFTB) at NASA's Goddard Space Flight Center.

Analysis of generic reentry vehicle flight dynamics

NASA Astrophysics Data System (ADS)

Metsker, Yu.; Weinand, K.; Geulen, G.; Haidn, O. J.

2018-06-01

The knowledge of reentry vehicles (RV) flight characteristics regarding geometrical shape, dimensions, and mechanical properties is essential for precise prediction of their flight trajectory, impact point, and possible deviations according to simulation uncertainties. The flight characteristic estimations of existing RV require both body dimensions and mechanical properties of the objects. Due to comparatively simple and reliable methods of specifying the vehicle outer dimensions, e. g., photos and videomaterials, the estimation of mechanical properties is a subject of higher uncertainties. Within this study, a generic medium range ballistic missile (MRBM) RV was examined for several modifications such as center of gravity (CoG) position, weight moment of inertia, and initial reentry flight states. Combinations of these variables with constant aerodynamic properties for maximal lateral accelerations will be determined. Basing on these, potential evasion maneuver capabilities of the RV will be described.

The main changes in plant exposured during space flight missions and prospectives of biological studies on ISS

NASA Astrophysics Data System (ADS)

Nechitailo, Galina S.; Kuznetsov, Anatoli

The fundamental result of biological investigations with plants in space flight is an experimen-tal evidence of vegetative growth from seeds to harvest, with passing of all those stages of development when the plant can be used for food. The changes of plant observed after space flight mission gives a knowledge, which has to be used for precise selection of the plants for future space missions. The experimental investigation of the plants under space flight condi-tions showed that the germinations ability, rate of growth and biometric parameters decrease in comparison with Earth plants. The first two of these factors can be caused by the influence of specific cultivation in space, but the third factor is caused by the influence of space flight conditions, in particular, microgravity. The investigations of germination, plants deaths at var-ious stages of growth, survival probability, and recessive mutations indicated an impairment of genetic apparatus of meristem cells, which results the lethal effect at various stages of develop-ment. The density of paramagnetic centers in seeds was measured in order to determine the free radical concentration under space flight conditions. The concentration of paramagnetic centers is higher for plants with high density of these centers initially. Perhaps, the observed genetic effects in plants under space flight conditions are connected with free radicals. The changes are observed in cells of the plants. The changes included twist, contraction and deformation of the cell walls, curvature and loose arrangement of lamellae in chloroplasts, break of outer membrane of mitochondria and disappearance of mitochondria cristae. A large number of stach grains is observed in chloroplasts. The seeds of various plants were successfully used in space flights: welsh onion, wheat, peas, maize, barley, tomatoes, etc. Mostly stabe plants to space flight factors are found as peas, wheat and tomatoes. Ten generation of wheat and tomatoues exposed in space flights were grown on Earth after flight. The investigation of these plants is used for recommendations of next space flight missions on ISS including new sorts of plants.

How Lovebirds Maneuver Rapidly Using Super-Fast Head Saccades and Image Feature Stabilization

PubMed Central

Kress, Daniel; van Bokhorst, Evelien; Lentink, David

2015-01-01

Diurnal flying animals such as birds depend primarily on vision to coordinate their flight path during goal-directed flight tasks. To extract the spatial structure of the surrounding environment, birds are thought to use retinal image motion (optical flow) that is primarily induced by motion of their head. It is unclear what gaze behaviors birds perform to support visuomotor control during rapid maneuvering flight in which they continuously switch between flight modes. To analyze this, we measured the gaze behavior of rapidly turning lovebirds in a goal-directed task: take-off and fly away from a perch, turn on a dime, and fly back and land on the same perch. High-speed flight recordings revealed that rapidly turning lovebirds perform a remarkable stereotypical gaze behavior with peak saccadic head turns up to 2700 degrees per second, as fast as insects, enabled by fast neck muscles. In between saccades, gaze orientation is held constant. By comparing saccade and wingbeat phase, we find that these super-fast saccades are coordinated with the downstroke when the lateral visual field is occluded by the wings. Lovebirds thus maximize visual perception by overlying behaviors that impair vision, which helps coordinate maneuvers. Before the turn, lovebirds keep a high contrast edge in their visual midline. Similarly, before landing, the lovebirds stabilize the center of the perch in their visual midline. The perch on which the birds land swings, like a branch in the wind, and we find that retinal size of the perch is the most parsimonious visual cue to initiate landing. Our observations show that rapidly maneuvering birds use precisely timed stereotypic gaze behaviors consisting of rapid head turns and frontal feature stabilization, which facilitates optical flow based flight control. Similar gaze behaviors have been reported for visually navigating humans. This finding can inspire more effective vision-based autopilots for drones. PMID:26107413

Pre-Flight Testing of Spaceborne GPS Receivers using a GPS Constellation Simulator

NASA Technical Reports Server (NTRS)

Kizhner, Semion; Davis, Edward; Alonso, R.

1999-01-01

The NASA Goddard Space Flight Center (GSFC) Global Positioning System (GPS) applications test facility has been established within the GSFC Guidance Navigation and Control Center. The GPS test facility is currently housing the Global Simulation Systems Inc. (GSSI) STR2760 GPS satellite 40-channel attitude simulator and a STR4760 12-channel navigation simulator. The facility also contains a few other resources such as an atomic time standard test bed, a rooftop antenna platform and a radome. It provides a new capability for high dynamics GPS simulations of space flight that is unique within the aerospace community. The GPS facility provides a critical element for the development and testing of GPS based technologies i.e. position, attitude and precise time determination used on-board a spacecraft, suborbital rocket balloon. The GPS simulation system is configured in a transportable rack and is available for GPS component development as well as for component, spacecraft subsystem and system level testing at spacecraft integration and tests sites. The GPS facility has been operational since early 1996 and has utilized by space flight projects carrying GPS experiments, such as the OrbView-2 and the Argentine SAC-A spacecrafts. The SAC-A pre-flight test data obtained by using the STR2760 simulator and the comparison with preliminary analysis of the GPS data from SAC-A telemetry are summarized. This paper describes pre-flight tests and simulations used to support a unique spaceborne GPS experiment. The GPS experiment mission objectives and the test program are described, as well as the GPS test facility configuration needed to verify experiment feasibility. Some operational and critical issues inherent in GPS receiver pre-flight tests and simulations using this GPS simulation, and test methodology are described. Simulation and flight data are presented. A complete program of pre-flight testing of spaceborne GPS receivers using a GPS constellation simulator is detailed.

Pre-Flight Testing of Spaceborne GPS Receivers Using a GPS Constellation Simulator

NASA Technical Reports Server (NTRS)

Kizhner, Semion; Davis, Edward; Alonso, Roberto

1999-01-01

The NASA Goddard Space Flight Center (GSFC) Global Positioning System (GPS) applications test facility has been established within the GSFC Guidance Navigation and Control Center. The GPS test facility is currently housing the Global Simulation Systems Inc. (GSSI) STR2760 GPS satellite 40-channel attitude simulator and a STR4760 12-channel navigation simulator. The facility also contains a few other resources such as an atomic time standard test bed, a rooftop antenna platform and a radome. It provides a new capability for high dynamics GPS simulations of space flight that is unique within the aerospace community. The GPS facility provides a critical element for the development and testing of GPS based technologies i.e. position, attitude and precise time determination used on-board a spacecraft, suborbital rocket or balloon. The GPS simulator system is configured in a transportable rack and is available for GPS component development as well as for component, spacecraft subsystem and system level testing at spacecraft integration and test sites. The GPS facility has been operational since early 1996 and has been utilized by space flight projects carrying GPS experiments, such as the OrbView-2 and the Argentine SAC-A spacecrafts. The SAC-A pre-flight test data obtained by using the STR2760 simulator and the comparison with preliminary analysis of the GPS data from SAC-A telemetry are summarized. This paper describes pre-flight tests and simulations used to support a unique spaceborne GPS experiment. The GPS experiment mission objectives and the test program are described, as well as the GPS test facility configuration needed to verify experiment feasibility. Some operational and critical issues inherent in GPS receiver pre-flight tests and simulations using this GPS simulator, and test methodology are described. Simulation and flight data are presented. A complete program of pre-flight testing of spaceborne GPS receivers using a GPS constellation simulator is detailed.

Space Science

NASA Image and Video Library

1999-04-01

NASA's Space Optics Manufacturing Center has been working to expand our view of the universe via sophisticated new telescopes. The Optics Center's goal is to develop low-cost, advanced space optics technologies for the NASA program in the 21st century - including the long-term goal of imaging Earth-like planets in distant solar systems. To reduce the cost of mirror fabrication, Marshall Space Flight Center (MSFC) has developed replication techniques, the machinery, and materials to replicate electro-formed nickel mirrors. The process allows fabricating precisely shaped mandrels to be used and reused as masters for replicating high-quality mirrors. Image shows Dr. Alan Shapiro cleaning mirror mandrel to be applied with highly reflective and high-density coating in the Large Aperture Coating Chamber, MFSC Space Optics Manufacturing Technology Center (SOMTC).

A compact, fast UV photometer for measurement of ozone from research aircraft

NASA Astrophysics Data System (ADS)

Gao, R. S.; Ballard, J.; Watts, L. A.; Thornberry, T. D.; Ciciora, S. J.; McLaughlin, R. J.; Fahey, D. W.

2012-09-01

In situ measurements of atmospheric ozone (O3) are performed routinely from many research aircraft platforms. The most common technique depends on the strong absorption of ultraviolet (UV) light by ozone. As atmospheric science advances to the widespread use of unmanned aircraft systems (UASs), there is an increasing requirement for minimizing instrument space, weight, and power while maintaining instrument accuracy, precision and time response. The design and use of a new, dual-beam, UV photometer instrument for in situ O3 measurements is described. A polarization optical-isolator configuration is utilized to fold the UV beam inside the absorption cells, yielding a 60-cm absorption length with a 30-cm cell. The instrument has a fast sampling rate (2 Hz at <200 hPa, 1 Hz at 200-500 hPa, and 0.5 Hz at ≥ 500 hPa), high accuracy (3% excluding operation in the 300-450 hPa range, where the accuracy may be degraded to about 5%), and excellent precision (1.1 × 1010 O3 molecules cm-3 at 2 Hz, which corresponds to 3.0 ppb at 200 K and 100 hPa, or 0.41 ppb at 273 K and 1013 hPa). The size (36 l), weight (18 kg), and power (50-200 W) make the instrument suitable for many UASs and other airborne platforms. Inlet and exhaust configurations are also described for ambient sampling in the troposphere and lower stratosphere (1000-50 hPa) that control the sample flow rate to maximize time response while minimizing loss of precision due to induced turbulence in the sample cell. In-flight and laboratory intercomparisons with existing O3 instruments show that measurement accuracy is maintained in flight.

Suppression of biodynamic interference in head-tracked teleoperation

NASA Technical Reports Server (NTRS)

Lifshitz, S.; Merhav, S. J.; Grunwald, A. J.; Tucker, G. E.; Tischler, M. B.

1991-01-01

The utility of helmet-tracked sights to provide pointing commands for teleoperation of cameras, lasers, or antennas in aircraft is degraded by the presence of uncommanded, involuntary heat motion, referred to as biodynamic interference. This interference limits the achievable precision required in pointing tasks. The noise contributions due to biodynamic interference consists of an additive component which is correlated with aircraft vibration and an uncorrelated, nonadditive component, referred to as remnant. An experimental simulation study is described which investigated the improvements achievable in pointing and tracking precision using dynamic display shifting in the helmet-mounted display. The experiment was conducted in a six degree of freedom motion base simulator with an emulated helmet-mounted display. Highly experienced pilot subjects performed precision head-pointing tasks while manually flying a visual flight-path tracking task. Four schemes using adaptive and low-pass filtering of the head motion were evaluated to determine their effects on task performance and pilot workload in the presence of whole-body vibration characteristic of helicopter flight. The results indicate that, for tracking tasks involving continuously moving targets, improvements of up to 70 percent can be achieved in percent on-target dwelling time and of up to 35 percent in rms tracking error, with the adaptive plus low-pass filter configuration. The results with the same filter configuration for the task of capturing randomly-positioned, stationary targets show an increase of up to 340 percent in the number of targets captured and an improvement of up to 24 percent in the average capture time. The adaptive plus low-pass filter combination was considered to exhibit the best overall display dynamics by each of the subjects.

An Evaluation of a Flight Deck Interval Management Algorithm Including Delayed Target Trajectories

NASA Technical Reports Server (NTRS)

Swieringa, Kurt A.; Underwood, Matthew C.; Barmore, Bryan; Leonard, Robert D.

2014-01-01

NASA's first Air Traffic Management (ATM) Technology Demonstration (ATD-1) was created to facilitate the transition of mature air traffic management technologies from the laboratory to operational use. The technologies selected for demonstration are the Traffic Management Advisor with Terminal Metering (TMA-TM), which provides precise timebased scheduling in the terminal airspace; Controller Managed Spacing (CMS), which provides controllers with decision support tools enabling precise schedule conformance; and Interval Management (IM), which consists of flight deck automation that enables aircraft to achieve or maintain precise in-trail spacing. During high demand operations, TMA-TM may produce a schedule and corresponding aircraft trajectories that include delay to ensure that a particular aircraft will be properly spaced from other aircraft at each schedule waypoint. These delayed trajectories are not communicated to the automation onboard the aircraft, forcing the IM aircraft to use the published speeds to estimate the target aircraft's estimated time of arrival. As a result, the aircraft performing IM operations may follow an aircraft whose TMA-TM generated trajectories have substantial speed deviations from the speeds expected by the spacing algorithm. Previous spacing algorithms were not designed to handle this magnitude of uncertainty. A simulation was conducted to examine a modified spacing algorithm with the ability to follow aircraft flying delayed trajectories. The simulation investigated the use of the new spacing algorithm with various delayed speed profiles and wind conditions, as well as several other variables designed to simulate real-life variability. The results and conclusions of this study indicate that the new spacing algorithm generally exhibits good performance; however, some types of target aircraft speed profiles can cause the spacing algorithm to command less than optimal speed control behavior.

A Document Visualization Tool Customized to Explore DRDC Reports (Un outil de visualisation de document concu precisement pour explorer les rapports de RDDC)

DTIC Science & Technology

2011-08-01

context of flight simulators . ................................................................................................................... 14...particular area? Suppose a commander at CFB Shearwater wanted to find out more about how he/she can best deal with issues of pilots’ motion sickness...in the flight simulator on base. As a first step, one would enter, “motion sickness” as a query in HanDles, and get the relevant documents returned

Design, Integration and Flight Test of a Pair of Autonomous Spacecraft Flying in Formation

DTIC Science & Technology

2013-05-01

representatives from the Air Force Research Laboratory, NASA’s Goddard Space Flight Center, the Jet Propulsion Laboratory, Boeing, Lockheed Martin, as...categories: elliptical , hyperbolic and parabolic (known as “Keplerian orbits”), each with their own characteristics and applications. These equations...of M-SAT’s operation is that of an elliptical nature, or more precisely a near-circular orbit. The primary method of determining the orbital elements

Ground-based lidar measurements of stratospheric ozone. The NASA/GSFC stratospheric ozone lidar trailer experiment STROZ LITE

NASA Technical Reports Server (NTRS)

Mcgee, Thomas J.; Butler, James; Burris, John; Heaps, William S.

1990-01-01

The major research objective is the measurement of high precision vertical profiles of ozone between 20-40 kilometers. The precision is such that the instrument should be capable of detecting a small trend (on the order of less that 1 percent per year) over a 5-10 year period. Temperature was measured between 30 and 365 km. The Goddard Space Flight Center (GSFC) mobile lidar was installed at Table Mountain and a comparison between it and the permanent Jet Propulsion Laboratory (JPL) lidar was made over the course of about 3 weeks. The lidars agreed very well between 20 and 40 km, and under certain conditions up to 45-47 km. There were several anomalies that both lidars followed very well. Agreement with Rocket Ozonesonde (ROCOZ) and electrochemical concentration cell (ECC) sondes was also very good.

Timing in a FLASH

NASA Astrophysics Data System (ADS)

Hoek, M.; Cardinali, M.; Corell, O.; Dickescheid, M.; Ferretti B., M. I.; Lauth, W.; Schlimme, B. S.; Sfienti, C.; Thiel, M.

2017-12-01

A prototype detector, called FLASH (Fast Light Acquiring Start Hodoscope), was built to provide precise Time-of-Flight (TOF) measurements and reference timestamps for detector setups at external beam lines. Radiator bars, made of synthetic fused silica, were coupled to a fast MCP-PMT with 64 channels and read out with custom electronics using Time-over-Threshold (TOT) for signal characterization. The TRB3 system, a high-precision TDC implemented in an FPGA, was used as data acquisition system. The performance of a system consisting of two FLASH units was investigated at a dedicated test experiment at the Mainz Microtron (MAMI) accelerator using its 855 MeV electron beam. The TOT measurement enabled time walk corrections and an overall TOF resolution of ∼70 ps could be achieved which translates into a resolution of ∼50 ps per FLASH unit. The intrinsic resolution of the frontend electronics including the TDC was measured to be less than 25 ps.

LIDAR-Aided Inertial Navigation with Extended Kalman Filtering for Pinpoint Landing

NASA Technical Reports Server (NTRS)

Busnardo, David M.; Aitken, Matthew L.; Tolson, Robert H.; Pierrottet, Diego; Amzajerdian, Farzin

2011-01-01

In support of NASA s Autonomous Landing and Hazard Avoidance Technology (ALHAT) project, an extended Kalman filter routine has been developed for estimating the position, velocity, and attitude of a spacecraft during the landing phase of a planetary mission. The proposed filter combines measurements of acceleration and angular velocity from an inertial measurement unit (IMU) with range and Doppler velocity observations from an onboard light detection and ranging (LIDAR) system. These high-precision LIDAR measurements of distance to the ground and approach velocity will enable both robotic and manned vehicles to land safely and precisely at scientifically interesting sites. The filter has been extensively tested using a lunar landing simulation and shown to improve navigation over flat surfaces or rough terrain. Experimental results from a helicopter flight test performed at NASA Dryden in August 2008 demonstrate that LIDAR can be employed to significantly improve navigation based exclusively on IMU integration.

Space Science

NASA Image and Video Library

1999-04-01

NASA's Space Optics Manufacturing Center has been working to expand our view of the universe via sophisticated new telescopes. The Optics Center's goal is to develop low-cost, advanced space optics technologies for the NASA program in the 21st century - including the long-term goal of imaging Earth-like planets in distant solar systems. To reduce the cost of mirror fabrication, Marshall Space Flight Center (MSFC) has developed replication techniques, the machinery, and materials to replicate electro-formed nickel mirrors. The process allows fabricating precisely shaped mandrels to be used and reused as masters for replicating high-quality mirrors. MSFC's Space Optics Manufacturing Technology Center (SOMTC) has grinding and polishing equipment ranging from conventional spindles to custom-designed polishers. These capabilities allow us to grind precisely and polish a variety of optical devices, including x-ray mirror mandrels. This image shows Charlie Griffith polishing the half-meter mandrel at SOMTC.

Mars Science Laboratory Boot Robustness Testing

NASA Technical Reports Server (NTRS)

Banazadeh, Payam; Lam, Danny

2011-01-01

Mars Science Laboratory (MSL) is one of the most complex spacecrafts in the history of mankind. Due to the nature of its complexity, a large number of flight software (FSW) requirements have been written for implementation. In practice, these requirements necessitate very complex and very precise flight software with no room for error. One of flight software's responsibilities is to be able to boot up and check the state of all devices on the spacecraft after the wake up process. This boot up and initialization is crucial to the mission success since any misbehavior of different devices needs to be handled through the flight software. I have created a test toolkit that allows the FSW team to exhaustively test the flight software under variety of different unexpected scenarios and validate that flight software can handle any situation after booting up. The test includes initializing different devices on spacecraft to different configurations and validate at the end of the flight software boot up that the flight software has initialized those devices to what they are suppose to be in that particular scenario.

Investigation of piloting aids for manual control of hypersonic maneuvers

NASA Technical Reports Server (NTRS)

Raney, David L.; Phillips, Michael R.; Person, Lee H., Jr.

1995-01-01

An investigation of piloting aids designed to provide precise maneuver control for an air-breathing hypersonic vehicle is described. Stringent constraints and nonintuitive high-speed flight effects associated with maneuvering in the hypersonic regime raise the question of whether manual control of such a vehicle should even be considered. The objectives of this research were to determine the extent of manual control that is desirable for a vehicle maneuvering in this regime and to identify the form of aids that must be supplied to the pilot to make such control feasible. A piloted real-time motion-based simulation of a hypersonic vehicle concept was used for this study, and the investigation focused on a single representative cruise turn maneuver. Piloting aids, which consisted of an auto throttle, throttle director, autopilot, flight director, and two head-up display configurations, were developed and evaluated. Two longitudinal control response types consisting of a rate-command/attitude-hold system and a load factor-rate/load-factor-hold system were also compared. The complete set of piloting aids, which consisted of the autothrottle, throttle director, and flight director, improved the average Cooper-Harper flying qualities ratings from 8 to 2.6, even though identical inner-loop stability and control augmentation was provided in all cases. The flight director was determined to be the most critical of these aids, and the cruise turn maneuver was unachievable to adequate performance specifications in the absence of this flight director.

ARC-2003-ACD03-0112-050

NASA Image and Video Library

2003-09-05

NRTC/RITA Precision Pathway Terminal Guidance: UH-60 RASCAL (#012) (National Rotocraft Technology Center/Rotorcraft Industry Technology Association) runway independent aircraft; Sikorsky Helicopter pilot Kevin Bredenbeck preparing for flight in RASCAL with Dave Arterburn

ARC-2003-ACD03-0112-046

NASA Image and Video Library

2003-09-05

NRTC/RITA Precision Pathway Terminal Guidance: UH-60 RASCAL (#012) (National Rotocraft Technology Center/Rotorcraft Industry Technology Association) runway independent aircraft - Sikorsky Helicopter pilot Kevin Bredenbeck preparing for flight in RASCAL with Dave Arterburn

ARC-2003-ACD03-0112-044

NASA Image and Video Library

2003-09-05

NRTC/RITA Precision Pathway Terminal Guidance: UH-60 RASCAL (#012) (National Rotocraft Technology Center/Rotorcraft Industry Technology Association) runway independent aircraft - Sikorsky Helicopter pilot Kevin Bredenbeck preparing for flight in RASCAL with Dave Arterburn

Physics-based simulations of aerial attacks by peregrine falcons reveal that stooping at high speed maximizes catch success against agile prey.

PubMed

Mills, Robin; Hildenbrandt, Hanno; Taylor, Graham K; Hemelrijk, Charlotte K

2018-04-01

The peregrine falcon Falco peregrinus is renowned for attacking its prey from high altitude in a fast controlled dive called a stoop. Many other raptors employ a similar mode of attack, but the functional benefits of stooping remain obscure. Here we investigate whether, when, and why stooping promotes catch success, using a three-dimensional, agent-based modeling approach to simulate attacks of falcons on aerial prey. We simulate avian flapping and gliding flight using an analytical quasi-steady model of the aerodynamic forces and moments, parametrized by empirical measurements of flight morphology. The model-birds' flight control inputs are commanded by their guidance system, comprising a phenomenological model of its vision, guidance, and control. To intercept its prey, model-falcons use the same guidance law as missiles (pure proportional navigation); this assumption is corroborated by empirical data on peregrine falcons hunting lures. We parametrically vary the falcon's starting position relative to its prey, together with the feedback gain of its guidance loop, under differing assumptions regarding its errors and delay in vision and control, and for three different patterns of prey motion. We find that, when the prey maneuvers erratically, high-altitude stoops increase catch success compared to low-altitude attacks, but only if the falcon's guidance law is appropriately tuned, and only given a high degree of precision in vision and control. Remarkably, the optimal tuning of the guidance law in our simulations coincides closely with what has been observed empirically in peregrines. High-altitude stoops are shown to be beneficial because their high airspeed enables production of higher aerodynamic forces for maneuvering, and facilitates higher roll agility as the wings are tucked, each of which is essential to catching maneuvering prey at realistic response delays.

A new fabrication method for precision antenna reflectors for space flight and ground test

NASA Technical Reports Server (NTRS)

Sharp, G. Richard; Wanhainen, Joyce S.; Ketelsen, Dean A.

1991-01-01

Communications satellites are using increasingly higher frequencies that require increasingly precise antenna reflectors for use in space. Traditional industry fabrication methods for space antenna reflectors employ successive modeling techniques using high- and low-temperature molds for reflector face sheets and then a final fit-up of the completed honeycomb sandwich panel antenna reflector to a master pattern. However, as new missions are planned at much higher frequencies, greater accuracies will be necessary than are achievable using these present methods. A new approach for the fabrication of ground-test solid-surface antenna reflectors is to build a rigid support structure with an easy-to-machine surface. This surface is subsequently machined to the desired reflector contour and coated with a radio-frequency-reflective surface. This method was used to fabricate a 2.7-m-diameter ground-test antenna reflector to an accuracy of better than 0.013 mm (0.0005 in.) rms. A similar reflector for use on spacecraft would be constructed in a similar manner but with space-qualified materials. The design, analysis, and fabrication of the 2.7-m-diameter precision antenna reflector for antenna ground tests and the extension of this technology to precision, space-based antenna reflectors are described.

Air Traffic Management Technology Demonstration-1 Concept of Operations (ATD-1 ConOps)

NASA Technical Reports Server (NTRS)

Baxley, Brian T.; Johnson, William C.; Swenson, Harry; Robinson, John E.; Prevot, Thomas; Callantine, Todd; Scardina, John; Greene, Michael

2012-01-01

The operational goal of the ATD-1 ConOps is to enable aircraft, using their onboard FMS capabilities, to fly Optimized Profile Descents (OPDs) from cruise to the runway threshold at a high-density airport, at a high throughput rate, using primarily speed control to maintain in-trail separation and the arrival schedule. The three technologies in the ATD-1 ConOps achieve this by calculating a precise arrival schedule, using controller decision support tools to provide terminal controllers with speeds for aircraft to fly to meet times at a particular meter points, and onboard software providing flight crews with speeds for the aircraft to fly to achieve a particular spacing behind preceding aircraft.

Rebuilding the space technology base

NASA Technical Reports Server (NTRS)

Povinelli, Frederick P.; Stephenson, Frank W.; Sokoloski, Martin M.; Montemerlo, Melvin D.; Venneri, Samuel L.; Mulville, Daniel R.; Hirschbein, Murray S.; Smith, Paul H.; Schnyer, A. Dan; Lum, Henry

1989-01-01

NASA's Civil Space Technology Initiative (CSTI) will not only develop novel technologies for space exploration and exploitation, but also take mature technologies into their demonstration phase in earth orbit. In the course of five years, CSTI will pay off in ground- and space-tested hardware, software, processes, methods for low-orbit transport and operation, and fundamental scientific research on the orbital environment. Attention is given to LOX/hydrogen and LOX/hydrocarbon reusable engines, liquid/solid fuel hybrid boosters, and aeroassist flight experiments for the validation of aerobraking with atmospheric friction. Also discussed are advanced scientific sensors, systems autonomy and telerobotics, control of flexible structures, precise segmented reflectors, high-rate high-capacity data handling, and advanced nuclear power systems.

Design of the EO-1 Pulsed Plasma Thruster Attitude Control Experiment

NASA Technical Reports Server (NTRS)

Zakrzwski, Charles; Sanneman, Paul; Hunt, Teresa; Blackman, Kathie; Bauer, Frank H. (Technical Monitor)

2001-01-01

The Pulsed Plasma Thruster (PPT) Experiment on the Earth Observing 1 (EO-1) spacecraft has been designed to demonstrate the capability of a new generation PPT to perform spacecraft attitude control. The PPT is a small, self-contained pulsed electromagnetic Propulsion system capable of delivering high specific impulse (900-1200 s), very small impulse bits (10-1000 micro N-s) at low average power (less than 1 to 100 W). EO-1 has a single PPT that can produce torque in either the positive or negative pitch direction. For the PPT in-flight experiment, the pitch reaction wheel will be replaced by the PPT during nominal EO-1 nadir pointing. A PPT specific proportional-integral-derivative (PID) control algorithm was developed for the experiment. High fidelity simulations of the spacecraft attitude control capability using the PPT were conducted. The simulations, which showed PPT control performance within acceptable mission limits, will be used as the benchmark for on-orbit performance. The flight validation will demonstrate the ability of the PPT to provide precision pointing resolution. response and stability as an attitude control actuator.

Dynamic subnanosecond time-of-flight detection for ultra-precise diffusion monitoring and optimization of biomarker preservation

NASA Astrophysics Data System (ADS)

Bauer, Daniel R.; Stevens, Benjamin; Taft, Jefferson; Chafin, David; Petre, Vinnie; Theiss, Abbey P.; Otter, Michael

2014-03-01

Recently, it has been demonstrated that the preservation of cancer biomarkers, such as phosphorylated protein epitopes, in formalin-fixed paraffin-embedded tissue is highly dependent on the localized concentration of the crosslinking agent. This study details a real-time diffusion monitoring system based on the acoustic time-of-flight (TOF) between pairs of 4 MHz focused transducers. Diffusion affects TOF because of the distinct acoustic velocities of formalin and interstitial fluid. Tissue is placed between the transducers and vertically translated to obtain TOF values at multiple locations with a spatial resolution of approximately 1 mm. Imaging is repeated for several hours until osmotic equilibrium is reached. A post-processing technique, analogous to digital acoustic interferometry, enables detection of subnanosecond TOF differences. Reference subtraction is used to compensate for environmental effects. Diffusion measurements with TOF monitoring ex vivo human tonsil tissue are well-correlated with a single exponential curve (R2>0.98) with a magnitude of up to 50 ns, depending on the tissue size (2-6 mm). The average exponential decay constant of 2 and 6 mm diameter samples are 20 and 315 minutes, respectively, although times varied significantly throughout the tissue (σmax=174 min). This technique can precisely monitor diffusion progression and could be used to mitigate effects from tissue heterogeneity and intersample variability, enabling improved preservation of cancer biomarkers distinctly sensitive to degradation during preanalytical tissue processing.

The Super-TIGER Instrument to Probe Galactic Cosmic-Ray Origins

NASA Astrophysics Data System (ADS)

Ward, John E.

2013-04-01

Super-TIGER is a large area (5.4 m^2) balloon-borne instrument designed to measure cosmic-ray nuclei in the charge interval 30 <= Z <= 42 with individual-element resolution and high statistical precision, and make exploratory measurements through Z = 56. These measurements will provide sensitive tests of the emerging model of cosmic-ray origins in OB associations and models of the mechanism for selection of nuclei for acceleration. Furthermore, Super-TIGER will measure with high statistical accuracy the energy spectra of the more abundant elements in the interval 10 <= Z <= 28 at energies 0.8 < E < 10 GeV/nucleon to test the hypothesis that nearby micro-quasars could superpose features on the energy spectra. Super-TIGER, which builds on the heritage of the smaller TIGER, was constructed by a collaboration involving WUSTL, NASA/GSFC, Caltech, JPL and U Minn. It was successfully launched from Antarctica in December 2012, collecting high-quality data for over one month. Particle charge and energy were measured with a combination of plastic scintillators, acrylic and silica-aerogel Cherenkov detectors, and a scintillating fiber hodoscope. Details of the flight, instrument performance, data analysis and preliminary results of the Super-TIGER flight will be presented.

Modern digital flight control system design for VTOL aircraft

NASA Technical Reports Server (NTRS)

Broussard, J. R.; Berry, P. W.; Stengel, R. F.

1979-01-01

Methods for and results from the design and evaluation of a digital flight control system (DFCS) for a CH-47B helicopter are presented. The DFCS employed proportional-integral control logic to provide rapid, precise response to automatic or manual guidance commands while following conventional or spiral-descent approach paths. It contained altitude- and velocity-command modes, and it adapted to varying flight conditions through gain scheduling. Extensive use was made of linear systems analysis techniques. The DFCS was designed, using linear-optimal estimation and control theory, and the effects of gain scheduling are assessed by examination of closed-loop eigenvalues and time responses.

Effect of light intensity on flight control and temporal properties of photoreceptors in bumblebees.

PubMed

Reber, Therese; Vähäkainu, Antti; Baird, Emily; Weckström, Matti; Warrant, Eric; Dacke, Marie

2015-05-01

To control flight, insects rely on the pattern of visual motion generated on the retina as they move through the environment. When light levels fall, vision becomes less reliable and flight control thus becomes more challenging. Here, we investigated the effect of light intensity on flight control by filming the trajectories of free-flying bumblebees (Bombus terrestris, Linnaeus 1758) in an experimental tunnel at different light levels. As light levels fell, flight speed decreased and the flight trajectories became more tortuous but the bees were still remarkably good at centring their flight about the tunnel's midline. To investigate whether this robust flight performance can be explained by visual adaptations in the bumblebee retina, we also examined the response speed of the green-sensitive photoreceptors at the same light intensities. We found that the response speed of the photoreceptors significantly decreased as light levels fell. This indicates that bumblebees have both behavioural (reduction in flight speed) and retinal (reduction in response speed of the photoreceptors) adaptations to allow them to fly in dim light. However, the more tortuous flight paths recorded in dim light suggest that these adaptations do not support flight with the same precision during the twilight hours of the day. © 2015. Published by The Company of Biologists Ltd.

An Exploratory Study of Runway Arrival Procedures: Time Based Arrival and Self-Spacing

NASA Technical Reports Server (NTRS)

Houston, Vincent E.; Barmore, Bryan

2009-01-01

The ability of a flight crew to deliver their aircraft to its arrival runway on time is important to the overall efficiency of the National Airspace System (NAS). Over the past several years, the NAS has been stressed almost to its limits resulting in problems such as airport congestion, flight delay, and flight cancellation to reach levels that have never been seen before in the NAS. It is predicted that this situation will worsen by the year 2025, due to an anticipated increase in air traffic operations to one-and-a-half to three times its current level. Improved arrival efficiency, in terms of both capacity and environmental impact, is an important part of improving NAS operations. One way to improve the arrival performance of an aircraft is to enable the flight crew to precisely deliver their aircraft to a specified point at either a specified time or specified interval relative to another aircraft. This gives the flight crew more control to make the necessary adjustments to their aircraft s performance with less tactical control from the controller; it may also decrease the controller s workload. Two approaches to precise time navigation have been proposed: Time-Based Arrivals (e.g., required times of arrival) and Self-Spacing. Time-Based Arrivals make use of an aircraft s Flight Management System (FMS) to deliver the aircraft to the runway threshold at a given time. Self-Spacing enables the flight crew to achieve an ATC assigned spacing goals at the runway threshold relative to another aircraft. The Joint Planning and Development Office (JPDO), a multi-agency initiative established to plan and coordinate the development of the Next Generation Air Transportation System (NextGen), has asked for data for both of these concepts to facilitate future research and development. This paper provides a first look at the delivery performance of these two concepts under various initial and environmental conditions in an air traffic simulation environment.

Research on flight stability performance of rotor aircraft based on visual servo control method

NASA Astrophysics Data System (ADS)

Yu, Yanan; Chen, Jing

2016-11-01

control method based on visual servo feedback is proposed, which is used to improve the attitude of a quad-rotor aircraft and to enhance its flight stability. Ground target images are obtained by a visual platform fixed on aircraft. Scale invariant feature transform (SIFT) algorism is used to extract image feature information. According to the image characteristic analysis, fast motion estimation is completed and used as an input signal of PID flight control system to realize real-time status adjustment in flight process. Imaging tests and simulation results show that the method proposed acts good performance in terms of flight stability compensation and attitude adjustment. The response speed and control precision meets the requirements of actual use, which is able to reduce or even eliminate the influence of environmental disturbance. So the method proposed has certain research value to solve the problem of aircraft's anti-disturbance.

Space Flight-Associated Neuro-ocular Syndrome.

PubMed

Lee, Andrew G; Mader, Thomas H; Gibson, C Robert; Tarver, William

2017-09-01

New and unique physiologic and pathologic systemic and neuro-ocular responses have been documented in astronauts during and after long-duration space flight. Although the precise cause remains unknown, space flight-associated neuro-ocular syndrome (SANS) has been adopted as an appropriate descriptive term. The Space Medicine Operations Division of the US National Aeronautics and Space Administration (NASA) has documented the variable occurrence of SANS in astronauts returning from long-duration space flight on the International Space Station. These clinical findings have included unilateral and bilateral optic disc edema, globe flattening, choroidal and retinal folds, hyperopic refractive error shifts, and nerve fiber layer infarcts. The clinical findings of SANS have been correlated with structural changes on intraorbital and intracranial magnetic resonance imaging and in-flight and terrestrial ultrasonographic studies and ocular optical coherence tomography. Further study of SANS is ongoing for consideration of future manned missions to space, including a return trip to the moon or Mars.

Flight Testing the Rotor Systems Research Aircraft (RSRA)

NASA Technical Reports Server (NTRS)

Hall, G. W.; Merrill, R. K.

1983-01-01

In the late 1960s, efforts to advance the state-of-the-art in rotor systems technology indicated a significant gap existed between our ability to accurately predict the characteristics of a complex rotor system and the results obtained through flight verification. Even full scale wind tunnel efforts proved inaccurate because of the complex nature of a rotating, maneuvering rotor system. The key element missing, which prevented significant advances, was our inability to precisely measure the exact rotor state as a function of time and flight condition. Two Rotor Research Aircraft (RSRA) were designed as pure research aircraft and dedicated rotor test vehicles whose function is to fill the gap between theory, wind tunnel testing, and flight verification. The two aircraft, the development of the piloting techniques required to safely fly the compound helicopter, the government flight testing accomplished to date, and proposed future research programs.

Flight Testing a Real-Time Hazard Detection System for Safe Lunar Landing on the Rocket-Powered Morpheus Vehicle

NASA Technical Reports Server (NTRS)

Trawny, Nikolas; Huertas, Andres; Luna, Michael E.; Villalpando, Carlos Y.; Martin, Keith E.; Carson, John M.; Johnson, Andrew E.; Restrepo, Carolina; Roback, Vincent E.

2015-01-01

The Hazard Detection System (HDS) is a component of the ALHAT (Autonomous Landing and Hazard Avoidance Technology) sensor suite, which together provide a lander Guidance, Navigation and Control (GN&C) system with the relevant measurements necessary to enable safe precision landing under any lighting conditions. The HDS consists of a stand-alone compute element (CE), an Inertial Measurement Unit (IMU), and a gimbaled flash LIDAR sensor that are used, in real-time, to generate a Digital Elevation Map (DEM) of the landing terrain, detect candidate safe landing sites for the vehicle through Hazard Detection (HD), and generate hazard-relative navigation (HRN) measurements used for safe precision landing. Following an extensive ground and helicopter test campaign, ALHAT was integrated onto the Morpheus rocket-powered terrestrial test vehicle in March 2014. Morpheus and ALHAT then performed five successful free flights at the simulated lunar hazard field constructed at the Shuttle Landing Facility (SLF) at Kennedy Space Center, for the first time testing the full system on a lunar-like approach geometry in a relevant dynamic environment. During these flights, the HDS successfully generated DEMs, correctly identified safe landing sites and provided HRN measurements to the vehicle, marking the first autonomous landing of a NASA rocket-powered vehicle in hazardous terrain. This paper provides a brief overview of the HDS architecture and describes its in-flight performance.

Astronautics and aeronautics, 1970. Chronology on science, technology, and policy

NASA Technical Reports Server (NTRS)

1972-01-01

An immediate reference to aerospace-related events of 1970 is provided to help historians in preserving historical accuracy and precision. Chronologies of major NASA launches, and manned space flights for 1970 are included.

Development of an ion time-of-flight spectrometer for neutron depth profiling

NASA Astrophysics Data System (ADS)

Cetiner, Mustafa Sacit

Ion time-of-flight spectrometry techniques are investigated for applicability to neutron depth profiling. Time-of-flight techniques are used extensively in a wide range of scientific and technological applications including energy and mass spectroscopy. Neutron depth profiling is a near-surface analysis technique that gives concentration distribution versus depth for certain technologically important light elements. The technique uses thermal or sub-thermal neutrons to initiate (n, p) or (n, alpha) reactions. Concentration versus depth distribution is obtained by the transformation of the energy spectrum into depth distribution by using stopping force tables of the projectiles in the substrate, and by converting the number of counts into concentration using a standard sample of known dose value. Conventionally, neutron depth profiling measurements are based on charged particle spectrometry, which employs semiconductor detectors such as a surface barrier detector (SBD) and the associated electronics. Measurements with semiconductor detectors are affected by a number of broadening mechanisms, which result from the interactions between the projectile ion and the detector material as well as fluctuations in the signal generation process. These are inherent features of the detection mechanism that involve the semiconductor detectors and cannot be avoided. Ion time-of-flight spectrometry offers highly precise measurement capabilities, particularly for slow particles. For high-energy low-mass particles, measurement resolution tends to degrade with all other parameters fixed. The threshold for more precise ion energy measurements with respect to conventional techniques, such as direct energy measurement by a surface barrier detector, is directly related to the design and operating parameters of the device. Time-of-flight spectrometry involves correlated detection of two signals by a coincidence unit. In ion time-of-flight spectroscopy, the ion generates the primary input signal. Without loss of generality, the secondary signal is obtained by the passage of the ion through a thin carbon foil, which produces ion-induced secondary electron emission (IISEE). The time-of-flight spectrometer physically acts as an ion/electron separator. The electrons that enter the active volume of the spectrometer are transported onto the microchannel plate detector to generate the secondary signal. The electron optics can be designed in variety of ways depending on the nature of the measurement and physical requirements. Two ion time-of-flight spectrometer designs are introduced: the parallel electric and magnetic (PEM) field spectrometer and the cross electric and magnetic (CEM) field spectrometer. The CEM field spectrometers have been extensively used in a wide range of applications where precise mass differentiation is required. The PEM field spectrometers have lately found interest in mass spectroscopy applications. The application of the PEM field spectrometer for energy measurements is a novel approach. The PEM field spectrometer used in the measurements employs axial electric and magnetic fields along the nominal direction of the incident ion. The secondary electrons are created by a thin carbon foil on the entrance disk and transported on the microchannel plate that faces the carbon foil. The initial angular distribution of the secondary electrons has virtually no effect on the transport time of the secondary electrons from the surface of the carbon foil to the electron microchannel plate detector. Therefore, the PEM field spectrometer can offer high-resolution energy measurement for relatively lower electric fields. The measurements with the PEM field spectrometer were made with the Tandem linear particle accelerator at the IBM T. J. Watson Research Center at Yorktown Heights, NY. The CEM field spectrometer developed for the thesis employs axial electric field along the nominal direction of the ion, and has perpendicular magnetic field. As the electric field accelerates and then decelerates the emitted secondary electron beam, the magnetic field steers the beam away from the source and focuses it onto the electron microchannel plate detector. The initial momentum distribution of the electron beam is observed to have profound effect on the electron transport time. Hence, the CEM field spectrometer measurements suffer more from spectral broadening at similar operating parameters. The CEM field spectrometer measurements were obtained with a 210Po alpha source at the Penn State Radiation Science and Engineering Center, University Park, PA. Although the PEM field spectrometer suffers less from electron transport time dispersion, the CEM field spectrometer is more suited for application to neutron depth profiling. The multiple small-diameter apertures used in the PEM field configuration considerably reduces the geometric efficiency of the spectrometer. Most of the neutron depth profiling measurements, where isotropic emission of charged particles is observed, have relatively low count rates; hence, high detection efficiency is essential.

Airborne Antenna System for Minimum-Cycle-Slip GPS Reception

NASA Technical Reports Server (NTRS)

Wright, C. Wayne

2009-01-01

A system that includes a Global Positioning System (GPS) antenna and associated apparatus for keeping the antenna aimed upward has been developed for use aboard a remote-sensing-survey airplane. The purpose served by the system is to enable minimum- cycle-slip reception of GPS signals used in precise computation of the trajectory of the airplane, without having to restrict the airplane to maneuvers that increase the flight time needed to perform a survey. Cycle slip signifies loss of continuous track of the phase of a signal. Minimum-cycle-slip reception is desirable because maintaining constant track of the phase of the carrier signal from each available GPS satellite is necessary for surveying to centimeter or subcentimeter precision. Even a loss of signal for as short a time as a nanosecond can cause cycle slip. Cycle slips degrade the quality and precision of survey data acquired during a flight. The two principal causes of cycle slip are weakness of signals and multipath propagation. Heretofore, it has been standard practice to mount a GPS antenna rigidly on top of an airplane, and the radiation pattern of the antenna is typically hemispherical, so that all GPS satellites above the horizon are viewed by the antenna during level flight. When the airplane must be banked for a turn or other maneuver, the reception hemisphere becomes correspondingly tilted; hence, the antenna no longer views satellites that may still be above the Earth horizon but are now below the equatorial plane of the tilted reception hemisphere. Moreover, part of the reception hemisphere (typically, on the inside of a turn) becomes pointed toward ground, with a consequent increase in received noise and, therefore, degradation of GPS measurements. To minimize the likelihood of loss of signal and cycle slip, bank angles of remote-sensing survey airplanes have generally been limited to 10 or less, resulting in skidding or slipping uncoordinated turns. An airplane must be banked in order to make a coordinated turn. For small-radius, short-time coordinated turns, it is necessary to employ banks as steep as 45 , and turns involving such banks are times and for confining airplanes as closely as possible to areas to be surveyed. The idea underlying the design is that if the antenna can be kept properly aimed, then the incidence of cycle slips caused by loss or weakness of signals can be minimized. The system includes an articulating GPS antenna and associated electronic circuitry mounted under a radome atop an airplane. The electronic circuitry includes a microprocessor-based interface-circuit-and-data-translation module. The system receives data on the current attitude of the airplane from the inertial navigation system of the airplane. The microprocessor decodes the attitude data and uses them to compute commands for the GPS-antenna-articulating mechanism to tilt the antenna, relative to the airplane, in opposition to the roll or bank of the airplane to keep the antenna pointed toward the zenith. The system was tested aboard the hurricane- hunting airplane of the National Oceanic and Atmospheric Administration (NOAA) [see figure] during an 11-hour flight to observe the landfall of Hurricane Bret in late summer of 1999. No bank-angle restrictions were imposed during the flight. Post-flight analysis of the GPS trajectory data revealed that no cycle slip had occurred.considered normal maneuvers. These steep banks are highly desirable for minimizing flight

A precision mechanical nerve stimulator

NASA Technical Reports Server (NTRS)

Tcheng, Ping; Supplee, Frank H., Jr.; Prass, Richard L.

1988-01-01

An electromechanical device, used to apply and monitor stimulating pulses to a mammalian motor nerve, has been successfully developed at NASA Langley Research Center. Two existing force transducers, a flight skin friction balance and a miniature skin friction balance which were designed for making aerodynamic drag measurements, were modified and incorporated to form this precision instrument. The nerve stimulator is a type one servomechanism capable of applying and monitoring stimulating pulses of 0 to 10 grams with a precision of better than +/- 0.05 grams. Additionally, the device can be independently used to apply stimulating pulses by displacing the nerve from 0 to 0.25 mm with a precision of better than +/- 0.001 mm while measuring the level of the load applied.

A NASA technician paints NASA's first Orion full-scale abort flight test crew module.

NASA Image and Video Library

2008-03-31

A full-scale flight-test mockup of the Constellation program's Orion crew vehicle arrived at NASA's Dryden Flight Research Center in late March 2008 to undergo preparations for the first short-range flight test of the spacecraft's astronaut escape system later that year. Engineers and technicians at NASA's Langley Research Center fabricated the structure, which precisely represents the size, outer shape and mass characteristics of the Orion space capsule. The Orion crew module mockup was ferried to NASA Dryden on an Air Force C-17. After painting in the Edwards Air Force Base paint hangar, the conical capsule was taken to Dryden for installation of flight computers, instrumentation and other electronics prior to being sent to the U.S. Army's White Sands Missile Range in New Mexico for integration with the escape system and the first abort flight test in late 2008. The tests were designed to ensure a safe, reliable method of escape for astronauts in case of an emergency.

Sporting a fresh paint job, NASA's first Orion full-scale abort flight test crew module awaits avionics and other equipment installation.

NASA Image and Video Library

2008-04-01

A full-scale flight-test mockup of the Constellation program's Orion crew vehicle arrived at NASA's Dryden Flight Research Center in late March 2008 to undergo preparations for the first short-range flight test of the spacecraft's astronaut escape system later that year. Engineers and technicians at NASA's Langley Research Center fabricated the structure, which precisely represents the size, outer shape and mass characteristics of the Orion space capsule. The Orion crew module mockup was ferried to NASA Dryden on an Air Force C-17. After painting in the Edwards Air Force Base paint hangar, the conical capsule was taken to Dryden for installation of flight computers, instrumentation and other electronics prior to being sent to the U.S. Army's White Sands Missile Range in New Mexico for integration with the escape system and the first abort flight test in late 2008. The tests were designed to ensure a safe, reliable method of escape for astronauts in case of an emergency.

The X-31A quasi-tailless flight test results

NASA Technical Reports Server (NTRS)

Bosworth, John T.; Stoliker, P. C.

1996-01-01

A quasi-tailless flight investigation was launched using the X-31A enhanced fighter maneuverability airplane. In-flight simulations were used to assess the effect of partial to total vertical tail removal. The rudder control surface was used to cancel the stabilizing effects of the vertical tail, and yaw thrust vector commands were used to restabilize and control the airplane. The quasi-tailless mode was flown supersonically with gentle maneuvering and subsonically in precision approaches and ground attack profiles. Pilot ratings and a full set of flight test measurements were recorded. This report describes the results obtained and emphasizes the lessons learned from the X-31A flight test experiment. Sensor-related issues and their importance to a quasi-tailless simulation and to ultimately controlling a directionally unstable vehicle are assessed. The X-31A quasi-tailless flight test experiment showed that tailless and reduced tail fighter aircraft are definitely feasible. When the capability is designed into the airplane from the beginning, the benefits have the potential to outweigh the added complexity required.

Cobalt: Development and Maturation of GN&C Technologies for Precision Landing

NASA Technical Reports Server (NTRS)

Carson, John M.; Restrepo, Carolina; Seubert, Carl; Amzajerdian, Farzin

2016-01-01

The CoOperative Blending of Autonomous Landing Technologies (COBALT) instrument is a terrestrial test platform for development and maturation of guidance, navigation and control (GN&C) technologies for precision landing. The project is developing a third-generation Langley Research Center (LaRC) navigation doppler lidar (NDL) for ultra-precise velocity and range measurements, which will be integrated and tested with the Jet Propulsion Laboratory (JPL) lander vision system (LVS) for terrain relative navigation (TRN) position estimates. These technologies together provide precise navigation knowledge that is critical for a controlled and precise touchdown. The COBALT hardware will be integrated in 2017 into the GN&C subsystem of the Xodiac rocket-propulsive vertical test bed (VTB) developed by Masten Space Systems, and two terrestrial flight campaigns will be conducted: one open-loop (i.e., passive) and one closed-loop (i.e., active).

Optical metrology for Starlight Separated Spacecraft Stellar Interferometry Mission

NASA Technical Reports Server (NTRS)

Dubovitsky, S.; Lay, O. P.; Peters, R. D.; Abramovici, A.; Asbury, C. G.; Kuhnert, A. C.; Mulder, J. L.

2002-01-01

We describe a high-precision inter-spacecraft metrology system designed for NASA 's StarLight mission, a space-based separated-spacecraft stellar interferometer. It consists of dual-target linear metrology, based on a heterodyne interferometer with carrier phase modulation, and angular metrology designed to sense the pointing of the laser beam and provides bearing information. The dual-target operation enables one metrology beam to sense displacement of two targets independently. We present the current design, breadboard implementation of the Metrology Subsystem in a stellar interferometer testbed and the present state of development of flight qualifiable subsystem components.

High-Precision Pulse Generator

NASA Technical Reports Server (NTRS)

Katz, Richard; Kleyner, Igor

2011-01-01

A document discusses a pulse generator with subnanosecond resolution implemented with a low-cost field-programmable gate array (FPGA) at low power levels. The method used exploits the fast carry chains of certain FPGAs. Prototypes have been built and tested in both Actel AX and Xilinx Virtex 4 technologies. In-flight calibration or control can be performed by using a similar and related technique as a time interval measurement circuit by measuring a period of the stable oscillator, as the delays through the fast carry chains will vary as a result of manufacturing variances as well as the result of environmental conditions (voltage, aging, temperature, and radiation).

Helicopter Flight Test of a Compact, Real-Time 3-D Flash Lidar for Imaging Hazardous Terrain During Planetary Landing

NASA Technical Reports Server (NTRS)

Roback, VIncent E.; Amzajerdian, Farzin; Brewster, Paul F.; Barnes, Bruce W.; Kempton, Kevin S.; Reisse, Robert A.; Bulyshev, Alexander E.

2013-01-01

A second generation, compact, real-time, air-cooled 3-D imaging Flash Lidar sensor system, developed from a number of cutting-edge components from industry and NASA, is lab characterized and helicopter flight tested under the Autonomous Precision Landing and Hazard Detection and Avoidance Technology (ALHAT) project. The ALHAT project is seeking to develop a guidance, navigation, and control (GN&C) and sensing system based on lidar technology capable of enabling safe, precise crewed or robotic landings in challenging terrain on planetary bodies under any ambient lighting conditions. The Flash Lidar incorporates a 3-D imaging video camera based on Indium-Gallium-Arsenide Avalanche Photo Diode and novel micro-electronic technology for a 128 x 128 pixel array operating at a video rate of 20 Hz, a high pulse-energy 1.06 µm Neodymium-doped: Yttrium Aluminum Garnet (Nd:YAG) laser, a remote laser safety termination system, high performance transmitter and receiver optics with one and five degrees field-of-view (FOV), enhanced onboard thermal control, as well as a compact and self-contained suite of support electronics housed in a single box and built around a PC-104 architecture to enable autonomous operations. The Flash Lidar was developed and then characterized at two NASA-Langley Research Center (LaRC) outdoor laser test range facilities both statically and dynamically, integrated with other ALHAT GN&C subsystems from partner organizations, and installed onto a Bell UH-1H Iroquois "Huey" helicopter at LaRC. The integrated system was flight tested at the NASA-Kennedy Space Center (KSC) on simulated lunar approach to a custom hazard field consisting of rocks, craters, hazardous slopes, and safe-sites near the Shuttle Landing Facility runway starting at slant ranges of 750 m. In order to evaluate different methods of achieving hazard detection, the lidar, in conjunction with the ALHAT hazard detection and GN&C system, operates in both a narrow 1deg FOV raster-scanning mode in which successive, gimbaled images of the hazard field are mosaicked together as well as in a wider, 4.85deg FOV staring mode in which digital magnification, via a novel 3-D superresolution technique, is used to effectively achieve the same spatial precision attained with the more narrow FOV optics. The lidar generates calibrated and corrected 3-D range images of the hazard field in real-time and passes them to the ALHAT Hazard Detection System (HDS) which stitches the images together to generate on-the-fly Digital Elevation Maps (DEM's) and identifies hazards and safe-landing sites which the ALHAT GN&C system can then use to guide the host vehicle to a safe landing on the selected site. Results indicate that, for the KSC hazard field, the lidar operational range extends from 100m to 1.35 km for a 30 degree line-of-sight angle and a range precision as low as 8 cm which permits hazards as small as 25 cm to be identified. Based on the Flash Lidar images, the HDS correctly found and reported safe sites in near-real-time during several of the flights. A follow-on field test, planned for 2013, seeks to complete the closing of the GN&C loop for fully-autonomous operations on-board the Morpheus robotic, rocket-powered, free-flyer test bed in which the ALHAT system would scan the KSC hazard field (which was vetted during the present testing) and command the vehicle to landing on one of the selected safe sites.

Recommended Changes to Interval Management to Achieve Operational Implementation

NASA Technical Reports Server (NTRS)

Baxley, Brian; Swieringa, Kurt; Roper, Roy; Hubbs, Clay; Goess, Paul; Shay, Richard

2017-01-01

A 19-day flight test of an Interval Management (IM) avionics prototype was conducted in Washington State using three aircraft to precisely achieve and maintain a spacing interval behind the preceding aircraft. NASA contracted with Boeing, Honeywell, and United Airlines to build this prototype, and then worked closely with them, the FAA, and other industry partners to test this prototype in flight. Four different IM operation types were investigated during this test in the en route, arrival, and final approach phases of flight. Many of the IM operations met or exceeded the design goals established prior to the test. However, there were issues discovered throughout the flight test, including the rate and magnitude of IM commanded speed changes and the difference between expected and actual aircraft deceleration rates.

Comparison of model and flight test data for an augmented jet flap STOL research aircraft

NASA Technical Reports Server (NTRS)

Cook, W. L.; Whittley, D. C.

1975-01-01

Aerodynamic design data for the Augmented Jet Flap STOL Research Aircraft or commonly known as the Augmentor-Wing Jet-STOL Research Aircraft was based on results of tests carried out on a large scale research model in the NASA Ames 40- by 80-Foot Wind Tunnel. Since the model differs in some respects from the aircraft, precise correlation between tunnel and flight test is not expected, however the major areas of confidence derived from the wind tunnel tests are delineated, and for the most part, tunnel results compare favorably with flight experience. In some areas the model tests were known to be nonrepresentative so that a degree of uncertainty remained: these areas of greater uncertainty are identified, and discussed in the light of subsequent flight tests.

A Forest Fire Sensor Web Concept with UAVSAR

NASA Astrophysics Data System (ADS)

Lou, Y.; Chien, S.; Clark, D.; Doubleday, J.; Muellerschoen, R.; Zheng, Y.

2008-12-01

We developed a forest fire sensor web concept with a UAVSAR-based smart sensor and onboard automated response capability that will allow us to monitor fire progression based on coarse initial information provided by an external source. This autonomous disturbance detection and monitoring system combines the unique capabilities of imaging radar with high throughput onboard processing technology and onboard automated response capability based on specific science algorithms. In this forest fire sensor web scenario, a fire is initially located by MODIS/RapidFire or a ground-based fire observer. This information is transmitted to the UAVSAR onboard automated response system (CASPER). CASPER generates a flight plan to cover the alerted fire area and executes the flight plan. The onboard processor generates the fuel load map from raw radar data, used with wind and elevation information, predicts the likely fire progression. CASPER then autonomously alters the flight plan to track the fire progression, providing this information to the fire fighting team on the ground. We can also relay the precise fire location to other remote sensing assets with autonomous response capability such as Earth Observation-1 (EO-1)'s hyper-spectral imager to acquire the fire data.

Flared landing approach flying qualities. Volume 1: Experiment design and analysis

NASA Technical Reports Server (NTRS)

Weingarten, Norman C.; Berthe, Charles J., Jr.; Rynaski, Edmund G.; Sarrafian, Shahan K.

1986-01-01

An inflight research study was conducted utilizing the USAF Total Inflight Simulator (TIFS) to investigate longitudinal flying qualities for the flared landing approach phase of flight. The purpose of the experiment was to generate a consistent set of data for: (1) determining what kind of commanded response the pilot prefers in order to flare and land an airplane with precision, and (2) refining a time history criterion that took into account all the necessary variables and their characteristics that would accurately predict flying qualities. The result of the first part provides guidelines to the flight control system designer, using MIL-F-8785-(C) as a guide, that yield the dynamic behavior pilots perfer in flared landings. The results of the second part provides the flying qualities engineer with a newly derived flying qualities predictive tool which appears to be highly accurate. This time domain predictive flying qualities criterion was applied to the flight data as well as six previous flying qualities studies, and the results indicate that the criterion predicted the flying qualities level 81% of the time and the Cooper-Harper pilot rating, within + or - 1, 60% of the time.

Local Observability Analysis of Star Sensor Installation Errors in a SINS/CNS Integration System for Near-Earth Flight Vehicles.

PubMed

Yang, Yanqiang; Zhang, Chunxi; Lu, Jiazhen

2017-01-16

Strapdown inertial navigation system/celestial navigation system (SINS/CNS) integrated navigation is a fully autonomous and high precision method, which has been widely used to improve the hitting accuracy and quick reaction capability of near-Earth flight vehicles. The installation errors between SINS and star sensors have been one of the main factors that restrict the actual accuracy of SINS/CNS. In this paper, an integration algorithm based on the star vector observations is derived considering the star sensor installation error. Then, the star sensor installation error is accurately estimated based on Kalman Filtering (KF). Meanwhile, a local observability analysis is performed on the rank of observability matrix obtained via linearization observation equation, and the observable conditions are presented and validated. The number of star vectors should be greater than or equal to 2, and the times of posture adjustment also should be greater than or equal to 2. Simulations indicate that the star sensor installation error could be readily observable based on the maneuvering condition; moreover, the attitude errors of SINS are less than 7 arc-seconds. This analysis method and conclusion are useful in the ballistic trajectory design of near-Earth flight vehicles.

Characterization of modulated time-of-flight range image sensors

NASA Astrophysics Data System (ADS)

Payne, Andrew D.; Dorrington, Adrian A.; Cree, Michael J.; Carnegie, Dale A.

2009-01-01

A number of full field image sensors have been developed that are capable of simultaneously measuring intensity and distance (range) for every pixel in a given scene using an indirect time-of-flight measurement technique. A light source is intensity modulated at a frequency between 10-100 MHz, and an image sensor is modulated at the same frequency, synchronously sampling light reflected from objects in the scene (homodyne detection). The time of flight is manifested as a phase shift in the illumination modulation envelope, which can be determined from the sampled data simultaneously for each pixel in the scene. This paper presents a method of characterizing the high frequency modulation response of these image sensors, using a pico-second laser pulser. The characterization results allow the optimal operating parameters, such as the modulation frequency, to be identified in order to maximize the range measurement precision for a given sensor. A number of potential sources of error exist when using these sensors, including deficiencies in the modulation waveform shape, duty cycle, or phase, resulting in contamination of the resultant range data. From the characterization data these parameters can be identified and compensated for by modifying the sensor hardware or through post processing of the acquired range measurements.

Rapid and accurate estimation of release conditions in the javelin throw.

PubMed

Hubbard, M; Alaways, L W

1989-01-01

We have developed a system to measure initial conditions in the javelin throw rapidly enough to be used by the thrower for feedback in performance improvement. The system consists of three subsystems whose main tasks are: (A) acquisition of automatically digitized high speed (200 Hz) video x, y position data for the first 0.1-0.2 s of the javelin flight after release (B) estimation of five javelin release conditions from the x, y position data and (C) graphical presentation to the thrower of these release conditions and a simulation of the subsequent flight together with optimal conditions and flight for the sam release velocity. The estimation scheme relies on a simulation model and is at least an order of magnitude more accurate than previously reported measurements of javelin release conditions. The system provides, for the first time ever in any throwing event, the ability to critique nearly instantly in a precise, quantitative manner the crucial factors in the throw which determine the range. This should be expected to much greater control and consistency of throwing variables by athletes who use system and could even lead to an evolution of new throwing techniques.

Synthetic Vision Displays for Planetary and Lunar Lander Vehicles

NASA Technical Reports Server (NTRS)

Arthur, Jarvis J., III; Prinzel, Lawrence J., III; Williams, Steven P.; Shelton, Kevin J.; Kramer, Lynda J.; Bailey, Randall E.; Norman, Robert M.

2008-01-01

Aviation research has demonstrated that Synthetic Vision (SV) technology can substantially enhance situation awareness, reduce pilot workload, improve aviation safety, and promote flight path control precision. SV, and related flight deck technologies are currently being extended for application in planetary exploration vehicles. SV, in particular, holds significant potential for many planetary missions since the SV presentation provides a computer-generated view for the flight crew of the terrain and other significant environmental characteristics independent of the outside visibility conditions, window locations, or vehicle attributes. SV allows unconstrained control of the computer-generated scene lighting, terrain coloring, and virtual camera angles which may provide invaluable visual cues to pilots/astronauts, not available from other vision technologies. In addition, important vehicle state information may be conformally displayed on the view such as forward and down velocities, altitude, and fuel remaining to enhance trajectory control and vehicle system status. The paper accompanies a conference demonstration that introduced a prototype NASA Synthetic Vision system for lunar lander spacecraft. The paper will describe technical challenges and potential solutions to SV applications for the lunar landing mission, including the requirements for high-resolution lunar terrain maps, accurate positioning and orientation, and lunar cockpit display concepts to support projected mission challenges.

Laboratory and In-Flight In-Situ X-ray Imaging and Scattering Facility for Materials, Biotechnology and Life Sciences

NASA Technical Reports Server (NTRS)

2003-01-01

We propose a multifunctional X-ray facility for the Materials, Biotechnology and Life Sciences Programs to visualize formation and behavior dynamics of materials, biomaterials, and living organisms, tissues and cells. The facility will combine X-ray topography, phase micro-imaging and scattering capabilities with sample units installed on the goniometer. This should allow, for the first time, to monitor under well defined conditions, in situ, in real time: creation of imperfections during growth of semiconductors, metal, dielectric and biomacromolecular crystals and films, high-precision diffraction from crystals within a wide range of temperatures and vapor, melt, solution conditions, internal morphology and changes in living organisms, tissues and cells, diffraction on biominerals, nanotubes and particles, radiation damage, also under controlled formation/life conditions. The system will include an ultrabright X-ray source, X-ray mirror, monochromator, image-recording unit, detectors, and multipurpose diffractometer that fully accommodate and integrate furnaces and samples with other experimental environments. The easily adjustable laboratory and flight versions will allow monitoring processes under terrestrial and microgravity conditions. The flight version can be made available using a microsource combined with multilayer or capillary optics.

Time Variations of Cosmic-Ray Helium Isotopes with Bess-Polar I

NASA Technical Reports Server (NTRS)

Abe, K.; Fuke, H.; Haino, S.; Hams, T.; Hasegawa, M.; Horikoshi, A.; Itazaki, A.; Kim, K. C.; Kumazawa, T.; Kusumoto, A.;

Time Variations of Cosmic-Ray Helium Isotopes with BESS-Polar I

NASA Technical Reports Server (NTRS)

Abe, K.; Fuke, H.; Haino, S.; Hams, T.; Hasegawa, M.; Horikoshi, A.; Itazaki, A.; Kim, K. C.; Kumazawa, T.; Kusumoto, A.;

Instrumentation and measurement strategy for the NOAA SENEX aircraft campaign as part of the Southeast Atmosphere Study 2013

NASA Astrophysics Data System (ADS)

Warneke, Carsten; Trainer, Michael; de Gouw, Joost A.; Parrish, David D.; Fahey, David W.; Ravishankara, A. R.; Middlebrook, Ann M.; Brock, Charles A.; Roberts, James M.; Brown, Steven S.; Neuman, Jonathan A.; Lerner, Brian M.; Lack, Daniel; Law, Daniel; Hübler, Gerhard; Pollack, Iliana; Sjostedt, Steven; Ryerson, Thomas B.; Gilman, Jessica B.; Liao, Jin; Holloway, John; Peischl, Jeff; Nowak, John B.; Aikin, Kenneth C.; Min, Kyung-Eun; Washenfelder, Rebecca A.; Graus, Martin G.; Richardson, Mathew; Markovic, Milos Z.; Wagner, Nick L.; Welti, André; Veres, Patrick R.; Edwards, Peter; Schwarz, Joshua P.; Gordon, Timothy; Dube, William P.; McKeen, Stuart A.; Brioude, Jerome; Ahmadov, Ravan; Bougiatioti, Aikaterini; Lin, Jack J.; Nenes, Athanasios; Wolfe, Glenn M.; Hanisco, Thomas F.; Lee, Ben H.; Lopez-Hilfiker, Felipe D.; Thornton, Joel A.; Keutsch, Frank N.; Kaiser, Jennifer; Mao, Jingqiu; Hatch, Courtney D.

2016-07-01

Natural emissions of ozone-and-aerosol-precursor gases such as isoprene and monoterpenes are high in the southeastern US. In addition, anthropogenic emissions are significant in the southeastern US and summertime photochemistry is rapid. The NOAA-led SENEX (Southeast Nexus) aircraft campaign was one of the major components of the Southeast Atmosphere Study (SAS) and was focused on studying the interactions between biogenic and anthropogenic emissions to form secondary pollutants. During SENEX, the NOAA WP-3D aircraft conducted 20 research flights between 27 May and 10 July 2013 based out of Smyrna, TN. Here we describe the experimental approach, the science goals and early results of the NOAA SENEX campaign. The aircraft, its capabilities and standard measurements are described. The instrument payload is summarized including detection limits, accuracy, precision and time resolutions for all gas-and-aerosol phase instruments. The inter-comparisons of compounds measured with multiple instruments on the NOAA WP-3D are presented and were all within the stated uncertainties, except two of the three NO2 measurements. The SENEX flights included day- and nighttime flights in the southeastern US as well as flights over areas with intense shale gas extraction (Marcellus, Fayetteville and Haynesville shale). We present one example flight on 16 June 2013, which was a daytime flight over the Atlanta region, where several crosswind transects of plumes from the city and nearby point sources, such as power plants, paper mills and landfills, were flown. The area around Atlanta has large biogenic isoprene emissions, which provided an excellent case for studying the interactions between biogenic and anthropogenic emissions. In this example flight, chemistry in and outside the Atlanta plumes was observed for several hours after emission. The analysis of this flight showcases the strategies implemented to answer some of the main SENEX science questions.

Instrumentation and Measurement Strategy for the NOAA SENEX Aircraft Campaign as Part of the Southeast Atmosphere Study 2013

PubMed Central

Warneke, C.; Trainer, M.; de Gouw, J.A.; Parrish, D.D.; Fahey, D.W.; Ravishankara, A.R.; Middlebrook, A.M.; Brock, C.A.; Roberts, J.M.; Brown, S.S.; Neuman, J.A.; Lerner, B.M.; Lack, D.; Law, D.; Hübler, G.; Pollack, I.; Sjostedt, S.; Ryerson, T.B.; Gilman, J.B.; Liao, J.; Holloway, J.; Peischl, J.; Nowak, J.B.; Aikin, K.; Min, K.-E.; Washenfelder, R.A.; Graus, M.G.; Richardson, M.; Markovic, M.Z.; Wagner, N.L.; Welti, A.; Veres, P.R.; Edwards, P.; Schwarz, J.P.; Gordon, T.; Dube, W.P.; McKeen, S.; Brioude, J.; Ahmadov, R.; Bougiatioti, A.; Lin, J.J.; Nenes, A.; Wolfe, G.M.; Hanisco, T.F.; Lee, B.H.; Lopez-Hilfiker, F.D.; Thornton, J.A.; Keutsch, F.N.; Kaiser, J.; Mao, J.; Hatch, C.

2018-01-01

Natural emissions of ozone-and-aerosol-precursor gases such as isoprene and monoterpenes are high in the southeast of the US. In addition, anthropogenic emissions are significant in the Southeast US and summertime photochemistry is rapid. The NOAA-led SENEX (Southeast Nexus) aircraft campaign was one of the major components of the Southeast Atmosphere Study (SAS) and was focused on studying the interactions between biogenic and anthropogenic emissions to form secondary pollutants. During SENEX, the NOAA WP-3D aircraft conducted 20 research flights between 27 May and 10 July 2013 based out of Smyrna, TN. Here we describe the experimental approach, the science goals and early results of the NOAA SENEX campaign. The aircraft, its capabilities and standard measurements are described. The instrument payload is summarized including detection limits, accuracy, precision and time resolutions for all gas-and-aerosol phase instruments. The inter-comparisons of compounds measured with multiple instruments on the NOAA WP-3D are presented and were all within the stated uncertainties, except two of the three NO2 measurements. The SENEX flights included day- and nighttime flights in the Southeast as well as flights over areas with intense shale gas extraction (Marcellus, Fayetteville and Haynesville shale). We present one example flight on 16 June 2013, which was a daytime flight over the Atlanta region, where several crosswind transects of plumes from the city and nearby point sources, such as power plants, paper mills and landfills, were flown. The area around Atlanta has large biogenic isoprene emissions, which provided an excellent case for studying the interactions between biogenic and anthropogenic emissions. In this example flight, chemistry in and outside the Atlanta plumes was observed for several hours after emission. The analysis of this flight showcases the strategies implemented to answer some of the main SENEX science questions. PMID:29619117

Instrumentation and Measurement Strategy for the NOAA SENEX Aircraft Campaign as Part of the Southeast Atmosphere Study 2013

NASA Technical Reports Server (NTRS)

Warneke, C.; Trainer, M.; de Gouw, J. A.; Parrish, D. D.; Fahey, D. W.; Ravishankara, A. R.; Middlebrook, A. M.; Brock, C. A.; Roberts, J. M.; Brown, S. S.;

Instrumentation and Measurement Strategy for the NOAA SENEX Aircraft Campaign as Part of the Southeast Atmosphere Study 2013.

PubMed

Warneke, C; Trainer, M; de Gouw, J A; Parrish, D D; Fahey, D W; Ravishankara, A R; Middlebrook, A M; Brock, C A; Roberts, J M; Brown, S S; Neuman, J A; Lerner, B M; Lack, D; Law, D; Hübler, G; Pollack, I; Sjostedt, S; Ryerson, T B; Gilman, J B; Liao, J; Holloway, J; Peischl, J; Nowak, J B; Aikin, K; Min, K-E; Washenfelder, R A; Graus, M G; Richardson, M; Markovic, M Z; Wagner, N L; Welti, A; Veres, P R; Edwards, P; Schwarz, J P; Gordon, T; Dube, W P; McKeen, S; Brioude, J; Ahmadov, R; Bougiatioti, A; Lin, J J; Nenes, A; Wolfe, G M; Hanisco, T F; Lee, B H; Lopez-Hilfiker, F D; Thornton, J A; Keutsch, F N; Kaiser, J; Mao, J; Hatch, C

2016-01-01

Natural emissions of ozone-and-aerosol-precursor gases such as isoprene and monoterpenes are high in the southeast of the US. In addition, anthropogenic emissions are significant in the Southeast US and summertime photochemistry is rapid. The NOAA-led SENEX (Southeast Nexus) aircraft campaign was one of the major components of the Southeast Atmosphere Study (SAS) and was focused on studying the interactions between biogenic and anthropogenic emissions to form secondary pollutants. During SENEX, the NOAA WP-3D aircraft conducted 20 research flights between 27 May and 10 July 2013 based out of Smyrna, TN. Here we describe the experimental approach, the science goals and early results of the NOAA SENEX campaign. The aircraft, its capabilities and standard measurements are described. The instrument payload is summarized including detection limits, accuracy, precision and time resolutions for all gas-and-aerosol phase instruments. The inter-comparisons of compounds measured with multiple instruments on the NOAA WP-3D are presented and were all within the stated uncertainties, except two of the three NO 2 measurements. The SENEX flights included day- and nighttime flights in the Southeast as well as flights over areas with intense shale gas extraction (Marcellus, Fayetteville and Haynesville shale). We present one example flight on 16 June 2013, which was a daytime flight over the Atlanta region, where several crosswind transects of plumes from the city and nearby point sources, such as power plants, paper mills and landfills, were flown. The area around Atlanta has large biogenic isoprene emissions, which provided an excellent case for studying the interactions between biogenic and anthropogenic emissions. In this example flight, chemistry in and outside the Atlanta plumes was observed for several hours after emission. The analysis of this flight showcases the strategies implemented to answer some of the main SENEX science questions.

Longitudinal Handling Qualities of the Tu-144LL Airplane and Comparisons With Other Large, Supersonic Aircraft

NASA Technical Reports Server (NTRS)

Cox, Timothy H.; Marshall, Alisa

2000-01-01

Four flights have been conducted using the Tu-144LL supersonic transport aircraft with the dedicated objective of collecting quantitative data and qualitative pilot comments. These data are compared with the following longitudinal flying qualities criteria: Neal-Smith, short-period damping, time delay, control anticipation parameter, phase delay (omega(sp)*T(theta(2))), pitch bandwidth as a function of time delay, and flight path as a function of pitch bandwidth. Determining the applicability of these criteria and gaining insight into the flying qualities of a large, supersonic aircraft are attempted. Where appropriate, YF-12, XB-70, and SR-71 pilot ratings are compared with the Tu-144LL results to aid in the interpretation of the Tu-144LL data and to gain insight into the application of criteria. The data show that approach and landing requirements appear to be applicable to the precision flightpath control required for up-and-away flight of large, supersonic aircraft. The Neal-Smith, control anticipation parameter, and pitch-bandwidth criteria tend to correlate with the pilot comments better than the phase delay criterion, omega(sp)*T(theta(2)). The data indicate that the detrimental flying qualities implication of decoupled pitch-attitude and flightpath responses occurring for high-speed flight may be mitigated by requiring the pilot to close the loop on flightpath or vertical speed.

Discussion and Practical Aspects on Control Allocation for a Multi-Rotor Helicopter

NASA Astrophysics Data System (ADS)

Ducard, G. J. J.; Hua, M.-D.

2011-09-01

This paper presents practical methods to improve the flight performance of an unmanned multi-rotor helicopter by using an efficient control allocation strategy. The flying vehicle considered is an hexacopter. It is indeed particularly suited for long missions and for carrying a significant payload such as all the sensors needed in the context of cartography, photogrammetry, inspection, surveillance and transportation. Moreover, a stable flight is often required for precise data recording during the mission. Therefore, a high performance flight control system is required to operate the UAV. However, the flight performance of a multi-rotor vehicle is tightly dependent on the control allocation strategy that is used to map the virtual control vector v = [T, L, M, N ]T composed of the thrust and the torques in roll, pitch and yaw, respectively, to the propellers' speed. This paper shows that a control allocation strategy based on the classical approach of pseudo-inverse matrix only exploits a limited range of the vehicle capabilities to generate thrust and moments. Thus, in this paper, a novel approach is presented, which is based on a weighted pseudo-inverse matrix method capable of exploiting a much larger domain in v. The proposed control allocation algorithm is designed with explicit laws for fast operation and low computational load, suitable for a small microcontroller with limited floating-point operation capability.

NASA's first Orion full-scale abort flight test crew module was placed in NASA Dryden's Abort Flight Test integration area for equipment installation.

NASA Image and Video Library

2008-04-01

A full-scale flight-test mockup of the Constellation program's Orion crew vehicle arrived at NASA's Dryden Flight Research Center in late March 2008 to undergo preparations for the first short-range flight test of the spacecraft's astronaut escape system later that year. Engineers and technicians at NASA's Langley Research Center fabricated the structure, which precisely represents the size, outer shape and mass characteristics of the Orion space capsule. The Orion crew module mockup was ferried to NASA Dryden on an Air Force C-17. After painting in the Edwards Air Force Base paint hangar, the conical capsule was taken to Dryden for installation of flight computers, instrumentation and other electronics prior to being sent to the U.S. Army's White Sands Missile Range in New Mexico for integration with the escape system and the first abort flight test in late 2008. The tests were designed to ensure a safe, reliable method of escape for astronauts in case of an emergency.

NASA Dryden Flight Research Center personnel accompany NASA's first Orion full-scale abort flight test crew module as it heads to its new home.

NASA Image and Video Library

2008-04-01

A full-scale flight-test mockup of the Constellation program's Orion crew vehicle arrived at NASA's Dryden Flight Research Center in late March 2008 to undergo preparations for the first short-range flight test of the spacecraft's astronaut escape system later that year. Engineers and technicians at NASA's Langley Research Center fabricated the structure, which precisely represents the size, outer shape and mass characteristics of the Orion space capsule. The Orion crew module mockup was ferried to NASA Dryden on an Air Force C-17. After painting in the Edwards Air Force Base paint hangar, the conical capsule was taken to Dryden for installation of flight computers, instrumentation and other electronics prior to being sent to the U.S. Army's White Sands Missile Range in New Mexico for integration with the escape system and the first abort flight test in late 2008. The tests were designed to ensure a safe, reliable method of escape for astronauts in case of an emergency.

Particulate Characterization and Control Evaluation for Carbon Fiber Composite Aircraft Crash Recovery Operations

DTIC Science & Technology

2010-03-01

Advanced Composite Office, Wright-Patterson BEE Flight, and USAFSAM for their help procuring the materials and supplies needed to perform this study...through the cyclone. (Cohen & Charles S . McCammonn, 2001) The major limitation of the cyclone is that the cut curve of the cyclone does not precisely...If the pump is not precisely calibrated to the specified flow the cut point will be altered. (Cohen & Charles S . McCammonn, 2001) Once the sample

Design and implementation of a compliant robot with force feedback and strategy planning software

NASA Technical Reports Server (NTRS)

Premack, T.; Strempek, F. M.; Solis, L. A.; Brodd, S. S.; Cutler, E. P.; Purves, L. R.

1984-01-01

Force-feedback robotics techniques are being developed for automated precision assembly and servicing of NASA space flight equipment. Design and implementation of a prototype robot which provides compliance and monitors forces is in progress. Computer software to specify assembly steps and makes force feedback adjustments during assembly are coded and tested for three generically different precision mating problems. A model program demonstrates that a suitably autonomous robot can plan its own strategy.

Gravity Probe B: Testing Einstein with Gyroscopes

NASA Technical Reports Server (NTRS)

Geveden, Rex D.; May, Todd

2003-01-01

Some 40 years in the making, NASA' s historic Gravity Probe B (GP-B) mission is scheduled to launch aboard a Delta II in 2003. GP-B will test two extraordinary predictions from Einstein's General Relativity: geodetic precession and the Lense-Thirring effect (frame-dragging). Employing tiny, ultra-precise gyroscopes, GP-B features a measurement accuracy of 0.5 milli-arc-seconds per year. The extraordinary measurement precision is made possible by a host of breakthrough technologies, including electro-statically suspended, super-conducting quartz gyroscopes; virtual elimination of magnetic flux; a solid quartz star tracking telescope; helium microthrusters for drag-free control of the spacecraft; and a 2400 liter superfluid helium dewar. This paper will provide an overview of the science, key technologies, flight hardware, integration and test, and flight operations of the GP-B space vehicle. It will also examine some of the technical management challenges of a large-scale, technology-driven, Principal Investigator-led mission.

Gravity Probe B: Testing Einstein with Gyroscopes

NASA Technical Reports Server (NTRS)

Geveden, Rex D.; May, Todd

2003-01-01

Some 40 years in the making, NASA s historic Gravity Probe B (GP-B) mission is scheduled to launch aboard a Delta I1 in 2003. GP-B will test two extraordinary predictions from Einstein s General Relativity: geodetic precession and the Lense-Thirring effect (frame-dragging). Employing tiny, ultra-precise gyroscopes, GP-B features a measurement accuracy of 0.5 milli-arc-seconds per year. The extraordinary measurement precision is made possible by a host of breakthrough technologies, including electro-statically suspended, super-conducting quartz gyroscopes; virtual elimination of magnetic flux; a solid quartz star- tracking telescope; helium microthrusters for drag-free control of the spacecraft; and a 2400 liter superfluid helium dewar. This paper will provide an overview of the science, key technologies, flight hardware, integration and test, and flight operations of the GP-B space vehicle. It will also examine some of the technical management challenges of a large-scale, technology-driven, Principal Investigator-led mission.

Precision Cleaning - Path to Premier

NASA Technical Reports Server (NTRS)

Mackler, Scott E.

2008-01-01

ITT Space Systems Division s new Precision Cleaning facility provides critical cleaning and packaging of aerospace flight hardware and optical payloads to meet customer performance requirements. The Precision Cleaning Path to Premier Project was a 2007 capital project and is a key element in the approved Premier Resource Management - Integrated Supply Chain Footprint Optimization Project. Formerly precision cleaning was located offsite in a leased building. A new facility equipped with modern precision cleaning equipment including advanced process analytical technology and improved capabilities was designed and built after outsourcing solutions were investigated and found lacking in ability to meet quality specifications and schedule needs. SSD cleans parts that can range in size from a single threaded fastener all the way up to large composite structures. Materials that can be processed include optics, composites, metals and various high performance coatings. We are required to provide verification to our customers that we have met their particulate and molecular cleanliness requirements and we have that analytical capability in this new facility. The new facility footprint is approximately half the size of the former leased operation and provides double the amount of throughput. Process improvements and new cleaning equipment are projected to increase 1st pass yield from 78% to 98% avoiding $300K+/yr in rework costs. Cost avoidance of $350K/yr will result from elimination of rent, IT services, transportation, and decreased utility costs. Savings due to reduced staff expected to net $4-500K/yr.

Mission Report on the Orbiter Camera Payload System (OCPS) Large Format Camera (LFC) and Attitude Reference System (ARS)

NASA Technical Reports Server (NTRS)

Mollberg, Bernard H.; Schardt, Bruton B.

1988-01-01

The Orbiter Camera Payload System (OCPS) is an integrated photographic system which is carried into earth orbit as a payload in the Space Transportation System (STS) Orbiter vehicle's cargo bay. The major component of the OCPS is a Large Format Camera (LFC), a precision wide-angle cartographic instrument that is capable of producing high resolution stereo photography of great geometric fidelity in multiple base-to-height (B/H) ratios. A secondary, supporting system to the LFC is the Attitude Reference System (ARS), which is a dual lens Stellar Camera Array (SCA) and camera support structure. The SCA is a 70-mm film system which is rigidly mounted to the LFC lens support structure and which, through the simultaneous acquisition of two star fields with each earth-viewing LFC frame, makes it possible to determine precisely the pointing of the LFC optical axis with reference to the earth nadir point. Other components complete the current OCPS configuration as a high precision cartographic data acquisition system. The primary design objective for the OCPS was to maximize system performance characteristics while maintaining a high level of reliability compatible with Shuttle launch conditions and the on-orbit environment. The full-up OCPS configuration was launched on a highly successful maiden voyage aboard the STS Orbiter vehicle Challenger on October 5, 1984, as a major payload aboard mission STS 41-G. This report documents the system design, the ground testing, the flight configuration, and an analysis of the results obtained during the Challenger mission STS 41-G.

Microfabricated X-Ray Optics Technology Development for the Constellation-X Mission

NASA Technical Reports Server (NTRS)

Schattenburg, Mark L.

2003-01-01

During the period of this Cooperative Agreement, MIT developed advanced methods for applying silicon micro-stuctures for the precision assembly of foil x-ray optics in support of the Constellution-X Spectroscopy X-ray Telescope (SXT) development effort at Goddard Space Flight Center (GSFC). MIT developed improved methods for fabricating and characterizing the precision silicon micro-combs. MIT also developed and characterized assembly tools and several types of metrology tools in order to characterize and reduce the errors associated with precision assembly of foil optics. Results of this effort were published and presented to the scientific community and the GSFC SXT team.

Research and technology, 1990: Goddard Space Flight Center

NASA Technical Reports Server (NTRS)

1990-01-01

Goddard celebrates 1990 as a banner year in space based astronomy. From above the Earth's obscuring atmosphere, four major orbiting observatories examined the heavens at wavelengths that spanned the electromagnetic spectrum. In the infrared and microwave, the Cosmic Background Explorer (COBE), measured the spectrum and angular distribution of the cosmic background radiation to extraordinary precision. In the optical and UV, the Hubble Space Telescope has returned spectacular high resolution images and spectra of a wealth of astronomical objects. The Goddard High Resolution Spectrograph has resolved dozens of UV spectral lines which are as yet unidentified because they have never before been seen in any astronomical spectrum. In x rays, the Roentgen Satellite has begun returning equally spectacular images of high energy objects within our own and other galaxies.

Phonotactic flight of the parasitoid fly Emblemasoma auditrix (Diptera: Sarcophagidae).

PubMed

Tron, Nanina; Lakes-Harlan, Reinhard

2017-01-01

The parasitoid fly Emblemasoma auditrix locates its hosts using acoustic cues from sound producing males of the cicada Okanagana rimosa. Here, we experimentally analysed the flight path of the phonotaxis from a landmark to the target, a hidden loudspeaker in the field. During flight, the fly showed only small lateral deviations. The vertical flight direction angles were initially negative (directed downwards relative to starting position), grew positive (directed upwards) in the second half of the flight, and finally flattened (directed horizontally or slightly upwards), typically resulting in a landing above the loudspeaker. This phonotactic flight pattern was largely independent from sound pressure level or target distance, but depended on the elevation of the sound source. The flight velocity was partially influenced by sound pressure level and distance, but also by elevation. The more elevated the target, the lower was the speed. The accuracy of flight increased with elevation of the target as well as the landing precision. The minimal vertical angle difference eliciting differences in behaviour was 10°. By changing the elevation of the acoustic target after take-off, we showed that the fly is able to orientate acoustically while flying.

UAVSAR Instrument: Current Operations and Planned Upgrades

NASA Technical Reports Server (NTRS)

Lou, Yunling; Hensley, Scott; Chao, Roger; Chapin, Elaine; Heavy, Brandon; Jones, Cathleen; Miller, Timothy; Naftel, Chris; Fratello, David

2011-01-01

The Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) instrument is a pod-based Lband polarimetric synthetic aperture radar (SAR), specifically designed to acquire airborne repeat track SAR data for differential interferometric measurements. This instrument is currently installed on the NASA Gulfstream- III (G-III) aircraft with precision real-time Global Positioning System (GPS) and a sensor-controlled flight management system for precision repeat-pass data acquisitions. UAVSAR has conducted engineering and preliminary science data flights since October 2007 on the G-III. We are porting the radar to the Global Hawk Unmanned Airborne Vehicle (UAV) to enable long duration/long range data campaigns. We plan to install two radar pods (each with its own active array antenna) under the wings of the Global Hawk to enable the generation of precision topographic maps and single pass polarimetric-interferometry (SPI) providing vertical structure of ice and vegetation. Global Hawk's range of 8000 nm will enable regional surveys with far fewer sorties as well as measurements of remote locations without the need for long and complicated deployments. We are also developing P-band polarimetry and Ka-band single-pass interferometry capabilities on UAVSAR by replacing the radar antenna and front-end electronics to operate at these

Application of phase matching autofocus in airborne long-range oblique photography camera

NASA Astrophysics Data System (ADS)

Petrushevsky, Vladimir; Guberman, Asaf

2014-06-01

The Condor2 long-range oblique photography (LOROP) camera is mounted in an aerodynamically shaped pod carried by a fast jet aircraft. Large aperture, dual-band (EO/MWIR) camera is equipped with TDI focal plane arrays and provides high-resolution imagery of extended areas at long stand-off ranges, at day and night. Front Ritchey-Chretien optics is made of highly stable materials. However, the camera temperature varies considerably in flight conditions. Moreover, a composite-material structure of the reflective objective undergoes gradual dehumidification in dry nitrogen atmosphere inside the pod, causing some small decrease of the structure length. The temperature and humidity effects change a distance between the mirrors by just a few microns. The distance change is small but nevertheless it alters the camera's infinity focus setpoint significantly, especially in the EO band. To realize the optics' resolution potential, the optimal focus shall be constantly maintained. In-flight best focus calibration and temperature-based open-loop focus control give mostly satisfactory performance. To get even better focusing precision, a closed-loop phase-matching autofocus method was developed for the camera. The method makes use of an existing beamsharer prism FPA arrangement where aperture partition exists inherently in an area of overlap between the adjacent detectors. The defocus is proportional to an image phase shift in the area of overlap. Low-pass filtering of raw defocus estimate reduces random errors related to variable scene content. Closed-loop control converges robustly to precise focus position. The algorithm uses the temperature- and range-based focus prediction as an initial guess for the closed-loop phase-matching control. The autofocus algorithm achieves excellent results and works robustly in various conditions of scene illumination and contrast.

Evaluation of a technique to simplify area navigation and required navigation performance charts

DOT National Transportation Integrated Search

2013-06-30

Performance based navigation (PBN), an enabler for the Federal Aviation Administration's Next Generation Air Transportation System (NextGEN), supports the design of more precise flight procedures. However, these new procedures can be visually complex...

High precision mass measurements for wine metabolomics

PubMed Central

Roullier-Gall, Chloé; Witting, Michael; Gougeon, Régis D.; Schmitt-Kopplin, Philippe

2014-01-01

An overview of the critical steps for the non-targeted Ultra-High Performance Liquid Chromatography coupled with Quadrupole Time-of-Flight Mass Spectrometry (UPLC-Q-ToF-MS) analysis of wine chemistry is given, ranging from the study design, data preprocessing and statistical analyses, to markers identification. UPLC-Q-ToF-MS data was enhanced by the alignment of exact mass data from FTICR-MS, and marker peaks were identified using UPLC-Q-ToF-MS2. In combination with multivariate statistical tools and the annotation of peaks with metabolites from relevant databases, this analytical process provides a fine description of the chemical complexity of wines, as exemplified in the case of red (Pinot noir) and white (Chardonnay) wines from various geographic origins in Burgundy. PMID:25431760

Multispectral and DSLR sensors for assessing crop stress in corn and cotton using fixed-wing unmanned air systems

NASA Astrophysics Data System (ADS)

Valasek, John; Henrickson, James V.; Bowden, Ezekiel; Shi, Yeyin; Morgan, Cristine L. S.; Neely, Haly L.

2016-05-01

As small unmanned aircraft systems become increasingly affordable, reliable, and formally recognized under federal regulation, they become increasingly attractive as novel platforms for civil applications. This paper details the development and demonstration of fixed-wing unmanned aircraft systems for precision agriculture tasks. Tasks such as soil moisture content and high throughput phenotyping are considered. Rationale for sensor, vehicle, and ground equipment selections are provided, in addition to developed flight operation procedures for minimal numbers of crew. Preliminary imagery results are presented and analyzed, and these results demonstrate that fixed-wing unmanned aircraft systems modified to carry non-traditional sensors at extended endurance durations can provide high quality data that is usable for serious scientific analysis.

High precision mass measurements for wine metabolomics

NASA Astrophysics Data System (ADS)

Roullier-Gall, Chloé; Witting, Michael; Gougeon, Régis; Schmitt-Kopplin, Philippe

2014-11-01

An overview of the critical steps for the non-targeted Ultra-High Performance Liquid Chromatography coupled with Quadrupole Time-of-Flight Mass Spectrometry (UPLC-Q-ToF-MS) analysis of wine chemistry is given, ranging from the study design, data preprocessing and statistical analyses, to markers identification. UPLC-Q-ToF-MS data was enhanced by the alignment of exact mass data from FTICR-MS, and marker peaks were identified using UPLC-Q-ToF-MS². In combination with multivariate statistical tools and the annotation of peaks with metabolites from relevant databases, this analytical process provides a fine description of the chemical complexity of wines, as exemplified in the case of red (Pinot noir) and white (Chardonnay) wines from various geographic origins in Burgundy.

An in flight investigation of pitch rate flight control systems and application of frequency domain and time domain predictive criteria

NASA Technical Reports Server (NTRS)

Berthe, C. J.; Chalk, C. R.; Sarrafian, S.

1984-01-01

The degree of attitude control provided by current integral-proportional pitch rate command-type control systems, while a prerequisite for flared landing, is insufficient for 'Level 1' performance. The pilot requires 'surrogate' feedback cues to precisely control flight path in the landing flare. Monotonic stick forces and pilot station vertical acceleration are important cues which can be provided by means of angle-of-attack and pitch rate feedback in order to achieve conventional short period and phugoid characteristics. Integral-proportional pitch rate flight control systems can be upgraded to Level 1 flared landing performance by means of lead/lag and washout prefilters in the command path. Strong pilot station vertical acceleration cues can provide Level 1 flared landing performance even in the absence of monotonic stick forces.

Design, Development & Flight Testing Of The U.S. Army 4200 sq ft Parafoil Recovery System

NASA Technical Reports Server (NTRS)

Bennett, Thomas W.; Fox, Roy

2007-01-01

The purpose of this paper is to describe the design, development and flight testing of the U.S. Army 4200 ft(sup 2) parafoil recovery system built under NASA Contract NAS9-00076. The 4200 ft(sup 2) parafoil described herein was a potential candidate to fulfill the U.S. Army requirement for a 10,000 lb useable payload precision guided recovery system. Design heritage as well as specific features, like lower surface inlets, confluence fitting, upper surface energy modulator design, deployment bag design and 60 ft diameter Ringslot drogue will be discussed. Initial flight test results, ground testing of various components to verify design margin and configuration changes will also be discussed. The 4200 ft(sup 2) parafoil recovery system completed three flight tests during 2003 at payload weights of over 15,000 lbs.

Design, Development and Flight Testing of the U.S. Army 4200 sq ft Parafoil Recovery System

NASA Technical Reports Server (NTRS)

Bennett, Thomas W.; Fox, Roy, Jr.

2005-01-01

The purpose of this paper is to describe the design, development and flight-testing of the U.S. Army 4200 sq ft parafoil recovery system built under NASA Contract NAS 9-00076. The 4200 f? parafoil described herein was a potential candidate to fulfill the U.S. Army requirement for a 10,000 lb useable payload precision guided recovery system. Design heritage as well as specific features, like lower surface inlets, confluence fitting, upper surface energy modulator design, deployment bag design and 60 ft diameter Ringslot drogue will be discussed. Initial flight test results, ground testing of various components to verify design margin and configuration changes will also be discussed. The 4200 sq ft parafoil recovery system completed three flight tests during 2003 at payload weights of over 15,000 Ibs

A Lightweight, Precision-Deployable, Optical Bench for High Energy Astrophysics Missions

NASA Astrophysics Data System (ADS)

Danner, Rolf; Dailey, D.; Lillie, C.

2011-09-01

The small angle of total reflection for X-rays, forcing grazing incidence optics with large collecting areas to long focal lengths, has been a fundamental barrier to the advancement of high-energy astrophysics. Design teams around the world have long recognized that a significant increase in effective area beyond Chandra and XMM-Newton requires either a deployable optical bench or separate X-ray optics and instrument module on formation flying spacecraft. Here, we show that we have in hand the components for a lightweight, precision-deployable optical bench that, through its inherent design features, is the affordable path to the next generation of imaging high-energy astrophysics missions. We present our plans for a full-scale engineering model of a deployable optical bench for Explorer-class missions. We intend to use this test article to raise the technology readiness level (TRL) of the tensegrity truss for a lightweight, precision-deployable optical bench for high-energy astrophysics missions from TRL 3 to TRL 5 through a set of four well-defined technology milestones. The milestones cover the architecture's ability to deploy and control the focal point, characterize the deployed dynamics, determine long-term stability, and verify the stowed load capability. Our plan is based on detailed design and analysis work and the construction of a first prototype by our team. Building on our prior analysis and the high TRL of the architecture components we are ready to move on to the next step. The key elements to do this affordably are two existing, fully characterized, flight-quality, deployable booms. After integrating them into the test article, we will demonstrate that our architecture meets the deployment accuracy, adjustability, and stability requirements. The same test article can be used to further raise the TRL in the future.

Precision laser range finder system design for Advanced Technology Laboratory applications

NASA Technical Reports Server (NTRS)

Golden, K. E.; Kohn, R. L.; Seib, D. H.

1974-01-01

Preliminary system design of a pulsed precision ruby laser rangefinder system is presented which has a potential range resolution of 0.4 cm when atmospheric effects are negligible. The system being proposed for flight testing on the advanced technology laboratory (ATL) consists of a modelocked ruby laser transmitter, course and vernier rangefinder receivers, optical beacon retroreflector tracking system, and a network of ATL tracking retroreflectors. Performance calculations indicate that spacecraft to ground ranging accuracies of 1 to 2 cm are possible.

Flight Test Techniques Used to Evaluate Performance Benefits During Formation Flight

NASA Technical Reports Server (NTRS)

Ray, Ronald J.; Cobleigh, Brent R.; Vachon, M. Jake; SaintJohn, Clinton

2002-01-01

The Autonomous Formation Flight research project has been implemented at the NASA Dryden Flight Research Center to demonstrate the benefits of formation flight and develop advanced technologies to facilitate exploiting these benefits. Two F/A-18 aircraft have been modified to precisely control and monitor relative position, and to determine performance of the trailing airplane. Flight test maneuvers and analysis techniques have been developed to determine the performance advantages, including drag and fuel flow reductions and improvements in range factor. By flying the trailing airplane through a matrix of lateral, longitudinal, and vertical offset positions, a detailed map of the performance benefits has been obtained at two flight conditions. Significant performance benefits have been obtained during this flight test phase. Drag reductions of more than 20 percent and fuel flow reductions of more than 18 percent have been measured at flight conditions of Mach 0.56 and an altitude of 25,000 ft. The results show favorable agreement with published theory and generic predictions. An F/A-18 long-range cruise mission at Mach 0.8 and an altitude of 40,000 ft has been simulated in the optimum formation position and has demonstrated a 14-percent fuel reduction when compared with a controlled chase airplane of similar configuration.

Chemical Analysis of the Chinese Liquor Luzhoulaojiao by Comprehensive Two-Dimensional Gas Chromatography/Time-of-Flight Mass Spectrometry

PubMed Central

Yao, Feng; Yi, Bin; Shen, Caihong; Tao, Fei; Liu, Yumin; Lin, Zhixin; Xu, Ping

2015-01-01

Luzhoulaojiao liquor is a type of Chinese liquor that dates back hundreds of years, but whose precise chemical composition remains unknown. This paper describes the screening of the liquor and the identification of its compounds using comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (GC × GC/TOF-MS). Samples were prepared by both liquid-liquid extraction and solid-phase microextraction, which facilitated the detection of thousands of compounds in the liquor, thus demonstrating the superior performance of the proposed method over those reported in previous studies. A total of 320 compounds were common to all 18 types of Luzhoulaojiao liquor studied here, and 13 abundant and potentially bioactive compounds were further quantified. The results indicated that the high-performance method presented here is well suited for the detection and identification of compounds in liquors. This study also contributes to enriching our knowledge of the contents of Chinese liquors. PMID:25857434

Cavity-Enhanced Quantum-Cascade Laser-Based Instrument for Trace gas Measurements

NASA Astrophysics Data System (ADS)

Provencal, R.; Gupta, M.; Owano, T.; Baer, D.; Ricci, K.; O'Keefe, A.

2005-12-01

An autonomous instrument based on Off-Axis Integrated Cavity Output Spectroscopy has been successfully deployed for measurements of CO in the troposphere and tropopause onboard a NASA DC-8 aircraft. The instrument consists of a measurement cell comprised of two high reflectivity mirrors, a continuous-wave quantum-cascade laser, gas sampling system, control and data acquisition electronics, and data analysis software. The instrument reports CO mixing ratio at a 1-Hz rate based on measured absorption, gas temperature and pressure using Beer's Law. During several flights in May-June 2004 and January 2005 that reached altitudes of 41000 ft, the instrument recorded CO values with a precision of 0.2 ppbv (1-s averaging time). Despite moderate turbulence and measurements of particulate-laden airflows, the instrument operated consistently and did not require any maintenance, mirror cleaning, or optical realignment during the flights. We will also present recent development efforts to extend the instrument's capabilities for the measurements of CH4, N2O and CO in real time.

Characterization and quantitative analysis of phenylpropanoid amides in eggplant (Solanum melongena L.) by high performance liquid chromatography coupled with diode array detection and hybrid ion trap time-of-flight mass spectrometry.

PubMed

Sun, Jing; Song, Yue-Lin; Zhang, Jing; Huang, Zheng; Huo, Hui-Xia; Zheng, Jiao; Zhang, Qian; Zhao, Yun-Fang; Li, Jun; Tu, Peng-Fei

2015-04-08

Eggplant (Solanum melongena L.) is a famous edible and medicinal plant. Despite being widely cultivated and used, data on certain parts other than the fruit are limited. The present study focused on the qualitative and quantitative analysis of the chemical constituents, particularly phenylpropanoid amides (PAs), in eggplant. The mass fragmentation patterns of PAs were proposed using seven authentic compounds with the assistance of a hybrid ion trap time-of-flight mass spectrometer. Thirty-seven compounds (27 PAs and 10 others) were detected and plausibly assigned in the different parts of eggplant. Afterward, a reliable method based on liquid chromatography coupled with diode array detection was developed, validated, and applied for the simultaneous determination of seven PAs and three caffeoylquinic acids in 17 batches of eggplant roots with satisfactory accuracy, precision, and reproducibility, which could not only provide global chemical insight of eggplant but also offer a reliable tool for quality control.

Online Recorded Data-Based Composite Neural Control of Strict-Feedback Systems With Application to Hypersonic Flight Dynamics.

PubMed

Xu, Bin; Yang, Daipeng; Shi, Zhongke; Pan, Yongping; Chen, Badong; Sun, Fuchun

2017-09-25

This paper investigates the online recorded data-based composite neural control of uncertain strict-feedback systems using the backstepping framework. In each step of the virtual control design, neural network (NN) is employed for uncertainty approximation. In previous works, most designs are directly toward system stability ignoring the fact how the NN is working as an approximator. In this paper, to enhance the learning ability, a novel prediction error signal is constructed to provide additional correction information for NN weight update using online recorded data. In this way, the neural approximation precision is highly improved, and the convergence speed can be faster. Furthermore, the sliding mode differentiator is employed to approximate the derivative of the virtual control signal, and thus, the complex analysis of the backstepping design can be avoided. The closed-loop stability is rigorously established, and the boundedness of the tracking error can be guaranteed. Through simulation of hypersonic flight dynamics, the proposed approach exhibits better tracking performance.

Propellant Feed Subsystem for a 26 kW flight arcjet propulsion system

NASA Astrophysics Data System (ADS)

Vaughan, C. E.; Morris, J. P.

1993-06-01

The USAF arcjet ATTD program demanded the development of a low-cost ammonia Propellant Feed Subsystem (PFS). A flow rate of 240 +/- 5 mg/sec during a total of ten 15-min ammonia outflows was required for the flight mission. The precision of the flow tolerance required a departure from the design of previous ammonia propellant feed systems. Since a propellant management device was not used, thermocapillary forces were explored as a means to limit outflow of liquid phase ammonia. A high energy density feedline heater with an internal wick was developed to guarantee that only gas phase propellant would reach the arcjet. A digital control algorithm was developed to implement bang-bang control of mass flow rate metered by a sonic venturi. Development tests of this system have been completed. The system is capable of continuous gas phase outflows regardless of orientation. Integrated tests with the arcjet and power conditioning unit have also been successfully completed.

Chemical Analysis of the Chinese Liquor Luzhoulaojiao by Comprehensive Two-Dimensional Gas Chromatography/Time-of-Flight Mass Spectrometry

NASA Astrophysics Data System (ADS)

Yao, Feng; Yi, Bin; Shen, Caihong; Tao, Fei; Liu, Yumin; Lin, Zhixin; Xu, Ping

2015-04-01

Luzhoulaojiao liquor is a type of Chinese liquor that dates back hundreds of years, but whose precise chemical composition remains unknown. This paper describes the screening of the liquor and the identification of its compounds using comprehensive two-dimensional gas chromatography/time-of-flight mass spectrometry (GC × GC/TOF-MS). Samples were prepared by both liquid-liquid extraction and solid-phase microextraction, which facilitated the detection of thousands of compounds in the liquor, thus demonstrating the superior performance of the proposed method over those reported in previous studies. A total of 320 compounds were common to all 18 types of Luzhoulaojiao liquor studied here, and 13 abundant and potentially bioactive compounds were further quantified. The results indicated that the high-performance method presented here is well suited for the detection and identification of compounds in liquors. This study also contributes to enriching our knowledge of the contents of Chinese liquors.

Robotic Lunar Landers For Science And Exploration

NASA Technical Reports Server (NTRS)

Cohen, B. A.; Bassler, J. A.; Morse, B. J.; Reed, C. L. B.

2010-01-01

NASA Marshall Space Flight Center and The Johns Hopkins University Applied Physics Laboratory have been conducting mission studies and performing risk reduction activities for NASA s robotic lunar lander flight projects. In 2005, the Robotic Lunar Exploration Program Mission #2 (RLEP-2) was selected as an ESMD precursor robotic lander mission to demonstrate precision landing and determine if there was water ice at the lunar poles; however, this project was canceled. Since 2008, the team has been supporting SMD designing small lunar robotic landers for science missions, primarily to establish anchor nodes of the International Lunar Network (ILN), a network of lunar geophysical nodes. Additional mission studies have been conducted to support other objectives of the lunar science community. This paper describes the current status of the MSFC/APL robotic lunar mission studies and risk reduction efforts including high pressure propulsion system testing, structure and mechanism development and testing, long cycle time battery testing, combined GN&C and avionics testing, and two autonomous lander test articles.

Global fast dynamic terminal sliding mode control for a quadrotor UAV.

PubMed

Xiong, Jing-Jing; Zhang, Guo-Bao

2017-01-01

A control method based on global fast dynamic terminal sliding mode control (TSMC) technique is proposed to design the flight controller for performing the finite-time position and attitude tracking control of a small quadrotor UAV. Firstly, the dynamic model of the quadrotor is divided into two subsystems, i.e., a fully actuated subsystem and an underactuated subsystem. Secondly, the dynamic flight controllers of the quadrotor are formulated based on global fast dynamic TSMC, which is able to guarantee that the position and velocity tracking errors of all system state variables converge to zero in finite-time. Moreover, the global fast dynamic TSMC is also able to eliminate the chattering phenomenon caused by the switching control action and realize the high precision performance. In addition, the stabilities of two subsystems are demonstrated by Lyapunov theory, respectively. Lastly, the simulation results are given to illustrate the effectiveness and robustness of the proposed control method in the presence of external disturbances. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

Real-time, autonomous precise satellite orbit determination using the global positioning system

NASA Astrophysics Data System (ADS)

Goldstein, David Ben

2000-10-01

The desire for autonomously generated, rapidly available, and highly accurate satellite ephemeris is growing with the proliferation of constellations of satellites and the cost and overhead of ground tracking resources. Autonomous Orbit Determination (OD) may be done on the ground in a post-processing mode or in real-time on board a satellite and may be accomplished days, hours or immediately after observations are processed. The Global Positioning System (GPS) is now widely used as an alternative to ground tracking resources to supply observation data for satellite positioning and navigation. GPS is accurate, inexpensive, provides continuous coverage, and is an excellent choice for autonomous systems. In an effort to estimate precise satellite ephemeris in real-time on board a satellite, the Goddard Space Flight Center (GSFC) created the GPS Enhanced OD Experiment (GEODE) flight navigation software. This dissertation offers alternative methods and improvements to GEODE to increase on board autonomy and real-time total position accuracy and precision without increasing computational burden. First, GEODE is modified to include a Gravity Acceleration Approximation Function (GAAF) to replace the traditional spherical harmonic representation of the gravity field. Next, an ionospheric correction method called Differenced Range Versus Integrated Doppler (DRVID) is applied to correct for ionospheric errors in the GPS measurements used in GEODE. Then, Dynamic Model Compensation (DMC) is added to estimate unmodeled and/or mismodeled forces in the dynamic model and to provide an alternative process noise variance-covariance formulation. Finally, a Genetic Algorithm (GA) is implemented in the form of Genetic Model Compensation (GMC) to optimize DMC forcing noise parameters. Application of GAAF, DRVID and DMC improved GEODE's position estimates by 28.3% when applied to GPS/MET data collected in the presence of Selective Availability (SA), 17.5% when SA is removed from the GPS/MET data and 10.8% on SA free TOPEX data. Position estimates with RSS errors below I meter are now achieved using SA free TOPEX data. DRVID causes an increase in computational burden while GAAF and DMC reduce computational burden. The net effect of applying GAAF, DRVID and DMC is an improvement in GEODE's accuracy/precision without an increase in computational burden.

Status of a UAVSAR designed for repeat pass interferometry for deformation measurements

NASA Technical Reports Server (NTRS)

Hensley, Scott; Wheeler, Kevin; Sadowy, Greg; Miller, Tim; Shaffer, Scott; Muellerschoen, Ron; Jones, Cathleen; Zebker, Howard; Madsen, Soren; Paul, Rose

2005-01-01

NASA's Jet Propulsion Laboratory is currently implementing a reconfigurable polarimetric L-band synthetic aperture radar (SAR), specifically designed to acquire airborne repeat track interferometric (RTI) SAR data, also known as differential interferometric measurements. Differential interferometry can provide key deformation measurements, important for the scientific studies of Earthquakes and volcanoes. Using precision real-time GPS and a sensor controlled flight management system, the system will be able to fly predefined paths with great precision. The expected performance of the flight control system will constrain the flight path to be within a 10 m diameter tube about the desired flight track. The radar wilI be designed to operate on a UAV (Unpiloted Aria1 Vehicle) but will initially be demonstrated on a minimally piloted vehicle (MPV), such as the Proteus buitt by Scaled Composites or on a NASA Gulfstream III. The radar design is a fully polarimetric with an 80 MHz bandwidth (2 m range resolution) and 16 km range swath. The antenna is an electronically steered along track to assure that the actual antenna pointing can be controlled independent of the wind direction and speed. Other features supported by the antenna include an elevation monopulse option and a pulse-to-pulse resteering capability that will enable some novel modes of operation. The system will nominally operate at 45,000 ft (13800 m). The program began out as an Instrument Incubator Project (IIP) funded by NASA Earth Science and Technology Office (ESTO).

Airborne field strength monitoring

NASA Astrophysics Data System (ADS)

Bredemeyer, J.; Kleine-Ostmann, T.; Schrader, T.; Münter, K.; Ritter, J.

2007-06-01

In civil and military aviation, ground based navigation aids (NAVAIDS) are still crucial for flight guidance even though the acceptance of satellite based systems (GNSS) increases. Part of the calibration process for NAVAIDS (ILS, DME, VOR) is to perform a flight inspection according to specified methods as stated in a document (DOC8071, 2000) by the International Civil Aviation Organization (ICAO). One major task is to determine the coverage, or, in other words, the true signal-in-space field strength of a ground transmitter. This has always been a challenge to flight inspection up to now, since, especially in the L-band (DME, 1GHz), the antenna installed performance was known with an uncertainty of 10 dB or even more. In order to meet ICAO's required accuracy of ±3 dB it is necessary to have a precise 3-D antenna factor of the receiving antenna operating on the airborne platform including all losses and impedance mismatching. Introducing precise, effective antenna factors to flight inspection to achieve the required accuracy is new and not published in relevant papers yet. The authors try to establish a new balanced procedure between simulation and validation by airborne and ground measurements. This involves the interpretation of measured scattering parameters gained both on the ground and airborne in comparison with numerical results obtained by the multilevel fast multipole algorithm (MLFMA) accelerated method of moments (MoM) using a complex geometric model of the aircraft. First results will be presented in this paper.

Test Capability Enhancements to the NASA Langley 8-Foot High Temperature Tunnel

NASA Technical Reports Server (NTRS)

Harvin, S. F.; Cabell, K. F.; Gallimore, S. D.; Mekkes, G. L.

2006-01-01

The NASA Langley 8-Foot High Temperature Tunnel produces true enthalpy environments simulating flight from Mach 4 to Mach 7, primarily for airbreathing propulsion and aerothermal/thermo-structural testing. Flow conditions are achieved through a methane-air heater and nozzles producing aerodynamic Mach numbers of 4, 5 or 7 and have exit diameters of 8 feet or 4.5 feet. The 12-ft long free-jet test section, housed inside a 26-ft vacuum sphere, accommodates large test articles. Recently, the facility underwent significant upgrades to support hydrocarbon fueled scramjet engine testing and to expand flight simulation capability. The upgrades were required to meet engine system development and flight clearance verification requirements originally defined by the joint NASA-Air Force X-43C Hypersonic Flight Demonstrator Project and now the Air Force X-51A Program. Enhancements to the 8-Ft. HTT were made in four areas: 1) hydrocarbon fuel delivery; 2) flight simulation capability; 3) controls and communication; and 4) data acquisition/processing. The upgrades include the addition of systems to supply ethylene and liquid JP-7 to test articles; a Mach 5 nozzle with dynamic pressure simulation capability up to 3200 psf, the addition of a real-time model angle-of-attack system; a new programmable logic controller sub-system to improve process controls and communication with model controls; the addition of MIL-STD-1553B and high speed data acquisition systems and a classified data processing environment. These additions represent a significant increase to the already unique test capability and flexibility of the facility, and complement the existing array of test support hardware such as a model injection system, radiant heaters, six-component force measurement system, and optical flow field visualization hardware. The new systems support complex test programs that require sophisticated test sequences and precise management of process fluids. Furthermore, the new systems, such as the real-time angle of attack system and the new programmable logic controller enhance the test efficiency of the facility. The motivation for the upgrades and the expanded capabilities is described here.

The Bess Investigation of the Origin of Cosmic-ray Antiprotons and Search for Cosmological Antimatter

NASA Technical Reports Server (NTRS)

Mitchell, John; Yamamoto, Akira; Yoshimura, Koji; Makida, Yasuhiro; Matsuda, Shinya; Hasegawa, Masaya; Horikoshi, Atsushi; Tanaka,Ken-ichi; Suzuki, Junichi; Nishimura, Jun;

Enhanced flight symbology for wide-field-of-view helmet-mounted displays

NASA Astrophysics Data System (ADS)

Rogers, Steven P.; Asbury, Charles N.; Szoboszlay, Zoltan P.

2003-09-01

A series of studies was conducted to improve the Army aviator's ability to perform night missions by developing innovative symbols that capitalize on the advantages of new wide field-of-view (WFOV) helmet-mounted displays (HMDs). The most important outcomes of the research were two new symbol types called the Cylinder and the Flight Path Predictor. The Cylinder provides a large symbolic representation of real-world orientation that enables pilots to maintain the world frame of reference even if the visibility of the world is lost due to dust, smoke, snow, or inadvertent instrument meteorological conditions (IMC). Furthermore, the Cylinder is peripherally presented, supporting the "ambient" visual mode so that it does not require the conscious attention of the viewer. The Flight Path Predictor was developed to show the predicted flight path of a maneuvering aircraft using earth-referenced HMD symbology. The experimental evidence and the pilot interview results show that the new HMD symbology sets are capable of preventing spatial disorientation, improving flight safety, enhancing flight maneuver precision, and reducing workload so that the pilot can more effectively perform the critical mission tasks.

A NASA painter applies the first primer coat to NASA's Orion full-scale abort flight test crew module in the Edwards Air Force Base paint hangar.

NASA Image and Video Library

2008-03-29

A full-scale flight-test mockup of the Constellation program's Orion crew vehicle arrived at NASA's Dryden Flight Research Center in late March 2008 to undergo preparations for the first short-range flight test of the spacecraft's astronaut escape system later that year. Engineers and technicians at NASA's Langley Research Center fabricated the structure, which precisely represents the size, outer shape and mass characteristics of the Orion space capsule. The Orion crew module mockup was ferried to NASA Dryden on an Air Force C-17. After painting in the Edwards Air Force Base paint hangar, the conical capsule was taken to Dryden for installation of flight computers, instrumentation and other electronics prior to being sent to the U.S. Army's White Sands Missile Range in New Mexico for integration with the escape system and the first abort flight test in late 2008. The tests were designed to ensure a safe, reliable method of escape for astronauts in case of an emergency.

Paint shop technicians carefully apply masking prior to painting the Orion full-scale abort flight test crew module in the Edwards Air Force Base paint hangar.

NASA Image and Video Library

2008-03-29

A full-scale flight-test mockup of the Constellation program's Orion crew vehicle arrived at NASA's Dryden Flight Research Center in late March 2008 to undergo preparations for the first short-range flight test of the spacecraft's astronaut escape system later that year. Engineers and technicians at NASA's Langley Research Center fabricated the structure, which precisely represents the size, outer shape and mass characteristics of the Orion space capsule. The Orion crew module mockup was ferried to NASA Dryden on an Air Force C-17. After painting in the Edwards Air Force Base paint hangar, the conical capsule was taken to Dryden for installation of flight computers, instrumentation and other electronics prior to being sent to the U.S. Army's White Sands Missile Range in New Mexico for integration with the escape system and the first abort flight test in late 2008. The tests were designed to ensure a safe, reliable method of escape for astronauts in case of an emergency.

NASA paint shop technicians prepare the Orion full-scale flight test crew module for painting in the Edwards Air Force Base paint hangar.

NASA Image and Video Library

2008-03-29

A full-scale flight-test mockup of the Constellation program's Orion crew vehicle arrived at NASA's Dryden Flight Research Center in late March 2008 to undergo preparations for the first short-range flight test of the spacecraft's astronaut escape system later that year. Engineers and technicians at NASA's Langley Research Center fabricated the structure, which precisely represents the size, outer shape and mass characteristics of the Orion space capsule. The Orion crew module mockup was ferried to NASA Dryden on an Air Force C-17. After painting in the Edwards Air Force Base paint hangar, the conical capsule was taken to Dryden for installation of flight computers, instrumentation and other electronics prior to being sent to the U.S. Army's White Sands Missile Range in New Mexico for integration with the escape system and the first abort flight test in late 2008. The tests were designed to ensure a safe, reliable method of escape for astronauts in case of an emergency.

A new stratospheric sounding platform based on unmanned aerial vehicle (UAV) droppable from meteorological balloon

NASA Astrophysics Data System (ADS)

Efremov, Denis; Khaykin, Sergey; Lykov, Alexey; Berezhko, Yaroslav; Lunin, Aleksey

High-resolution measurements of climate-relevant trace gases and aerosols in the upper troposphere and stratosphere (UTS) have been and remain technically challenging. The high cost of measurements onboard airborne platforms or heavy stratospheric balloons results in a lack of accurate information on vertical distribution of atmospheric constituents. Whereas light-weight instruments carried by meteorological balloons are becoming progressively available, their usage is constrained by the cost of the equipment or the recovery operations. The evolving need in cost-efficient observations for UTS process studies has led to development of small airborne platforms - unmanned aerial vehicles (UAV), capable of carrying small sensors for in-situ measurements. We present a new UAV-based stratospheric sounding platform capable of carrying scientific payload of up to 2 kg. The airborne platform comprises of a latex meteorological balloon and detachable flying wing type UAV with internal measurement controller. The UAV is launched on a balloon to stratospheric altitudes up to 20 km, where it can be automatically released by autopilot or by a remote command sent from the ground control. Having been released from the balloon the UAV glides down and returns to the launch position. Autopilot using 3-axis gyro, accelerometer, barometer, compas and GPS navigation provides flight stabilization and optimal way back trajectory. Backup manual control is provided for emergencies. During the flight the onboard measurement controller stores the data into internal memory and transmits current flight parameters to the ground station via telemetry. Precise operation of the flight control systems ensures safe landing at the launch point. A series of field tests of the detachable stratospheric UAV has been conducted. The scientific payload included the following instruments involved in different flights: a) stratospheric Lyman-alpha hygrometer (FLASH); b) backscatter sonde; c) electrochemical ozone sonde; d) optical CO2 sensor; e) radioactivity sensor; f) solar radiation sensor. In addition, each payload included temperature sensor, barometric sensor and a GPS receiver. Design features of measurement systems onboard UAV and flight results are presented. Possible applications for atmospheric studies and validation of remote ground-based and space-borne observations is discussed.

Review of operational aspects of initial experiments utilizing the U.S. MLS. [microwave landing system effectiveness

NASA Technical Reports Server (NTRS)

Walsh, T. M.; Morello, S. A.; Reeder, J. P.

1976-01-01

An exercise to support the Federal Aviation Administration in demonstrating the U.S. candidate for an international microwave landing system (MLS) was conducted by NASA. During this demonstration the MLS was utilized to provide the TCV Boeing 737 research airplane with guidance for automatic control during transition from conventional RNAV to MLS RNAV in curved, descending flight; flare; touchdown; and roll-out. Flight profiles, system configuration, displays, and operating procedures used in the demonstration are described, and preliminary results of flight data analysis are discussed. Recent experiences with manually controlled flight in the NAFEC MLS environment are also discussed. The demonstration shows that in automatic three-dimensional flight, the volumetric signal coverage of the MLS can be exploited to enable a commercial carrier class airplane to perform complex curved, descending paths with precision turns into short final approaches terminating in landing and roll-out, even when subjected to strong and gusty tail and cross wind components and severe wind shear.

Acoustic flight tests of rotorcraft noise-abatement approaches using local differential GPS guidance

NASA Technical Reports Server (NTRS)

Chen, Robert T. N.; Hindson, William S.; Mueller, Arnold W.

1995-01-01

This paper presents the test design, instrumentation set-up, data acquisition, and the results of an acoustic flight experiment to study how noise due to blade-vortex interaction (BVI) may be alleviated. The flight experiment was conducted using the NASA/Army Rotorcraft Aircrew Systems Concepts Airborne Laboratory (RASCAL) research helicopter. A Local Differential Global Positioning System (LDGPS) was used for precision navigation and cockpit display guidance. A laser-based rotor state measurement system on board the aircraft was used to measure the main rotor tip-path-plane angle-of-attack. Tests were performed at Crows Landing Airfield in northern California with an array of microphones similar to that used in the standard ICAO/FAA noise certification test. The methodology used in the design of a RASCAL-specific, multi-segment, decelerating approach profile for BVI noise abatement is described, and the flight data pertaining to the flight technical errors and the acoustic data for assessing the noise reduction effectiveness are reported.

Avionic Pictorial Tunnel-/Pathway-/Highway-In-The-Sky Workshops

NASA Technical Reports Server (NTRS)

Parrish, Russell V. (Compiler)

2003-01-01

In 1994-96, Langley Research Center held a series of interactive workshops investigating highway-in-the-sky concepts, which enable precise flight path control. These workshops brought together government and industry display designers and pilots to discuss and fly various concepts in an iterative manner. The primary emphasis of the first workshops was the utility and usability of pathways and the pros and cons of various features available. The final workshops were focused on the specific applications to the eXternal Visibility System (XVS) of the NASA High-speed Research Program, which was concerned with replacement of the forward windows in a High-speed Civil Transport with electronic displays and high resolution video cameras to enable a "No-Droop" configuration. The primary concerns in the XVS application were the prevention of display clutter and obscuration of hazards, as the camera image was the primary means of traffic separation in clear visibility conditions. These concerns were not so prominent in the first workshops, which assumed a Synthetic Vision System application in which hazard locations are known and obscuration is handled easily. The resulting consensus concept has been used since in simulation and flight test activities of many Government programs. and other concepts have been influenced by the workshop discussions.

First Airborne Lidar Measurements of Methane and Carbon Dioxide Applying the MERLIN Demonstrator CHARM-F

NASA Astrophysics Data System (ADS)

Amediek, Axel; Büdenbender, Christian; Ehret, Gerhard; Fix, Andreas; Gerbig, Christoph; Kiemle, Chritstoph; Quatrevalet, Mathieu; Wirth, Martin

2016-04-01

CHARM-F is the new airborne four-wavelengths lidar for simultaneous soundings of atmospheric CO2 and CH4. Due to its high technological conformity it is also a demonstrator for MERLIN, the French-German satellite mission providing a methane lidar. MERLIN's Preliminary Design Review was successfully passed recently. The launch is planned for 2020. First CHARM-F measurements were performed in Spring 2015 onboard the German research aircraft HALO. The aircraft's maximum flight altitude of 15 km and special features of the lidar, such as a relatively large laser ground spot, result in data similar to those obtained by a spaceborne system. The CHARM-F and MERLIN lidars are designed in the IPDA (integrated path differential absorption) configuration using short double pulses, which gives column averaged gas mixing ratios between the system and ground. The successfully completed CHARM-F flight measurements provide a valuable dataset, which supports the retrieval algorithm development for MERLIN notably. Furthermore, the dataset allows detailed analyses of measurement sensitivities, general studies on the IPDA principle and on system design questions. These activities are supported by another instrument onboard the aircraft during the flight campaign: a cavity ring down spectrometer, providing in-situ data of carbon dioxide, methane and water vapor with high accuracy and precision, which is ideal for validation purposes of the aircraft lidar. For the near future, detailed characterizations of CHARM-F are planned, further support of the MERLIN design, as well as the scientific aircraft campaign CoMet.

2007 Research and Engineering Annual Report

NASA Technical Reports Server (NTRS)

Stoliker, Patrick; Bowers, Albion; Cruciani, Everlyn

2008-01-01

Selected research and technology activities at NASA Dryden Flight Research Center are summarized. These following activities exemplify the Center's varied and productive research efforts: Developing a Requirements Development Guide for an Automatic Ground Collision Avoidance System; Digital Terrain Data Compression and Rendering for Automatic Ground Collision Avoidance Systems; Nonlinear Flutter/Limit Cycle Oscillations Prediction Tool; Nonlinear System Identification Using Orthonormal Bases: Application to Aeroelastic/Aeroservoelastic Systems; Critical Aerodynamic Flow Feature Indicators: Towards Application with the Aerostructures Test Wing; Multidisciplinary Design, Analysis, and Optimization Tool Development Using a Genetic Algorithm; Structural Model Tuning Capability in an Object-Oriented Multidisciplinary Design, Analysis, and Optimization Tool; Extension of Ko Straight-Beam Displacement Theory to the Deformed Shape Predictions of Curved Structures; F-15B with Phoenix Missile and Pylon Assembly--Drag Force Estimation; Mass Property Testing of Phoenix Missile Hypersonic Testbed Hardware; ARMD Hypersonics Project Materials and Structures: Testing of Scramjet Thermal Protection System Concepts; High-Temperature Modal Survey of the Ruddervator Subcomponent Test Article; ARMD Hypersonics Project Materials and Structures: C/SiC Ruddervator Subcomponent Test and Analysis Task; Ground Vibration Testing and Model Correlation of the Phoenix Missile Hypersonic Testbed; Phoenix Missile Hypersonic Testbed: Performance Design and Analysis; Crew Exploration Vehicle Launch Abort System-Pad Abort-1 (PA-1) Flight Test; Testing the Orion (Crew Exploration Vehicle) Launch Abort System-Ascent Abort-1 (AA-1) Flight Test; SOFIA Flight-Test Flutter Prediction Methodology; SOFIA Closed-Door Aerodynamic Analyses; SOFIA Handling Qualities Evaluation for Closed-Door Operations; C-17 Support of IRAC Engine Model Development; Current Capabilities and Future Upgrade Plans of the C-17 Data Rack; Intelligent Data Mining Capabilities as Applied to Integrated Vehicle Health Management; STARS Flight Demonstration No. 2 IP Data Formatter; Space-Based Telemetry and Range Safety (STARS) Flight Demonstration No. 2 Range User Flight Test Results; Aerodynamic Effects of the Quiet Spike(tm) on an F-15B Aircraft; F-15 Intelligent Flight Controls-Increased Destabilization Failure; F-15 Integrated Resilient Aircraft Control (IRAC) Improved Adaptive Controller; Aeroelastic Analysis of the Ikhana/Fire Pod System; Ikhana: Western States Fire Missions Utilizing the Ames Research Center Fire Sensor; Ikhana: Fiber-Optic Wing Shape Sensors; Ikhana: ARTS III; SOFIA Closed-Door Flutter Envelope Flight Testing; F-15B Quiet Spike(TM) Aeroservoelastic Flight Test Data Analysis; and UAVSAR Platform Precision Autopilot Flight Results.

Cavity-enhanced quantum-cascade laser-based instrument for carbon monoxide measurements.

PubMed

Provencal, Robert; Gupta, Manish; Owano, Thomas G; Baer, Douglas S; Ricci, Kenneth N; O'Keefe, Anthony; Podolske, James R

2005-11-01

An autonomous instrument based on off-axis integrated cavity output spectroscopy has been developed and successfully deployed for measurements of carbon monoxide in the troposphere and tropopause onboard a NASA DC-8 aircraft. The instrument (Carbon Monoxide Gas Analyzer) consists of a measurement cell comprised of two high-reflectivity mirrors, a continuous-wave quantum-cascade laser, gas sampling system, control and data-acquisition electronics, and data-analysis software. CO measurements were determined from high-resolution CO absorption line shapes obtained by tuning the laser wavelength over the R(7) transition of the fundamental vibration band near 2172.8 cm(-1). The instrument reports CO mixing ratio (mole fraction) at a 1-Hz rate based on measured absorption, gas temperature, and pressure using Beer's Law. During several flights in May-June 2004 and January 2005 that reached altitudes of 41,000 ft (12.5 km), the instrument recorded CO values with a precision of 0.2 ppbv (1-s averaging time) and an accuracy limited by the reference CO gas cylinder (uncertainty < 1.0%). Despite moderate turbulence and measurements of particulate-laden airflows, the instrument operated consistently and did not require any maintenance, mirror cleaning, or optical realignment during the flights.

A new technique for high performance tandem time-of- flight mass spectrometry

NASA Astrophysics Data System (ADS)

Katz, Daniel Louis

2001-08-01

The main result of this written dissertation is a mathematical solution to the problem of multiplex recording for high performance tandem time-of-flight mass spectrometry. The prescription is to use a time-lag accelerator in the second stage to match the ion optical properties of the decay fragments to the requirements of the electrostatic ion mirror. With this technique the ion mirror is able to focus the full mass range of fragment ions at a single voltage setting, permitting acquisition of the entire mass spectrum from a single ionization event. This work was performed in support of a joint project carried out by researchers at Oregon State University and The University of Uppsala, Sweden, to design, build and test a tandem instrument featuring precision selection of the precursor species in the first stage of the spectrometer, a means of fragmenting the precursor species, and multiplex recording of the resulting fragment spectrum in the second stage. A patent application has been filed on the complete instrument with the United States Patent Office, a copy of which has been included as an appendix, and a prototype of that instrument has been constructed and awaits testing at Oregon State University.

Mesures spectroscopiques de constituants et de polluants atmosphériques par techniques in situ et à distance, au sol ou embarquéesSpectroscopic measurements of atmospheric constituents and pollutants by in situ and remote techniques from the ground and in flight

NASA Astrophysics Data System (ADS)

Camy-Peyret, Claude; Payan, Sébastien; Jeseck, Pascal; Té, Yao

2001-09-01

Infrared spectroscopy is a powerful tool for precise measurements of atmospheric trace species concentrations through the use of characteristic spectral signatures of the different molecular species and their associated vibration-rotation bands in the mid- or near-infrared. Different methods based on quantitative spectroscopy permit tropospheric or stratospheric measurements: in situ long path absorption, atmospheric absorption/emission by Fourier transform spectroscopy with high spectral resolution instruments on the ground, airborne, balloon-borne or satellite-borne.

Space Optic Manufacturing - X-ray Mirror

NASA Technical Reports Server (NTRS)

1998-01-01

NASA's Space Optics Manufacturing Center has been working to expand our view of the universe via sophisticated new telescopes. The Optics Center's goal is to develop low-cost, advanced space optics technologies for the NASA program in the 21st century - including the long-term goal of imaging Earth-like planets in distant solar systems. To reduce the cost of mirror fabrication, Marshall Space Flight Center (MSFC) has developed replication techniques, the machinery and materials to replicate electro-formed nickel mirrors. The process allows fabricating precisely shaped mandrels to be used and reused as masters for replicating high-quality mirrors. This image shows a lightweight replicated x-ray mirror with gold coatings applied.

Space Science

NASA Image and Video Library

1998-08-31

NASA's Space Optics Manufacturing Center has been working to expand our view of the universe via sophisticated new telescopes. The Optics Center's goal is to develop low-cost, advanced space optics technologies for the NASA program in the 21st century - including the long-term goal of imaging Earth-like planets in distant solar systems. To reduce the cost of mirror fabrication, Marshall Space Flight Center (MSFC) has developed replication techniques, the machinery and materials to replicate electro-formed nickel mirrors. The process allows fabricating precisely shaped mandrels to be used and reused as masters for replicating high-quality mirrors. This image shows a lightweight replicated x-ray mirror with gold coatings applied.

Space Science

NASA Image and Video Library

1999-04-01

NASA's Space Optics Manufacturing Center has been working to expand our view of the universe via sophisticated new telescopes. The Optics Center's goal is to develop low-cost, advanced space optics technologies to the NASA program in the 21st century - including the long-term goal of imaging Earth-like planets in distant solar systems. To reduce the cost of mirror fabrication, Marshall Space Flight Center (MSFC) has developed replication techniques, the machinery, and materials to replicate electro-formed nickel mirrors. The process allows fabricating precisely shaped mandrels to be used and reused as masters for replicating high-quality mirrors. Photograph shows J.R. Griffith inspecting a replicated x-ray mirror mandrel.

Pricise Target Geolocation Based on Integeration of Thermal Video Imagery and Rtk GPS in Uavs

NASA Astrophysics Data System (ADS)

Hosseinpoor, H. R.; Samadzadegan, F.; Dadras Javan, F.

2015-12-01

There are an increasingly large number of uses for Unmanned Aerial Vehicles (UAVs) from surveillance, mapping and target geolocation. However, most of commercial UAVs are equipped with low-cost navigation sensors such as C/A code GPS and a low-cost IMU on board, allowing a positioning accuracy of 5 to 10 meters. This low accuracy which implicates that it cannot be used in applications that require high precision data on cm-level. This paper presents a precise process for geolocation of ground targets based on thermal video imagery acquired by small UAV equipped with RTK GPS. The geolocation data is filtered using a linear Kalman filter, which provides a smoothed estimate of target location and target velocity. The accurate geo-locating of targets during image acquisition is conducted via traditional photogrammetric bundle adjustment equations using accurate exterior parameters achieved by on board IMU and RTK GPS sensors and Kalman filtering and interior orientation parameters of thermal camera from pre-flight laboratory calibration process.

Polarization Calibration of the Chromospheric Lyman-Alpha SpectroPolarimeter for a 0.1% Polarization Sensitivity in the VUV Range. Part II: In-Flight Calibration

NASA Astrophysics Data System (ADS)

Giono, G.; Ishikawa, R.; Narukage, N.; Kano, R.; Katsukawa, Y.; Kubo, M.; Ishikawa, S.; Bando, T.; Hara, H.; Suematsu, Y.; Winebarger, A.; Kobayashi, K.; Auchère, F.; Trujillo Bueno, J.; Tsuneta, S.; Shimizu, T.; Sakao, T.; Cirtain, J.; Champey, P.; Asensio Ramos, A.; Štěpán, J.; Belluzzi, L.; Manso Sainz, R.; De Pontieu, B.; Ichimoto, K.; Carlsson, M.; Casini, R.; Goto, M.

2017-04-01

The Chromospheric Lyman-Alpha SpectroPolarimeter is a sounding rocket instrument designed to measure for the first time the linear polarization of the hydrogen Lyman-{α} line (121.6 nm). The instrument was successfully launched on 3 September 2015 and observations were conducted at the solar disc center and close to the limb during the five-minutes flight. In this article, the disc center observations are used to provide an in-flight calibration of the instrument spurious polarization. The derived in-flight spurious polarization is consistent with the spurious polarization levels determined during the pre-flight calibration and a statistical analysis of the polarization fluctuations from solar origin is conducted to ensure a 0.014% precision on the spurious polarization. The combination of the pre-flight and the in-flight polarization calibrations provides a complete picture of the instrument response matrix, and a proper error transfer method is used to confirm the achieved polarization accuracy. As a result, the unprecedented 0.1% polarization accuracy of the instrument in the vacuum ultraviolet is ensured by the polarization calibration.

Actogram analysis of free-flying migratory birds: new perspectives based on acceleration logging.

PubMed

Bäckman, Johan; Andersson, Arne; Pedersen, Lykke; Sjöberg, Sissel; Tøttrup, Anders P; Alerstam, Thomas

2017-07-01

The use of accelerometers has become an important part of biologging techniques for large-sized birds with accelerometer data providing information about flight mode, wing-beat pattern, behaviour and energy expenditure. Such data show that birds using much energy-saving soaring/gliding flight like frigatebirds and swifts can stay airborne without landing for several months. Successful accelerometer studies have recently been conducted also for free-flying small songbirds during their entire annual cycle. Here we review the principles and possibilities for accelerometer studies in bird migration. We use the first annual actograms (for red-backed shrike Lanius collurio) to explore new analyses and insights that become possible with accelerometer data. Actogram data allow precise estimates of numbers of flights, flight durations as well as departure/landing times during the annual cycle. Annual and diurnal rhythms of migratory flights, as well as prolonged nocturnal flights across desert barriers are illustrated. The shifting balance between flight, rest and different intensities of activity throughout the year as revealed by actogram data can be used to analyse exertion levels during different phases of the life cycle. Accelerometer recording of the annual activity patterns of individual birds will open up a new dimension in bird migration research.

Mapping snow depth in complex alpine terrain with close range aerial imagery - estimating the spatial uncertainties of repeat autonomous aerial surveys over an active rock glacier

NASA Astrophysics Data System (ADS)

Goetz, Jason; Marcer, Marco; Bodin, Xavier; Brenning, Alexander

2017-04-01

Snow depth mapping in open areas using close range aerial imagery is just one of the many cases where developments in structure-from-motion and multi-view-stereo (SfM-MVS) 3D reconstruction techniques have been applied for geosciences - and with good reason. Our ability to increase the spatial resolution and frequency of observations may allow us to improve our understanding of how snow depth distribution varies through space and time. However, to ensure accurate snow depth observations from close range sensing we must adequately characterize the uncertainty related to our measurement techniques. In this study, we explore the spatial uncertainties of snow elevation models for estimation of snow depth in a complex alpine terrain from close range aerial imagery. We accomplish this by conducting repeat autonomous aerial surveys over a snow-covered active-rock glacier located in the French Alps. The imagery obtained from each flight of an unmanned aerial vehicle (UAV) is used to create an individual digital elevation model (DEM) of the snow surface. As result, we obtain multiple DEMs of the snow surface for the same site. These DEMs are obtained from processing the imagery with the photogrammetry software Agisoft Photoscan. The elevation models are also georeferenced within Photoscan using the geotagged imagery from an onboard GNSS in combination with ground targets placed around the rock glacier, which have been surveyed with highly accurate RTK-GNSS equipment. The random error associated with multi-temporal DEMs of the snow surface is estimated from the repeat aerial survey data. The multiple flights are designed to follow the same flight path and altitude above the ground to simulate the optimal conditions of repeat survey of the site, and thus try to estimate the maximum precision associated with our snow-elevation measurement technique. The bias of the DEMs is assessed with RTK-GNSS survey observations of the snow surface elevation of the area on and surrounding the rock glacier. Additionally, one of the challenges with processing snow cover imagery with SfM-MVS is dealing with the general homogeneity of the surface, which makes is difficult for automated-feature detection algorithms to identify key features for point matching. This challenge depends on the snow cover surface conditions, such as scale, lighting conditions (high vs. low contrast), and availability of snow-free features within a scene, among others. We attempt to explore this aspect by spatial modelling the factors influencing the precision and bias of the DEMs from image, flight, and terrain attributes.

The CHEOPS calibration bench

NASA Astrophysics Data System (ADS)

Wildi, F.; Chazelas, B.; Deline, A.; Sarajlic, M.; Sordet, M.

2017-09-01

CHEOPS is an ESA Class S Mission aiming at the characterization of exoplanets through the precise measurement of their radius, using the transit method [1]. To achieve this goal, the payload is designed to be a high precision "absolute" photometer, looking at one star at a time. It will be able to cover la large fraction of the sky by repointing. Its launch is expected at the end of 2017 [2, this conference]. CHEOPS' main science is the measure of the transit of exoplanets of radius ranging from 1 to 6 Earth radii orbiting bright stars. The required photometric stability to reach this goal is of 20 ppm in 6 hours for a 9th magnitude star. The CHEOPS' only instrument is a Ritchey-Chretien style telescope with 300 mm effective aperture diameter, which provides a defocussed image of the target star on a single frame-transfer backside illuminated CCD detector cooled to -40°C and stabilized within 10 mK [2]. CHEOPS being in a LEO, it is equipped with a high performance baffle. The spacecraft platform provides a pointing stability of < 2 arcsec rms. This relatively modest pointing performance makes high quality flat-fielding necessary In the rest of this article we will refer to the only CHEOPS instrument simply as "CHEOP" Its behavior will be calibrated thoroughly on the ground and only a small subset of the calibrations can be redone in flight. The main focuses of the calibrations are the photonic gain stability and sensibility to the environment variations and the Flat field that has to be known at a precision better than 0.1%.

Graviresponses of Paramecium biaurelia during parabolic flights.

PubMed

Krause, Martin; Bräucker, Richard; Hemmersbach, Ruth

2006-12-01

The thresholds of graviorientation and gravikinesis in Paramecium biaurelia were investigated during the 5th DLR (German Aerospace Center) parabolic-flight campaign at Bordeaux in June 2003. Parabolic flights are a useful tool for the investigation of swimming behaviour in protists at different accelerations. At normal gravity (1 g) and hypergravity (1 g to 1.8 g), precision of orientation and locomotion rates depend linearly on the applied acceleration as seen in earlier centrifuge experiments. After transition from hypergravity to decreased gravity (minimal residual acceleration of <10(-2) g), graviorientation as well as gravikinesis show a full relaxation with different kinetics. The use of twelve independent cell samples per flight guarantees high data numbers and secures the statistical significance of the obtained data. The relatively slow change of acceleration between periods of microgravity and hypergravity (0.4 g/s) enabled us to determine the thresholds of graviorientation at 0.6 g and of gravikinesis at 0.4 g. The gravity-unrelated propulsion rate of the sample was found to be 874 microm/s, exceeding the locomotion rate of horizontally swimming cells (855 microm/s). The measured thresholds of graviresponses were compared with data obtained from earlier centrifuge experiments on the sounding rocket Maxus-2. Measured thresholds of gravireactions indicate that small energies, close to the thermal noise level, are sufficient for the gravitransduction process. Data from earlier hypergravity experiments demonstrate that mechanosensitive ion channels are functioning over a relative wide range of acceleration. From this, we may speculate that gravireceptor channels derive from mechanoreceptor channels.

Handling Qualities Evaluations of Low Complexity Model Reference Adaptive Controllers for Reduced Pitch and Roll Damping Scenarios

NASA Technical Reports Server (NTRS)

Hanson, Curt; Schaefer, Jacob; Burken, John J.; Johnson, Marcus; Nguyen, Nhan

2011-01-01

National Aeronautics and Space Administration (NASA) researchers have conducted a series of flight experiments designed to study the effects of varying levels of adaptive controller complexity on the performance and handling qualities of an aircraft under various simulated failure or damage conditions. A baseline, nonlinear dynamic inversion controller was augmented with three variations of a model reference adaptive control design. The simplest design consisted of a single adaptive parameter in each of the pitch and roll axes computed using a basic gradient-based update law. A second design was built upon the first by increasing the complexity of the update law. The third and most complex design added an additional adaptive parameter to each axis. Flight tests were conducted using NASA s Full-scale Advanced Systems Testbed, a highly modified F-18 aircraft that contains a research flight control system capable of housing advanced flight controls experiments. Each controller was evaluated against a suite of simulated failures and damage ranging from destabilization of the pitch and roll axes to significant coupling between the axes. Two pilots evaluated the three adaptive controllers as well as the non-adaptive baseline controller in a variety of dynamic maneuvers and precision flying tasks designed to uncover potential deficiencies in the handling qualities of the aircraft, and adverse interactions between the pilot and the adaptive controllers. The work was completed as part of the Integrated Resilient Aircraft Control Project under NASA s Aviation Safety Program.

Passive microwave remote sensing of salinity in coastal zones

NASA Technical Reports Server (NTRS)

Swift, Calvin T.; Blume, Hans-Juergen C.; Kendall, Bruce M.

1987-01-01

The theory of measuring coastal-zone salinity from airborne microwave radiometers is developed. The theory, as presented, shows that precision measurements of salinity favor the lower microwave frequencies. To this end, L- and S-Band systems were built, and the flight results have shown that accuracies of at least one part per thousand were achieved.The aircraft results focus on flights conducted over the Chesapeake Bay and the mouth of the Savanna River off the Georgia Coast. This paper presents no new work, but rather summarizes the capabilities of the remote sensing technique.

1201050

NASA Image and Video Library

2012-10-26

FROM RIGHT, MARSHALL RESEARCHER DR. DAVID SMITH, U.S. ARMY RESEARCHER KRISHNA MYNENI AND ARMY CONTRACTOR HONGROK CHANG HAVE BEGUN A THREE-YEAR NASA PROJECT TO DEVELOP INNOVATIVE NEW GYROSCOPES THAT COULD DRAMATICALLY IMPROVE IN-FLIGHT NAVIGATION CAPABILITIES FOR SPACE VEHICLES, MILITARY AIR AND SEA ASSETS AND COMMERCIAL VEHICLES. THE “FAST LIGHT OPTICAL GYROSCOPES FOR PRECISE INERTIAL NAVIGATION” PROJECT INCLUDES RESEARCHERS AT NASA’S MARSHALL SPACE FLIGHT CENTER IN HUNTSVILLE, ALA.; THE U.S. ARMY AVIATION AND MISSILE RESEARCH, DEVELOPMENT AND ENGINEERING CENTER (AMRDEC) AT REDSTONE ARSENAL IN HUNTSVILLE; AND NORTHWESTERN UNIVERSITY IN EVANSTON, ILL.

Mariner 9 navigation

NASA Technical Reports Server (NTRS)

Neil, W. J.; Jordan, J. F.; Zielenbach, J. W.; Wong, S. K.; Mitchell, R. T.; Webb, W. A.; Koskela, P. E.

1973-01-01

A final, comprehensive description of the navigation of Mariner 9-the first U.S. spacecraft to orbit another planet is provided. The Mariner 9 navigation function included not only precision flight path control but also pointing of the spacecraft's scientific instruments mounted on a two degree of freedom scan platform. To the extent appropriate, each section describes the perflight analyses on which the operational strategies and performance predictions were based. Inflight results are then discussed and compared with the preflight predictions. Postflight analyses, which were primarily concerned with developing a thorough understanding of unexpected in-flight results, are also presented.

Direct speed of sound measurement within the atmosphere during a national holiday in New Zealand

NASA Astrophysics Data System (ADS)

Vollmer, M.

2018-05-01

Measuring the speed of sound belongs to almost any physics curriculum. Two methods dominate, measuring resonance phenomena of standing waves or time-of-flight measurements. The second type is conceptually simpler, however, performing such experiments with dimensions of meters usually requires precise electronic time measurement equipment if accurate results are to be obtained. Here a time-of-flight measurement from a video recording is reported with a dimension of several km and an accuracy for the speed of sound of the order of 1%.

Investigation of air transportation technology at Massachusetts Institute of Technology, 1985

NASA Technical Reports Server (NTRS)

Simpson, Robert W.

1987-01-01

Two areas of research are discussed, an investigation into runway approach flying with Loran C and a series of research topics in the development of experimental validation of methodologies to support aircraft icing analysis. Flight tests with the Loran C led to the conclusion that it is a suitable system for non-precision approaches, and that time-difference corrections made every eight weeks in the instrument approach plates will produce acceptable errors. In the area of aircraft icing analysis, wind tunnel and flight test results are discussed.

Determining XV-15 aeroelastic modes from flight data with frequency-domain methods

NASA Technical Reports Server (NTRS)

Acree, C. W., Jr.; Tischler, Mark B.

1993-01-01

The XV-15 tilt-rotor wing has six major aeroelastic modes that are close in frequency. To precisely excite individual modes during flight test, dual flaperon exciters with automatic frequency-sweep controls were installed. The resulting structural data were analyzed in the frequency domain (Fourier transformed). All spectral data were computed using chirp z-transforms. Modal frequencies and damping were determined by fitting curves to frequency-response magnitude and phase data. The results given in this report are for the XV-15 with its original metal rotor blades. Also, frequency and damping values are compared with theoretical predictions made using two different programs, CAMRAD and ASAP. The frequency-domain data-analysis method proved to be very reliable and adequate for tracking aeroelastic modes during flight-envelope expansion. This approach required less flight-test time and yielded mode estimations that were more repeatable, compared with the exponential-decay method previously used.

An Atmospheric Guidance Algorithm Testbed for the Mars Surveyor Program 2001 Orbiter and Lander

NASA Technical Reports Server (NTRS)

Striepe, Scott A.; Queen, Eric M.; Powell, Richard W.; Braun, Robert D.; Cheatwood, F. McNeil; Aguirre, John T.; Sachi, Laura A.; Lyons, Daniel T.

1998-01-01

An Atmospheric Flight Team was formed by the Mars Surveyor Program '01 mission office to develop aerocapture and precision landing testbed simulations and candidate guidance algorithms. Three- and six-degree-of-freedom Mars atmospheric flight simulations have been developed for testing, evaluation, and analysis of candidate guidance algorithms for the Mars Surveyor Program 2001 Orbiter and Lander. These simulations are built around the Program to Optimize Simulated Trajectories. Subroutines were supplied by Atmospheric Flight Team members for modeling the Mars atmosphere, spacecraft control system, aeroshell aerodynamic characteristics, and other Mars 2001 mission specific models. This paper describes these models and their perturbations applied during Monte Carlo analyses to develop, test, and characterize candidate guidance algorithms.

Far Ultraviolet Refractive Index of Optical Materials for Solar Blind Channel (SBC) Filters for HST Advanced Camera for Surveys

NASA Technical Reports Server (NTRS)

Leviton, Douglas B.; Madison, Timothy J.; Petrone, Peter

1998-01-01

Refractive index measurements using the minimum deviation method have been carried out for prisms of a variety of far ultraviolet optical materials used in the manufacture of Solar Blind Channel (SBC) filters for the HST Advanced Camera for Surveys (ACS). Some of the materials measured are gaining popularity in a variety of high technology applications including high power excimer lasers and advanced microlithography optics operating in a wavelength region where high quality knowledge of optical material properties is sparse. Our measurements are of unusually high accuracy and precision for this wavelength region owing to advanced instrumentation in the large vacuum chamber of the Diffraction Grating Evaluation Facility (DGEF) at Goddard Space Flight Center (GSFC). Index values for CaF2, BaF2, LiF, and far ultraviolet grades of synthetic sapphire and synthetic fused silica are reported and compared with values from the literature.

The Gravity Recovery and Interior Laboratory mission

NASA Astrophysics Data System (ADS)

Lehman, D. H.; Hoffman, T. L.; Havens, G. G.

The Gravity Recovery and Interior Laboratory (GRAIL) mission, launched in September 2011, successfully completed its Primary Science Mission in June 2012 and Extended Mission in December 2012. Competitively selected under a NASA Announcement of Opportunity in December 2007, GRAIL is a Discovery Program mission subject to a mandatory project cost cap. The purpose of the mission is to precisely map the gravitational field of the Moon to reveal its internal structure from crust to core, determine its thermal evolution, and extend this knowledge to other planets. The mission used twin spacecraft flying in tandem to provide the gravity map. The GRAIL Flight System, consisting of the spacecraft and payload, was developed based on significant heritage from previous missions such as an experimental U.S. Air Force satellite, the Mars Reconnaissance Orbiter (MRO) mission, and the Gravity Recovery and Climate Experiment (GRACE) mission. The Mission Operations System (MOS) was based on high-heritage multimission operations developed by NASA's Jet Propulsion Laboratory and Lockheed Martin. Both the Flight System and MOS were adapted to meet the unique challenges posed by the GRAIL mission design. This paper summarizes the implementation challenges and accomplishments of getting GRAIL ready for launch. It also discusses the in-flight challenges and experiences of operating two spacecraft, and mission results.

Attitude Determination Using a MEMS-Based Flight Information Measurement Unit

PubMed Central

Ma, Der-Ming; Shiau, Jaw-Kuen; Wang, I.-Chiang; Lin, Yu-Heng

2012-01-01

Obtaining precise attitude information is essential for aircraft navigation and control. This paper presents the results of the attitude determination using an in-house designed low-cost MEMS-based flight information measurement unit. This study proposes a quaternion-based extended Kalman filter to integrate the traditional quaternion and gravitational force decomposition methods for attitude determination algorithm. The proposed extended Kalman filter utilizes the evolution of the four elements in the quaternion method for attitude determination as the dynamic model, with the four elements as the states of the filter. The attitude angles obtained from the gravity computations and from the electronic magnetic sensors are regarded as the measurement of the filter. The immeasurable gravity accelerations are deduced from the outputs of the three axes accelerometers, the relative accelerations, and the accelerations due to body rotation. The constraint of the four elements of the quaternion method is treated as a perfect measurement and is integrated into the filter computation. Approximations of the time-varying noise variances of the measured signals are discussed and presented with details through Taylor series expansions. The algorithm is intuitive, easy to implement, and reliable for long-term high dynamic maneuvers. Moreover, a set of flight test data is utilized to demonstrate the success and practicality of the proposed algorithm and the filter design. PMID:22368455

Attitude determination using a MEMS-based flight information measurement unit.

PubMed

Ma, Der-Ming; Shiau, Jaw-Kuen; Wang, I-Chiang; Lin, Yu-Heng

2012-01-01

Obtaining precise attitude information is essential for aircraft navigation and control. This paper presents the results of the attitude determination using an in-house designed low-cost MEMS-based flight information measurement unit. This study proposes a quaternion-based extended Kalman filter to integrate the traditional quaternion and gravitational force decomposition methods for attitude determination algorithm. The proposed extended Kalman filter utilizes the evolution of the four elements in the quaternion method for attitude determination as the dynamic model, with the four elements as the states of the filter. The attitude angles obtained from the gravity computations and from the electronic magnetic sensors are regarded as the measurement of the filter. The immeasurable gravity accelerations are deduced from the outputs of the three axes accelerometers, the relative accelerations, and the accelerations due to body rotation. The constraint of the four elements of the quaternion method is treated as a perfect measurement and is integrated into the filter computation. Approximations of the time-varying noise variances of the measured signals are discussed and presented with details through Taylor series expansions. The algorithm is intuitive, easy to implement, and reliable for long-term high dynamic maneuvers. Moreover, a set of flight test data is utilized to demonstrate the success and practicality of the proposed algorithm and the filter design.

The Gravity Recovery and Interior Laboratory Mission

NASA Technical Reports Server (NTRS)

Lehman, David H.; Hoffman, Tom L.; Havens, Glen G.

2013-01-01

The Gravity Recovery and Interior Laboratory (GRAIL) mission, launched in September 2011, successfully completed its Primary Science Mission in June 2012 and is currently in Extended Mission operations. Competitively selected under a NASA Announcement of Opportunity in December 2007, GRAIL is a Discovery Program mission subject to a mandatory project cost cap. The purpose of the mission is to precisely map the gravitational field of the Moon to reveal its internal structure from crust to core, determine its thermal evolution, and extend this knowledge to other planets. The mission uses twin spacecraft flying in tandem to provide the gravity map. The GRAIL Flight System, consisting of the spacecraft and payload, was developed based on significant heritage from previous missions such an experimental U.S. Air Force satellite, the Mars Reconnaissance Orbiter (MRO) mission, and the Gravity Recovery and Climate Experiment (GRACE) mission. The Mission Operations System (MOS) was based on high-heritage multimission operations developed by NASA's Jet Propulsion Laboratory and Lockheed Martin. Both the Flight System and MOS were adapted to meet the unique challenges posed by the GRAIL mission design. This paper summarizes the implementation challenges and accomplishments of getting GRAIL ready for launch. It also discusses the in-flight challenges and experiences of operating two spacecraft, and mission results.

Local Observability Analysis of Star Sensor Installation Errors in a SINS/CNS Integration System for Near-Earth Flight Vehicles

PubMed Central

Yang, Yanqiang; Zhang, Chunxi; Lu, Jiazhen

2017-01-01

Strapdown inertial navigation system/celestial navigation system (SINS/CNS) integrated navigation is a fully autonomous and high precision method, which has been widely used to improve the hitting accuracy and quick reaction capability of near-Earth flight vehicles. The installation errors between SINS and star sensors have been one of the main factors that restrict the actual accuracy of SINS/CNS. In this paper, an integration algorithm based on the star vector observations is derived considering the star sensor installation error. Then, the star sensor installation error is accurately estimated based on Kalman Filtering (KF). Meanwhile, a local observability analysis is performed on the rank of observability matrix obtained via linearization observation equation, and the observable conditions are presented and validated. The number of star vectors should be greater than or equal to 2, and the times of posture adjustment also should be greater than or equal to 2. Simulations indicate that the star sensor installation error could be readily observable based on the maneuvering condition; moreover, the attitude errors of SINS are less than 7 arc-seconds. This analysis method and conclusion are useful in the ballistic trajectory design of near-Earth flight vehicles. PMID:28275211

The Northrop Grumman External Occulter Testbed: Preliminary Results

NASA Astrophysics Data System (ADS)

Lo, Amy; Glassman, T.; Lillie, C.

2007-05-01

We have built a subscale testbed to demonstrate and validate the performance of the New Worlds Observer (NWO), a terrestrial planet finder external-occulter mission concept. The external occulter concept allows observations of nearby exo-Earths using two spacecraft: one carrying an occulter that is tens of meters in diameter and the other carrying a generic space telescope. The occulter is completely opaque, resembling a flower, with petals having a hypergaussian profile that enable 10-10 intensity suppression of stars that potentially harbor terrestrial planets. The baseline flight NWO system has a 30 meter occulter flying 30,000 km in front of a 4 meter class telescope. Testing the flight configuration on the ground is not feasible, so we have matched the Fresnel number of the flight configuration ( 10) using a subscale occulter. Our testbed consists of an 80 meter length evacuated tube, with a high precision occulter in the center of the tube. The occulter is 4 cm in diameter, manufactured with ¼ micron metrological accuracy and less than 2 micron tip truncation. This mimics a 30 meter occulter with millimeter figure accuracy and less than centimeter tip truncation. Our testbed is an evolving experiment, and we report here the first, preliminary, results using a single wavelength laser (532 nm) as the source.

High-precision Non-Contact Measurement of Creep of Ultra-High Temperature Materials for Aerospace

NASA Technical Reports Server (NTRS)

Rogers, Jan R.; Hyers, Robert

2008-01-01

For high-temperature applications (greater than 2,000 C) such as solid rocket motors, hypersonic aircraft, nuclear electric/thermal propulsion for spacecraft, and more efficient jet engines, creep becomes one of the most important design factors to be considered. Conventional creep-testing methods, where the specimen and test apparatus are in contact with each other, are limited to temperatures approximately 1,700 C. Development of alloys for higher-temperature applications is limited by the availability of testing methods at temperatures above 2000 C. Development of alloys for applications requiring a long service life at temperatures as low as 1500 C, such as the next generation of jet turbine superalloys, is limited by the difficulty of accelerated testing at temperatures above 1700 C. For these reasons, a new, non-contact creep-measurement technique is needed for higher temperature applications. A new non-contact method for creep measurements of ultra-high-temperature metals and ceramics has been developed and validated. Using the electrostatic levitation (ESL) facility at NASA Marshall Space Flight Center, a spherical sample is rotated quickly enough to cause creep deformation due to centrifugal acceleration. Very accurate measurement of the deformed shape through digital image analysis allows the stress exponent n to be determined very precisely from a single test, rather than from numerous conventional tests. Validation tests on single-crystal niobium spheres showed excellent agreement with conventional tests at 1985 C; however the non-contact method provides much greater precision while using only about 40 milligrams of material. This method is being applied to materials including metals and ceramics for non-eroding throats in solid rockets and next-generation superalloys for turbine engines. Recent advances in the method and the current state of these new measurements will be presented.

Proceedings of the 20th International Symposium on Space Flight Dynamics

NASA Technical Reports Server (NTRS)

Woodard, Mark (Editor); Stengle, Tom (Editor)

2007-01-01

Topics include: Measuring Image Navigation and Registration Performance at the 3-Sigma Level Using Platinum Quality Landmarks; Flight Dynamics Performances of the MetOp A Satellite during the First Months of Operations; Visual Navigation - SARE Mission; Determining a Method of Enabling and Disabling the Integral Torque in the SDO Science and Inertial Mode Controllers; Guaranteeing Pointing Performance of the SDO Sun-Pointing Controllers in Light of Nonlinear Effects; SDO Delta H Mode Design and Analysis; Observing Mode Attitude Controller for the Lunar Reconnaissance Orbiter; Broken-Plane Maneuver Applications for Earth to Mars Trajectories; ExoMars Mission Analysis and Design - Launch, Cruise and Arrival Analyses; Mars Reconnaissance Orbiter Aerobraking Daily Operations and Collision Avoidance; Mars Reconnaissance Orbiter Interplanetary Cruise Navigation; Motion Parameters Determination of the SC and Phobos in the Project Phobos-Grunt; GRAS NRT Precise Orbit Determination: Operational Experience; Orbit Determination of LEO Satellites for a Single Pass through a Radar: Comparison of Methods; Orbit Determination System for Low Earth Orbit Satellites; Precise Orbit Determination for ALOS; Anti-Collision Function Design and Performances of the CNES Formation Flying Experiment on the PRISMA Mission; CNES Approaching Guidance Experiment within FFIORD; Maneuver Recovery Analysis for the Magnetospheric Multiscale Mission; SIMBOL-X: A Formation Flying Mission on HEO for Exploring the Universe; Spaceborne Autonomous and Ground Based Relative Orbit Control for the TerraSAR-X/TanDEM-X Formation; First In-Orbit Experience of TerraSAR-X Flight Dynamics Operations; Automated Target Planning for FUSE Using the SOVA Algorithm; Space Technology 5 Post-Launch Ground Attitude Estimation Experience; Standardizing Navigation Data: A Status Update; and A Study into the Method of Precise Orbit Determination of a HEO Orbiter by GPS and Accelerometer.

Design and realization of the control system for the three-channel birefringent filter

NASA Astrophysics Data System (ADS)

Zhu, Dan

2008-07-01

Space Solar Telescope is one of the large-scale scientific programs under development in China. In it, an important part is the filter, a birefringent filter with three-channels. It consists of 17 rotatable wave plates. In coordination with other mechanical and optical components, complicated and precise adjustments of their attitudes are necessary, which requests a high-accuracy control system to ensure their concertedness. The paper describes the design and realization of the control system. It mainly has a hardware plate and a software one. The former uses an industrial controller, a control card and step motors, while the latter uses the technique construction of the object oriented. That is modularization design with lengthwise dividing as per functions and breadthwise dividing as per element layers. Shift arithmetic for whole spectrum in programs is for intelligent spectral scanning. At the same time, the control information is roundly recorded in the data base of the system. Tests show that the system is characterized by high precision, good stabilization, high data safety and user-friendly interface, totally meeting the design requirements. Also discussed in this paper is some new conceivability to realize the handiness and miniaturization of the filter to fit the use in space flight in the future.

Prompt and Precise Prototyping

NASA Technical Reports Server (NTRS)

2003-01-01

For Sanders Design International, Inc., of Wilton, New Hampshire, every passing second between the concept and realization of a product is essential to succeed in the rapid prototyping industry where amongst heavy competition, faster time-to-market means more business. To separate itself from its rivals, Sanders Design aligned with NASA's Marshall Space Flight Center to develop what it considers to be the most accurate rapid prototyping machine for fabrication of extremely precise tooling prototypes. The company's Rapid ToolMaker System has revolutionized production of high quality, small-to-medium sized prototype patterns and tooling molds with an exactness that surpasses that of computer numerically-controlled (CNC) machining devices. Created with funding and support from Marshall under a Small Business Innovation Research (SBIR) contract, the Rapid ToolMaker is a dual-use technology with applications in both commercial and military aerospace fields. The advanced technology provides cost savings in the design and manufacturing of automotive, electronic, and medical parts, as well as in other areas of consumer interest, such as jewelry and toys. For aerospace applications, the Rapid ToolMaker enables fabrication of high-quality turbine and compressor blades for jet engines on unmanned air vehicles, aircraft, and missiles.

Integration of a synthetic vision system with airborne laser range scanner-based terrain referenced navigation for precision approach guidance

NASA Astrophysics Data System (ADS)

Uijt de Haag, Maarten; Campbell, Jacob; van Graas, Frank

2005-05-01

Synthetic Vision Systems (SVS) provide pilots with a virtual visual depiction of the external environment. When using SVS for aircraft precision approach guidance systems accurate positioning relative to the runway with a high level of integrity is required. Precision approach guidance systems in use today require ground-based electronic navigation components with at least one installation at each airport, and in many cases multiple installations to service approaches to all qualifying runways. A terrain-referenced approach guidance system is envisioned to provide precision guidance to an aircraft without the use of ground-based electronic navigation components installed at the airport. This autonomy makes it a good candidate for integration with an SVS. At the Ohio University Avionics Engineering Center (AEC), work has been underway in the development of such a terrain referenced navigation system. When used in conjunction with an Inertial Measurement Unit (IMU) and a high accuracy/resolution terrain database, this terrain referenced navigation system can provide navigation and guidance information to the pilot on a SVS or conventional instruments. The terrain referenced navigation system, under development at AEC, operates on similar principles as other terrain navigation systems: a ground sensing sensor (in this case an airborne laser scanner) gathers range measurements to the terrain; this data is then matched in some fashion with an onboard terrain database to find the most likely position solution and used to update an inertial sensor-based navigator. AEC's system design differs from today's common terrain navigators in its use of a high resolution terrain database (~1 meter post spacing) in conjunction with an airborne laser scanner which is capable of providing tens of thousands independent terrain elevation measurements per second with centimeter-level accuracies. When combined with data from an inertial navigator the high resolution terrain database and laser scanner system is capable of providing near meter-level horizontal and vertical position estimates. Furthermore, the system under development capitalizes on 1) The position and integrity benefits provided by the Wide Area Augmentation System (WAAS) to reduce the initial search space size and; 2) The availability of high accuracy/resolution databases. This paper presents results from flight tests where the terrain reference navigator is used to provide guidance cues for a precision approach.

Physics-based simulations of aerial attacks by peregrine falcons reveal that stooping at high speed maximizes catch success against agile prey

PubMed Central

Hildenbrandt, Hanno

2018-01-01

The peregrine falcon Falco peregrinus is renowned for attacking its prey from high altitude in a fast controlled dive called a stoop. Many other raptors employ a similar mode of attack, but the functional benefits of stooping remain obscure. Here we investigate whether, when, and why stooping promotes catch success, using a three-dimensional, agent-based modeling approach to simulate attacks of falcons on aerial prey. We simulate avian flapping and gliding flight using an analytical quasi-steady model of the aerodynamic forces and moments, parametrized by empirical measurements of flight morphology. The model-birds’ flight control inputs are commanded by their guidance system, comprising a phenomenological model of its vision, guidance, and control. To intercept its prey, model-falcons use the same guidance law as missiles (pure proportional navigation); this assumption is corroborated by empirical data on peregrine falcons hunting lures. We parametrically vary the falcon’s starting position relative to its prey, together with the feedback gain of its guidance loop, under differing assumptions regarding its errors and delay in vision and control, and for three different patterns of prey motion. We find that, when the prey maneuvers erratically, high-altitude stoops increase catch success compared to low-altitude attacks, but only if the falcon’s guidance law is appropriately tuned, and only given a high degree of precision in vision and control. Remarkably, the optimal tuning of the guidance law in our simulations coincides closely with what has been observed empirically in peregrines. High-altitude stoops are shown to be beneficial because their high airspeed enables production of higher aerodynamic forces for maneuvering, and facilitates higher roll agility as the wings are tucked, each of which is essential to catching maneuvering prey at realistic response delays. PMID:29649207

Age-related variation in body temperature, thermoregulation and activity in a thermally polymorphic dragonfly

PubMed

Marden; Kramer; Frisch

1996-01-01

Thoracic temperatures (Tth) of Libellula pulchella dragonflies during activity in the field were compared between age classes and with laboratory measures of optimal thoracic temperature for flight performance (Tth,opt; a trait that varies during adult maturation in this species). Newly emerged adults (tenerals) had mean Tth values during flight (34.5 °C; range 29-40 °C) that did not differ from their mean Tth,opt (34.6 °C; range 28.5-43.8 °C). Mature adults had higher and more precisely regulated thoracic temperatures (mean Tth 41.7 °C; range 37.5-45.2 °C), which were somewhat lower than their mean Tth,opt (43.6 °C; range 38.7-49.9 °C). Among matures, behaviors requiring the highest levels of flight exertion (aerial copulation; mate guarding; escalated territorial contests) caused an elevation of Tth above that of concurrently sampled individuals engaged in routine flight (mean Tth difference 1.3 °C), which raised mean Tth to a level that was not significantly different from Tth,opt (42.5 versus 43.5 °C). Compared with tenerals, matures spent more time flying, made longer-duration flights and showed a more restricted pattern of daily activity. Sympatric Anax junius dragonflies that regulate Tth endothermically had a uniform pattern of activity across the entire day, i.e. occupied a broader ecological niche than that of L. pulchella. These results support the hypotheses that optimal body temperature evolves to match the elevated body temperatures that occur during exercise and that the ecological benefits of an expanded niche are a secondary benefit rather than a primary selective force during the evolution of homeothermy and high body temperatures.

Science Enabling ASICs and FEEs for the JUICE and JEO Missions

NASA Technical Reports Server (NTRS)

Paschalidis, Nicholas; Sittler, Ed; Cooper, John; Christian, Eric; Moore, Tom

2011-01-01

A family of science enabling radiation hard Application Specific Integrated Circuits (ASICs), Front End Electronics (FEEs) and Event Processing Systems, with flight heritage on many NASA missions, is presented. These technologies play an important role in the miniaturization of instruments -and spacecraft systems- at the same time increasing performance and reducing power. The technologies target time of flight, position sensing, and energy measurements as well as standard housekeeping and telemetry functions for particle and fields instruments, but find applications in other instrument categories too. More specifically the technologies include: the TOF chip, 1D and 2D Delay Lines with MCP detectors, for high precision fast and low power time of flight and position sensing; the Energy chip for multichannel SSD readout with time over threshold and standard voltage read out for TDC and ADC digitization; Fast multi channel read out chip with commandable thresholds; the TRIO chip for multiplexed ADC and housekeeping etc. It should be mentioned that the ASICs include basic trigger capabilities to enable random event processing in a heavy background of penetrators and UV foreground. Typical instruments include time of flight versus energy and look angle particle analyzers such as: plasma composition, energetic particle, neutral atom imaging as well as fast plasma and deltaE/E ion/electron telescopes. Flight missions include: Cassini/LEMMS, IMAGE/HENA, MESSENGER/EPPS/MLA/X-ray/MLA, STEREO, PLUTO-NH/PEPSSI/LORI, IBEX-Lo, JUNO/JEDI, RBSP/RBSPICE, MMS/HPCA/EPD, SO/SIS. Given the proven capability on heavy radiation missions such as JUNO, MMS and RBSB, as well diverse long duration missions such as MESSENGER, PLUTO and Cassini, it is expected that these technologies will play an important role in the particle and fields (at least) instruments on the upcoming JUICE and JEO missions.

Interior of Spacewedge #3

NASA Image and Video Library

1996-01-22

This photo shows the instrumentation and equipment inside the Spacewedge #3, a remotely-piloted research vehicle flown at the Dryden Flight Research Center, Edwards, California, to help develop technology for autonomous return systems for spacecraft as well as methods to deliver large Army cargo payloads to precise landings.

Flight Performance of a Man Portable Guided Projectile Concept

DTIC Science & Technology

2014-02-01

include precision guided technologies. The focus of this study is maneuvering projectiles launched from man portable weapon systems . A novel guided...5 Figure 5. Body-fixed coordinate system and aerodynamic angles...20 Figure 20. Earth and body-fixed coordinate systems and Euler angles. ........................................24

Direct Mass Measurements in the Light Neutron-Rich Region Using a Combined Energy and Time-of-Flight Technique

NASA Astrophysics Data System (ADS)

Pillai, C.; Swenson, L. W.; Vieira, D. J.; Butler, G. W.; Wouters, J. M.; Rokni, S. H.; Vaziri, K.; Remsberg, L. P.

This experiment has demonstrated that direct mass measurements can be performed (albeit of low precision in this first attempt) using the M proportional to ET(2) method. This technique has the advantage that many particle-bound nuclei, produced in fragmentation reactions can be measured simultaneously, independent of their N or Z. The main disadvantage of this approach is that both energy and time-of-flight must be measured precisely on an absolute scale. Although some mass walk with N and Z was observed in this experiment, these uncertainties were largely removed by extrapolating the smooth dependence observed for known nuclei which lie closer to the valley of (BETA)-stability. Mass measurements for several neutron-rich light nuclei ranging from C-17 to NE-26 have been performed. In all cases these measurements agree with the latest mass compilation of Wapstra and Audi. The masses of N-20 N and F-24 have been determined for the first time.

Doppler Lidar Sensor for Precision Landing on the Moon and Mars

NASA Technical Reports Server (NTRS)

Amzajerdian, Farzin; Petway, Larry; Hines, Glenn; Barnes, Bruce; Pierrottet, Diego; Lockhard, George

2012-01-01

Landing mission concepts that are being developed for exploration of planetary bodies are increasingly ambitious in their implementations and objectives. Most of these missions require accurate position and velocity data during their descent phase in order to ensure safe soft landing at the pre-designated sites. To address this need, a Doppler lidar is being developed by NASA under the Autonomous Landing and Hazard Avoidance (ALHAT) project. This lidar sensor is a versatile instrument capable of providing precision velocity vectors, vehicle ground relative altitude, and attitude. The capabilities of this advanced technology have been demonstrated through two helicopter flight test campaigns conducted over a vegetation-free terrain in 2008 and 2010. Presently, a prototype version of this sensor is being assembled for integration into a rocket-powered terrestrial free-flyer vehicle. Operating in a closed loop with vehicle's guidance and navigation system, the viability of this advanced sensor for future landing missions will be demonstrated through a series of flight tests in 2012.

Repair of major system elements on Skylab

NASA Technical Reports Server (NTRS)

Pace, R. E., Jr.

1974-01-01

In-flight maintenance, as conceived and preplanned for the Skylab mission was limited to simple scheduled and unscheduled replacement tasks and minor contingency repairs. Tools and spares were provided accordingly. However, failures during the mission dictated complicated and sophisticated repairs to major systems so that the mission could continue. These repairs included the release of a large structure that failed to deploy, the assembly and deployment of large mechanical devices, the installation and checkout of precision electronic equipment, troubleshooting and repair of precision electromechanical equipment, and tapping into and recharging a cooling system. The repairs were conducted both inside the spacecraft and during extravehicular activities. Some of the repair tasks required team effort on the part of the crewmen including close procedural coordination between internal and extravehicular crewmen. The Skylab experience indicates that crewmen can, with adequate training, make major system repairs in space using standard or special tools. Design of future spacecraft systems should acknowledge this capability and provide for more extensive in-flight repair and maintenance.

Open-Loop Performance of COBALT Precision Landing Payload on a Commercial Sub-Orbital Rocket

NASA Technical Reports Server (NTRS)

Restrepo, Carolina I.; Carson, John M., III; Amzajerdian, Farzin; Seubert, Carl R.; Lovelace, Ronney S.; McCarthy, Megan M.; Tse, Teming; Stelling, Richard; Collins, Steven M.

2018-01-01

An open-loop flight test campaign of the NASA COBALT (CoOperative Blending of Autonomous Landing Technologies) platform was conducted onboard the Masten Xodiac suborbital rocket testbed. The COBALT platform integrates NASA Guidance, Navigation and Control (GN&C) sensing technologies for autonomous, precise soft landing, including the Navigation Doppler Lidar (NDL) velocity and range sensor and the Lander Vision System (LVS) Terrain Relative Navigation (TRN) system. A specialized navigation filter running onboard COBALT fuses the NDL and LVS data in real time to produce a navigation solution that is independent of GPS and suitable for future, autonomous, planetary, landing systems. COBALT was a passive payload during the open loop tests. COBALT's sensors were actively taking data and processing it in real time, but the Xodiac rocket flew with its own GPS-navigation system as a risk reduction activity in the maturation of the technologies towards space flight. A future closed-loop test campaign is planned where the COBALT navigation solution will be used to fly its host vehicle.

COBALT: Development of a Platform to Flight Test Lander GN&C Technologies on Suborbital Rockets

NASA Technical Reports Server (NTRS)

Carson, John M., III; Seubert, Carl R.; Amzajerdian, Farzin; Bergh, Chuck; Kourchians, Ara; Restrepo, Carolina I.; Villapando, Carlos Y.; O'Neal, Travis V.; Robertson, Edward A.; Pierrottet, Diego;

The characterization and application of a low resource FPGA-based time to digital converter

NASA Astrophysics Data System (ADS)

Balla, Alessandro; Mario Beretta, Matteo; Ciambrone, Paolo; Gatta, Maurizio; Gonnella, Francesco; Iafolla, Lorenzo; Mascolo, Matteo; Messi, Roberto; Moricciani, Dario; Riondino, Domenico

2014-03-01

Time to Digital Converters (TDCs) are very common devices in particles physics experiments. A lot of "off-the-shelf" TDCs can be employed but the necessity of a custom DAta acQuisition (DAQ) system makes the TDCs implemented on the Field-Programmable Gate Arrays (FPGAs) desirable. Most of the architectures developed so far are based on the tapped delay lines with precision down to 10 ps, obtained with high FPGA resources usage and non-linearity issues to be managed. Often such precision is not necessary; in this case TDC architectures with low resources occupancy are preferable allowing the implementation of data processing systems and of other utilities on the same device. In order to reconstruct γγ physics events tagged with High Energy Tagger (HET) in the KLOE-2 (K LOng Experiment 2), we need to measure the Time Of Flight (TOF) of the electrons and positrons from the KLOE-2 Interaction Point (IP) to our tagging stations (11 m apart). The required resolution must be better than the bunch spacing (2.7 ns). We have developed and implemented on a Xilinx Virtex-5 FPGA a 32 channel TDC with a precision of 255 ps and low non-linearity effects along with an embedded data acquisition system and the interface to the online FARM of KLOE-2. The TDC is based on a low resources occupancy technique: the 4×Oversampling technique which, in this work, is pushed to its best resolution and its performances were exhaustively measured.

Perseus High Altitude Remotely Piloted Aircraft on Ramp

NASA Technical Reports Server (NTRS)

1991-01-01

The Perseus proof-of-concept vehicle waits on Rogers Dry Lake in the pre-dawn darkness before a test flight at the Dryden Flight Research Center, Edwards, California. Perseus B is a remotely piloted aircraft developed as a design-performance testbed under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project. Perseus is one of several flight vehicles involved in the ERAST project. A piston engine, propeller-powered aircraft, Perseus was designed and built by Aurora Flight Sciences Corporation, Manassas, Virginia. The objectives of Perseus B's ERAST flight tests have been to reach and maintain horizontal flight above altitudes of 60,000 feet and demonstrate the capability to fly missions lasting from 8 to 24 hours, depending on payload and altitude requirements. The Perseus B aircraft established an unofficial altitude record for a single-engine, propeller-driven, remotely piloted aircraft on June 27, 1998. It reached an altitude of 60,280 feet. In 1999, several modifications were made to the Perseus aircraft including engine, avionics, and flight-control-system improvements. These improvements were evaluated in a series of operational readiness and test missions at the Dryden Flight Research Center, Edwards, California. Perseus is a high-wing monoplane with a conventional tail design. Its narrow, straight, high-aspect-ratio wing is mounted atop the fuselage. The aircraft is pusher-designed with the propeller mounted in the rear. This design allows for interchangeable scientific-instrument payloads to be placed in the forward fuselage. The design also allows for unobstructed airflow to the sensors and other devices mounted in the payload compartment. The Perseus B that underwent test and development in 1999 was the third generation of the Perseus design, which began with the Perseus Proof-Of-Concept aircraft. Perseus was initially developed as part of NASA's Small High-Altitude Science Aircraft (SHASA) program, which later evolved into the ERAST project. The Perseus Proof-Of-Concept aircraft first flew in November 1991 and made three low-altitude flights within a month to validate the Perseus aerodynamic model and flight control systems. Next came the redesigned Perseus A, which incorporated a closed-cycle combustion system that mixed oxygen carried aboard the aircraft with engine exhaust to compensate for the thin air at high altitudes. The Perseus A was towed into the air by a ground vehicle and its engine started after it became airborne. Prior to landing, the engine was stopped, the propeller locked in horizontal position, and the Perseus A glided to a landing on its unique bicycle-type landing gear. Two Perseus A aircraft were built and made 21 flights in 1993-1994. One of the Perseus A aircraft reached over 50,000 feet in altitude on its third test flight. Although one of the Perseus A aircraft was destroyed in a crash after a vertical gyroscope failed in flight, the other aircraft completed its test program and remains on display at Aurora's facility in Manassas. Perseus B first flew Oct. 7, 1994, and made two flights in 1996 before being damaged in a hard landing on the dry lakebed after a propeller shaft failure. After a number of improvements and upgrades-including extending the original 58.5-foot wingspan to 71.5 feet to enhance high-altitude performance--the Perseus B returned to Dryden in the spring of 1998 for a series of four flights. Thereafter, a series of modifications were made including external fuel pods on the wing that more than doubled the fuel capacity to 100 gallons. Engine power was increased by more than 20 percent by boosting the turbocharger output. Fuel consumption was reduced with fuel control modifications and a leaner fuel-air mixture that did not compromise power. The aircraft again crashed on Oct. 1, 1999, near Barstow, California, suffering moderate damage to the aircraft but no property damage, fire, or injuries in the area of the crash. Perseus B is flown remotely by a pilot from a mobile flight control station on the ground. A Global Positioning System (GPS) unit provides navigation data for continuous and precise location during flight. The ground control station features dual independent consoles for aircraft control and systems monitoring. A flight termination system, required for all remotely piloted aircraft being flown in military-restricted airspace, includes a parachute system deployed on command plus a C-Band radar beacon and a Mode-C transponder to aid in location. Dryden has provided hanger and office space for the Perseus B aircraft and for the flight test development team when on site for flight or ground testing. NASA's ERAST project is developing aeronautical technologies for a new generation of remotely piloted and autonomous aircraft for a variety of upper-atmospheric science missions and commercial applications. Dryden is the lead center in NASA for ERAST management and operations. Perseus B is approximately 25 feet long, has a wingspan of 71.5 feet, and stands 12 feet high. Perseus B is powered by a Rotax 914, four-cylinder piston engine mounted in the mid-fuselage area and integrated with an Aurora-designed three-stage turbocharger, connected to a lightweight two-blade propeller.

Perseus in Flight

NASA Technical Reports Server (NTRS)

1991-01-01

The Perseus proof-of-concept vehicle flies over Rogers Dry Lake at the Dryden Flight Research Center, Edwards, California, to test basic design concepts for the remotely-piloted, high-altitude vehicle. Perseus B is a remotely piloted aircraft developed as a design-performance testbed under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project. Perseus is one of several flight vehicles involved in the ERAST project. A piston engine, propeller-powered aircraft, Perseus was designed and built by Aurora Flight Sciences Corporation, Manassas, Virginia. The objectives of Perseus B's ERAST flight tests have been to reach and maintain horizontal flight above altitudes of 60,000 feet and demonstrate the capability to fly missions lasting from 8 to 24 hours, depending on payload and altitude requirements. The Perseus B aircraft established an unofficial altitude record for a single-engine, propeller-driven, remotely piloted aircraft on June 27, 1998. It reached an altitude of 60,280 feet. In 1999, several modifications were made to the Perseus aircraft including engine, avionics, and flight-control-system improvements. These improvements were evaluated in a series of operational readiness and test missions at the Dryden Flight Research Center, Edwards, California. Perseus is a high-wing monoplane with a conventional tail design. Its narrow, straight, high-aspect-ratio wing is mounted atop the fuselage. The aircraft is pusher-designed with the propeller mounted in the rear. This design allows for interchangeable scientific-instrument payloads to be placed in the forward fuselage. The design also allows for unobstructed airflow to the sensors and other devices mounted in the payload compartment. The Perseus B that underwent test and development in 1999 was the third generation of the Perseus design, which began with the Perseus Proof-Of-Concept aircraft. Perseus was initially developed as part of NASA's Small High-Altitude Science Aircraft (SHASA) program, which later evolved into the ERAST project. The Perseus Proof-Of-Concept aircraft first flew in November 1991 and made three low-altitude flights within a month to validate the Perseus aerodynamic model and flight control systems. Next came the redesigned Perseus A, which incorporated a closed-cycle combustion system that mixed oxygen carried aboard the aircraft with engine exhaust to compensate for the thin air at high altitudes. The Perseus A was towed into the air by a ground vehicle and its engine started after it became airborne. Prior to landing, the engine was stopped, the propeller locked in horizontal position, and the Perseus A glided to a landing on its unique bicycle-type landing gear. Two Perseus A aircraft were built and made 21 flights in 1993-1994. One of the Perseus A aircraft reached over 50,000 feet in altitude on its third test flight. Although one of the Perseus A aircraft was destroyed in a crash after a vertical gyroscope failed in flight, the other aircraft completed its test program and remains on display at Aurora's facility in Manassas. Perseus B first flew Oct. 7, 1994, and made two flights in 1996 before being damaged in a hard landing on the dry lakebed after a propeller shaft failure. After a number of improvements and upgrades-including extending the original 58.5-foot wingspan to 71.5 feet to enhance high-altitude performance--the Perseus B returned to Dryden in the spring of 1998 for a series of four flights. Thereafter, a series of modifications were made including external fuel pods on the wing that more than doubled the fuel capacity to 100 gallons. Engine power was increased by more than 20 percent by boosting the turbocharger output. Fuel consumption was reduced with fuel control modifications and a leaner fuel-air mixture that did not compromise power. The aircraft again crashed on Oct. 1, 1999, near Barstow, California, suffering moderate damage to the aircraft but no property damage, fire, or injuries in the area of the crash. Perseus B is flown remotely by a pilot from a mobile flight control station on the ground. A Global Positioning System (GPS) unit provides navigation data for continuous and precise location during flight. The ground control station features dual independent consoles for aircraft control and systems monitoring. A flight termination system, required for all remotely piloted aircraft being flown in military-restricted airspace, includes a parachute system deployed on command plus a C-Band radar beacon and a Mode-C transponder to aid in location. Dryden has provided hanger and office space for the Perseus B aircraft and for the flight test development team when on site for flight or ground testing. NASA's ERAST project is developing aeronautical technologies for a new generation of remotely piloted and autonomous aircraft for a variety of upper-atmospheric science missions and commercial applications. Dryden is the lead center in NASA for ERAST management and operations. Perseus B is approximately 25 feet long, has a wingspan of 71.5 feet, and stands 12 feet high. Perseus B is powered by a Rotax 914, four-cylinder piston engine mounted in the mid-fuselage area and integrated with an Aurora-designed three-stage turbocharger, connected to a lightweight two-blade propeller.

Biomechanical basis of wing and haltere coordination in flies

PubMed Central

Deora, Tanvi; Singh, Amit Kumar; Sane, Sanjay P.

2015-01-01

The spectacular success and diversification of insects rests critically on two major evolutionary adaptations. First, the evolution of flight, which enhanced the ability of insects to colonize novel ecological habitats, evade predators, or hunt prey; and second, the miniaturization of their body size, which profoundly influenced all aspects of their biology from development to behavior. However, miniaturization imposes steep demands on the flight system because smaller insects must flap their wings at higher frequencies to generate sufficient aerodynamic forces to stay aloft; it also poses challenges to the sensorimotor system because precise control of wing kinematics and body trajectories requires fast sensory feedback. These tradeoffs are best studied in Dipteran flies in which rapid mechanosensory feedback to wing motor system is provided by halteres, reduced hind wings that evolved into gyroscopic sensors. Halteres oscillate at the same frequency as and precisely antiphase to the wings; they detect body rotations during flight, thus providing feedback that is essential for controlling wing motion during aerial maneuvers. Although tight phase synchrony between halteres and wings is essential for providing proper timing cues, the mechanisms underlying this coordination are not well understood. Here, we identify specific mechanical linkages within the thorax that passively mediate both wing–wing and wing–haltere phase synchronization. We demonstrate that the wing hinge must possess a clutch system that enables flies to independently engage or disengage each wing from the mechanically linked thorax. In concert with a previously described gearbox located within the wing hinge, the clutch system enables independent control of each wing. These biomechanical features are essential for flight control in flies. PMID:25605915

Touchdown: The Development of Propulsion Controlled Aircraft at NASA Dryden

NASA Technical Reports Server (NTRS)

Tucker, Tom

1999-01-01

This monograph relates the important history of the Propulsion Controlled Aircraft project at NASA's Dryden Flight Research Center. Spurred by a number of airplane crashes caused by the loss of hydraulic flight controls, a NASA-industry team lead by Frank W. Burcham and C. Gordon Fullerton developed a way to land an aircraft safely using only engine thrust to control the airplane. In spite of initial skepticism, the team discovered that, by manually manipulating an airplane's thrust, there was adequate control for extended up-and-away flight. However, there was not adequate control precision for safe runway landings because of the small control forces, slow response, and difficulty in damping the airplane phugoid and Dutch roll oscillations. The team therefore conceived, developed, and tested the first computerized Propulsion Controlled Aircraft (PCA) system. The PCA system takes pilot commands, uses feedback from airplane measurements, and computes commands for the thrust of each engine, yielding much more precise control. Pitch rate and velocity feedback damp the phugoid oscillation, while yaw rate feedback damps the Dutch roll motion. The team tested the PCA system in simulators and conducted flight research in F-15 and MD-11 airplanes. Later, they developed less sophisticated variants of PCA called PCA Lite and PCA Ultralite to make the system cheaper and therefore more attractive to industry. This monograph tells the PCA story in a non- technical way with emphasis on the human aspects of the engineering and flic,ht-research effort. It thereby supplements the extensive technical literature on PCA and makes the development of this technology accessible to a wide audience.

Tunable diode laser in-situ CH4 measurements aboard the CARIBIC passenger aircraft: instrument performance assessment

NASA Astrophysics Data System (ADS)

Dyroff, C.; Zahn, A.; Sanati, S.; Christner, E.; Rauthe-Schöch, A.; Schuck, T. J.

2013-10-01

A laser spectrometer for automated monthly measurements of methane (CH4) mixing ratios aboard the CARIBIC passenger aircraft is presented. The instrument is based on a commercial Fast Greenhouse Gas Analyzer (FGGA, Los Gatos Res.), which was adapted to meet the requirements imposed by unattended airborne employment. The modified instrument is described. A laboratory characterization was performed to determine the instrument stability, precision, cross sensitivity to H2O, and accuracy. For airborne operation a calibration strategy is described, that utilizes CH4 measurements obtained from flask samples taken during the same flights. The precision of airborne measurements is 2 ppbv for 10 s averages. The accuracy at aircraft cruising altitude is 3.85 ppbv. During aircraft ascent and descent, where no flask samples were obtained, instrumental drifts can be less accurately considered and the uncertainty is estimated to be 12.4 ppbv. A linear humidity bias correction was applied to the CH4 measurements, which was most important in the lower troposphere. On average, the correction bias was around 6.5 ppbv at an altitude of 2 km, and negligible at cruising flight level. Observations from 103 long-distance flights are presented that span a large part of the northern hemispheric upper troposphere and lowermost stratosphere (UT/LMS), with occasional crossing of the tropics on flights to southern Africa. These accurate data mark the largest UT/LMS in-situ CH4 dataset worldwide. An example of a tracer-tracer correlation study with ozone is given, highlighting the possibility for accurate cross-tropopause transport analyses.

Tunable diode laser in-situ CH4 measurements aboard the CARIBIC passenger aircraft: instrument performance assessment

NASA Astrophysics Data System (ADS)

Dyroff, C.; Zahn, A.; Sanati, S.; Christner, E.; Rauthe-Schöch, A.; Schuck, T. J.

2014-03-01

A laser spectrometer for automated monthly measurements of methane (CH4) mixing ratios aboard the CARIBIC passenger aircraft is presented. The instrument is based on a commercial Fast Greenhouse Gas Analyser (FGGA, Los Gatos Res.), which was adapted to meet the requirements imposed by unattended airborne operation. It was characterised in the laboratory with respect to instrument stability, precision, cross sensitivity to H2O, and accuracy. For airborne operation, a calibration strategy is described that utilises CH4 measurements obtained from flask samples taken during the same flights. The precision of airborne measurements is 2 ppb for 10 s averages. The accuracy at aircraft cruising altitude is 3.85 ppb. During aircraft ascent and descent, where no flask samples were obtained, instrumental drifts can be less accurately determined and the uncertainty is estimated to be 12.4 ppb. A linear humidity bias correction was applied to the CH4 measurements, which was most important in the lower troposphere. On average, the correction bias was around 6.5 ppb at an altitude of 2 km, and negligible at cruising flight level. Observations from 103 long-distance flights are presented that span a large part of the northern hemispheric upper troposphere and lowermost stratosphere (UT/LMS), with occasional crossing of the tropics on flights to southern Africa. These accurate data mark the largest UT/LMS in-situ CH4 dataset worldwide. An example of a tracer-tracer correlation study with ozone is given, highlighting the possibility for accurate cross-tropopause transport analyses.

Small-scale fixed wing airplane software verification flight test

NASA Astrophysics Data System (ADS)

Miller, Natasha R.

The increased demand for micro Unmanned Air Vehicles (UAV) driven by military requirements, commercial use, and academia is creating a need for the ability to quickly and accurately conduct low Reynolds Number aircraft design. There exist several open source software programs that are free or inexpensive that can be used for large scale aircraft design, but few software programs target the realm of low Reynolds Number flight. XFLR5 is an open source, free to download, software program that attempts to take into consideration viscous effects that occur at low Reynolds Number in airfoil design, 3D wing design, and 3D airplane design. An off the shelf, remote control airplane was used as a test bed to model in XFLR5 and then compared to flight test collected data. Flight test focused on the stability modes of the 3D plane, specifically the phugoid mode. Design and execution of the flight tests were accomplished for the RC airplane using methodology from full scale military airplane test procedures. Results from flight test were not conclusive in determining the accuracy of the XFLR5 software program. There were several sources of uncertainty that did not allow for a full analysis of the flight test results. An off the shelf drone autopilot was used as a data collection device for flight testing. The precision and accuracy of the autopilot is unknown. Potential future work should investigate flight test methods for small scale UAV flight.

COBALT CoOperative Blending of Autonomous Landing Technology

NASA Technical Reports Server (NTRS)

Carson, John M. III; Restrepo, Carolina I.; Robertson, Edward A.; Seubert, Carl R.; Amzajerdian, Farzin

2016-01-01

COBALT is a terrestrial test platform for development and maturation of GN&C (Guidance, Navigation and Control) technologies for PL&HA (Precision Landing and Hazard Avoidance). The project is developing a third generation, Langley Navigation Doppler Lidar (NDL) for ultra-precise velocity and range measurements, which will be integrated and tested with the JPL Lander Vision System (LVS) for Terrain Relative Navigation (TRN) position estimates. These technologies together provide navigation that enables controlled precision landing. The COBALT hardware will be integrated in 2017 into the GN&C subsystem of the Xodiac rocket-propulsive Vertical Test Bed (VTB) developed by Masten Space Systems (MSS), and two terrestrial flight campaigns will be conducted: one open-loop (i.e., passive) and one closed-loop (i.e., active).

Evaluation of a technique to simplify depictions of visually complex aeronautical procedures for NextGen

DOT National Transportation Integrated Search

2013-10-04

Performance based navigation supports the design of more precise flight procedures. However, these new procedures can be visually complex, which may impact the usability of charts that depict the procedures. The purpose of the study was to evaluate w...

Geochronology as a Framework for Planetary History through 2050

NASA Technical Reports Server (NTRS)

Cohen, Barbara; Arevalo, R., Jr.; Bottke, W. F., Jr.; Conrad, P. G.; Farley, K. A.; Fassett, C. I.; Jolliff, B. L.; Lawrence, S. J.; Mahaffy, Paul; Malespin, C.;

Development of Unmanned Aerial Vehicles for Site-Specific Crop Production Management

USDA-ARS?s Scientific Manuscript database

Unmanned Aerial Vehicles (UAV) have been developed and applied to support the practice of precision agriculture. Compared to piloted aircrafts, an Unmanned Aerial Vehicle can focus on much smaller crop fields with much lower flight altitude than regular airplanes to perform site-specific management ...

Perseus Post-flight

NASA Technical Reports Server (NTRS)

1991-01-01

Crew members check out the Perseus proof-of-concept vehicle on Rogers Dry Lake, adjacent to the Dryden Flight Research Center, Edwards, California, after a test flight in 1991. Perseus B is a remotely piloted aircraft developed as a design-performance testbed under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) project. Perseus is one of several flight vehicles involved in the ERAST project. A piston engine, propeller-powered aircraft, Perseus was designed and built by Aurora Flight Sciences Corporation, Manassas, Virginia. The objectives of Perseus B's ERAST flight tests have been to reach and maintain horizontal flight above altitudes of 60,000 feet and demonstrate the capability to fly missions lasting from 8 to 24 hours, depending on payload and altitude requirements. The Perseus B aircraft established an unofficial altitude record for a single-engine, propeller-driven, remotely piloted aircraft on June 27, 1998. It reached an altitude of 60,280 feet. In 1999, several modifications were made to the Perseus aircraft including engine, avionics, and flight-control-system improvements. These improvements were evaluated in a series of operational readiness and test missions at the Dryden Flight Research Center, Edwards, California. Perseus is a high-wing monoplane with a conventional tail design. Its narrow, straight, high-aspect-ratio wing is mounted atop the fuselage. The aircraft is pusher-designed with the propeller mounted in the rear. This design allows for interchangeable scientific-instrument payloads to be placed in the forward fuselage. The design also allows for unobstructed airflow to the sensors and other devices mounted in the payload compartment. The Perseus B that underwent test and development in 1999 was the third generation of the Perseus design, which began with the Perseus Proof-Of-Concept aircraft. Perseus was initially developed as part of NASA's Small High-Altitude Science Aircraft (SHASA) program, which later evolved into the ERAST project. The Perseus Proof-Of-Concept aircraft first flew in November 1991 and made three low-altitude flights within a month to validate the Perseus aerodynamic model and flight control systems. Next came the redesigned Perseus A, which incorporated a closed-cycle combustion system that mixed oxygen carried aboard the aircraft with engine exhaust to compensate for the thin air at high altitudes. The Perseus A was towed into the air by a ground vehicle and its engine started after it became airborne. Prior to landing, the engine was stopped, the propeller locked in horizontal position, and the Perseus A glided to a landing on its unique bicycle-type landing gear. Two Perseus A aircraft were built and made 21 flights in 1993-1994. One of the Perseus A aircraft reached over 50,000 feet in altitude on its third test flight. Although one of the Perseus A aircraft was destroyed in a crash after a vertical gyroscope failed in flight, the other aircraft completed its test program and remains on display at Aurora's facility in Manassas. Perseus B first flew Oct. 7, 1994, and made two flights in 1996 before being damaged in a hard landing on the dry lakebed after a propeller shaft failure. After a number of improvements and upgrades-including extending the original 58.5-foot wingspan to 71.5 feet to enhance high-altitude performance--the Perseus B returned to Dryden in the spring of 1998 for a series of four flights. Thereafter, a series of modifications were made including external fuel pods on the wing that more than doubled the fuel capacity to 100 gallons. Engine power was increased by more than 20 percent by boosting the turbocharger output. Fuel consumption was reduced with fuel control modifications and a leaner fuel-air mixture that did not compromise power. The aircraft again crashed on Oct. 1, 1999, near Barstow, California, suffering moderate damage to the aircraft but no property damage, fire, or injuries in the area of the crash. Perseus B is flown remotely by a pilot from a mobile flight control station on the ground. A Global Positioning System (GPS) unit provides navigation data for continuous and precise location during flight. The ground control station features dual independent consoles for aircraft control and systems monitoring. A flight termination system, required for all remotely piloted aircraft being flown in military-restricted airspace, includes a parachute system deployed on command plus a C-Band radar beacon and a Mode-C transponder to aid in location. Dryden has provided hanger and office space for the Perseus B aircraft and for the flight test development team when on site for flight or ground testing. NASA's ERAST project is developing aeronautical technologies for a new generation of remotely piloted and autonomous aircraft for a variety of upper-atmospheric science missions and commercial applications. Dryden is the lead center in NASA for ERAST management and operations. Perseus B is approximately 25 feet long, has a wingspan of 71.5 feet, and stands 12 feet high. Perseus B is powered by a Rotax 914, four-cylinder piston engine mounted in the mid-fuselage area and integrated with an Aurora-designed three-stage turbocharger, connected to a lightweight two-blade propeller.

Space Technology 7 Disturbance Reduction System - precision control flight Validation

NASA Technical Reports Server (NTRS)

Carmain, Andrew J.; Dunn, Charles; Folkner, William; Hruby, Vlad; Spence, Doug; O'Donnell, James; Markley, Landis; Maghami, Peiman; Hsu, Oscar; Demmons, N.;

Platform Precision Autopilot Overview and Mission Performance

NASA Technical Reports Server (NTRS)

Strovers, Brian K.; Lee, James A.

2009-01-01

The Platform Precision Autopilot is an instrument landing system-interfaced autopilot system, developed to enable an aircraft to repeatedly fly nearly the same trajectory hours, days, or weeks later. The Platform Precision Autopilot uses a novel design to interface with a NASA Gulfstream III jet by imitating the output of an instrument landing system approach. This technique minimizes, as much as possible, modifications to the baseline Gulfstream III jet and retains the safety features of the aircraft autopilot. The Platform Precision Autopilot requirement is to fly within a 5-m (16.4-ft) radius tube for distances to 200 km (108 nmi) in the presence of light turbulence for at least 90 percent of the time. This capability allows precise repeat-pass interferometry for the Unmanned Aerial Vehicle Synthetic Aperture Radar program, whose primary objective is to develop a miniaturized, polarimetric, L-band synthetic aperture radar. Precise navigation is achieved using an accurate differential global positioning system developed by the Jet Propulsion Laboratory. Flight-testing has demonstrated the ability of the Platform Precision Autopilot to control the aircraft within the specified tolerance greater than 90 percent of the time in the presence of aircraft system noise and nonlinearities, constant pilot throttle adjustments, and light turbulence.

Analysis of Method TO-14 target analytes using a cryofocusing high-speed gas chromatograph interfaced to a high-speed time-of-flight mass spectrometer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berkley, R.E.; Gardner, B.D.; Holland, J.F.

1997-12-31

A high-speed gas chromatograph coupled with a high-speed time-of-flight mass spectrometer was used to gain a six-fold increase in overall rate of analytical throughput for analysis of EPA Method TO-14 target compounds. Duration of chromatograms was 180 seconds. One hundred mass spectra per second, ranging from 35 to 270 mass units, were collected. Single ion chromatograms were searched at appropriate retention times for chromatographic peaks, which were integrated. Thirty-eight of the forty-one TO-14 target compounds were calibrated using standards at five concentrations from 2.5 to 40 ppb. Four grab samples of ambient air were collected at four different locations atmore » an automobile repair facility, and two grab samples were collected less than one minute apart at a site near a chemical plant, just before and just after passage of three large diesel trucks. All samples were analyzed on the same day they were collected. Most of the duplicate analyses were in close agreement. Ability of the high-speed TOF/GC/MS system to perform analyses of TO-14 target compounds rapidly and precisely was demonstrated. This paper has been reviewed according to US Environmental Protection Agency peer and administrative review policies and approved for presentation and publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.« less

Foraging at the edge of the world: low-altitude, high-speed manoeuvering in barn swallows

PubMed Central

Warrick, Douglas R.; Hedrick, Tyson L.; Crandell, Kristen E.

2016-01-01

While prior studies of swallow manoeuvering have focused on slow-speed flight and obstacle avoidance in still air, swallows survive by foraging at high speeds in windy environments. Recent advances in field-portable, high-speed video systems, coupled with precise anemometry, permit measures of high-speed aerial performance of birds in a natural state. We undertook the present study to test: (i) the manner in which barn swallows (Hirundo rustica) may exploit wind dynamics and ground effect while foraging and (ii) the relative importance of flapping versus gliding for accomplishing high-speed manoeuvers. Using multi-camera videography synchronized with wind-velocity measurements, we tracked coursing manoeuvers in pursuit of prey. Wind speed averaged 1.3–2.0 m s−1 across the atmospheric boundary layer, exhibiting a shear gradient greater than expected, with instantaneous speeds of 0.02–6.1 m s−1. While barn swallows tended to flap throughout turns, they exhibited reduced wingbeat frequency, relying on glides and partial bounds during maximal manoeuvers. Further, the birds capitalized on the near-earth wind speed gradient to gain kinetic and potential energy during both flapping and gliding turns; providing evidence that such behaviour is not limited to large, fixed-wing soaring seabirds and that exploitation of wind gradients by small aerial insectivores may be a significant aspect of their aeroecology. This article is part of the themed issue ‘Moving in a moving medium: new perspectives on flight'. PMID:27528781

SPHERES as Formation Flight Algorithm Development and Validation Testbed: Current Progress and Beyond

NASA Technical Reports Server (NTRS)

Kong, Edmund M.; Saenz-Otero, Alvar; Nolet, Simon; Berkovitz, Dustin S.; Miller, David W.; Sell, Steve W.

2004-01-01

The MIT-SSL SPHERES testbed provides a facility for the development of algorithms necessary for the success of Distributed Satellite Systems (DSS). The initial development contemplated formation flight and docking control algorithms; SPHERES now supports the study of metrology, control, autonomy, artificial intelligence, and communications algorithms and their effects on DSS projects. To support this wide range of topics, the SPHERES design contemplated the need to support multiple researchers, as echoed from both the hardware and software designs. The SPHERES operational plan further facilitates the development of algorithms by multiple researchers, while the operational locations incrementally increase the ability of the tests to operate in a representative environment. In this paper, an overview of the SPHERES testbed is first presented. The SPHERES testbed serves as a model of the design philosophies that allow for the various researches being carried out on such a facility. The implementation of these philosophies are further highlighted in the three different programs that are currently scheduled for testing onboard the International Space Station (ISS) and three that are proposed for a re-flight mission: Mass Property Identification, Autonomous Rendezvous and Docking, TPF Multiple Spacecraft Formation Flight in the first flight and Precision Optical Pointing, Tethered Formation Flight and Mars Orbit Sample Retrieval for the re-flight mission.