75 FR 43479 - Proposed Flood Elevation Determinations
Federal Register 2010, 2011, 2012, 2013, 2014
2010-07-26
.... * National Geodetic Vertical Datum. + North American Vertical Datum. Depth in feet above ground. [caret] Mean... Evelyns Drive. * National Geodetic Vertical Datum. + North American Vertical Datum. Depth in feet above.... * National Geodetic Vertical Datum. + North American Vertical Datum. Depth in feet above ground. [caret] Mean...
Rydlund, Jr., Paul H.; Noll, Michael L.
2017-03-07
Datum conversions from the National Geodetic Vertical Datum of 1929 to the North American Vertical Datum of 1988 among inland and coastal gages throughout the hydrologic regions of New England, the Mid-Atlantic, and the South Atlantic-Gulf have implications among river and storm surge forecasting, general commerce, and water-control operations. The process of data conversions may involve the application of a recovered National Geodetic Vertical Datum of 1929–North American Vertical Datum of 1988 offset, a simplistic datum transformation using VDatum or VERTCON software, or a survey, depending on a gaging network datum evaluation, anticipated uncertainties for data use among the cooperative water community, and methods used to derive the conversion. Datum transformations from National Geodetic Vertical Datum of 1929 to North American Vertical Datum of 1988 using VERTCON purport errors of ± 0.13 foot at the 95 percent confidence level among modeled points, claiming more consistency along the east coast. Survey methods involving differential and trigonometric leveling, along with observations using Global Navigation Satellite System technology, afford a variety of approaches to establish or perpetuate a datum during a survey. Uncertainties among leveling approaches are generally < 0.1 foot, and and Global Navigation Satellite System approaches may be categorized with uncertainties of ≤0.1 foot for a Level I quality category and ≥0.1 foot for Level II or III quality categories (defined by the U.S. Geological Survey) by observation and review of experienced practice. The conversion process is initiated with an evaluation of the inland and coastal gage network datum, beginning with altitude datum components and the history of those components queried through the U.S. Geological Survey Groundwater Site Inventory database. Subsequent edits to the Groundwater Site Inventory database may be required and a consensus reached among the U.S. Geological Survey Water Science Centers to identify the outstanding workload categorized as in-office datum transformations or offset applications versus out-of-office survey efforts. Datum conversions or datum establishment for the inland or coastal gaging network should meet datum uncertainty requirements among other Federal agencies. Datum uncertainty requirements are ±0.25 foot for U.S. Army Corps of Engineers water-control or construction projects and ±0.16 foot for Federal Emergency Management Agency field surveys and checkpoint surveys used for mapping. River level forecasts generally are defined as ± 0.10 foot among the National Oceanic and Atmospheric Administration–National Weather Service. Collaboration and communication among the cooperative water community is necessary during a datum conversion or datum change. Datum notification time-change requirements set by the National Oceanic and Atmospheric Administration–National Weather Service vary from 30 to 120 days, depending on datum conversion or datum-change case scenarios. Notification times associated with these case scenarios may be useful to the National Oceanic and Atmospheric Administration–National Weather Service and U.S. Army Corps of Engineers, because their daily operations are time sensitive, unlike the notification time change requirements of other entities that make up the cooperative water community. At the time of this writing, a future geopotential datum resulting from Gravity for the Redefinition of the American Vertical Datum is anticipated in 2022. A future version of VDatum and VERTCON is anticipated to provide a transformation among North American Vertical Datum of 1988 elevations to the new geopotential datum.
2008-02-28
Range, and Section are entered. Datum: Geometric reference surface. Original Site Location datum is defined by user’s map datum; e.g. NAD27...Section are entered. Datum: Geometric reference surface. Original Site Location datum is defined by user’s map datum; e.g. NAD27 Conus or NAD83...Calculated and recorded automatically if the fields UTM_N and UTM_E or Township, Range, and Section are entered. 41 Datum: Geometric reference surface
76 FR 49676 - Final Flood Elevation Determinations
Federal Register 2010, 2011, 2012, 2013, 2014
2011-08-11
... shoreline......... *26 City of Deltona. * National Geodetic Vertical Datum. + North American Vertical Datum... Boulevard. * National Geodetic Vertical Datum. + North American Vertical Datum. Depth in feet above ground... feet +1000 upstream of Southeast 45th Street. * National Geodetic Vertical Datum. + North American...
Code of Federal Regulations, 2013 CFR
2013-07-01
... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Datum. 334.6 Section 334.6... AND RESTRICTED AREA REGULATIONS § 334.6 Datum. (a) Geographic coordinates expressed in terms of... datum is the North American Datum of 1983 (NAD 83), unless such geographic coordinates are expressly...
Code of Federal Regulations, 2012 CFR
2012-07-01
... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Datum. 334.6 Section 334.6... AND RESTRICTED AREA REGULATIONS § 334.6 Datum. (a) Geographic coordinates expressed in terms of... datum is the North American Datum of 1983 (NAD 83), unless such geographic coordinates are expressly...
Code of Federal Regulations, 2014 CFR
2014-07-01
... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Datum. 334.6 Section 334.6... AND RESTRICTED AREA REGULATIONS § 334.6 Datum. (a) Geographic coordinates expressed in terms of... datum is the North American Datum of 1983 (NAD 83), unless such geographic coordinates are expressly...
Code of Federal Regulations, 2011 CFR
2011-07-01
... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Datum. 334.6 Section 334.6... AND RESTRICTED AREA REGULATIONS § 334.6 Datum. (a) Geographic coordinates expressed in terms of... datum is the North American Datum of 1983 (NAD 83), unless such geographic coordinates are expressly...
Enhanced definition and required examples of common datum imposed by ISO standard
NASA Astrophysics Data System (ADS)
Yan, Yiqing; Bohn, Martin
2017-12-01
According to the ISO Geometrical Product Specifications (GPS), the establishment and definition of common datum for geometrical components are not fully defined. There are two main limitations of this standard. Firstly: the explications of ISO examples of common datums are not matched with their corresponding definitions, and secondly: a full definition of common datum is missing. This paper suggests a new approach for an enhanced definition and concrete examples of common datum and proposes a holistic methodology for establishment of common datum for each geometrical component. This research is based on the analysis of physical behaviour of geometrical components, orientation constraints and invariance classes of datums. This approach fills the definition gaps of common datum based on ISO GPS, thereby eliminating those deficits. As a result, an improved methodology for a fully functional defined definition of common datum was formulated.
75 FR 29246 - Proposed Flood Elevation Determinations
Federal Register 2010, 2011, 2012, 2013, 2014
2010-05-25
.... Pacific Railroad. Just upstream of State None +2352 Highway 19. * National Geodetic Vertical Datum. + North American Vertical Datum. Depth in feet above ground. [caret] Mean Sea Level, rounded to the... Vertical Datum. + North American Vertical Datum. Depth in feet above ground. [caret] Mean Sea Level...
75 FR 59095 - Final Flood Elevation Determinations
Federal Register 2010, 2011, 2012, 2013, 2014
2010-09-27
... Mile 673........ +202 * National Geodetic Vertical Datum. + North American Vertical Datum. Depth in...,434 upstream of Northeast 24th Street. * National Geodetic Vertical Datum. + North American Vertical Datum. Depth in feet above ground. [caret] Mean Sea Level, rounded to the nearest 0.1 meter. ADDRESSES...
77 FR 6976 - Final Flood Elevation Determinations
Federal Register 2010, 2011, 2012, 2013, 2014
2012-02-10
... Datum. + North American Vertical Datum. Depth in feet above ground. [caret] Mean Sea Level, rounded to... Unincorporated Areas of approximately 0.5 mile Taney County. upstream of the White River confluence. Big Shoals... confluence. * National Geodetic Vertical Datum. + North American Vertical Datum. Depth in feet above ground...
76 FR 43923 - Final Flood Elevation Determinations
Federal Register 2010, 2011, 2012, 2013, 2014
2011-07-22
... downstream of Big Bethel +9 Road. Approximately 20 feet upstream of the confluence +22 with Newmarket Creek... Approximately 30 feet downstream of I-64 +22 *National Geodetic Vertical Datum. +North American Vertical Datum... Center Street. * National Geodetic Vertical Datum. + North American Vertical Datum. Depth in feet above...
Alaska Tidal Datum Portal | Alaska Division of Geological & Geophysical
Engineering Geology Alaska Tidal Datum Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to Portal Unambiguous vertical datums in the coastal environment are critical to the evaluation of natural human life, property, and the coastal environment. January 2017 - Update Summary Alaska Tidal Datum
Alaska Tidal Datum Portal - Alaska Tidal Datum Calculator | Alaska Division
Coastal Hazards Program Guide to Geologic Hazards in Alaska MAPTEACH Tsunami Inundation Mapping Energy Portal main content Alaska Tidal Datum Portal Unambiguous vertical datums in the coastal environment are projects to ensure protection of human life, property, and the coastal environment. January 2017 - Update
Federal Register 2010, 2011, 2012, 2013, 2014
2010-04-02
...), Including the Replacement of the North American Datum of 1983 (NAD 83) and the North American Vertical Datum... Datum of 1983 (NAD 83), the North American Vertical Datum of 1988 (NAVD 88), and other state and... effort to support these rapid changes in positioning technologies, NGS has adopted a plan to replace NAD...
Towards the Implementation of Semi-Dynamic Datum for Malaysia
NASA Astrophysics Data System (ADS)
Shariff, N. S.; Gill, J.; Amin, Z. M.; Omar, K. M.
2017-10-01
A semi-dynamic datum provides positions with respect to time while taking into account the secular and non-secular deformations, making it the best approach to adapt with the dynamic processes of the earth. Malaysia, as yet, employs a static datum, i.e., GDM2000, at epoch 2000; though Malaysia has evidently been affected by seismic activity for the past decade. Therefore, this paper seeks to propose a design for implementing a semi-dynamic datum for Malaysia. Methodologically, GPS time series analyses are carried out to investigate the seismic activity of Malaysia, which essentially contributes to the proposed design of the semi-dynamic datum for Malaysia. The implications of implementing a semi-dynamic datum for Malaysia are discussed as well. The results indicate that Malaysia undergoes a complex deformation; whereby the earthquakes - primarily the 2004 Sumatra-Andaman, 2005 Nias and 2012 Northern Sumatra earthquakes - have affected the underlying secular velocities of Malaysia. Consequently, from this information, the proposed design, particularly the secular and non-secular deformation models, is described in detail. The proposed semi-dynamic datum comprises a transformation, temporal, and spatial module, and utilizes a bilinear interpolation method. Overall, this paper aims to contribute to the feasibility of a semi-dynamic datum approach for Malaysia.
Levels at streamflow gaging stations
Kennedy, E.J.
1988-01-01
This manual establishes the surveying procedures for setting gages at a streamflow gaging station to datum and for checking them periodically for errors caused by vertical movement of the gage-supporting structures. The surveying terms and concepts used are explained; and the details of testing, adjusting, and operating the instruments are outlined. Notekeeping, adjusting level circuits, checking gages, summarizing results, locating the nearest National Geodetic Vertical Datum of 1929 bench mark, and relating the gage datum to the national datum are described.
A Gravimetric Geoid Model for Vertical Datum in Canada
NASA Astrophysics Data System (ADS)
Veronneau, M.; Huang, J.
2004-05-01
The need to realize a new vertical datum for Canada dates back to 1976 when a study group at Geodetic Survey Division (GSD) investigated problems related to the existing vertical system (CGVD28) and recommended a redefinition of the vertical datum. The US National Geodetic Survey and GSD cooperated in the development of a new North American Vertical Datum (NAVD88). Although the USA adopted NAVD88 in 1993 as its datum, Canada declined to do so as a result of unexplained discrepancies of about 1.5 m from east to west coasts (likely due to systematic errors). The high cost of maintaining the vertical datum by the traditional spirit leveling technique coupled with budgetary constraints has forced GSD to modify its approach. A new attempt (project) to modernize the vertical datum is currently in process in Canada. The advance in space-based technologies (e.g. GPS, satellite radar altimetry, satellite gravimetry) and new developments in geoid modeling offer an alternative to spirit leveling. GSD is planning to implement, after stakeholder consultations, a geoid model as the new vertical datum for Canada, which will allow space-based technology users access to an accurate and uniform datum all across the Canadian landmass and surrounding oceans. CGVD28 is only accessible through a limited number of benchmarks, primarily located in southern Canada. The new vertical datum would be less sensitive to geodynamic activities (post-glacial rebound and earthquake), local uplift and subsidence, and deterioration of the benchmarks. The adoption of a geoid model as a vertical datum does not mean that GSD is neglecting the current benchmarks. New heights will be given to the benchmarks by a new adjustment of the leveling observations, which will be constrained to the geoid model at selected stations of the Active Control System (ACS) and Canadian Base Network (CBN). This adjustment will not correct vertical motion at benchmarks, which has occurred since the last leveling observations. The presentation provides an overview of the "Height Modernization" project, and discusses the accuracy of the existing geoid models in Canada.
Wave equation datuming applied to marine OBS data and to land high resolution seismic profiling
NASA Astrophysics Data System (ADS)
Barison, Erika; Brancatelli, Giuseppe; Nicolich, Rinaldo; Accaino, Flavio; Giustiniani, Michela; Tinivella, Umberta
2011-03-01
One key step in seismic data processing flows is the computation of static corrections, which relocate shots and receivers at the same datum plane and remove near surface weathering effects. We applied a standard static correction and a wave equation datuming and compared the obtained results in two case studies: 1) a sparse ocean bottom seismometers dataset for deep crustal prospecting; 2) a high resolution land reflection dataset for hydrogeological investigation. In both cases, a detailed velocity field, obtained by tomographic inversion of the first breaks, was adopted to relocate shots and receivers to the datum plane. The results emphasize the importance of wave equation datuming to properly handle complex near surface conditions. In the first dataset, the deployed ocean bottom seismometers were relocated to the sea level (shot positions) and a standard processing sequence was subsequently applied to the output. In the second dataset, the application of wave equation datuming allowed us to remove the coherent noise, such as ground roll, and to improve the image quality with respect to the application of static correction. The comparison of the two approaches evidences that the main reflecting markers are better resolved when the wave equation datuming procedure is adopted.
77 FR 26959 - Final Flood Elevation Determinations
Federal Register 2010, 2011, 2012, 2013, 2014
2012-05-08
... Creek confluence. * National Geodetic Vertical Datum. + North American Vertical Datum. Depth in feet... County, Indiana, and Incorporated Areas Docket No.: FEMA-B-1171 Big Walnut Creek Approximately 845 feet... feet upstream +692 of Houck Road (North County Road 25 East). * National Geodetic Vertical Datum...
Apparatus and method for detecting flaws in conductive material
Hockey, Ronald L.; Riechers, Douglas M.
1999-01-01
The present invention is an improved sensing unit for detecting flaws in conductive material wherein the sensing coil is positioned away from a datum of either the datum point, the datum orientation, or a combination thereof. Position of the sensing coil away from a datum increases sensitivity for detecting flaws having a characteristic volume less than about 1 mm.sup.3, and further permits detection of subsurface flaws. Use of multiple sensing coils permits quantification of flaw area or volume.
Levels at streamflow gaging stations
Kennedy, E.J.
1990-01-01
This manual establishes the surveying procedures for (1) setting gages at a streamflow gaging station to datum and (2) checking the gages periodically for errors caused by vertical movement of the structures that support them. Surveying terms and concepts are explained, and procedures for testing, adjusting, and operating the instruments are described in detail. Notekeeping, adjusting level circuits, checking gages, summarizing results, locating the nearest National Geodetic Vertical Datum of 1929 bench mark, and relating the gage datum to the national datum are also described.
CGVD2013: The Geoid-based Vertical Datum in Canada
NASA Astrophysics Data System (ADS)
Robin, C. M. I.; Veronneau, M.; Huang, J.
2016-12-01
In November 2013, Canada established the Canadian Geodetic Vertical Datum of 2013 (CGVD2013). This new datum is defined by an equipotential surface (Wo =62,636,856 m2/s2) and realized by a geoid model (CGG2013), making it compatible with Global Navigation Satellite Systems (GNSS) for positioning. The adoption of CGVD2013 represents a major shift from the old vertical datum (CGVD28), which was defined by the mean sea level at selected tide gauges and propagated in land by precise levelling measurements. This new vertical datum represents also a major impact for the users, who have relied on the access to benchmarks for the last 100 years to conduct their surveys. The presentation will not only discuss the advantages for Canada to moving to a geoid-based datum, but also discuss the challenges in maintaining such as vertical datum in a period where technology is moving rapidly and data are coming in large numbers allowing the possibility of a quick turnaround in the release of new realisations of the geoid-based vertical datum. This is quite different as when benchmarks were re-surveyed at a 20- to 30-year cycle or sometime never revisited again, resulting in heights that were very consistent over many years (even though benchmarks are moving up and down). The question is how to fulfil users who want to live in a static world as much as possible, but simultaneously updating the vertical datum to assure utmost accuracy for scientific and technological requirements. Consequently, the presentation will give a look at the future American height system, as the US National Geodetic Survey is in the process of updating by 2022 the geometric and height reference systems, being NAD 83 and NAVD 88, respectively.
Datum Feature Extraction and Deformation Analysis Method Based on Normal Vector of Point Cloud
NASA Astrophysics Data System (ADS)
Sun, W.; Wang, J.; Jin, F.; Liang, Z.; Yang, Y.
2018-04-01
In order to solve the problem lacking applicable analysis method in the application of three-dimensional laser scanning technology to the field of deformation monitoring, an efficient method extracting datum feature and analysing deformation based on normal vector of point cloud was proposed. Firstly, the kd-tree is used to establish the topological relation. Datum points are detected by tracking the normal vector of point cloud determined by the normal vector of local planar. Then, the cubic B-spline curve fitting is performed on the datum points. Finally, datum elevation and the inclination angle of the radial point are calculated according to the fitted curve and then the deformation information was analyzed. The proposed approach was verified on real large-scale tank data set captured with terrestrial laser scanner in a chemical plant. The results show that the method could obtain the entire information of the monitor object quickly and comprehensively, and reflect accurately the datum feature deformation.
Code of Federal Regulations, 2010 CFR
2010-07-01
... datum is the North American Datum of 1983 (NAD 83), unless such geographic coordinates are expressly labeled NAD 83. Geographic coordinates without the NAD 83 reference may be plotted on maps or charts referenced to NAD 83 only after application of the appropriate corrections that are published on the...
Links - Helpful Tools | Alaska Division of Geological & Geophysical Surveys
Tidal Datum Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to Geologic Hazards in Systems Alaska Tidal Datum Portal For Alaska's coastal communities, an understanding and awareness of local tidal datums is critical to assessing vulnerability and planning responses to coastal geohazards
Simulator Design and Instructional Features for Carrier Landing: A Field Transfer Study
1986-06-18
the datum bars. This light is known as the meatball . It is visible to the pilot through the center lens and is seen as level with the datum bars when... meatball is seen through higher or lower Fresnel lenses to give the appearance of moving vertically above or below the line of the datum bars Figure A-i...degrees) by keeping the meatball level with the datum bars, so that a hook attached to the ý:ail of the aircraft will contact the landing deck midway
Upcoming replacements for NAD83, NAVD88 and IGLD85
NASA Astrophysics Data System (ADS)
Smith, D. A.; Snay, R.
2009-05-01
The National Geodetic Survey (NGS), part of the National Oceanic and Atmospheric Administration (NOAA) is responsible for defining, maintaining and providing access to the National Spatial Reference System (NSRS) for the United States. The NSRS is the official system to which all civil federal mapping agencies should refer, and contains, amongst other things, the official geopotential (historically "vertical") datum of NAVD 88, the 3-D geometric reference system (historically "horizontal datum") of NAD 83 and great lakes datum (IGLD 85). Although part of the United States NSRS, all three of these datums have been created through international partnerships across North America. Unfortunately, time has shown both the systematic errors existent within these datums, as well as the inherent weaknesses of relying exclusively on passive monuments to define and provide access to these datums. In recognition of these issues, the National Geodetic Survey has issued a "10 year plan", available online, which outlines steps which will be taken to update NAD 83, NAVD 88 and IGLD 85 concurrently around the year 2018. The primary source of success will be in the refinement of the CORS network and the upcoming execution of the GRAV-D project (Gravity for the Re-definition of the American Vertical Datum). Conversations are ongoing with colleagues in Canada, Mexico, Central America and the Caribbean in order to coordinate all of these efforts across the entire continent. The largest changes expected to occur are the removal of over 2 meters of non-geocentricity in NAD 83; the removal of decimeters of bias and over a meter of tilt in NAVD 88; the addition of the ability to track crustal motions (subsidence, tectonics, etc) in the datums; the removal of leveling as a tool for long-line height differencing; the use of a "best" geoid as the orthometric height reference surface; the addition of datum velocities (motions of the 3-D geometric reference system origin and motions of the geoid); and the use of GNSS technology as the way to access both orthometric and dynamic heights in the vertical datum. This talk will outline the broad plan of action and invite further collaboration along these lines.
33 CFR 110.235 - Pacific Ocean (Mamala Bay), Honolulu Harbor, Hawaii (Datum: NAD 83).
Code of Federal Regulations, 2011 CFR
2011-07-01
... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Pacific Ocean (Mamala Bay), Honolulu Harbor, Hawaii (Datum: NAD 83). 110.235 Section 110.235 Navigation and Navigable Waters COAST... Pacific Ocean (Mamala Bay), Honolulu Harbor, Hawaii (Datum: NAD 83). (a) The anchorage grounds—(1...
33 CFR 110.235 - Pacific Ocean (Mamala Bay), Honolulu Harbor, Hawaii (Datum: NAD 83).
Code of Federal Regulations, 2014 CFR
2014-07-01
... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Pacific Ocean (Mamala Bay), Honolulu Harbor, Hawaii (Datum: NAD 83). 110.235 Section 110.235 Navigation and Navigable Waters COAST... Pacific Ocean (Mamala Bay), Honolulu Harbor, Hawaii (Datum: NAD 83). (a) The anchorage grounds—(1...
33 CFR 110.235 - Pacific Ocean (Mamala Bay), Honolulu Harbor, Hawaii (Datum: NAD 83).
Code of Federal Regulations, 2012 CFR
2012-07-01
... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Pacific Ocean (Mamala Bay), Honolulu Harbor, Hawaii (Datum: NAD 83). 110.235 Section 110.235 Navigation and Navigable Waters COAST... Pacific Ocean (Mamala Bay), Honolulu Harbor, Hawaii (Datum: NAD 83). (a) The anchorage grounds—(1...
33 CFR 110.235 - Pacific Ocean (Mamala Bay), Honolulu Harbor, Hawaii (Datum: NAD 83).
Code of Federal Regulations, 2013 CFR
2013-07-01
... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Pacific Ocean (Mamala Bay), Honolulu Harbor, Hawaii (Datum: NAD 83). 110.235 Section 110.235 Navigation and Navigable Waters COAST... Pacific Ocean (Mamala Bay), Honolulu Harbor, Hawaii (Datum: NAD 83). (a) The anchorage grounds—(1...
33 CFR 110.235 - Pacific Ocean (Mamala Bay), Honolulu Harbor, Hawaii (Datum: NAD 83).
Code of Federal Regulations, 2010 CFR
2010-07-01
... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Pacific Ocean (Mamala Bay), Honolulu Harbor, Hawaii (Datum: NAD 83). 110.235 Section 110.235 Navigation and Navigable Waters COAST... Pacific Ocean (Mamala Bay), Honolulu Harbor, Hawaii (Datum: NAD 83). (a) The anchorage grounds—(1...
33 CFR 110.168 - Hampton Roads, Virginia and adjacent waters (Datum: NAD 83).
Code of Federal Regulations, 2010 CFR
2010-07-01
... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Hampton Roads, Virginia and adjacent waters (Datum: NAD 83). 110.168 Section 110.168 Navigation and Navigable Waters COAST GUARD..., Virginia and adjacent waters (Datum: NAD 83). (a) Anchorage Grounds—(1) Anchorage A [Naval Anchorage]. The...
33 CFR 110.128d - Island of Oahu, Hawaii. (Datum: OHD)
Code of Federal Regulations, 2010 CFR
2010-07-01
... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Island of Oahu, Hawaii. (Datum: OHD) 110.128d Section 110.128d Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.128d Island of Oahu, Hawaii. (Datum...
Flynn, Robert H.; Rydlund, Jr., Paul H.; Martin, Daniel J.
2016-03-08
Lake-gage water-surface elevations determined during the 3 days of surveys were converted to water-surface elevations referenced to the North American Vertical Datum of 1988 by using calculated offsets and historical water-surface elevations. In this report, an “offset” refers to the adjustment that needs to be applied to published data from a particular gage to produce elevation data referenced to the North American Vertical Datum of 1988. Offsets presented in this report can be used in the evaluation of water-surface elevations in a common datum for Lake Champlain and the Richelieu River. In addition, the water-level data referenced to the common datum (as determined from the offsets) may be used to calibrate flow models and support future modeling studies developed for Lake Champlain and the Richelieu River.
The Unified Levelling Network of Sarawak and its Adjustment
NASA Astrophysics Data System (ADS)
Som, Z. A. M.; Yazid, A. M.; Ming, T. K.; Yazid, N. M.
2016-09-01
The height reference network of Sarawak has seen major improvement in over the past two decades. The most significant improvement was the establishment of extended precise leveling network of which is now able to connect all three major datum points at Pulau Lakei, Original and Bintulu. Datum by following the major accessible routes across Sarawak. This means the leveling network in Sarawak has now been inter-connected and unified. By having such a unified network leads to the possibility of having a common single least squares adjustment been performed for the first time. The least squares adjustment of this unified levelling network was attempted in order to compute the height of all Bench Marks established in the entire levelling network. The adjustment was done by using MoreFix levelling adjustment package developed at FGHT UTM. The computational procedure adopted is linear parametric adjustment by minimum constraint. Since Sarawak has three separate datums therefore three separate adjustments were implemented by utilizing datum at Pulau Lakei, Original Miri and Bintulu Datum respectively. Results of the MoreFix unified adjustment agreed very well with adjustment repeated using Starnet. Further the results were compared with solution given by Jupem and they are in good agreement as well. The difference in height analysed were within 10mm for the case of minimum constraint at Pulau Lakei datum and with much better agreement in the case of Original Miri Datum.
33 CFR 100.717 - Annual Fort Myers Beach Offshore Grand Prix; Fort Myers, FL.
Code of Federal Regulations, 2011 CFR
2011-07-01
...°58.30′ W). All coordinates referenced use datum: NAD 83. (b) Special local regulations. (1) No vessel... coordinates referenced use datum: NAD 83. (3) All vessel traffic, not involved with the Fort Myers Beach... clear of the racecourse. All coordinates referenced use datum: NAD 83. (4) All vessel traffic, not...
33 CFR 100.717 - Annual Fort Myers Beach Offshore Grand Prix; Fort Myers, FL.
Code of Federal Regulations, 2010 CFR
2010-07-01
...°58.30′ W). All coordinates referenced use datum: NAD 83. (b) Special local regulations. (1) No vessel... coordinates referenced use datum: NAD 83. (3) All vessel traffic, not involved with the Fort Myers Beach... clear of the racecourse. All coordinates referenced use datum: NAD 83. (4) All vessel traffic, not...
33 CFR 100.717 - Annual Fort Myers Beach Offshore Grand Prix; Fort Myers, FL.
Code of Federal Regulations, 2013 CFR
2013-07-01
...°58.30′ W). All coordinates referenced use datum: NAD 83. (b) Special local regulations. (1) No vessel... coordinates referenced use datum: NAD 83. (3) All vessel traffic, not involved with the Fort Myers Beach... clear of the racecourse. All coordinates referenced use datum: NAD 83. (4) All vessel traffic, not...
33 CFR 100.717 - Annual Fort Myers Beach Offshore Grand Prix; Fort Myers, FL.
Code of Federal Regulations, 2014 CFR
2014-07-01
...°58.30′ W). All coordinates referenced use datum: NAD 83. (b) Special local regulations. (1) No vessel... coordinates referenced use datum: NAD 83. (3) All vessel traffic, not involved with the Fort Myers Beach... clear of the racecourse. All coordinates referenced use datum: NAD 83. (4) All vessel traffic, not...
33 CFR 100.717 - Annual Fort Myers Beach Offshore Grand Prix; Fort Myers, FL.
Code of Federal Regulations, 2012 CFR
2012-07-01
...°58.30′ W). All coordinates referenced use datum: NAD 83. (b) Special local regulations. (1) No vessel... coordinates referenced use datum: NAD 83. (3) All vessel traffic, not involved with the Fort Myers Beach... clear of the racecourse. All coordinates referenced use datum: NAD 83. (4) All vessel traffic, not...
NASA directory of observation station locations, volume 1
NASA Technical Reports Server (NTRS)
1973-01-01
Geodetic information for NASA tracking stations and for observation stations cooperating in NASA geodetic satellite programs is presented. A Geodetic Data Sheet is provided for each station, giving the position of the station and describing briefly how it was established. Geodetic positions and geocentric coordinates of these stations are tabulated on local or major geodetic datums and on selected world geodetic systems. The principal tracking facilities used by NASA, including the Spaceflight Tracking and Data Network, the Deep Space Network, and several large radio telescopes are discussed. Positions of these facilities are tabulated on their local or national datums, the Mercury Spheroid 1960, the Modified Mercury Datum 1968, and the Spaceflight Tracking and Data Network System. Observation stations in the NASA Geodetic Satellites Program are included along with stations participating in the National Geodetic Satellite Program. Positions of these facilities are given on local or preferred major datums, and on the Modified Mercury Datum 1968.
Federal Register 2010, 2011, 2012, 2013, 2014
2011-12-12
... Datum for Surveying and Mapping Activities for the Islands of St. Croix, St. John, and St. Thomas... datum for surveying and mapping activities for the islands of St. Croix, St. John, and St. Thomas of the... by other Federal surveying and mapping agencies on St. Croix, St. John, and St. Thomas, with the...
33 CFR 100.736 - Annual Fort Myers Beach air show; Fort Myers Beach, FL.
Code of Federal Regulations, 2010 CFR
2010-07-01
...°59′15″ W. All coordinates referenced use datum: NAD 83. (2) Air Box Area. The air box area is... coordinates referenced use datum: NAD 83. (b) Special local regulations. (1) Vessels and persons are... referenced use datum: NAD 83. (c) Dates. This section will be enforced annually on the second consecutive...
Wave equation datuming applied to S-wave reflection seismic data
NASA Astrophysics Data System (ADS)
Tinivella, U.; Giustiniani, M.; Nicolich, R.
2018-05-01
S-wave high-resolution reflection seismic data was processed using Wave Equation Datuming technique in order to improve signal/noise ratio, attenuating coherent noise, and seismic resolution and to solve static corrections problems. The application of this algorithm allowed obtaining a good image of the shallow subsurface geological features. Wave Equation Datuming moves shots and receivers from a surface to another datum (the datum plane), removing time shifts originated by elevation variation and/or velocity changes in the shallow subsoil. This algorithm has been developed and currently applied to P wave, but it reveals the capacity to highlight S-waves images when used to resolve thin layers in high-resolution prospecting. A good S-wave image facilitates correlation with well stratigraphies, optimizing cost/benefit ratio of any drilling. The application of Wave Equation Datuming requires a reliable velocity field, so refraction tomography was adopted. The new seismic image highlights the details of the subsoil reflectors and allows an easier integration with borehole information and geological surveys than the seismic section obtained by conventional CMP reflection processing. In conclusion, the analysis of S-wave let to characterize the shallow subsurface recognizing levels with limited thickness once we have clearly attenuated ground roll, wind and environmental noise.
77 FR 13232 - Security Zones; G8/North Atlantic Treaty Organization (NATO) Summit, Chicago, IL
Federal Register 2010, 2011, 2012, 2013, 2014
2012-03-06
... point located in the approximate position 41[deg]51'37'' N, 087[deg]36'44'' W. [DATUM: NAD 83]. (2... located in the approximate position 41[deg]53'19'' N, 087[deg]36'17'' W. [DATUM: NAD 83]. (3) Security..., 087[deg]36'28'' W. [DATUM: NAD 83] and the juncture of the north and south branches of the Chicago...
NASA Astrophysics Data System (ADS)
He, Lin; Li, Jiancheng; Chu, Yonghai; Zhang, Tengxu
2017-04-01
National height reference systems have conventionally been linked to the coastal local mean sea level, observed at one tide gauge, such as the China national height datum 1985. Due to the effect of the local sea surface topography, the reference level surface of local datum is inconsistent with the global datum or other local datum. In order to unify or connect the local datum to the global height datum, it is necessary to obtain the zero-height geopotential value of local datum or the height offset with respect to the global datum. The GRACE and GOCE satellite mission are promising for purposes of unification of local vertical datums because they have brought a significant improvement in modeling of low-frequency or rather medium-frequency part of the Earth's static gravity field in the past ten years. The focus of this work is directed to the evaluation of most available Global Geopotential Models (GGMs) from GOCE and GRACE, both satellite only as well as combined ones. From the evaluation with the 649 GPS/Levelling benchmarks (BMs) in China, the GOCE/GRACE GGMs provide the accuracy at 42-52cm level, up to their max degree and order. The latest release 5 DIR, TIM GGMs improve the accuracies by 6-10cm compared to the release 1 models. The DIR_R1 is based on the fewer GOCE data performs equally well with the DIR_R4 and DIR_R5 model, this is attributed to the fact that during its development which used a priori information from EIGEN-51C. The zero-height geopotential value W0LVD for the China Local Vertical Datum (LVD) is 62636855.1606m2s-2 from the originally GOCE/GRACE GGMs. Taking into account the GPS/Levelling data contains the full spectral information, and the GOCE-only or GRACE-GOCE combined model are limited to the long wavelengths. To improve the accuracy of the GGMs, it is indispensable to account for the remaining signal above this maximum degree, known as the omission error of the GGM. The effect of GRACE/GOCE omission error is investigated by extending the models with the high-resolution gravity field model EGM2008. In China, the effect of the GRACE/GOCE GGMs omission error is at the decimeter level. The combined GGMs (up to 2160 degree and order) could provide an accuracy at 20cm level, which is better than that from EGM2008. Meanwhile, if an appropriate degree and order is chosen for the GOCE-only or GRACE-GOCE combined GGMs to connect with the EGM2008, the extended GGMs provide an accuracy at 16cm level. From the extended GGMs, the geopotential value W0LVD determined for the China local vertical datum is 62636853.4351 m2s-2 indicates a bias of about 2.5649 m2/s-2 compared to the conventional value of 62,636,856.0 m2s-2. This is support by National key research and development program No:2016YFB0501702. Keywords: Global Geopotential Models; GRACE; GOCE; GPS/Levelling; zero-height geopotential
2002-01-01
Level Datum of 1929. Horizontal datum: In this report, horizontal coordinate information is referenced to the North American Datum of 1927 (NAD27...ileopa Ilex opaca Ait. var. opaca American holly junsil Juniperus silicicola (Small) Bailey 1 southern red cedar liqsty Liquidambar styraciflua L...swamp gum nyssyl Nyssa sylvatica Marsh.1 blackgum ostvir Ostrya virginiana (Mill.) K. Koch eastern hophornbeam perpal Persea palustris (Raf.) Sarg
Determination of Tide Heights from Airborne Bathymetric Data
1989-12-01
MEASUREMENT ERROR, A FORTRAN FUNCTION ............................. 60 v D. THE MEASUREMENT ERROR .......................... 61 E. THE REFERENCE PLANE ...soundings made to a chart datum. The chart datum is a "tide based" plane which usually corresponds to some mean of the low waters for the local tidal...regime. A low water plane is used so depths published on a nautical chart are shown in their least favorable aspect. If the chart datum is very
Federal Register 2010, 2011, 2012, 2013, 2014
2011-04-18
..., 087[deg]23'07.60'' W [DATUM: NAD 83]. (ii) Enforcement Period This safety zone will be enforced each...]24'50.08'' N, 086[deg]39'08.52'' W [DATUM: NAD 83]. (ii) Enforcement Period This safety zone will be...[deg]57'46.14'' W, and 46[deg]40'19.68'' N, 085[deg]57'43.08'' W [DATUM: NAD 83], with the West Bay...
Modernizing the National Spatial Reference System
NASA Astrophysics Data System (ADS)
Smith, D. A.
2016-12-01
The National Spatial Reference System (NSRS) is that system of datums, reference frames, shorelines, software and standards which serve the entire federal civilian geospatial community. It is the mission of the National Geodetic Survey (NGS) to define, maintain and provide access to the NSRS. Currently the NSRS contains three geometric reference frames (NAD 83(2011), NAD 83(PA11) and NAD 83(MA11)), one dynamic height datum (IGLD 85) and 6 vertical datums (NAVD 88, PRVD02, ASVD02, NMVD03, GUVD04, VIVD09). All of these datums are built on aging technology and contain systematic errors that grow more noticeable as access to accurate positioning becomes more widespread. It was determined by NGS in 2007 that this was not sustainable and as such, all datums and reference frames are scheduled to be replaced in 2022. [At the time of this abstract, the exact names of the replacements are being finalized and are expected to be announced by the AGU fall meeting.] Replacing the official datums and reference frames requires a carefully coordinated effort of dozens of interrelated technical projects spanning years (over a decade in some cases) and involving a majority of NGS employees. This talk will cover the plans thus far, projects completed, projects underway and will summarize the NSRS as it is expected to look and be accessed in 2022 and beyond.
[Design and implementation of field questionnaire survey system of taeniasis/cysticercosis].
Huan-Zhang, Li; Jing-Bo, Xue; Men-Bao, Qian; Xin-Zhong, Zang; Shang, Xia; Qiang, Wang; Ying-Dan, Chen; Shi-Zhu, Li
2018-04-17
A taeniasis/cysticercosis information management system was designed to achieve the dynamic monitoring of the epidemic situation of taeniasis/cysticercosis and improve the intelligence level of disease information management. The system includes three layer structures (application layer, technical core layer, and data storage layer) and designs a datum transmission and remote communication system of traffic information tube in Browser/Server architecture. The system is believed to promote disease datum collection. Additionally, the system may provide the standardized data for convenience of datum analysis.
Code of Federal Regulations, 2010 CFR
2010-07-01
... circle of 1,000 feet radius centered at latitude 21°17′43.6″ N., longitude 158°07′36.1″ W. (Datum NAD 83... anchorage A to the shoreline at latitude 21°18′10.6″ N., longitude 158°06′47.1″ W. (Datum NAD 83) (3... beginning. (Datum NAD 83) (4) Nonanchorage area B. The waters extending 300 feet on either side of a line...
Weighted-outer-product associative neural network
NASA Astrophysics Data System (ADS)
Ji, Han-Bing
1991-11-01
A weighted outer product learning (WOPL) scheme for associative memory neural network is presented in which learning orders are incorporated to the Hopfield model. WOPL can be guaranteed to achieve correct recall of some stored datums no matter whether or not they are stable in the Hopfield model, and whether the number of stored datums is small or large. A technically sufficient condition is also discussed for how to suitably choose learning orders to fully utilize WOPL for correct recall of as many stored datums as possible.
Geometrical specifications accuracy influence on the quality of electromechanical devices
NASA Astrophysics Data System (ADS)
Glukhov, V. I.; Lakeenko, M. N.; Dolzhikov, S. N.
2017-06-01
To improve the quality of electromechanical products is possible due to the geometrical specifications optimization of values and tolerances. Electromechanical products longevity designates the rolling-contact bearings of the armature shaft. Longevity of the rolling-contact bearings is less than designed one, since assembly and fitting alter gaps, sizes and geometric tolerances for the working parts of the basic rolling bearing details. Geometrical models of the rolling-contact bearing details for the armature shaft and the end shield are developed on the basis of an electric locomotive traction motor in the present work. The basic elements of the details conjugating with the adjacent details and materializing the generalized and auxiliary coordinate systems are determined. Function, informativeness and the number of geometrical specifications for the elements location are specified. The recommendations on amending the design documentation due to geometrical models to improve the accuracy and the quality of the products are developed: the replacement of the common axis of the shaft’s technological datums by the common axis of the basic design datums; coaxiality tolerances for these design datums with respect to their common axis; the modifiers for these auxiliary datums and these datums location tolerances according to the principles of datums uniformity, inversion and the shortest dimension chains. The investigation demonstrated that the problem of enhancing the durability, longevity, and efficiency coefficient for electromechanical products can be solved with the systematic normalizations of geometrical specifications accuracy on the basis of the coordinate systems introduced in the standards on geometrical product specifications (GPS).
NASA directory of observation station locations, volume 2
NASA Technical Reports Server (NTRS)
1971-01-01
The directory documents geodetic information for NASA tracking stations and observation stations in the NASA Geodetic Satellites Program, including stations participating in the National Geodetic Satellite Program. Station positions of these facilities are given on local or preferred major datums, and on the Modified Mercury Datum 1968. A geodetic data sheet is provided for each station, giving the position of the station and describing briefly how it was established. Geodetic positions and geocentric coordinates of these stations are tabulated on local or major geodetic datums, and on selected world geodetic systems when available information permits.
33 CFR 100.718 - Annual Suncoast Kilo Run; Sarasota Bay, Sarasota, FL.
Code of Federal Regulations, 2010 CFR
2010-07-01
... datum: NAD 83. (b) Special local regulations. (1) In accordance with these regulations, the regulated... referenced use datum: NAD 83. (3) Entry into the regulated area shall be in accordance with this regulation...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Karl Anderson, Steve Plimpton
2015-01-27
The FireHose Streaming Benchmarks are a suite of stream-processing benchmarks defined to enable comparison of streaming software and hardware, both quantitatively vis-a-vis the rate at which they can process data, and qualitatively by judging the effort involved to implement and run the benchmarks. Each benchmark has two parts. The first is a generator which produces and outputs datums at a high rate in a specific format. The second is an analytic which reads the stream of datums and is required to perform a well-defined calculation on the collection of datums, typically to find anomalous datums that have been created inmore » the stream by the generator. The FireHose suite provides code for the generators, sample code for the analytics (which users are free to re-implement in their own custom frameworks), and a precise definition of each benchmark calculation.« less
Labay, Keith A.; Haeussler, Peter J.
2008-01-01
A new Digital Elevation Model was created using the best available high-resolution topography and multibeam bathymetry surrounding the area of Seward, Alaska. Datasets of (1) LIDAR topography collected for the Kenai Watershed Forum, (2) Seward harbor soundings from the U.S. Army Corp of Engineers, and (3) multibeam bathymetry from the National Oceanic and Atmospheric Administration contributed to the final combined product. These datasets were placed into a common coordinate system, horizontal datum, vertical datum, and data format prior to being combined. The projected coordinate system of Universal Transverse Mercator Zone 6 North American Datum of 1927 was used for the horizontal coordinates. Z-values in meters were referenced to the tidal datum of Mean High Water. Gaps between the datasets were interpolated to create the final seamless 5-meter grid covering the area of interest around Seward, Alaska.
33 CFR 100.720 - Annual Suncoast Offshore Grand Prix; Gulf of Mexico, Sarasota, FL.
Code of Federal Regulations, 2011 CFR
2011-07-01
... of the racecourse. All coordinates referenced use datum: NAD 83. (4) Big Sarasota Pass will be closed... datum: NAD 1983. (b) Special local regulations. (1) No anchoring will be permitted seaward of the...
33 CFR 100.720 - Annual Suncoast Offshore Grand Prix; Gulf of Mexico, Sarasota, FL.
Code of Federal Regulations, 2010 CFR
2010-07-01
... datum: NAD 1983. (b) Special local regulations. (1) No anchoring will be permitted seaward of the... of the racecourse. All coordinates referenced use datum: NAD 83. (4) Big Sarasota Pass will be closed...
33 CFR 110.72d - Ashley River anchorage areas, SC.
Code of Federal Regulations, 2010 CFR
2010-07-01
... following the southwest boundary of the Ashley River Channel. All coordinates referenced use datum: NAD 1983... coordinates referenced use datum: NAD 1983. [CGD07-96-017, 61 FR 40994, Aug. 7, 1996; 61 FR 63715, Dec. 2...
33 CFR 100.720 - Annual Suncoast Offshore Grand Prix; Gulf of Mexico, Sarasota, FL.
Code of Federal Regulations, 2013 CFR
2013-07-01
... of the racecourse. All coordinates referenced use datum: NAD 83. (4) Big Sarasota Pass will be closed... datum: NAD 1983. (b) Special local regulations. (1) No anchoring will be permitted seaward of the...
33 CFR 100.720 - Annual Suncoast Offshore Grand Prix; Gulf of Mexico, Sarasota, FL.
Code of Federal Regulations, 2012 CFR
2012-07-01
... of the racecourse. All coordinates referenced use datum: NAD 83. (4) Big Sarasota Pass will be closed... datum: NAD 1983. (b) Special local regulations. (1) No anchoring will be permitted seaward of the...
33 CFR 100.720 - Annual Suncoast Offshore Grand Prix; Gulf of Mexico, Sarasota, FL.
Code of Federal Regulations, 2014 CFR
2014-07-01
... of the racecourse. All coordinates referenced use datum: NAD 83. (4) Big Sarasota Pass will be closed... datum: NAD 1983. (b) Special local regulations. (1) No anchoring will be permitted seaward of the...
2014-11-01
location, based on the evidence provided in Datum ( OSINT , IMINT, and the BLUEBOOK). The targetSum and normalizationConstraint attributes indicate that the...34LessThanOrEqualTo" id="Pp" name="P(Attack | IMINT, OSINT )" type="AttackProbabilityReport_Pp"> <Datum locationId=ŕ-1" datumType=" OSINT ...AttackProbabilityProbe_Ppc targetSum=蔴.0" normalizationConstraint="LessThanOrEqualTo" id="Ppc" name="P(Attack | HUMINT, IMINT, OSINT )" type
Monitoring Inland Storm Surge and Flooding from Hurricane Rita
McGee, Benton D.; Tollett, Roland W.; Mason, Jr., Robert R.
2006-01-01
Pressure transducers (sensors) and high-water marks were used to document the inland water levels related to storm surge generated by Hurricane Rita in southwestern Louisiana and southeastern Texas. On September 22-23, 2005, an experimental monitoring network of sensors was deployed at 33 sites over an area of about 4,000 square miles to record the timing, extent, and magnitude of inland hurricane storm surge and coastal flooding. Sensors were programmed to record date and time, temperature, and barometric or water pressure. Water pressure was corrected for changes in barometric pressure and salinity. Elevation surveys using global-positioning systems and differential levels were used to relate all storm-surge water-level data, reference marks, benchmarks, sensor measuring points, and high-water marks to the North American Vertical Datum of 1988 (NAVD 88). The resulting data indicated that storm-surge water levels over 14 feet above NAVD 88 occurred at three locations, and rates of water-level rise greater than 5 feet per hour occurred at three locations near the Louisiana coast.
78 FR 43821 - Final Flood Elevation Determinations
Federal Register 2010, 2011, 2012, 2013, 2014
2013-07-22
............ +902 Unincorporated Areas of LaGrange County. Big Long Lake Entire shoreline......... +957 Unincorporated Areas of LaGrange County. Big Turkey Lake Entire shoreline within +932 Unincorporated Areas of... Vertical Datum. + North American Vertical Datum. Depth in feet above ground. [caret] Mean Sea Level...
76 FR 1121 - Proposed Flood Elevation Determinations
Federal Register 2010, 2011, 2012, 2013, 2014
2011-01-07
... approximately 410 feet of Lewis County. upstream of U.S. Route 61 Business. * National Geodetic Vertical Datum... intersection of Impact Drive and FM Road 2404. * National Geodetic Vertical Datum. + North American Vertical..., Environmental Consideration. An environmental impact assessment has not been prepared. Regulatory Flexibility...
77 FR 71702 - Final Flood Elevation Determinations
Federal Register 2010, 2011, 2012, 2013, 2014
2012-12-04
... from the requirements of 44 CFR part 10, Environmental Consideration. An environmental impact... Rock +3405 Creek (Lower) confluence. * National Geodetic Vertical Datum. + North American Vertical Datum. Depth in feet above ground. [caret] Mean Sea Level, rounded to the nearest 0.1 meter. ADDRESSES...
33 CFR 165.711 - Safety Zone: Port Everglades, Fort Lauderdale, FL.
Code of Federal Regulations, 2010 CFR
2010-07-01
... datum: NAD 83. (2) The waters around naval aircraft carriers departing Port Everglades in an area 700..., in approximate position 26°05.5′ N, 80°04.8′ W. All coordinates referenced use datum: NAD 83. (b...
Tidal impact on geophysical fields registed in GPO "Mikhnevo" area
NASA Astrophysics Data System (ADS)
Vinogradov, Evgeny; Besedina, Alina; Gorbunova, Ella
2013-04-01
Geophysical observatory "Mikhnevo" is situated in the centre of Russian Plate and characterized with stable response to lunisolar tides. Since February 2008, regular precision measurements of groundwater level are carried out in a measurement well synchronously with atmospheric pressure measurements (sampling interval is 1 s, the measurement accuracy is 0.1 mm for the level and 0.1 gPa for atmospheric pressure). According to the results of hydrogeological sampling, the pressure head in the aquifer under study is 8.1 m, its transmissivity is 3.0 m2/day, hydraulic conductivity was 0.13 m/day, the pressure conductivity factor and elastic water yield are 1.3 × 104 m2/day and 2.3 × 10-4, respectively. Using flow measurements and telemetry of the open part of bore hole, major intervals of water inflow were detected at depths of 92-94 m and 99-100 m. Rock transmissivity in the fissure-conducting zone increases to 5.0 m2/day. Based on tidal component analysis in the filtered hydrogeological data, five main kinds of tidal waves were extracted (?1, ?2, Q1, ?1 and 2). STS-2 and KSESh-R seismometers registration range extension made it possible to extract tidal waves from Z-component of ground displacement. Similar methodology of data processing was used for tides analysis in hydrogeological, seismic and barometric data. It should be noted that barometric component extracted from water level variations can, in some cases, lead to misrepresentation of the data in frequency range under consideration. That is why two variants of data were analysed - with included and excluded barometric component. To extract tides from water level variations, long-period and barometric components were excluded from original precise monitoring datum. Data series obtained in this way were used for monthly spectrum realization, which, in turn, allowed finding out amplitudes of main tidal waves ?1, ?1 and 2. The most significant luni-solar ?1 wave annual variations cycle correlates with hydraulic head. Maximum amplitudes of ?1 wave for the whole 4 year observation period are observed then the ground-water level is high. Variation range of ?1 wave amplitude is stable and reaches 2.9 mm per year. Most significant variations take place in spring-summer period. Main lunar waves amplitude variations do not exceed 1.1 mm. The phase shift increase between luni-solar tides response in seismic and hydrogeological data was found. Diurnal O1 wave variations analysis should be done with barometric component excluded datum because of amplitude difference. During period under consideration M2 and K1 waves amplitudes are comparable and about 4.1 mm, O1 amplitude is on it minimum about 3.7 mm. Maximum diurnal and semi-diurnal wave amplitudes of water level variations confine with minimum values of luni-solar attraction. On the contrary on the same periods we can see decrease of ground displacement amplitudes as a result of tidal forces. Main tidal waves were extracted from atmospheric pressure datum too. Luni-solar K1 wave has the most amplitude there and exceeds O1 and M2 values 5-7 times.
NASA Astrophysics Data System (ADS)
Grombein, T.; Seitz, K.; Heck, B.
2013-12-01
In general, national height reference systems are related to individual vertical datums defined by specific tide gauges. The discrepancy of these vertical datums causes height system biases that range in an order of 1-2 m at a global scale. Continental height systems can be connected by spirit leveling and gravity measurements along the leveling lines as performed for the definition of the European Vertical Reference Frame. In order to unify intercontinental height systems, an indirect connection is needed. For this purpose, global geopotential models derived from recent satellite missions like GOCE provide an important contribution. However, to achieve a highly-precise solution, a combination with local terrestrial gravity data is indispensable. Such combinations result in the solution of a Geodetic Boundary Value Problem (GBVP). In contrast to previous studies, mostly related to the traditional (scalar) free GBVP, the present paper discusses the use of the fixed GBVP for height system unification, where gravity disturbances instead of gravity anomalies are applied as boundary values. The basic idea of our approach is a conversion of measured gravity anomalies to gravity disturbances, where unknown datum parameters occur that can be associated with height system biases. In this way, the fixed GBVP can be extended by datum parameters for each datum zone. By evaluating the GBVP at GNSS/leveling benchmarks, the unknown datum parameters can be estimated in a least squares adjustment. Beside the developed theory, we present numerical results of a case study based on the spherical fixed GBVP and boundary values simulated by the use of the global geopotential model EGM2008. In a further step, the impact of approximations like linearization as well as topographic and ellipsoidal effects is taken into account by suitable reduction and correction terms.
78 FR 29652 - Final Flood Elevation Determinations
Federal Register 2010, 2011, 2012, 2013, 2014
2013-05-21
..., Louisiana, and Incorporated Areas Docket No.: FEMA-B-1110 Big Creek Just upstream of Burke +78... confluence with +79 Unincorporated Areas of Big Creek. Richland Parish. Just upstream of Smalling +85 Road.... * National Geodetic Vertical Datum. + North American Vertical Datum. Depth in feet above ground. [supcaret...
33 CFR 166.103 - Geographic coordinates.
Code of Federal Regulations, 2010 CFR
2010-07-01
... charts whose referenced horizontal datum is the North American Datum of 1983 (NAD 83), unless such geographic coordinates are expressly labeled NAD 83. Geographic coordinates without the NAD 83 reference may be plotted on maps or charts referenced to NAD 83 only after application of the appropriate...
Method For Detecting The Presence Of A Ferromagnetic Object
Roybal, Lyle G.
2000-11-21
A method for detecting a presence or an absence of a ferromagnetic object within a sensing area may comprise the steps of sensing, during a sample time, a magnetic field adjacent the sensing area; producing surveillance data representative of the sensed magnetic field; determining an absolute value difference between a maximum datum and a minimum datum comprising the surveillance data; and determining whether the absolute value difference has a positive or negative sign. The absolute value difference and the corresponding positive or negative sign thereof forms a representative surveillance datum that is indicative of the presence or absence in the sensing area of the ferromagnetic material.
33 CFR 147.10 - Establishment of safety zones.
Code of Federal Regulations, 2010 CFR
2010-07-01
... charts whose referenced horizontal datum is the North American Datum of 1983 (NAD 83), unless such geographic coordinates are expressly labeled NAD 83. Geographic coordinates without the NAD 83 reference may be plotted on maps or charts reference to NAD 83 only after application of the appropriate...
Code of Federal Regulations, 2010 CFR
2010-07-01
... horizontal datum is the North American Datum of 1983 (NAD 83), unless such geographic coordinates are expressly labeled NAD 83. Geographic coordinates without the NAD 83 reference may be plotted on maps or charts referenced to NAD 83 only after application of the appropriate corrections that are published on...
76 FR 62006 - Proposed Flood Elevation Determinations
Federal Register 2010, 2011, 2012, 2013, 2014
2011-10-06
... Sea Level, rounded to the nearest 0.1 meter. ** BFEs to be changed include the listed downstream and... above ground. [caret] Mean Sea Level, rounded to the nearest 0.1 meter. ** BFEs to be changed include... Datum. + North American Vertical Datum. Depth in feet above ground. [caret] Mean Sea Level, rounded to...
77 FR 41323 - Final Flood Elevation Determinations
Federal Register 2010, 2011, 2012, 2013, 2014
2012-07-13
.... Approximately 800 feet +7655 upstream of Virginia Street. * National Geodetic Vertical Datum. + North American Vertical Datum. Depth in feet above ground. [caret] Mean Sea Level, rounded to the nearest 0.1 meter..., Illinois, and Incorporated Areas Docket No.: FEMA-B-1197 Big Rock Creek Approximately 1.68 miles +648...
76 FR 13569 - Proposed Flood Elevation Determinations
Federal Register 2010, 2011, 2012, 2013, 2014
2011-03-14
..., FEMA published in the Federal Register a proposed rule that included erroneous Base Flood Elevation... for the proposed BFE of 1,290 feet, referenced to the North American Vertical Datum of 1988, should... Vertical Datum of 1988, should have located the proposed BFE as being approximately 0.24 mile upstream of...
76 FR 14359 - Proposed Flood Elevation Determinations
Federal Register 2010, 2011, 2012, 2013, 2014
2011-03-16
..., FEMA published in the Federal Register a proposed rule that included erroneous Base Flood Elevation... description for the proposed BFE of 1,032 feet, referenced to the North American Vertical Datum of 1988... description for the proposed BFE of 1,049 feet, referenced to the North American Vertical Datum of 1988...
Engineering Geology | Alaska Division of Geological & Geophysical Surveys
Tidal Datum Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to Geologic Hazards in Tidal Datum Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to Geologic Hazards in Highway and development of avalanche susceptibility and prediction models near Atigun Pass. Alaska coastal
33 CFR 100.01 - Purpose and intent.
Code of Federal Regulations, 2010 CFR
2010-07-01
... plotting on maps or charts whose referenced horizontal datum is the North American Datum of 1983 (NAD 83), unless such geographic coordinates are expressly labeled NAD 83. Geographic coordinates without the NAD 83 reference may be plotted on maps or charts referenced to NAD 83 only after application of the...
Code of Federal Regulations, 2010 CFR
2010-07-01
...″, longitude 072°03′19.7″. DATUM: NAD 83 (b) Beginning at a point on the shoreline of Pine Island at latitude... point at latitude 41°18′54.0″, longitude 072°03′17.5″. DATUM: NAD 83 Note: The areas designated by (a...
77 FR 49373 - Final Flood Elevation Determinations
Federal Register 2010, 2011, 2012, 2013, 2014
2012-08-16
.... Macon Bayou Just upstream of Private +108 City of Eudora. Road. Just upstream of Verser +108 Road... Areas of Road. Logan County. Just downstream of Newton +563 Road. Just upstream of West 9th +621 Street... Road. * National Geodetic Vertical Datum. + North American Vertical Datum. Depth in feet above ground...
76 FR 46705 - Proposed Flood Elevation Determinations
Federal Register 2010, 2011, 2012, 2013, 2014
2011-08-03
... ground. [caret] Mean Sea Level, rounded to the nearest 0.1 meter. ** BFEs to be changed include the.... Depth in feet above ground. [caret] Mean Sea Level, rounded to the nearest 0.1 meter. ** BFEs to be... Datum. + North American Vertical Datum. Depth in feet above ground. [caret] Mean Sea Level, rounded to...
33 CFR 100.719 - Annual Suncoast Offshore Challenge; Gulf of Mexico, Sarasota, FL.
Code of Federal Regulations, 2011 CFR
2011-07-01
... datum: NAD 1983. (b) Special local regulations. (1) No anchoring will be permitted seaward of the...-quarters situation until finally past and clear of the racecourse. All coordinates referenced use datum: NAD 1983. (4) Big Sarasota Pass will be closed to all inbound and outbound vessel traffic, other than...
Federal Register 2010, 2011, 2012, 2013, 2014
2013-06-18
... DEPARTMENT OF THE INTERIOR Bureau of Ocean Energy Management [MMAA104000] North American Datum of 1983 (NAD 83) Outer Continental Shelf (OCS) Provisional Official Protraction Diagram (OPDs) AGENCY... OPDs. SUMMARY: Notice is hereby given that effective with this publication two NAD 83-based OCS...
33 CFR 100.719 - Annual Suncoast Offshore Challenge; Gulf of Mexico, Sarasota, FL.
Code of Federal Regulations, 2013 CFR
2013-07-01
... datum: NAD 1983. (b) Special local regulations. (1) No anchoring will be permitted seaward of the...-quarters situation until finally past and clear of the racecourse. All coordinates referenced use datum: NAD 1983. (4) Big Sarasota Pass will be closed to all inbound and outbound vessel traffic, other than...
33 CFR 100.719 - Annual Suncoast Offshore Challenge; Gulf of Mexico, Sarasota, FL.
Code of Federal Regulations, 2014 CFR
2014-07-01
... datum: NAD 1983. (b) Special local regulations. (1) No anchoring will be permitted seaward of the...-quarters situation until finally past and clear of the racecourse. All coordinates referenced use datum: NAD 1983. (4) Big Sarasota Pass will be closed to all inbound and outbound vessel traffic, other than...
33 CFR 100.719 - Annual Suncoast Offshore Challenge; Gulf of Mexico, Sarasota, FL.
Code of Federal Regulations, 2012 CFR
2012-07-01
... datum: NAD 1983. (b) Special local regulations. (1) No anchoring will be permitted seaward of the...-quarters situation until finally past and clear of the racecourse. All coordinates referenced use datum: NAD 1983. (4) Big Sarasota Pass will be closed to all inbound and outbound vessel traffic, other than...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cao, Yanni; Cervone, Guido; Barkley, Zachary
Most atmospheric models, including the Weather Research and Forecasting (WRF) model, use a spherical geographic coordinate system to internally represent input data and perform computations. However, most geographic information system (GIS) input data used by the models are based on a spheroid datum because it better represents the actual geometry of the earth. WRF and other atmospheric models use these GIS input layers as if they were in a spherical coordinate system without accounting for the difference in datum. When GIS layers are not properly reprojected, latitudinal errors of up to 21 km in the midlatitudes are introduced. Recent studiesmore » have suggested that for very high-resolution applications, the difference in datum in the GIS input data (e.g., terrain land use, orography) should be taken into account. However, the magnitude of errors introduced by the difference in coordinate systems remains unclear. This research quantifies the effect of using a spherical vs. a spheroid datum for the input GIS layers used by WRF to study greenhouse gas transport and dispersion in northeast Pennsylvania.« less
Cao, Yanni; Cervone, Guido; Barkley, Zachary; ...
2017-09-19
Most atmospheric models, including the Weather Research and Forecasting (WRF) model, use a spherical geographic coordinate system to internally represent input data and perform computations. However, most geographic information system (GIS) input data used by the models are based on a spheroid datum because it better represents the actual geometry of the earth. WRF and other atmospheric models use these GIS input layers as if they were in a spherical coordinate system without accounting for the difference in datum. When GIS layers are not properly reprojected, latitudinal errors of up to 21 km in the midlatitudes are introduced. Recent studiesmore » have suggested that for very high-resolution applications, the difference in datum in the GIS input data (e.g., terrain land use, orography) should be taken into account. However, the magnitude of errors introduced by the difference in coordinate systems remains unclear. This research quantifies the effect of using a spherical vs. a spheroid datum for the input GIS layers used by WRF to study greenhouse gas transport and dispersion in northeast Pennsylvania.« less
NASA Astrophysics Data System (ADS)
Cao, Yanni; Cervone, Guido; Barkley, Zachary; Lauvaux, Thomas; Deng, Aijun; Taylor, Alan
2017-09-01
Most atmospheric models, including the Weather Research and Forecasting (WRF) model, use a spherical geographic coordinate system to internally represent input data and perform computations. However, most geographic information system (GIS) input data used by the models are based on a spheroid datum because it better represents the actual geometry of the earth. WRF and other atmospheric models use these GIS input layers as if they were in a spherical coordinate system without accounting for the difference in datum. When GIS layers are not properly reprojected, latitudinal errors of up to 21 km in the midlatitudes are introduced. Recent studies have suggested that for very high-resolution applications, the difference in datum in the GIS input data (e.g., terrain land use, orography) should be taken into account. However, the magnitude of errors introduced by the difference in coordinate systems remains unclear. This research quantifies the effect of using a spherical vs. a spheroid datum for the input GIS layers used by WRF to study greenhouse gas transport and dispersion in northeast Pennsylvania.
Gravimetric investigations on the North American Datum (1972 - 1973)
NASA Technical Reports Server (NTRS)
Mather, R. S.
1975-01-01
All the available unclassified gravity data on the North American Datum (NAD) and in the surrounding oceans was assembled late in 1972 for the investigation of the gravity field in North America and its relation to North American Datum 1927 (NAD 27). The gravity data in Canada and the United States was compiled on a common datum compatible with the International Gravity Standardization Network 1971 (IGSN 71). The variation in the error of representation in the region is studied along with the correlation characteristics of gravity anomalies with elevation. A free air geoid (FAG 73) was computed from a combination of surface gravity data and Goddard Earth Model (GEM) 4 and this was used as the basis for the computation of the non-Stokesian contributions to the height anomaly. The geocentric orientation parameters obtained by this astrogravimetric method are compared with those obtained by satellite techniques. The differences are found to be no greater than those between individual satellite solutions. The differences between the astrogravimetric solution and satellite solutions GSFC 73 and GEM 6 are studied in detail with a view to obtaining a better understanding of these discrepancies.
Pathway to 2022: The Ongoing Modernization of the United States National Spatial Reference System
NASA Astrophysics Data System (ADS)
Stone, W. A.; Caccamise, D.
2017-12-01
The National Oceanic and Atmospheric Administration's National Geodetic Survey (NGS) mission is "to define, maintain and provide access to the National Spatial Reference System (NSRS) to meet our nation's economic, social, and environmental needs." The NSRS is an assemblage of geophysical and geodetic models, tools, and data, with the most-visible components being the North American Datum of 1983 (NAD83) and the North American Vertical Datum of 1988 (NAVD88), which together provide a consistent spatial reference framework for myriad geospatial applications and positioning requirements throughout the United States. The NGS is engaged in an ongoing and comprehensive multi-year project of modernizing the NSRS, a makeover necessitated by technological developments and user accuracy requirements, all with a goal of providing a modern, accurate, accessible, and globally aligned national positioning framework exploiting the substantial power and utility of the Global Navigation Satellite System - of both today and tomorrow. The modernized NSRS will include four new-generation geometric terrestrial reference frames (replacing NAD83) and a technically unprecedented geopotential datum (replacing NAVD88), all to be released in 2022 (anticipated). This poster/presentation will describe the justification for this modernization effort and will update the status and planned evolution of the NSRS as 2022 draws ever closer. Also discussed will be recent developments, including the publication of "blueprint" documents addressing technical details of various facets of the modernized NSRS and a continued series of public Geospatial Summits. Supporting/ancillary projects such as Gravity for the Redefinition of the American Vertical Datum (GRAV-D), which will result in the generation of a highly accurate gravimetric geoid - or definitional reference surface (zero elevation) - for the future geopotential datum, and Geoid Slope Validation Surveys (GSVS), which are exploring the achievable accuracy of the new geopotential datum, will be summarized. Also included will be suggestions of user preparation for transition to the NSRS of tomorrow.
NASA Astrophysics Data System (ADS)
Porz, Lucas; Grombein, Thomas; Seitz, Kurt; Heck, Bernhard; Wenzel, Friedemann
2017-04-01
Regional height reference systems are generally related to individual vertical datums defined by specific tide gauges. The discrepancies of these vertical datums with respect to a unified global datum cause height system biases that range in an order of 1-2 m at a global scale. One approach for unification of height systems relates to the solution of a Geodetic Boundary Value Problem (GBVP). In particular, the fixed GBVP, using gravity disturbances as boundary values, is solved at GNSS/leveling benchmarks, whereupon height datum offsets can be estimated by least squares adjustment. In spherical approximation, the solution of the fixed GBVP is obtained by Hotine's spherical integral formula. However, this method relies on the global availability of gravity data. In practice, gravity data of the necessary resolution and accuracy is not accessible globally. Thus, the integration is restricted to an area within the vicinity of the computation points. The resulting truncation error can reach several meters in height, making height system unification without further consideration of this effect unfeasible. This study analyzes methods for reducing the truncation error by combining terrestrial gravity data with satellite-based global geopotential models and by modifying the integral kernel in order to accelerate the convergence of the resulting potential. For this purpose, EGM2008-derived gravity functionals are used as pseudo-observations to be integrated numerically. Geopotential models of different spectral degrees are implemented using a remove-restore-scheme. Three types of modification are applied to the Hotine-kernel and the convergence of the resulting potential is analyzed. In a further step, the impact of these operations on the estimation of height datum offsets is investigated within a closed loop simulation. A minimum integration radius in combination with a specific modification of the Hotine-kernel is suggested in order to achieve sub-cm accuracy for the estimation of height datum offsets.
33 CFR 100.740 - Annual Offshore Super Series Boat Race; Fort Myers Beach, FL.
Code of Federal Regulations, 2010 CFR
2010-07-01
... to original point 1: 26°27′43″N, 81°58′22″W. All coordinates referenced use datum: NAD 83. (2) The...°25′32″N, 81°53′57″W. All coordinates referenced use datum: NAD 83. (b) Special local regulations. (1...
NORTH AMERICAN DATUM 1983 IMPLEMENTATION IMPACTS ON THE USGS NATIONAL MAPPING PROGRAM.
Jones, William J.; Needham, Paul E.
1985-01-01
The U. S. Geological Survey has previously experienced the impacts on the National Mapping Program that are associated with implementing a readjustment of the horizontal datum. The impacts of these past readjustments were minimal compared to those of the current readjustment. The Geological Survey currently has produced and published over 60,000 different map products. The 7. 5-minute mapping program is nearing completion with over 85 percent of the conterminous States mapped. The intermediate-scale mapping program of the conterminous United States is scheduled for completion of planimetric editions by the end of 1986. It is apparent that until digital cartographic data are available, implementation of the North American Datum 1983 will primarily consist of cartographic adjustment of existing map products.
On the nullspace of TLS multi-station adjustment
NASA Astrophysics Data System (ADS)
Sterle, Oskar; Kogoj, Dušan; Stopar, Bojan; Kregar, Klemen
2018-07-01
In the article we present an analytic aspect of TLS multi-station least-squares adjustment with the main focus on the datum problem. The datum problem is, compared to previously published researches, theoretically analyzed and solved, where the solution is based on nullspace derivation of the mathematical model. The importance of datum problem solution is seen in a complete description of TLS multi-station adjustment solutions from a set of all minimally constrained least-squares solutions. On a basis of known nullspace, estimable parameters are described and the geometric interpretation of all minimally constrained least squares solutions is presented. At the end a simulated example is used to analyze the results of TLS multi-station minimally constrained and inner constrained least-squares adjustment solutions.
Gas Turbine Engine Carbon Oil Seals Computerized Assembly
NASA Technical Reports Server (NTRS)
Lee, Robert
2006-01-01
In a bearing compartment there are a series of parts when assembled determine the location of the bearing and seal as related to the centerline of rotation. We see part datums that do not establish A coincident path from the bearing to the seal. High engine vibration can cause severe oil leakage. The inability of the seal to respond fast enough to the rotating element Radial Seal: Sensitive to housing air pressure Sensitive to seal runout ? Axial Seal: Very sensitive to seal perpendicularity to shaft. Goals include: 1) Repeatable assembly process; 2) Accurate assembly process; 3) Minimize seal runout; 4) Design to engine centerline of rotation, i.e. bearings.
The Impact of Sea Level Rise on Geodetic Vertical Datum of Peninsular Malaysia
NASA Astrophysics Data System (ADS)
Din, A. H. M.; Abazu, I. C.; Pa'suya, M. F.; Omar, K. M.; Hamid, A. I. A.
2016-09-01
Sea level rise is rapidly turning into major issues among our community and all levels of the government are working to develop responses to ensure these matters are given the uttermost attention in all facets of planning. It is more interesting to understand and investigate the present day sea level variation due its potential impact, particularly on our national geodetic vertical datum. To determine present day sea level variation, it is vital to consider both in-situ tide gauge and remote sensing measurements. This study presents an effort to quantify the sea level rise rate and magnitude over Peninsular Malaysia using tide gauge and multi-mission satellite altimeter. The time periods taken for both techniques are 32 years (from 1984 to 2015) for tidal data and 23 years (from 1993 to 2015) for altimetry data. Subsequently, the impact of sea level rise on Peninsular Malaysia Geodetic Vertical Datum (PMGVD) is evaluated in this study. the difference between MSL computed from 10 years (1984 - 1993) and 32 years (1984 - 2015) tidal data at Port Kelang showed that the increment of sea level is about 27mm. The computed magnitude showed an estimate of the long-term effect a change in MSL has on the geodetic vertical datum of Port Kelang tide gauge station. This will help give a new insight on the establishment of national geodetic vertical datum based on mean sea level data. Besides, this information can be used for a wide variety of climatic applications to study environmental issues related to flood and global warming in Malaysia.
Results from the ESA-funded project 'Height System Unification with GOCE'
NASA Astrophysics Data System (ADS)
Sideris, M. G.; Rangelova, E. V.; Gruber, T.; Rummel, R. F.; Woodworth, P. L.; Hughes, C. W.; Ihde, J.; Liebsch, G.; Schäfer, U.; Rülke, A.; Gerlach, C.; Haagmans, R.
2013-12-01
The paper summarizes the main results of a project, supported by the European Space Agency, whose main goal is to identify the impact of GOCE gravity field models on height system unification. In particular, the Technical University Munich, the University of Calgary and the National Oceanography Centre in Liverpool, together with the Bavarian Academy of Sciences, the Federal German Agency for Cartography and Geodesy, and the Geodetic Surveys of Canada, USA and Mexico, have investigated the role of GOCE-derived gravity and geoid models for regional and global height datum connection. GOCE provides three important components of height unification: highly accurate potential differences (geopotential numbers), a global geoid- or quasi-geoid-based reference surface for elevations that is independent of inaccuracies and inconsistencies of local and regional data, and a consistent way to refer to the same datum all the relevant gravimetric, topographic and oceanographic data. We introduce briefly the methodology that has been applied in order to unify height system in North America, North Atlantic Ocean and Europe, and present results obtained using the available GOCE-derived satellite-only geopotential models, and their combination with terrestrial data and ocean models. The effects of various factors, such as data noise, omission errors, indirect bias terms, ocean models and temporal variations, on height datum unification are also presented, highlighting their magnitude and importance in the estimation of offsets between vertical datums. Based on the experiences gained in this project, a general roadmap has been developed for height datum unification in regions with good, as well as poor, coverage in gravity and geodetic height and tide gauge control stations.
Use of coastal altimeter and tide gauge data for a seamless land-sea vertical datum in Taiwan
NASA Astrophysics Data System (ADS)
Yen-Ti, C.; Hwang, C.
2017-12-01
Conventional topographic and hydrographic mappings use two separate reference surfaces, called orthometric datum (TWVD2001 in Taiwan) and chart datum. In Taiwan, land elevations are heights tied to a leveling control network with its zero height at the mean sea surface of Keelung Harbor (realized by the height of Benchmark K999). Ocean depths are counted from the lowest tidal surface defined by tidal measurements near the sites of depth measurements. This paper usesa new method to construct a unified vertical datum for land elevations and ocean depths around Taiwan. First, we determine an optimal mean sea surface model (MSSHM) using refined offshore altimeter data. Then, the ellipsoidal heights of the mean sea levels at 36 tide gauges around Taiwan are determined using GPS measurements at their nearby benchmarks, and are then combined with the altimeter-derived MSSHM to generate a final MSSHM that has a smooth transition from land to sea. We also construct an improved ocean tide model to obtain various tidal surfaces. Using the latest land, shipborne, airborne and altimeter-derived gravity data, we construct a hybrid geoid model to define a vertical datum on land. The final MSSHM is the zero surface that defines ocean tidal heights and lowest tidal values in a ellipsoidal system that is fully consistent with the geodetic system of GNSS. The use of the MSSHM and the hybrid geoid model enables a seamless connection to combine or compare coastal land and sea elevations from a wide range of sources.
Federal Register 2010, 2011, 2012, 2013, 2014
2010-09-10
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 2662-002; Project No. 12968... with a crest elevation of 75.38 feet local datum; (d) an 18.83-foot-long gravity-type ungated spillway...-generator; (2) a 134-acre reservoir at an elevation of 77.9 feet local datum with a usable storage capacity...
Straightness measurement using laser beam straight datum
NASA Astrophysics Data System (ADS)
Uchikoshi, Junichi; Shimada, Shoichi; Ikawa, Naoya; Komura, Akio
1995-08-01
Using the direction stabilized laser beam as a physical straight datum, instead of the tangible reference surface, a method is proposed for the measurement of an error motion of a slide table and/or surface profile of mechanical components. A specially designed 2D position sensor/compensator for laser beam center is developed combining a quadrant photo-diode (QPD) position sensor for beam center and the piezo-compensator which compensates the beam shift from the center of QPD. By the use the sensor/compensator proposed, the positional and angular fluctuations of laser beam path is evaluated with nanometric resolution. Combining the sensor with the piezo-driven mirror compensator, the directional stabilizer for the laser beam is also designed in the same manner as the sensor/compensator. The stabilized He-Ne laser beam can be used as the metrological datum of straightness within the accuracy of 2 X 10 -8 rad. By mounting the position sensor/compensator on a slide table, the carriage with working distance of 1 m is so designed and built as to move straight along the stabilized laser beam. The carriage can be used as a mechanical straight datum with the accuracy equivalent to the laser beam stability.
The relation of the European Datum to a geocentric reference system
NASA Technical Reports Server (NTRS)
Marsh, J. G.; Douglas, B. C.; Klosko, S. M.
1971-01-01
Over 31,000 precision reduced optical observations of GEOS-1 and 2 in 70 two-day orbital arcs were used at Goddard Space Flight Center (GSFC) in a dynamical solution to determine center-of-mass coordinates for 15 tracking stations on the European Datum. Comparisons with the results obtained at Centre National d'Etudes Spatiales (CNES) give agreement of about 1.5 ppm for chord lengths. After considering a scale correction to the European Datum (ED) of 1950 to account for the absence of geoid heights at the time of its reduction, agreement to a few ppm between the CNES/GSFC and the ED chords is obtained. However, a small systematic difference between survey and satellite results remains for stations in southeastern France and Switzerland.
1981-01-01
Meteorological Parameters at Meteorological Station 1, 31 May 1980 ........................ 68 $24 Relationship of Jubai. Port Datum to Tide Table Datum. .70 25...around which was a circular weight with two handles. Once assembled, the device was nositioned vertically at the point to be sampled and manually...limited use for sampling very fluid or unconsolidated sand or shell. In the former case, the upper few centimeters of cohesive sediment became embedded
Code of Federal Regulations, 2012 CFR
2012-07-01
... feet. (3) Height above water—15 feet when upper pool is at low water datum. (4) Draft—6 feet when lower pool is at low water datum. (e) Signals. (1) Craft desiring lockage in either direction shall give... securely moored until the exit lock gate is fully open and the lock horn sounds one blast. (7) When the...
Code of Federal Regulations, 2014 CFR
2014-07-01
... feet. (3) Height above water—15 feet when upper pool is at low water datum. (4) Draft—6 feet when lower pool is at low water datum. (e) Signals. (1) Craft desiring lockage in either direction shall give... securely moored until the exit lock gate is fully open and the lock horn sounds one blast. (7) When the...
Code of Federal Regulations, 2013 CFR
2013-07-01
... feet. (3) Height above water—15 feet when upper pool is at low water datum. (4) Draft—6 feet when lower pool is at low water datum. (e) Signals. (1) Craft desiring lockage in either direction shall give... securely moored until the exit lock gate is fully open and the lock horn sounds one blast. (7) When the...
Federal Register 2010, 2011, 2012, 2013, 2014
2011-06-30
...'' W [DATUM: NAD 83]. (ii) Enforcement Period. This safety zone will be enforced on July 4, 2011 from 9...'' N, 086[deg]39'08.52'' W [DATUM: NAD 83]. (ii) Enforcement Period. This safety zone will be enforced...: NAD 83], with the West Bay shoreline forming the South and West boundaries of the zone. (ii...
Federal Register 2010, 2011, 2012, 2013, 2014
2013-08-08
... of 1983'' (or ``NAD 83''). The new realizations are NAD 83 (2011) epoch 2010.00 [for the North America and Caribbean tectonic plates], NAD 83 (MA11) epoch 2010.00 [for the Mariana tectonic plate] and NAD 83 (PA11) epoch 2010.00 [for the Pacific tectonic plate]. These three realizations supersede all...
33 CFR 165.506 - Safety Zones; Fireworks Displays in the Fifth Coast Guard District.
Code of Federal Regulations, 2014 CFR
2014-07-01
... Table to § 165.506 reference Datum NAD 1983. Table to § 165.506 [All coordinates listed in the Table to § 165.506 reference Datum NAD 1983.] No. Date Location Regulated area (a) Coast Guard Sector Delaware... 078°01′18″ W, approximately 700 yards south of the waterfront at Southport, NC. 12 July 4th Big Foot...
Fast Magnetoresistive Random-Access Memory
NASA Technical Reports Server (NTRS)
Wu, Jiin-Chuan; Stadler, Henry L.; Katti, Romney R.
1991-01-01
Magnetoresistive binary digital memories of proposed new type expected to feature high speed, nonvolatility, ability to withstand ionizing radiation, high density, and low power. In memory cell, magnetoresistive effect exploited more efficiently by use of ferromagnetic material to store datum and adjacent magnetoresistive material to sense datum for readout. Because relative change in sensed resistance between "zero" and "one" states greater, shorter sampling and readout access times achievable.
Intercontinental height datum connection with GOCE and GPS-levelling data
NASA Astrophysics Data System (ADS)
Gruber, T.; Gerlach, C.; Haagmans, R.
2012-12-01
In this study an attempt is made to establish height system datum connections based upon a gravity field and steady-state ocean circulation explorer (GOCE) gravity field model and a set of global positioning system (GPS) and levelling data. The procedure applied in principle is straightforward. First local geoid heights are obtained point wise from GPS and levelling data. Then the mean of these geoid heights is computed for regions nominally referring to the same height datum. Subsequently, these local mean geoid heights are compared with a mean global geoid from GOCE for the same region. This way one can identify an offset of the local to the global geoid per region. This procedure is applied to a number of regions distributed worldwide. Results show that the vertical datum offset estimates strongly depend on the nature of the omission error, i.e. the signal not represented in the GOCE model. For a smooth gravity field the commission error of GOCE, the quality of the GPS and levelling data and the averaging control the accuracy of the vertical datum offset estimates. In case the omission error does not cancel out in the mean value computation, because of a sub-optimal point distribution or a characteristic behaviour of the omitted part of the geoid signal, one needs to estimate a correction for the omission error from other sources. For areas with dense and high quality ground observations the EGM2008 global model is a good choice to estimate the omission error correction in theses cases. Relative intercontinental height datum offsets are estimated by applying this procedure between the United State of America (USA), Australia and Germany. These are compared to historical values provided in the literature and computed with the same procedure. The results obtained in this study agree on a level of 10 cm to the historical results. The changes mainly can be attributed to the new global geoid information from GOCE, rather than to the ellipsoidal heights or the levelled heights. These historical levelling data are still in use in many countries. This conclusion is supported by other results on the validation of the GOCE models.
Gesch, Dean; Evans, Gayla; Mauck, James; Hutchinson, John; Carswell, William J.
2009-01-01
The National Elevation Dataset (NED) is the primary elevation data product produced and distributed by the USGS. The NED provides seamless raster elevation data of the conterminous United States, Alaska, Hawaii, and the island territories. The NED is derived from diverse source data sets that are processed to a specification with a consistent resolution, coordinate system, elevation units, and horizontal and vertical datums. The NED is the logical result of the maturation of the long-standing USGS elevation program, which for many years concentrated on production of topographic map quadrangle-based digital elevation models. The NED serves as the elevation layer of The National Map, and provides basic elevation information for earth science studies and mapping applications in the United States. The NED is a multi-resolution dataset that is updated bimonthly to integrate newly available, improved elevation source data. NED data are available nationally at grid spacings of 1 arc-second (approximately 30 meters) for the conterminous United States, and at 1/3 and 1/9 arc-seconds (approximately 10 and 3 meters, respectively) for parts of the United States. Most of the NED for Alaska is available at 2-arc-second (about 60 meters) grid spacing, where only lower resolution source data exist. Part of Alaska is available at the 1/3-arc-second resolution, and plans are in development for a significant upgrade in elevation data coverage of the State over the next 5 years. Specifications for the NED include the following: *Coordinate system: Geographic (decimal degrees of latitude and longitude), *Horizontal datum: North American Datum of 1983 (NAD 83), *Vertical datum: North American Vertical Datum of 1988 (NAVD 88) over the conterminous United States and varies in other areas, and *Elevation units: Decimal meters.
Dynamic Heights in the Great Lakes using OPUS Projects
NASA Astrophysics Data System (ADS)
Roman, D. R.; Li, X.
2015-12-01
The U.S. will be implementing new geometric and vertical reference frames in 2022 to replace the North American Datum of 1983 (NAD 83) and the North American Vertical Datum of 1988 (NAVD 88), respectively. Less emphasized is the fact that a new dynamic height datum will also be defined about the same time to replace the International Great Lakes Datum of 1985 (IGLD 85). IGLD 85 was defined concurrent with NAVD 88 and used the same geopotential values. This paper focuses on the use of an existing tool for determining geometric coordinates and a developing geopotential model as a means of determining dynamic heights. The Online Positioning User Service (OPUS) Projects (OP) is an online tool available from the National Geodetic Survey (NGS) for use in developing geometric coordinates from simultaneous observations at multiple sites during multiple occupations. With observations performed at the water level gauges throughout the Great Lakes, the geometric coordinates of the mean water level surface can be determined. NGS has also developed the xGEOID15B model from satellite, airborne and surface gravity data. Using the input geometric coordinates determined through OP, the geopotential values for the water surface at the water level stations around the Great Lakes were determined using the xGEOID15B model. Comparisons were made between water level sites for each Lake as well as to existing IGLD 85 heights. A principal advantage to this approach is the ability to generate new water level control stations using OP, while maintaining the consistency between orthometric and dynamic heights by using the same gravity field model. Such a process may provide a means for determining dynamic heights for a future Great Lakes Datum.
On the unification of geodetic leveling datums using satellite altimetry
NASA Technical Reports Server (NTRS)
Mather, R. S.; Rizos, C.; Morrison, T.
1978-01-01
Techniques are described for determining the height of Mean Sea Level (MSL) at coastal sites from satellite altimetry. Such information is of value in the adjustment of continental leveling networks. Numerical results are obtained from the 1977 GEOS-3 altimetry data bank at Goddard Space Flight Center using the Bermuda calibration of the altimeter. Estimates are made of the heights of MSL at the leveling datums for Australia and a hypothetical Galveston datum for central North America. The results obtained are in reasonable agreement with oceanographic estimates obtained by extrapolation. It is concluded that all gravity data in the Australian bank AUSGAD 76 and in the Rapp data file for central North America refer to the GEOS-3 altimeter geoid for 1976.0 with uncertainties which do not exceed + or - 0.1 mGal.
Code of Federal Regulations, 2010 CFR
2010-01-01
... set of boundary coordinates using the geographic positions of the North American Datum of 1983 (NAD 83). FGBNMS coordinates are now provided in both North American Datum of 1927 (NAD 27) and NAD 83. Point Latitude (N) Longitude (W) East Flower Garden Bank: (NAD 27) E-1 27 deg. 52′ 53.82718″ 93 deg. 37′ 41.30310...
Monitoring Inland Storm Surge and Flooding from Hurricane Ike in Texas and Louisiana, September 2008
East, Jeffery W.; Turco, Michael J.; Mason, Jr., Robert R.
2008-01-01
The U.S. Geological Survey (USGS) deployed a temporary monitoring network of 117 pressure transducers (sensors) at 65 sites over an area of about 5,000 square miles to record the timing, areal extent, and magnitude of inland hurricane storm surge and coastal flooding generated by Hurricane Ike, which struck southeastern Texas and southwestern Louisiana September 12-13, 2008. Fifty-six sites were in Texas and nine were in Louisiana. Sites were categorized as surge, riverine, or beach/wave on the basis of proximity to the Gulf Coast. One-hundred five sensors from 59 sites (fig. 1) were recovered; 12 sensors from six sites either were lost during the storm or were not retrieved. All 59 sites (41 surge, 10 riverine, 8 beach/wave) had sensors to record water pressure (fig. 2), which is expressed as water level in feet above North American Vertical Datum of 1988 (NAVD88), and 46 sites had an additional sensor to record barometric pressure, expressed in pounds per square inch. Figure 3 shows an example of water level and barometric pressure over time recorded by sensors during the storm.
The Neural Network In Coordinate Transformation
NASA Astrophysics Data System (ADS)
Urusan, Ahmet Yucel
2011-12-01
In international literature, Coordinate operations is divided into two categories. They are coordinate conversion and coordinate transformation. Coordinates converted from coordinate system A to coordinate system B in the same datum (mean origine, scale and axis directions are same) by coordinate conversion. There are two different datum in coordinate transformation. The basis of each datum to a different coordinate reference system. In Coordinate transformation, coordinates are transformed from coordinate reference system A to coordinate referance system B. Geodetic studies based on physical measurements. Coordinate transformation needs identical points which were measured in each coordinate reference system (A and B). However it is difficult (and need a big reserved budget) to measure in some places like as top of mountain, boundry of countries and seaside. In this study, this sample problem solution was researched. The method of learning which is one of the neural network methods, was used for solution of this problem.
Visual and Part-Task Manipulations for Teaching Simulated Carrier Landings.
1985-03-19
with FLOLS and Portion of Wake ............. 10 3 Configuration of FLOLS Simulation, Showing Datum Bars, Rate Arrows, and Meatball ...bars. This light, known as the meatball , is visible to the pilot through the center lens when he is within 9.5 minutes of arc of the glideslope and is...Seen as level with the datum bars. As the aircraft moves more * than 9.5 minutes of arc above or below the glideslope, the meatball is seen through
Levels at Streamflow Gaging Stations--A CD-ROM Based Training Class
Nolan, K. Michael; Jacobson, Nathan; Erickson, Robert; Landon, Stanley
2003-01-01
Streamgages record the elevation of the water surface above some reference surface, or datum. This datum is assumed to remain unchanged throughout the life of the gage. However, the elevation of gages and their supporting structures often change over time as a result of earthmovement, floods, ice, and debris. The surveying practice of leveling is used to establish datum for new gage structures and to check for vertical movement of those structures over time. Vertical changes in gage structures can affect stage-discharge relations and, thus, could result in incorrect discharge determinations. Datum checks are used to correct stage-discharge relations and allow the USGS to document gage datum throughout the life of a gage. This training presentation describes methods currently used by the U.S. Geological Survey to run levels at gaging stations. The presentation is narrated, but you control the pace of the presentation. If the computer you are using can view 'MPEG' videos you will be able to take advantage of videos found within the presentation. A test, found at the end of the presentation, can be taken to assess how well you understood the training material. The class is registered as class SW1307 with the National Training Center of the U.S. Geologcial Survey. The presentation was developed using Macromedia Director 8.5(1) and is contained in the file 'WRI-4002.exe', which should auto-launch after the CD-ROM is inserted in the PC. The program only runs on a windows-based personal computer (PC). A sound card and speakers are necessary to take advantage of the narration that accompanies the presentation. Text of narrations is provided, if you are unable to listen to the narrations. Instructions for installing and running the presentation are included in the file ' Intro.html'. The file 'Intro.html' is on the CD-ROM containing the presentation and is available from the presentation's help menu.
Conrads, P.A.; Smith, P.A.
1996-01-01
The one-dimensional, unsteady-flow model, BRANCH, and the Branched Lagrangian Transport Model (BLTM) were calibrated and validated for the Cooper and Wando Rivers near Charleston, South Carolina. Data used to calibrate the BRANCH model included water-level data at four locations on the Cooper River and two locations on the Wando River, measured tidal-cycle streamflows at five locations on the Wando River, and simulated tidal-cycle streamflows (using an existing validated BRANCH model of the Cooper River) for four locations on the Cooper River. The BRANCH model was used to generate the necessary hydraulic data used in the BLTM model. The BLTM model was calibrated and validated using time series of salinity concentrations at two locations on the Cooper River and at two locations on the Wando River. Successful calibration and validation of the BRANCH and BLTM models to water levels, stream flows, and salinity were achieved after applying a positive 0.45 foot datum correction to the downstream boundary. The sensitivity of the simulated salinity concentrations to changes in the downstream gage datum, channel geometry, and roughness coefficient in the BRANCH model, and to the dispersion factor in the BLTM model was evaluated. The simulated salinity concentrations were most sensitive to changes in the downstream gage datum. A decrease of 0.5 feet in the downstream gage datum increased the simulated 3-day mean salinity concentration by 107 percent (12.7 to 26.3 parts per thousand). The range of the salinity concentration went from a tidal oscillation with a standard deviation of 3.9 parts per thousand to a nearly constant concentration with a standard deviation of 0.0 parts per thousand. An increase in the downstream gage datum decreased the simulated 3-day mean salinity concentration by 47 percent (12.7 to 6.7 parts per thousand) and decreased the standard deviation from 3.9 to 3.4 parts per thousand.
Dynamic Heights in the Great Lakes at Different Epochs
NASA Astrophysics Data System (ADS)
Roman, D. R.
2016-12-01
Vertical control in the Great Lakes region is currently defined by the International Great Lakes Datum of 1985 (IGLD 85) in the form of dynamic heights. Starting in 2025, dynamic heights will be defined through GNSS-derived geometric coordinates and a geopotential model. This paper explores the behavior of an existing geopotential model at different epochs when the Great Lakes were at significantly different (meter-level) geopotential surfaces. Water surfaces were examined in 2015 and 2010 at six sites on Lakes Superior and Lake Erie (three on each Lake). These sites have collocated a Continuously Operating Reference Station (CORS) and a Water Level Sensor (WLS). The offset between the antenna phase center for the CORS and the WLS datum are known at each site. The WLS then measures the distance from its datum to the Lake surface via an open well. Thus it is possible to determine the height above an ellipsoid datum at these sites as long as both the CORS and WLS are operational. The geometric coordinates are then used to estimate the geopotential value from the xGEOID16B model. This accomplished in two steps. To provide an improved reference model, EGM2008 was spectrally enhanced using observations from the GOCE satellite gravity mission and aerogravity from the Gravity for the Redefinition of the American Vertical Datum (GRAV-D) Project. This enhanced model, xGEOID16B_Ref, is still only a five arcminute resolution model (d/o 2160), but resolves dynamic heights at about 2 cm on Lake Superior for December 2015. The reference model was primarily developed to determine a one arcminute geoid height grid, xGEOID16B, available on the NGS website. This geoid height model was used to iteratively develop improved geopotential value for each of the site locations, which then improved comparisons to the cm-level. Comparisons were then made at the 2010 epoch for these same locations to determine if the performance of the geopotential model was consistent.
2008-11-01
luchtdoelartillerie Kampweg 5 Postbus 23 3769 ZG Soesterberg www.tno.nl T +31 346 35 62 11 F +31 346 35 39 77 lnfo-DenV@tno.nl Datum Auteur (s...een hoger begripsniveau getild. Theorie wordt niet van te voren aangeboden door middel van kennisover- dracht, maar wordt gaandeweg opgedaan. De...346 35 39 77 lnfo-DenV@tno.nl TNO-rapportnummer TNO-DV 2008 A394 Opdrachtnummer 851.2116.0152.11 Datum november 2008 Auteur (s) ir. T.J
2008-11-01
Datum Auteur (s) november 2008 dr. LA. teRaa dr. I.PA. Lam dr. ir. M.W. Schouten Rubricering rappon Vastgesteld door Vastgesteld d.d. I ltd...DenV@tno.nl TNO-rapportnummer TNO-DV2008A418 Opdrachtnummer Datum november 2008 Auteur (s) dr. L.A. te Raa dr. F.P.A. Lam dr. ir. M.W. Schouten...verdamping. Een oceaanmodel is gebaseerd op wiskundige vergelijkingen die de dynamica en thermodynamica van de oceaan beschrijven. In theorie geven deze
Learning from Physical Analogies: A Study in Analogy and the Explanation Process
1988-12-27
support of the various transfer operations, the forward chaining ATRE rule system is paired with an abductive retriever. This is a backward chaining...pO) is believed.3 When a new datum is entered in the database, ATRE exhaustively runs all rules made executable by the datum’s presence in a forward ...ZR) INFLUENESST1 (CTA (AIOUN-O ?V-2)) NERTON V- (ASUM (DISSOLVE-RAT SELF))) ER ) (DSETT (SKSOLUTIO-S -12)COOL (NOTUM (LSSOU-THN-1 A CONTRATO V-P) ER
NASA Astrophysics Data System (ADS)
Gentilucci, Matteo; Bisci, Carlo; Fazzini, Massimiliano; Tognetti, Danilo
2016-04-01
The analysis is focused on more than 100 meteorological recording stations located in the Province of Macerata (Marche region, Adriatic side of Central Italy) and in its neighbours; it aims to check the time series of their climatological data (temperatures and precipitations), covering about one century of observations, in order to remove or rectify any errors. This small area (about 2.800Km2) features many different climate types, because of its varied topography ranging, moving westward, from the Adriatic coast to the Appennines (over 2.100m of altitude). In this irregular context, it is difficult to establish a common procedure for each sector; therefore, it has been followed the general guidelines of the WMO, with some important difference (mostly in the method). Data are classified on the basis of validation codes (VC): missing datum (VC=-1), correct or verified datum (VC=0), datum under investigation (VC=1), datum removed after the analysis (VC=2), datum reconstructed through interpolation or by estimating the errors of digitization (VC=3). The first step was the "Logical Control", consisting in the investigation of gross errors of digitization: the data found in this phase of the analysis has been removed without any other control (VC=2). The second step, represented by the "Internal Consistency Check", leads to the elimination (VC=2) of all the data out of range, estimated on the basis of the climate zone for each investigated variable. The third one is the "Tolerance Test", carried out comparing each datum with the historical record it belongs to, in order to apply this test, the normal distribution of data has been evaluated. The "Tolerance Test" usually defines only suspect data (VC=1) to be verified with further tests, such as the "Temporal Consistency" and the "Spatial Consistency". The "Temporal Consistency" allows an evaluation of the time sequence of data, setting a specified range for each station basing upon its historical records. Data out of range have been considered under investigation (VC=1). Data are finally compared with the ones contemporaneously recorded in a set of neighboring meteorological stations through the "Spatial Consistency" test, thus eliminating every suspicious datum (recoded VC=2 or VC=0, depending upon the results of this analysis). This procedure uses a series of different statistic steps to avoid uncertainties: at its end, all the investigated data are either accepted (VC=0) or refused (VC=2). Refused and missing data (VC=-1 and VC=2) have been reconstructed through interpolation using co-kriging techniques (assigning VC=3), when necessary, in the final stage of the process. All the above procedure has been developed using a database managing software in a GIS (ESRI ArcGIS ®) environment. The refused data are 1.286 in 77.021 (1,67%) for the precipitations and 375 in 1.821.054 for the temperatures (0,02%).
Ziegeweid, Jeffrey R.; Silliker, R. Jason; Densmore, Brenda K.; Krahulik, Justin
2016-08-15
Continuously recording water-level streamgages in Rainy Lake and Namakan Reservoir are used to regulate water levels according to rule curves established in 2000 by the International Joint Commission; however, water levels at streamgages were referenced to a variety of vertical datums, confounding efforts to model the flow of water through the system, regulate water levels during periods of high inflow, and evaluate the effectiveness of the rule curves. In October 2014, the U.S. Geological Survey, Natural Resources Canada, International Joint Commission, and National Park Service began a joint field study with the goal of obtaining precise elevations referenced to a uniform vertical datum for all reference marks used to set water levels at streamgages throughout Rainy Lake and Namakan Reservoir. This report was prepared by the U.S. Geological Survey in cooperation with Natural Resources Canada, International Joint Commission, and National Park Service.Three field crews deployed Global Navigation Satellite System receivers statically over 16 reference marks colocated with active and discontinued water-level streamgages throughout Rainy River, Rainy Lake, Namakan Reservoir, and select tributaries of Rainy Lake and Namakan Reservoir. A Global Navigation Satellite System receiver also was deployed statically over a National Geodetic Survey cooperative base network control station for use as a quality-control reference mark. Satellite data were collected simultaneously during a 5-day period and processed independently by the U.S. Geological Survey and Natural Resources Canada to obtain accurate positioning and elevations for the 17 surveyed reference marks. Processed satellite data were used to convert published water levels to elevations above sea level referenced to the Canadian Geodetic Vertical Datum of 2013 in order to compare water-surface elevations referenced to a uniform vertical datum throughout the study area. In this report, an “offset” refers to the correction applied to published data from a particular streamgage to produce elevation data referenced to a specified vertical datum.Offsets were applied to water-level data from surveyed streamgages to further evaluate the accuracy and utility of updated reference mark elevations presented in this report. Daily mean water levels from active streamgages surveyed in this study were converted to water-surface elevations referenced to the Canadian Geodetic Vertical Datum of 2013. Graphical comparisons of water-surface elevations for streamgages in Namakan Reservoir, Rainy Lake, and selected rivers are presented (referencing the Canadian Geodetic Vertical Datum of 2013). Offsets presented in this report can be used in the evaluation of rule curves and in flood damage curves that fully assess the benefits of one regulation approach over another. In addition, offsets may be used to calibrate hydraulic models developed for four narrows that connect lakes of Namakan Reservoir, refine digital elevation models, and support modeling studies designed to assess the effects of rule curves on aquatic vegetation, benthic invertebrates, northern pike, and walleye.
Construction of a 3-arcsecond digital elevation model for the Gulf of Maine
Twomey, Erin R.; Signell, Richard P.
2013-01-01
A system-wide description of the seafloor topography is a basic requirement for most coastal oceanographic studies. The necessary detail of the topography obviously varies with application, but for many uses, a nominal resolution of roughly 100 m is sufficient. Creating a digital bathymetric grid with this level of resolution can be a complex procedure due to a multiplicity of data sources, data coverages, datums and interpolation procedures. This report documents the procedures used to construct a 3-arcsecond (approximately 90-meter grid cell size) digital elevation model for the Gulf of Maine (71°30' to 63° W, 39°30' to 46° N). We obtained elevation and bathymetric data from a variety of American and Canadian sources, converted all data to the North American Datum of 1983 for horizontal coordinates and the North American Vertical Datum of 1988 for vertical coordinates, used a combination of automatic and manual techniques for quality control, and interpolated gaps using a surface-fitting routine.
Vraagstukken besmettingsbeheersing prio 3 (Questions Regarding Contamination Control, Priority 3)
2008-11-01
nl T +31 15 284 30 00 F +31 15 284 39 91 info-DenV@tno nl Datum nov ember 2008 Auteur (s) H.F.G. Oudmaijer Rubricering rapporl Vastgesteld door...F +31 15 284 39 91 info-DenV@tno.nl TNO-rapportnummer TNO-DV 2008 A495 Opdrachtnummer Datum november 2008 Auteur (s) H.F.G. Oudmaijer...zeep kan volgens de theorie beter vaak met een beetje water als in een keer met dezelfde totale massa water gespoeld moeten worden. Met een pH
Known unknowns, Google Earth, plate tectonics and Mt Bellenden Ker: some thoughts on locality data.
Mesibov, Robert
2012-01-01
Latitude/longitude data in locality records should be published with spatial uncertainties, datum(s) used and indications of how the data were obtained. Google Earth can be used to locate sampling sites, but the underlying georegistration of the satellite image should be checked. The little-known relabelling of a set of landmarks on Mt Bellenden Ker, a scientifically important collecting locality in tropical north Queensland, Australia, is documented as an example of the importance of checking records not accompanied by appropriately accurate latitude/longitude data.
NASA Astrophysics Data System (ADS)
Karbon, Maria; Heinkelmann, Robert; Mora-Diaz, Julian; Xu, Minghui; Nilsson, Tobias; Schuh, Harald
2017-07-01
The radio sources within the most recent celestial reference frame (CRF) catalog ICRF2 are represented by a single, time-invariant coordinate pair. The datum sources were chosen mainly according to certain statistical properties of their position time series. Yet, such statistics are not applicable unconditionally, and also ambiguous. However, ignoring systematics in the source positions of the datum sources inevitably leads to a degradation of the quality of the frame and, therefore, also of the derived quantities such as the Earth orientation parameters. One possible approach to overcome these deficiencies is to extend the parametrization of the source positions, similarly to what is done for the station positions. We decided to use the multivariate adaptive regression splines algorithm to parametrize the source coordinates. It allows a great deal of automation, by combining recursive partitioning and spline fitting in an optimal way. The algorithm finds the ideal knot positions for the splines and, thus, the best number of polynomial pieces to fit the data autonomously. With that we can correct the ICRF2 a priori coordinates for our analysis and eliminate the systematics in the position estimates. This allows us to introduce also special handling sources into the datum definition, leading to on average 30 % more sources in the datum. We find that not only the CPO can be improved by more than 10 % due to the improved geometry, but also the station positions, especially in the early years of VLBI, can benefit greatly.
DeWitt, Nancy T.; Stalk, Chelsea A.; Fredericks, Jake J.; Flocks, James G.; Kelso, Kyle W.; Farmer, Andrew S.; Tuten, Thomas M.; Buster, Noreen A.
2018-04-13
The U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center, in cooperation with the U.S. Army Corps of Engineers, Mobile District, conducted bathymetric surveys of the nearshore waters surrounding Ship and Horn Islands, Gulf Islands National Seashore, Mississippi. The objective of this study was to establish base-level elevation conditions around West Ship, East Ship, and Horn Islands and their associated active littoral system prior to restoration activities. These activities include the closure of Camille Cut and the placement of sediment in the littoral zone of East Ship Island. These surveys can be compared with future surveys to monitor sediment migration patterns post-restoration and can also be measured against historic bathymetric datasets to further our understanding of island evolution.The USGS collected 667 line-kilometers (km) of single-beam bathymetry data and 844 line-km of interferometric swath bathymetry data in July 2016 under Field Activity Number 2016-347-FA. Data are provided in three datums: (1) the International Terrestrial Reference Frame of 2000 (ellipsoid height); (2) the North American Datum of 1983 (NAD83) CORS96 realization and the North American Vertical Datum of 1988 with respect to the GEOID12B model (orthometric height); and (3) NAD83 (CORS96) and Mean Lower Low Water (tidal datum). Data products, including x,y,zpoint datasets, trackline shapefiles, digital and handwritten Field Activity Collection Systems logs, 50-meter digital elevation model, and formal Federal Geographic Data Committee metadata, are available for download.
Global height datum unification: a new approach in gravity potential space
NASA Astrophysics Data System (ADS)
Ardalan, A. A.; Safari, A.
2005-12-01
The problem of “global height datum unification” is solved in the gravity potential space based on: (1) high-resolution local gravity field modeling, (2) geocentric coordinates of the reference benchmark, and (3) a known value of the geoid’s potential. The high-resolution local gravity field model is derived based on a solution of the fixed-free two-boundary-value problem of the Earth’s gravity field using (a) potential difference values (from precise leveling), (b) modulus of the gravity vector (from gravimetry), (c) astronomical longitude and latitude (from geodetic astronomy and/or combination of (GNSS) Global Navigation Satellite System observations with total station measurements), (d) and satellite altimetry. Knowing the height of the reference benchmark in the national height system and its geocentric GNSS coordinates, and using the derived high-resolution local gravity field model, the gravity potential value of the zero point of the height system is computed. The difference between the derived gravity potential value of the zero point of the height system and the geoid’s potential value is computed. This potential difference gives the offset of the zero point of the height system from geoid in the “potential space”, which is transferred into “geometry space” using the transformation formula derived in this paper. The method was applied to the computation of the offset of the zero point of the Iranian height datum from the geoid’s potential value W 0=62636855.8 m2/s2. According to the geometry space computations, the height datum of Iran is 0.09 m below the geoid.
NASA Astrophysics Data System (ADS)
Pearson, Chris; Manandhar, Niraj; Denys, Paul
2017-09-01
Along with the damage to buildings and infrastructure, the April 25, 2015 Mw7.8 Gorkha earthquake caused significant deformation over a large area of eastern Nepal with displacements of over 2 m recorded in the vicinity of Kathmandu. Nepal currently uses a classical datum developed in 1984 by the Royal (UK) Engineers in collaboration with the Nepal Survey Department. It has served Nepal well; however, the recent earthquakes have provided an impetus for developing a semi-dynamic datum that will be based on ITRF2014 and have the capacity to correct for tectonic deformation. In the scenario we present here, the datum would be based on ITRF2014 with a reference epoch set some time after the end of the current sequence of earthquakes. The deformation model contains a grid of the secular velocity field combined with models of the Gorkha Earthquake and the May 12 Mw7.3 aftershock. We have developed a preliminary velocity field by collating GPS derived crustal velocities from four previous studies for Nepal and adjacent parts of China and India and aligning them to the ITRF. Patches for the co-seismic part of the deformation for the Gorkha earthquake and the May 12, 2015 Mw 7.2 aftershock are based on published dislocation models. High order control would be a CORS network based around the existing Nepal GPS Array. Coordinates for existing lower order control would be determined by readjusting existing survey measurements and these would be combined with a series of new control stations spread throughout Nepal.
NASA Astrophysics Data System (ADS)
Amjadiparvar, Babak; Sideris, Michael
2015-04-01
Precise gravimetric geoid heights are required when the unification of vertical datums is performed using the Geodetic Boundary Value Problem (GBVP) approach. Five generations of Global Geopotential Models (GGMs) derived from Gravity field and steady-state Ocean Circulation Explorer (GOCE) observations have been computed and released so far (available via IAG's International Centre for Global Earth Models, ICGEM, http://icgem.gfz-potsdam.de/ICGEM/). The performance of many of these models with respect to geoid determination has been studied in order to select the best performing model to be used in height datum unification in North America. More specifically, Release-3, 4 and 5 of the GOCE-based global geopotential models have been evaluated using GNSS-levelling data as independent control values. Comparisons against EGM2008 show that each successive release improves upon the previous one, with Release-5 models showing an improvement over EGM2008 in Canada and CONUS between spherical harmonic degrees 100 and 210. In Alaska and Mexico, a considerable improvement over EGM2008 was brought by the Release-5 models when used up to spherical harmonic degrees of 250 and 280, respectively. The positive impact of the Release-5 models was also felt when a gravimetric geoid was computed using the GOCE-based GGMs together with gravity and topography data in Canada. This geoid model, with appropriately modified Stokes kernel between spherical harmonic degrees 190 and 260, performed better than the official Canadian gravimetric geoid model CGG2013, thus illustrating the advantages of using the latest release GOCE-based models for vertical datum unification in North America.
NGS’ GRAV-D Project: Current update and future prospects
NASA Astrophysics Data System (ADS)
Childers, V. A.; Smith, D. A.; Roman, D. R.; Diehl, T. M.; Eckl, M. C.
2009-12-01
NOAA’s National Geodetic Survey (NGS) is tasked with establishing and maintaining the National Spatial Reference System, the vertical portion of which is called the North American Vertical Datum of 1988 (NAVD88). Although errors were known to exist in NAVD88, recent comparison with Gravity Recovery and Climate Experiment (GRACE) satellite gravity data demonstrated that the error was significant: 50 cm average with a 1 m tilt across the country. Instead of re-leveling the country to repair the datum, NGS has decided instead to establish a new vertical datum through the creation of a gravimetric geoid accurate to 2 cm. At this time, NGS's gravity holdings are of insufficient quality and density to allow for a geoid to be created at this level of accuracy. NGS has launched the Gravity for the Re-definition of the American Vertical Datum (GRAV-D) Project to both sufficiently densify our gravity holdings and to monitor and incorporate temporal changes to the geoid. GRAV-D will perform airborne gravity measurement of all of the US and its holdings in the next 10 years to provide a uniformly measured recovery of the gravity field at about a 20 km resolution. In addition, areas of most rapid change will be monitored through absolute and relative gravity measurements, the GRACE time-varying gravity field, and GPS/CORS networks. In FY09, GRAV-D performed a number of surveys in the Gulf of Mexico, Puerto Rico/US Virgin Islands, and Alaska. We discuss these surveys and a vision of the future given likely Congressional funding in FY10 and onward.
Crustal structure of Central Sicily
NASA Astrophysics Data System (ADS)
Giustiniani, Michela; Tinivella, Umberta; Nicolich, Rinaldo
2018-01-01
We processed crustal seismic profile SIRIPRO, acquired across Central Sicily. To improve the seismic image we utilized the wave equation datuming technique, a process of upward or downward continuation of the wave-field between two arbitrarily shaped surfaces. Wave equation datuming was applied to move shots and receivers to a given datum plane, removing time shifts related to topography and to near-surface velocity variations. The datuming procedure largely contributed to attenuate ground roll, enhance higher frequencies, increase resolution and improve the signal/noise ratio. Processed data allow recognizing geometries of crust structures differentiating seismic facies and offering a direct image of ongoing tectonic setting within variable lithologies characterizing the crust of Central Sicily. Migrated sections underline distinctive features of Hyblean Plateau foreland and above all a crustal thinning towards the Caltanissetta trough, to the contact with a likely deep Permo-Triassic rifted basin or rather a zone of a continent to oceanic transition. Inhomogeneity and fragmentation of Sicily crust, with a distinct separation of Central Sicily basin from western and eastern blocks, appear to have guided the tectonic transport inside the Caltanissetta crustal scale syncline and the accumulation of allochthonous terrains with south and north-verging thrusts. Major tectonic stack operated on the construction of a wide anticline of the Maghrebian chain in northern Sicily. Sequential south-verging imbrications of deep elements forming the anticline core denote a crust wedge indenting foreland structures. Deformation processes involved multiple detachment planes down to decoupling levels located near crust/mantle transition, supporting a presence of high-density lenses beneath the chain, interrelated to a southwards push of Tyrrhenian mantle and asthenosphere.
Brandão, Reuber Albuquerque; Caramaschi, Ulisses; Vaz-Silva, Wilian; Campos, Leandro Ambrósio
2013-12-20
Based on the analyses of specimens collected at several areas in the Cerrado domain from Central Brazil and others housed in scientific collections and on specimens collected at the type-locality, herein we describe three new species belonging to the P. cristiceps group: Proceratophrys bagnoi sp. nov., from UHE Serra da Mesa power plant (13°49'47.5"S, 48°19'17"W; 570 m a.s.l.; WGS84 datum), Municipality of Minaçu, State of Goiás; Proceratophrys branti sp. nov., from Jalapão, Municipality of Mateiros (05o15'25"S, 48o12'00"W; 109 m a.s.l.; WGS84 datum), State of Tocantins; and Proceratophrys dibernardoi sp. nov., Municipality of Mineiros (17o33'52"S, 52o33'20"W; 803 m a.s.l.; WGS84 datum), State of Goiás. The diversity of Proceratophrys in Brazilian Cerrado is still underscored and several species will be described in the following years.
Quality-Assurance Plan for Water-Quality Activities of the U.S. Geological Survey in Miami, Florida
2003-01-01
Jacqueline Lima GS-12 GS-10 GS-09 GS-09 GS-08 GS-07 GS-06 GS-06 GS-04 GS-04Eleanor Seymore Surface-Water Data Collections & Jon Woolverton Jorge Agis...Thomas J. Smith, III Gordon Anderson Kevin Whelan Don De Angelis Allison Snow GS-13 GS-07 GS-05 GS-12 GS-13 GS-07 GS-12 GS-13 GS-09 GS-07 GS-14 GS-07...fan, active, inactive, inventory only playa , month day year stream channel, digital rec- order, North American Datum of 1927 North American Datum of
Monitoring the Storm Tide of Hurricane Wilma in Southwestern Florida, October 2005
Soderqvist, Lars E.; Byrne, Michael J.
2007-01-01
Temporary monitoring stations employing non-vented pressure transducers were used to augment an existing U.S. Geological Survey coastal monitoring network to document the inland water levels related to the storm tide of Hurricane Wilma on the southwestern coast of Florida. On October 22, 2005, an experimental network consisting of 30 temporary stations was deployed over 90 miles of coastline to record the magnitude, extent, and timing of hurricane storm tide and coastal flooding. Sensors were programmed to record time, temperature, and barometric or water pressure. Water pressure was adjusted for changes in barometric pressure and salinity, and then converted to feet of water above the sensor. Elevation surveys using optical levels were conducted to reference storm tide water-level data and high-water marks to the North American Vertical Datum of 1988 (NAVD 88). Storm tide water levels more than 5 feet above NAVD 88 were recorded by sensors at several locations along the southwestern Florida coast. Temporary storm tide monitoring stations used for this effort have demonstrated their value in: (1) furthering the understanding of storm tide by allowing the U.S. Geological Survey to extend the scope of data collection beyond that of existing networks, and (2) serving as backup data collection at existing monitoring stations by utilizing nearby structures that are more likely to survive a major hurricane.
NASA Astrophysics Data System (ADS)
Filmer, M. S.; Hughes, C. W.; Woodworth, P. L.; Featherstone, W. E.; Bingham, R. J.
2018-04-01
The direct method of vertical datum unification requires estimates of the ocean's mean dynamic topography (MDT) at tide gauges, which can be sourced from either geodetic or oceanographic approaches. To assess the suitability of different types of MDT for this purpose, we evaluate 13 physics-based numerical ocean models and six MDTs computed from observed geodetic and/or ocean data at 32 tide gauges around the Australian coast. We focus on the viability of numerical ocean models for vertical datum unification, classifying the 13 ocean models used as either independent (do not contain assimilated geodetic data) or non-independent (do contain assimilated geodetic data). We find that the independent and non-independent ocean models deliver similar results. Maximum differences among ocean models and geodetic MDTs reach >150 mm at several Australian tide gauges and are considered anomalous at the 99% confidence level. These differences appear to be of geodetic origin, but without additional independent information, or formal error estimates for each model, some of these errors remain inseparable. Our results imply that some ocean models have standard deviations of differences with other MDTs (using geodetic and/or ocean observations) at Australian tide gauges, and with levelling between some Australian tide gauges, of ˜ ± 50 mm . This indicates that they should be considered as an alternative to geodetic MDTs for the direct unification of vertical datums. They can also be used as diagnostics for errors in geodetic MDT in coastal zones, but the inseparability problem remains, where the error cannot be discriminated between the geoid model or altimeter-derived mean sea surface.
Datum Transformation of Spatial Data and Application in Cadastre
NASA Astrophysics Data System (ADS)
Kısa, A.; Erkek, B.; Ekin, L.
2012-07-01
In Turkey, cadastral works have been started with local-based works in 1924 and speeded up after 1950's by using photogrammetry. Different measurement methods, coordinate systems and scales have been used in these works. As a result of primary cadastral activities two main products are generated; cadastral maps and title deeds. After this, cadastral data live on the maps, by cadastral activities carried out by cadastral offices and title deed data live on the registrations by land registration activities carried out by land registration offices. Up to 2005 different references systems such as local (graphic) and ED50 have been used for Cadastral maps production. 2000's Land Registry and Cadastre Information System (TAKBİS) Project has started as a pilot application by Land Registry and Cadastre (TKGM). After completion of pilot project spreading activities started in 2005 and still has been ongoing. On the other hand The government has taken the decision to finish primary cadastral activities within three years. The primary cadastral activities completed at the end of 2008. And also TKGM has completed metadata portal in 2008. At last, cadastral map updating (renovation) started in 2009 by using digital orthophoto with 30 cm GSD. Today people have great expectations in accomplishing digital cadastral services, they need correct, reliable, easy and quick accessible land register and cadastral survey information. Even such request expressed in INPIRE directive by using ISO 191XX data standards. This means we have great hard work for spatial data conversion, datum and data transformation for map and cadastral data harmonization. This paper presents results of investigation of used cadastral maps and used datums of the TKGM and possible transformation methods of datum and some recommendations for future applications.
1994-07-01
REPORT DOCUMENTATION PAGE Form Ap~ovd -qmp Pu~~~~~~~~~~hc~~~~~ omef.A Nu0001U~ 0Itg O Mcq ~n, ’tmoa1a q 0 0 fft *cuqIO~ ’Wi.q~ii os .ete .7qO0t.Aqea...water level heights. Using OTF technology it should be possible to obtain a time series of water surface heights to an accuracy of 1 to 2 ymfa...receiver location. 14. SUBJECT TERMS 15. NUMBER OF PAGES On-the-Fly, study of water levels , datum, Bay of Fundy 10 16. PRICE CODE 17. SECURITY
InSAR datum connection using GNSS-augmented radar transponders
NASA Astrophysics Data System (ADS)
Mahapatra, Pooja; der Marel, Hans van; van Leijen, Freek; Samiei-Esfahany, Sami; Klees, Roland; Hanssen, Ramon
2018-01-01
Deformation estimates from Interferometric Synthetic Aperture Radar (InSAR) are relative: they form a `free' network referred to an arbitrary datum, e.g. by assuming a reference point in the image to be stable. However, some applications require `absolute' InSAR estimates, i.e. expressed in a well-defined terrestrial reference frame, e.g. to compare InSAR results with those of other techniques. We propose a methodology based on collocated InSAR and Global Navigation Satellite System (GNSS) measurements, achieved by rigidly attaching phase-stable millimetre-precision compact active radar transponders to GNSS antennas. We demonstrate this concept through a simulated example and practical case studies in the Netherlands.
NASA Astrophysics Data System (ADS)
Perversi, Eleonora; Regazzini, Eugenio
2015-05-01
For a general inelastic Kac-like equation recently proposed, this paper studies the long-time behaviour of its probability-valued solution. In particular, the paper provides necessary and sufficient conditions for the initial datum in order that the corresponding solution converges to equilibrium. The proofs rest on the general CLT for independent summands applied to a suitable Skorokhod representation of the original solution evaluated at an increasing and divergent sequence of times. It turns out that, roughly speaking, the initial datum must belong to the standard domain of attraction of a stable law, while the equilibrium is presentable as a mixture of stable laws.
An Analysis of Strain Accumulation in the Western Part of Black Sea Region in Turkey
NASA Astrophysics Data System (ADS)
Deniz, I.; Avsar, N. B.; Deniz, R.; Mekik, C.; Kutoglu, S.
2014-12-01
Turkish National Horizontal Control Network (TNHCN) based on the European Datum 1950 (ED50) was used as the principal geodetic network until 2005 in Turkey. Since 2005, Turkish Large Scale Map and Map Information Production Regulation have required that that all the densification points have been produced within the same datum of Turkish National Fundamental GPS Network (TNFGN) put into practise in 2002 and based on International Terrestrial Reference Frame (ITRF). Hence, the common points were produced in both European Datum 1950 (ED50), and TNFGN.It is known that the geological and geophysical information about the network area can be obtained by the evaluation of the coordinate and scale variations in a geodetic network. For one such evaluation, the coordinate variations and velocities of network points, and also the strains are investigated. However, the principal problem in derivation of velocities arises from two different datums. In this context, the computation of velocities using the coordinate data of the ED50 and TNFGN is not accurate and reliable. Likewise, the analysis of strain from the coordinate differences is not reliable. However, due to the fact that the scale of a geodetic network is independent from datum, the strains can be derived from scale variations accurately and reliably.In this study, a test area limited 39.5°-42.0° northern latitudes and 31.0°-37.0° eastern longitudes was chosen. The benchmarks in this test area are composed of 30 geodetic control points derived with the aim of cadastral and engineering applications. We used data mining to investigate the common benchmarks in both reference systems for this area. Accordingly, the ED50 and TNFGN coordinates refer 1954 and 2005, respectively. Thus, it has been investigated the strain accumulation of 51 years in this region. It should be also noted that since 1954, the earthquakes have not registered greater than magnitude 6.0 in the test area. It is a considerable situation for this evaluation. The finite element analysis is used in order to derive the strain accumulation and rates in the test area (Figure 1). The results have been indicated that the minimum and maximum strains are 17μs and 3041μs, respectively.
Kasmarek, Mark C.; Johnson, Michaela R.; Ramage, Jason K.
2010-01-01
Most of the subsidence in the Houston-Galveston region has occurred as a direct result of groundwater withdrawals for municipal supply, industrial use, and irrigation that depressured and dewatered the Chicot and Evangeline aquifers causing compaction of the clay layers of the aquifer sediments. This report, prepared by the U.S. Geological Survey, in cooperation with the Harris-Galveston Subsidence District, City of Houston, Fort Bend Subsidence District, and Lone Star Groundwater Conservation District, is one in an annual series of reports depicting water-level altitudes and water-level changes in the Chicot, Evangeline, and Jasper aquifers and compaction in the Chicot and Evangeline aquifers in the Houston-Galveston region. The report contains maps showing 2010 water-level altitudes for the Chicot, Evangeline, and Jasper aquifers, respectively; maps showing 1-year (2009-10) water-level-altitude changes for each aquifer; maps showing 5-year (2005-10) water-level-altitude changes for each aquifer; maps showing long-term (1990-2010 and 1977-2010) water-level-altitude changes for the Chicot and Evangeline aquifers; a map showing long-term (2000-10) water-level-altitude change for the Jasper aquifer; a map showing locations of borehole extensometer sites; and graphs showing measured compaction of subsurface material at the extensometers from 1973, or later, through 2009. Tables listing the data used to construct each aquifer-data map and the compaction graphs are included. Water levels in the Chicot, Evangeline, and Jasper aquifers were measured during December 2009-March 2010. In 2010, water-level-altitude contours for the Chicot aquifer ranged from 200 feet below National Geodetic Vertical Datum of 1929 or North American Vertical Datum of 1988 (hereinafter, datum) in a small area in southwestern Harris County to 200 feet above datum in central to southwestern Montgomery County. Water-level-altitude changes in the Chicot aquifer ranged from a 49-foot decline to a 67-foot rise (2009-10), from a 25-foot decline to a 35-foot rise (2005-10), from a 40-foot decline to an 80-foot rise (1990-2010), and from a 140-foot decline to a 200-foot rise (1977-2010). In 2010, water-level-altitude contours for the Evangeline aquifer ranged from 300 feet below datum in north-central Harris County to 200 feet above datum at the boundary of Waller, Montgomery, and Grimes Counties. Water-level-altitude changes in the Evangeline aquifer ranged from a 58-foot decline to a 69-foot rise (2009-10), from an 80-foot decline to an 80-foot rise (2005-10), from a 200-foot decline to a 220-foot rise (1990-2010), and from a 320-foot decline to a 220-foot rise (1977-2010). In 2010, water-level-altitude contours for the Jasper aquifer ranged from 200 feet below datum in south-central Montgomery County to 250 feet above datum in eastern-central Grimes County. Water-level-altitude changes in the Jasper aquifer ranged from a 39-foot decline to a 39-foot rise (2009-10), from a 110-foot decline to no change (2005-10), and from a 180-foot decline to no change (2000-10). Compaction of subsurface materials (mostly in the clay layers) composing the Chicot and Evangeline aquifers was recorded continuously at 13 borehole extensometers at 11 sites. For the period of record beginning in 1973, or later, and ending in December 2009, cumulative clay compaction data measured by 12 extensometers ranged from 0.088 foot at the Texas City-Moses Lake site to 3.559 foot at the Addicks site. The rate of compaction varies from site to site because of differences in groundwater withdrawals near each site and differences among sites in the clay-to-sand ratio in the subsurface materials. Therefore, it is not possible to extrapolate or infer a rate of clay compaction for an area based on the rate of compaction measured at a nearby extensometer.
Absolute Gravity Datum in the Age of Cold Atom Gravimeters
NASA Astrophysics Data System (ADS)
Childers, V. A.; Eckl, M. C.
2014-12-01
The international gravity datum is defined today by the International Gravity Standardization Net of 1971 (IGSN-71). The data supporting this network was measured in the 1950s and 60s using pendulum and spring-based gravimeter ties (plus some new ballistic absolute meters) to replace the prior protocol of referencing all gravity values to the earlier Potsdam value. Since this time, gravimeter technology has advanced significantly with the development and refinement of the FG-5 (the current standard of the industry) and again with the soon-to-be-available cold atom interferometric absolute gravimeters. This latest development is anticipated to provide improvement in the range of two orders of magnitude as compared to the measurement accuracy of technology utilized to develop ISGN-71. In this presentation, we will explore how the IGSN-71 might best be "modernized" given today's requirements and available instruments and resources. The National Geodetic Survey (NGS), along with other relevant US Government agencies, is concerned about establishing gravity control to establish and maintain high order geodetic networks as part of the nation's essential infrastructure. The need to modernize the nation's geodetic infrastructure was highlighted in "Precise Geodetic Infrastructure, National Requirements for a Shared Resource" National Academy of Science, 2010. The NGS mission, as dictated by Congress, is to establish and maintain the National Spatial Reference System, which includes gravity measurements. Absolute gravimeters measure the total gravity field directly and do not involve ties to other measurements. Periodic "intercomparisons" of multiple absolute gravimeters at reference gravity sites are used to constrain the behavior of the instruments to ensure that each would yield reasonably similar measurements of the same location (i.e. yield a sufficiently consistent datum when measured in disparate locales). New atomic interferometric gravimeters promise a significant increase in accuracy. Our presentation will also explore the impact of such an instrument on our theory of how to constrain the gravity datum and on how to ensure stability, repeatability, and reproducibility across different absolute gravimeter systems.
NASA Astrophysics Data System (ADS)
Xiong, X.; Gao, R.; Li, Q.; Wang, H.
2012-12-01
The sedimentary basin and the orogenic belt are the basic two tectonic units of the continental lithosphere, and form the basin-mountain coupling system, The research of which is the key element to the oil and gas exploration, the global tectonic theory and models and the development of the geological theory. The Sichuan basin and adjacent orogenic belts is one of the most ideal sites to research the issues above, in particular by the recent deep seismic profiling datum. From the 1980s to now, there are 11 deep seismic sounding profiles and 6 deep seismic reflection profiles and massive seismic broadband observation stations deployed around and crossed the Sichuan basin, which provide us a big opportunity to research the deep structure and other forward issues in this region. Supported by the National Natural Science Foundation of China (Grant No. 41104056) and the Fundamental Research Funds of the Institute of Geological Sciences, CAGS (No. J1119), we sampled the Moho depth and low-velocity zone depth and the Pn velocity of these datum, then formed the contour map of the Moho depth and Pn velocity by the interpolation of the sampled datum. The result shows the Moho depth beneath Sichuan basin ranges from 40 to 44 km, the sharp Moho offset appears in the western margin of the Sichuan basin, and there is a subtle Moho depression in the central southern part of the Sichuan basin; the P wave velocity can be 6.0 km/s at ca. 10 km deep, and increases gradually deeper, the average P wave velocity in this region is ca. 6.3 km/s; the Pn velocity is ca. 8.0-8.02 km/s in Sichuan basin, and 7.70-7.76 km/s in Chuan-Dian region; the low velocity zone appears in the western margin of the Sichuan basin, which maybe cause the cause of the earthquake.
Moore, L.J.; Ruggiero, P.; List, J.H.
2006-01-01
More than one type of shoreline indicator can be used in shoreline change analyses, and quantifying the effects of this practice on the resulting shoreline change rates is important. Comparison of three high water line (proxy-based) shorelines and a mean high water intercept (datum-based) shoreline collected from simultaneous aerial photographic and lidar surveys of a relatively steep reflective beach (tan ?? = 0.07), which experiences a moderately energetic wave climate (annual average Hs = 1.2 m), reveals an average horizontal offset of 18.8 m between the two types of shoreline indicators. Vertical offsets are also substantial and are correlated with foreshore beach slope and corresponding variations in wave runup. Incorporating the average horizontal offset into both a short-term, endpoint shoreline change analysis and a long-term, linear regression analysis causes rates to be shifted an average of -0.5 m/y and -0.1 m/y, respectively. The rate shift increases with increasing horizontal offset and decreasing measurement intervals and, depending on the rapidity of shoreline change rates, is responsible for varying degrees of analysis error. Our results demonstrate that under many circumstances, the error attributable to proxy-datum offsets is small relative to shoreline change rates and thus not important. Furthermore, we find that when the error associated with proxy-datum offsets is large enough to be important, the shoreline change rates themselves are not likely to be significant. A total water level model reveals that the high water line digitized by three independent coastal labs for this study was generated by a combination of large waves and a high tide several days before the collection of aerial photography. This illustrates the complexity of the high water line as a shoreline indicator and calls into question traditional definitions, which consider the high water line a wetted bound or "marks left by the previous high tide.".
A simulation model of the oxygen alveolo-capillary exchange in normal and pathological conditions.
Brighenti, Chiara; Gnudi, Gianni; Avanzolini, Guido
2003-05-01
This paper presents a mathematical model of the oxygen alveolo-capillary exchange to provide the capillary oxygen partial pressure profile in normal and pathological conditions. In fact, a thickening of the blood-gas barrier, heavy exercise or a low oxygen partial pressure (PO2) in the alveolar space can reduce the O2 alveolo-capillary exchange. Since the reversible binding between haemoglobin and oxygen makes it impossible to determine the closed form for the mathematical description of the PO2 profile along the pulmonary capillaries, an approximate analytical solution of the capillary PO2 profile is proposed. Simulation results are compared with the capillary PO2 profile obtained by numerical integration and by a piecewise linear interpolation of the oxyhaemoglobin dissociation curve. Finally, the proposed model is evaluated in a large range of physiopathological diffusive conditions. The good fit to numerical solutions in all experimental conditions seems to represent a substantial improvement with respect to the approach based on a linear approximation of the oxyhaemoglobin dissociation curve, and makes this model a candidate to be incorporated into the integrated descriptions of the entire respiratory system, where the datum of primary interest is the value of end capillary PO2.
Numerical calculation on infrared characteristics of the special vehicle exhaust system
NASA Astrophysics Data System (ADS)
Feng, Yun-song; Li, Xiao-xia; Jin, Wei
2017-10-01
For mastery of infrared radiation characteristics and flow field of the special vehicle exhaust system, first, a physical model of the special vehicle exhaust system is established with the Gambit, and the mathematical model of flow field is determined. Secondly, software Fluent6.3 is used to simulated the 3-D exterior flow field of the special vehicle exhaust system, and the datum of flow field, such as temperature, pressure and density, are obtained. Thirdly, based on the plume temperature, the special vehicle exhaust space is divided. The exhaust is equivalent to a gray-body. A calculating model of the vehicle exhaust infrared radiation is established, and the exhaust infrared radiation characteristics are calculated by the software MATLAB, then the spatial distribution curves are drawn. Finally, the numerical results are analyzing, and the basic laws of the special vehicle exhaust infrared radiation are explored. The results show that with the increase of the engine speed, the temperature of the exhaust pipe wall of the special vehicle increases, and the temperature and pressure of the exhaust gas flow field increase, which leads to the enhancement of the infrared radiation intensity
The Interpretation of Wavelengths and Periods as Measured from Atmospheric Balloons.
NASA Astrophysics Data System (ADS)
de La Torre, Alejandro; Alexander, Pedro
1995-12-01
Transformations that take into account the characteristics of balloon motion and wave propagation to infer the `real' wavelengths and frequencies from the `apparent' ones measured during sounding are derived. To estimate the differences that may arise in the observations of internal gravity waves, a statistical relation between their wavelength and period recently found from theory and experiment is applied. It is shown that it may not be possible to determine from each apparent datum a unique real value, because up to four different transformations may be applicable for each experimental datum of wavelength or frequency. However, under certain conditions this ambiguity can be removed. The omission of the appropriate transformation may lead one to seriously misinterpret the data.
Traffic flow collection wireless sensor network node for intersection light control
NASA Astrophysics Data System (ADS)
Li, Xu; Li, Xue
2011-10-01
Wireless sensor network (WSN) is expected to be deployed in intersection to monitor the traffic flow continuously, and the monitoring datum can be used as the foundation of traffic light control. In this paper, a WSN based on ZigBee protocol for monitoring traffic flow is proposed. Structure, hardware and work flow of WSN nodes are designed. CC2431 from Texas Instrument is chosen as the main computational and transmission unit, and CC2591 as the amplification unit. The stability experiment and the actual environment experiment are carried out in the last of the paper. The results of experiments show that WSN has the ability to collect traffic flow information quickly and transmit the datum to the processing center in real time.
NASA Astrophysics Data System (ADS)
Poerbandono
2017-07-01
This paper assesses the presence of navigational hazards due to underestimation of charted depths originated from an establishment of a sea-level-related reference plane, i.e. datum. The study domain is situated in one of Indonesia's densest marine traffic, SW Java Sea, Indonesia. The assessment is based on the comparison of the authorized Chart Datum (CD), being uniformly located at 0.6 m below Mean Sea Level (MSL), and a spatially varying Lowest Astronomical Tide (LAT) generated for the purpose of this research. Hazards are considered here as the deviation of LAT from CD and quantified as the ratio of LAT -CD deviation with respect to the allowable Total Vertical Uncertainty (TVU), i.e. the international standard for accuracy of depth information on nautical charts. Underestimation of charted depth is expected for the case that LAT falls below CD. Such a risk magnifies with decreasing depths, as well as the increasing volume of traffic and draught of the vessel. It is found that most of the domain is in the interior of risk-free zone from using uniform CD. As much as 0.08 and 0.19 parts of the area are in zones where the uncertainty of CD contributes respectively to 50% and 30% of Total Vertical Uncertainty. These are zones where the hazard of navigation is expected to increase due to underestimated lowest tidal level.
A Global Terrestrial Reference Frame from simulated VLBI and SLR data in view of GGOS
NASA Astrophysics Data System (ADS)
Glaser, Susanne; König, Rolf; Ampatzidis, Dimitrios; Nilsson, Tobias; Heinkelmann, Robert; Flechtner, Frank; Schuh, Harald
2017-07-01
In this study, we assess the impact of two combination strategies, namely local ties (LT) and global ties (GT), on the datum realization of Global Terrestrial Reference Frames in view of the Global Geodetic Observing System requiring 1 mm-accuracy. Simulated Very Long Baseline Interferometry (VLBI) and Satellite Laser Ranging (SLR) data over a 7 year time span was used. The LT results show that the geodetic datum can be best transferred if the precision of the LT is at least 1 mm. Investigating different numbers of LT, the lack of co-located sites on the southern hemisphere is evidenced by differences of 9 mm in translation and rotation compared to the solution using all available LT. For the GT, the combination applying all Earth rotation parameters (ERP), such as pole coordinates and UT1-UTC, indicates that the rotation around the Z axis cannot be adequately transferred from VLBI to SLR within the combination. Applying exclusively the pole coordinates as GT, we show that the datum can be transferred with mm-accuracy within the combination. Furthermore, adding artificial stations in Tahiti and Nigeria to the current VLBI network results in an improvement in station positions by 13 and 12%, respectively, and in ERP by 17 and 11%, respectively. Extending to every day VLBI observations leads to 65% better ERP estimates compared to usual twice-weekly VLBI observations.
NASA Astrophysics Data System (ADS)
Youngman, M.; Weil, C.; Salisbury, T.; Villarreal, C.
2015-12-01
The U.S. National Geodetic Survey is collecting airborne gravity with the Gravity for the Redefinition of the American Vertical Datum (GRAV-D) project to produce a geoid supporting heights accurate to 2 centimeters, where possible, with a modernized U.S. vertical datum in 2022. Targeting 15.6 million square kilometers, the GRAV-D project is unprecedented in its scope of consistently collected airborne gravity data across the entire U.S. and its holdings. Currently over 42% of data collection has been completed by 42 surveys (field campaigns) covering 34 completed blocks (data collection areas). The large amount of data available offers a unique opportunity to evaluate the causes of data quality variation from survey to survey. Two metrics were chosen to use as a basis for comparing the quality of each survey/block: 1. total crossover error (i.e. difference in gravity recorded at all locations of crossing flight lines) and 2. the statistical difference of the airborne gravity from the EGM2008 global model. We have determined that the aircraft used for surveying contributes significantly to the variation in data quality. This paper will further expand upon that recent work, using statistical analysis to determine the contribution of aircraft selection to data quality taking into account other variables such as differences in survey setup or weather conditions during surveying.
Hurricane Rita surge data, southwestern Louisiana and southeastern Texas, September to November 2005
McGee, Benton D.; Goree, Burl B.; Tollett, Roland W.; Woodward, Brenda K.; Kress, Wade H.
2006-01-01
Pressure transducers and high-water marks were used to document the inland water levels related to storm surge generated by Hurricane Rita in southwestern Louisiana and southeastern Texas. On September 22-23, 2005, an experimental monitoring network consisting of 47 pressure transducers (sensors) was deployed at 33 sites over an area of about 4,000 square miles to record the timing, extent, and magnitude of inland hurricane storm surge and coastal flooding. Sensors were programmed to record date and time, temperature, and barometric or water pressure. Water pressure was corrected for changes in barometric pressure and salinity. Elevation surveys using global-positioning systems and differential levels were used to relate all storm-surge water-level data, reference marks, benchmarks, sensor measuring points, and high-water marks to the North American Vertical Datum of 1988 (NAVD 88). The resulting data indicated that storm-surge water levels over 14 feet above NAVD 88 occurred at three locations and rates of water-level rise greater than 5 feet per hour occurred at three locations near the Louisiana coast. Quality-assurance measures were used to assess the variability and accuracy of the water-level data recorded by the sensors. Water-level data from sensors were similar to data from co-located sensors, permanent U.S. Geological Survey streamgages, and water-surface elevations performed by field staff. Water-level data from sensors at selected locations were compared to corresponding high-water mark elevations. In general, the water-level data from sensors were similar to elevations of high quality high-water marks, while reporting consistently higher than elevations of lesser quality high-water marks.
77 FR 76916 - Final Flood Elevation Determinations
Federal Register 2010, 2011, 2012, 2013, 2014
2012-12-31
... Southeast. Sweat Mountain Creek At the Willeo Creek +941 Unincorporated Areas of confluence. Cobb County... upstream of the Sweat Mountain Creek confluence. * National Geodetic Vertical Datum. + North American...
Classification of Alzheimer's Patients through Ubiquitous Computing.
Nieto-Reyes, Alicia; Duque, Rafael; Montaña, José Luis; Lage, Carmen
2017-07-21
Functional data analysis and artificial neural networks are the building blocks of the proposed methodology that distinguishes the movement patterns among c's patients on different stages of the disease and classifies new patients to their appropriate stage of the disease. The movement patterns are obtained by the accelerometer device of android smartphones that the patients carry while moving freely. The proposed methodology is relevant in that it is flexible on the type of data to which it is applied. To exemplify that, it is analyzed a novel real three-dimensional functional dataset where each datum is observed in a different time domain. Not only is it observed on a difference frequency but also the domain of each datum has different length. The obtained classification success rate of 83 % indicates the potential of the proposed methodology.
75 FR 5929 - Proposed Flood Elevation Determinations
Federal Register 2010, 2011, 2012, 2013, 2014
2010-02-05
... City of Eureka Springs, miles upstream of Unincorporated Areas Magnetic Road. of Carroll County. Approximately 1,250 None +1,131 feet upstream of Magnetic Road. * National Geodetic Vertical Datum. + North...
47 CFR 0.121 - Location of field installations.
Code of Federal Regulations, 2011 CFR
2011-10-01
... throughout the United States. For the address and phone number of the closest office contact the Enforcement... geographical coordinates (coordinates are referenced to North American Datum 1983 (NAD83)): Allegan, Michigan...
47 CFR 0.121 - Location of field installations.
Code of Federal Regulations, 2010 CFR
2010-10-01
... throughout the United States. For the address and phone number of the closest office contact the Enforcement... geographical coordinates (coordinates are referenced to North American Datum 1983 (NAD83)): Allegan, Michigan...
Code of Federal Regulations, 2010 CFR
2010-07-01
... North American Datum of 1983 (NAD 83), unless such geographic coordinates are expressly labeled NAD 83. Geographic coordinates without the NAD 83 reference may be plotted on maps or charts referenced to NAD 83...
The Necessity of "Behaviorism."
ERIC Educational Resources Information Center
Schoenfeld, William N.
1993-01-01
Discusses the theory of behaviorism from a psychological perspective. Three issues are addressed: (1) the datum, including human verbal behavior; (2) the behavior stream; and (3) reduction, including a scientific viewpoint. (Contains two references.) (LRW)
47 CFR 101.1415 - Partitioning and disaggregation.
Code of Federal Regulations, 2010 CFR
2010-10-01
... American Datum (NAD83). (d) Unjust enrichment. 12 GHz licensees that received a bidding credit and... be subject to the provisions concerning unjust enrichment as set forth in § 1.2111 of this chapter...
Publications - IC 44 ed. 2004 | Alaska Division of Geological & Geophysical
Tidal Datum Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to Geologic Hazards in Map; Aeromagnetic Survey; Airborne Geophysical Survey; Alaska, State of; Bibliography; Coastal and
Code of Federal Regulations, 2010 CFR
2010-07-01
... North American Datum of 1983 (NAD 83), unless such geographic coordinates are expressly labeled NAD 83. Geographic coordinates without the NAD 83 reference may be plotted on maps or charts referenced to NAD 83...
Spanish Word Order in Non-Sentence Constructions
ERIC Educational Resources Information Center
Stiehm, Bruce G.
1975-01-01
In Spanish non-sentence constructions, beginning elements establish a datum of reference, while following elements narrow the possibilities of syntagmatic combination. Word order is examined in relation to paradigm contrast and syntagmatic complexity. (CK)
Language and Communication Datum.
ERIC Educational Resources Information Center
Sullivan, William J.
1989-01-01
Argues that communication is the primary function of language and that the signification function can be derived from it. Several theories of language are considered for their attitude toward the communication function. (26 references) (Author/VWL)
Classification of Alzheimer’s Patients through Ubiquitous Computing †
Nieto-Reyes, Alicia; Duque, Rafael; Montaña, José Luis; Lage, Carmen
2017-01-01
Functional data analysis and artificial neural networks are the building blocks of the proposed methodology that distinguishes the movement patterns among c’s patients on different stages of the disease and classifies new patients to their appropriate stage of the disease. The movement patterns are obtained by the accelerometer device of android smartphones that the patients carry while moving freely. The proposed methodology is relevant in that it is flexible on the type of data to which it is applied. To exemplify that, it is analyzed a novel real three-dimensional functional dataset where each datum is observed in a different time domain. Not only is it observed on a difference frequency but also the domain of each datum has different length. The obtained classification success rate of 83% indicates the potential of the proposed methodology. PMID:28753975
Allowable Trajectory Variations for Space Shuttle Orbiter Entry-Aeroheating CFD
NASA Technical Reports Server (NTRS)
Wood, William A.; Alter, Stephen J.
2008-01-01
Reynolds-number criteria are developed for acceptable variations in Space Shuttle Orbiter entry trajectories for use in computational aeroheating analyses. The criteria determine if an existing computational fluid dynamics solution for a particular trajectory can be extrapolated to a different trajectory. The criteria development begins by estimating uncertainties for seventeen types of computational aeroheating data, such as boundary layer thickness, at exact trajectory conditions. For each type of datum, the allowable uncertainty contribution due to trajectory variation is set to be half of the value of the estimated exact-trajectory uncertainty. Then, for the twelve highest-priority datum types, Reynolds-number relations between trajectory variation and output uncertainty are determined. From these relations the criteria are established for the maximum allowable trajectory variations. The most restrictive criterion allows a 25% variation in Reynolds number at constant Mach number between trajectories.
An non-uniformity voltage model for proton exchange membrane fuel cell
NASA Astrophysics Data System (ADS)
Li, Kelei; Li, Yankun; Liu, Jiawei; Guo, Ai
2017-01-01
The fuel cell used in transportation has environmental protection, high efficiency and no line traction power system which can greatly reduce line construction investment. That makes it a huge potential. The voltage uniformity is one of the most important factors affecting the operation life of proton exchange membrane fuel cell (PEMFC). On the basis of principle and classical model of the PEMFC, single cell voltage is calculated and the location coefficients are introduced so as to establish a non-uniformity voltage model. These coefficients are estimated with the experimental datum at stack current 50 A. The model is validated respectively with datum at 60 A and 100 A. The results show that the model reflects the basic characteristics of voltage non-uniformity and provides the beneficial reference for fuel cell control and single cell voltage detection.
NASA Technical Reports Server (NTRS)
Harten, A.; Tal-Ezer, H.
1981-01-01
This paper presents a family of two-level five-point implicit schemes for the solution of one-dimensional systems of hyperbolic conservation laws, which generalized the Crank-Nicholson scheme to fourth order accuracy (4-4) in both time and space. These 4-4 schemes are nondissipative and unconditionally stable. Special attention is given to the system of linear equations associated with these 4-4 implicit schemes. The regularity of this system is analyzed and efficiency of solution-algorithms is examined. A two-datum representation of these 4-4 implicit schemes brings about a compactification of the stencil to three mesh points at each time-level. This compact two-datum representation is particularly useful in deriving boundary treatments. Numerical results are presented to illustrate some properties of the proposed scheme.
Target tracking and pointing for arrays of phase-locked lasers
NASA Astrophysics Data System (ADS)
Macasaet, Van P.; Hughes, Gary B.; Lubin, Philip; Madajian, Jonathan; Zhang, Qicheng; Griswold, Janelle; Kulkarni, Neeraj; Cohen, Alexander; Brashears, Travis
2016-09-01
Arrays of phase-locked lasers are envisioned for planetary defense and exploration systems. High-energy beams focused on a threatening asteroid evaporate surface material, creating a reactionary thrust that alters the asteroid's orbit. The same system could be used to probe an asteroid's composition, to search for unknown asteroids, and to propel interplanetary and interstellar spacecraft. Phased-array designs are capable of producing high beam intensity, and allow beam steering and beam profile manipulation. Modular designs allow ongoing addition of emitter elements to a growing array. This paper discusses pointing control for extensible laser arrays. Rough pointing is determined by spacecraft attitude control. Lateral movement of the laser emitter tips behind the optical elements provides intermediate pointing adjustment for individual array elements and beam steering. Precision beam steering and beam formation is accomplished by coordinated phase modulation across the array. Added cells are incorporated into the phase control scheme by precise alignment to local mechanical datums using fast, optical relative position sensors. Infrared target sensors are also positioned within the datum scheme, and provide information about the target vector relative to datum coordinates at each emitter. Multiple target sensors allow refined determination of the target normal plane, providing information to the phase controller for each emitter. As emitters and sensors are added, local position data allows accurate prediction of the relative global position of emitters across the array, providing additional constraints to the phase controllers. Mechanical design and associated phase control that is scalable for target distance and number of emitters is presented.
Johnson, Michaela R.; Ramage, Jason K.; Kasmarek, Mark C.
2011-01-01
Most of the subsidence in the Houston–Galveston region has occurred as a direct result of groundwater withdrawals for municipal supply, industrial use, and irrigation that depressured and dewatered the Chicot and Evangeline aquifers causing compaction of the clay layers of the aquifer sediments. This report, prepared by the U.S. Geological Survey, in cooperation with the Harris–Galveston Subsidence District, City of Houston, Fort Bend Subsidence District, and Lone Star Groundwater Conservation District, is one in an annual series of reports depicting water-level altitudes and water-level changes in the Chicot, Evangeline, and Jasper aquifers and compaction in the Chicot and Evangeline aquifers in the Houston–Galveston region. The report contains maps showing 2011 water-level altitudes for the Chicot, Evangeline, and Jasper aquifers; maps showing 1-year (2010–11) water-level-altitude changes for each aquifer; maps showing 5-year (2006–11) water-level-altitude changes for each aquifer; maps showing long-term (1990–2011 and 1977–2011) water-level-altitude changes for the Chicot and Evangeline aquifers; a map showing long-term (2000–11) water-level-altitude change for the Jasper aquifer; a map showing locations of borehole extensometer sites; and graphs showing measured compaction of subsurface material at the extensometers from 1973, or later, through 2010. Tables listing the data used to construct each aquifer-data map and the compaction graphs are included.Water levels in the Chicot, Evangeline, and Jasper aquifers were measured during December 2010–February 2011. In 2011, water-level-altitude contours for the Chicot aquifer ranged from 200 feet below North American Vertical Datum of 1988 (hereinafter, datum) in a small area in southwestern Harris County to 200 feet above datum in central to southwestern Montgomery County. Water-level-altitude changes in the Chicot aquifer ranged from a 40-foot decline to a 33-foot rise (2010–11), from a 10-foot decline to an 80-foot rise (2006–11), from a 140-foot decline to a 100-foot rise (1990–2011), and from a 120-foot decline to a 200-foot rise (1977–2011). In 2011, water-level-altitude contours for the Evangeline aquifer ranged from 300 feet below datum in north-central Harris County to 200 feet above datum at the boundary of Waller, Montgomery, and Grimes Counties. Water-level-altitude changes in the Evangeline aquifer ranged from a 43-foot decline to a 73-foot rise (2010–11), from a 40-foot decline to a 160-foot rise (2006–11), from a 200-foot decline to a 240-foot rise (1990–2011), and from a 340-foot decline to a 260-foot rise (1977–2011). In 2011, water-level-altitude contours for the Jasper aquifer ranged from 200 feet below datum in south-central Montgomery County to 250 feet above datum in east-central Grimes County. Water-level-altitude changes in the Jasper aquifer ranged from a 45-foot decline to a 29-foot rise (2010–11), from a 90-foot decline to a 10-foot rise (2006–11), and from a 190-foot decline to no change (2000–11). Compaction of subsurface materials (mostly in the clay layers) composing the Chicot and Evangeline aquifers was recorded continuously at 13 borehole extensometers at 11 sites. For the period of record beginning in 1973, or later, and ending in December 2010, cumulative clay compaction data measured by 12 extensometers ranged from 0.100 foot at the Texas City–Moses Lake site to 3.544 foot at the Addicks site. The rate of compaction varies from site to site because of differences in groundwater withdrawals near each site and differences among sites in the clay-to-sand ratio in the subsurface materials. Therefore, it is not possible to extrapolate or infer a rate of clay compaction for an area based on the rate of compaction measured at a nearby extensometer.
Infrared characteristics and flow field of the exhaust plume outside twin engine nozzle
NASA Astrophysics Data System (ADS)
Feng, Yun-song
2016-01-01
For mastery of infrared radiation characteristics and flow field of exhaust plume of twin engine nozzles, first, a physical model of the double rectangular nozzles is established with the Gambit, and the mathematical model of flow field is determined. Secondly, software Fluent6.3 is used to simulated the 3-D exterior flow field of the twin engine nozzles, and the datum of flow field, such as temperature, pressure and density, are obtained. Finally, based on the plume temperature, the exhaust plume space is divided. The exhaust plume is equivalent to a gray-body. A calculating model of the plume infrared radiation is established, and the plume infrared radiation characteristics are calculated by the software MATLAB, then the spatial distribution curves are drawn. The result improves that with the height increasing the temperature, press and infrared radiant intensity diminish. Compared with engine afterburning condition, temperature and infrared radiant intensity increases and press has no obvious change.
33 CFR 165.1306 - Lake Union, Seattle, WA.
Code of Federal Regulations, 2010 CFR
2010-07-01
... safety zone. [Datum: NAD 1983] (b) Effective dates. This section is effective annually on July fourth... open until 10 p.m. and then be closed until the end of the fireworks display (approximately 30 minutes...
Publications - RI 97-14B | Alaska Division of Geological & Geophysical
Tidal Datum Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to Geologic Hazards in , State of; Alluvial Deposits; Avalanche; Cambrian; Carboniferous; Cenozoic; Coastal and River; Coastal
Publications - RI 97-15D | Alaska Division of Geological & Geophysical
Tidal Datum Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to Geologic Hazards in Coastal and River; Coastal and River Hazards; Construction Materials; Derivative; Engineering; Engineering
Publications - RI 2016-2 | Alaska Division of Geological & Geophysical
Tidal Datum Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to Geologic Hazards in ; Bathymetry; Coastal; Coastal and River; Earthquake Related Slope Failure; Emergency Preparedness; Engineering
Transformation pipelines for PROJ.4
NASA Astrophysics Data System (ADS)
Knudsen, Thomas; Evers, Kristian
2017-04-01
For more than 2 decades, PROJ.4 has been the globally leading map projection library for open source (and probably also closed source) geospatial software. While focusing on mathematically well defined 2D projections from geographical to planar coordinates, PROJ.4 has nevertheless, since its introduction in the 1980s, provided limited support for more general geodetic datum transformations, and has gradually introduced a higher degree of support for 3D coordinate data and reference systems. The support has, however, been implemented over a long period of time, as need became evident and opportunity was found, by a number of different people, with different needs and at different times. Hence, the PROJ.4 3D support has not been the result of neither deep geodetic, nor careful code architectural considerations. This has resulted in a library that supports only a subset of commonly occurring geodetic transformations. To be more specific: It supports any datum shift that can be completed by a combination of two Helmert shifts (to and from a pivot datum) and, potentially, also a non-linear planar correction derived from interpolation in a correction grid. While this is sufficient for most small scale mapping activities, it is not at all sufficient for operational geodetic use, nor for many of the rapidly emerging high accuracy geospatial applications in agriculture, construction, transportation and utilities. To improve this situation, we have introduced a new framework for implementation of geodetic transformations, which will appear in the next release of the PROJ.4 library. Before describing the details, let us first remark that most cases of geodetic transformations can be expressed as a series of elementary operations, the output of one operation being the input of the next. E.g. when going from UTM zone 32, datum ED50, to UTM zone 32, datum ETRS89, one must, in the simplest case, go through 5 steps: Back-project the UTM coordinates to geographic coordinates Convert the geographic coordinates to 3D cartesian geocentric coordinates Apply a Helmert transformation from ED50 to ETRS89 Convert back from cartesian to geographic coordinates Finally project the geographic coordinates to UTM zone 32 planar coordinates. The homology between these steps and a Unix shell style pipeline is evident. With this as its main architectural inspiration, the primary feature of our implementation is a pipeline driver, that takes as its user supplied arguments, a series of elementary operations, which it strings together in order to implement the full transformation needed. Also, we have added a number of elementary geodetic operations, including Helmert transformations, general high order polynomial shifts (2D Horner's scheme) and the abridged Molodensky transformation. In anticipation of upcoming support for full time-varying transformations, we also introduce a 4D spatiotemporal data type, and a programming interface (API) for handling this. With these improvements in place, we assert that PROJ.4 is now well on its way from being a mostly-map-projection library, to becoming an almost-generic-geodetic-transformation library.
Topobathymetric model of Mobile Bay, Alabama
Danielson, Jeffrey J.; Brock, John C.; Howard, Daniel M.; Gesch, Dean B.; Bonisteel-Cormier, Jamie M.; Travers, Laurinda J.
2013-01-01
Topobathymetric Digital Elevation Models (DEMs) are a merged rendering of both topography (land elevation) and bathymetry (water depth) that provides a seamless elevation product useful for inundation mapping, as well as for other earth science applications, such as the development of sediment-transport, sea-level rise, and storm-surge models. This 1/9-arc-second (approximately 3 meters) resolution model of Mobile Bay, Alabama was developed using multiple topographic and bathymetric datasets, collected on different dates. The topographic data were obtained primarily from the U.S. Geological Survey (USGS) National Elevation Dataset (NED) (http://ned.usgs.gov/) at 1/9-arc-second resolution; USGS Experimental Advanced Airborne Research Lidar (EAARL) data (2 meters) (http://pubs.usgs.gov/ds/400/); and topographic lidar data (2 meters) and Compact Hydrographic Airborne Rapid Total Survey (CHARTS) lidar data (2 meters) from the U.S. Army Corps of Engineers (USACE) (http://www.csc.noaa.gov/digitalcoast/data/coastallidar/). Bathymetry was derived from digital soundings obtained from the National Oceanic and Atmospheric Administration’s (NOAA) National Geophysical Data Center (NGDC) (http://www.ngdc.noaa.gov/mgg/geodas/geodas.html) and from water-penetrating lidar sources, such as EAARL and CHARTS. Mobile Bay is ecologically important as it is the fourth largest estuary in the United States. The Mobile and Tensaw Rivers drain into the bay at the northern end with the bay emptying into the Gulf of Mexico at the southern end. Dauphin Island (a barrier island) and the Fort Morgan Peninsula form the mouth of Mobile Bay. Mobile Bay is 31 miles (50 kilometers) long by a maximum width of 24 miles (39 kilometers) with a total area of 413 square miles (1,070 square kilometers). The vertical datum of the Mobile Bay topobathymetric model is the North American Vertical Datum of 1988 (NAVD 88). All the topographic datasets were originally referenced to NAVD 88 and no transformations were made to these input data. The NGDC hydrographic, multibeam, and trackline surveys were transformed from mean low water (MLW) or mean lower low water (MLLW) to NAVD 88 using VDatum (http://vdatum.noaa.gov). VDatum is a tool developed by the National Geodetic Survey (NGS) that performs transformations among tidal, ellipsoid-based, geoid-based, and orthometric datums using calibrated hydrodynamic models. The vertical accuracy of the input topographic data varied depending on the input source. Because the input elevation data were derived primarily from lidar, the vertical accuracy ranges from 6 to 20 centimeters in root mean square error (RMSE). he horizontal datum of the Mobile Bay topobathymetric model is the North American Datum of 1983 (NAD 83), geographic coordinates. All the topographic and bathymetric datasets were originally referenced to NAD 83, and no transformations were made to the input data. The bathymetric surveys were downloaded referenced to NAD 83 geographic, and therefore no horizontal transformations were required. The topbathymetric model of Mobile Bay and detailed metadata can be obtained from the USGS Web sites: http://nationalmap.gov/.
Publications - RI 97-15E | Alaska Division of Geological & Geophysical
Tidal Datum Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to Geologic Hazards in Metadata - Read me Keywords Avalanche; Coastal and River; Coastal and River Hazards; Derivative; Earthquake
Publications - PDF 98-37D | Alaska Division of Geological & Geophysical
Tidal Datum Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to Geologic Hazards in - Read me Keywords Coastal and River; Coastal and River Hazards; Construction Materials; Decorative Stone
Publications - RDF 2015-2 | Alaska Division of Geological & Geophysical
Tidal Datum Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to Geologic Hazards in -bay Shapefile 24.5 M Metadata - Read me Keywords Bathymetry; Bering Sea; Chukchi Sea; Coastal; Gambell
Presentations - Smith, J.R. and others, 2013 | Alaska Division of
Engineering Geology Alaska Tidal Datum Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to (1.4 M) Keywords Coastal; Coastal and River; Engineering Geology Posters and Presentations; Seward
33 CFR 80.01 - General basis and purpose of demarcation lines.
Code of Federal Regulations, 2010 CFR
2010-07-01
... American Datum of 1983 (NAD 83), unless such geographic coordinates are expressly labeled NAD 83. Geographic coordinates without the NAD 83 reference may be plotted on maps or charts referenced to NAD 83...
33 CFR 166.500 - Areas along the Atlantic Coast.
Code of Federal Regulations, 2010 CFR
2010-07-01
... Fairway. The area enclosed by rhumb lines, [North American Datum of 1927 (NAD-27)] joining points at...″ W (ii) Nantucket to Ambrose Safety Fairway. The area enclosed by rhumb lines, NAD-27, joining point...
Federal Register 2010, 2011, 2012, 2013, 2014
2011-01-18
...: Availability of Revised North American Datum of 1983 (NAD 83) Outer Continental Shelf Official Protraction... that effective with this publication, the following NAD 83-based Outer Continental Shelf (OCS) Official...
The Current Status of Mapping in the World - Spotlight on Australia
NASA Astrophysics Data System (ADS)
Trinder, J.
2014-04-01
Prior to 1950, there was very limited mapping in Australia covering only strategic areas. After World War II, the Federal Government funded the small scale mapping of the whole country. This involved the development of the Australian National Spheroid in 1966, the Australian Geodetic Datum in 1966 and 1984 (AGD66 and AGD84) which were replaced by the Australian Geocentric Datum in 1994 (GDA94). The mapping of the country was completed in 1987 with 100 % of the country mapped at 1:100,000 and 1:250,000 although about half of the 1:100,000 are unpublished products. The Federal Government through Geoscience Australia continues to provide digital data, such as the GEODATA 250K (now series 3). Mapping at larger scales is undertaken by the states and territories, including cadastral mapping. This paper will demonstrate the extent of mapping in Australia as part of the current UN global survey of mapping.
NASA Technical Reports Server (NTRS)
Reece, J. S.; Marsh, J.
1973-01-01
Simultaneous observations of the GEOS-I and II flashing lamps by the NASA MOTS and SPEOPT cameras on the North American Datum (NAD) were analyzed using geometrical techniques to provide an adjustment of the station coordinates. Two separate adjustments were obtained. An optical data only solution was computed in which the solution scale was provided by the Rosman-Mojave distance obtained from a dynamic station solution. In a second adjustment, scaling was provided by processing simultaneous laser ranging data from Greenbelt and Wallops Island in a combined optical-laser solution. Comparisons of these results with previous GSFC dynamical solutions indicate an rms agreement on the order of 4 meters or better in each coordinate. Comparison with a detailed gravimetric geoid of North America yields agreement of 3 meters or better for mainland U.S. stations and 7 and 3 meters, respectively, for Bermuda and Puerto Rico.
L(2) stability for weak solutions of the Navier-Stokes equations in R(3)
NASA Astrophysics Data System (ADS)
Secchi, P.
1985-11-01
We consider the motion of a viscous fluid filling the whole space R3, governed by the classical Navier-Stokes equations (1). Existence of global (in time) regular solutions for that system of non-linear partial differential equations is still an open problem. Up to now, the only available global existence theorem (other than for sufficiently small initial data) is that of weak (turbulent) solutions. From both the mathematical and the physical point of view, an interesting property is the stability of such weak solutions. We assume that v(t,x) is a solution, with initial datum vO(x). We suppose that the initial datum is perturbed and consider one weak solution u corresponding to the new initial velocity. Then we prove that, due to viscosity, the perturbed weak solution u approaches in a suitable norm the unperturbed one, as time goes to + infinity, without smallness assumptions on the initial perturbation.
NASA Astrophysics Data System (ADS)
Zimmermann, Mark; Ruggerone, Gregory T.; Freymueller, Jeffrey T.; Kinsman, Nicole; Ward, David H.; Hogrefe, Kyle R.
2018-03-01
We quantified the shallowing of the seafloor in five of six bays examined in the Chignik region of the Alaska Peninsula, confirming National Ocean Service observations that 1990s hydrographic surveys were shallower than previous surveys from the 1920s. Castle Bay, Chignik Lagoon, Hook Bay, Kujulik Bay and Mud Bay lost volume as calculated from Mean Lower Low Water (Chart Datum) to the deepest depths and four of these sites lost volume from Mean High Water to the deepest depths. Calculations relative to each datum were made because tidal datum records exhibited an increase in tidal range in this region from the 1920s to the 1990s. Our analysis showed that Mud Bay is quickly disappearing while Chignik Lagoon is being reduced to narrow channels. Anchorage Bay was the only site that increased in depth over time, perhaps due to erosion. Volcanoes dominate the landscape of the Chignik area. They have blanketed the region in deep ash deposits before the time frame of this study, and some have had smaller ash-producing eruptions during the time frame of this study. Remobilization of land-deposited ash and redeposition in marine areas - in some locations facilitated by extensive eelgrass (Zostera marina) beds (covering 54% of Chignik Lagoon and 68% of Mud Bay in 2010) - is the most likely cause of shallowing in the marine environment. Loss of shallow water marine habitat may alter future abundance and distribution of several fish, invertebrate and avian species.
Proposed U.S. Geological Survey standard for digital orthophotos
Hooper, David; Caruso, Vincent
1991-01-01
The U.S. Geological Survey has added the new category of digital orthophotos to the National Digital Cartographic Data Base. This differentially rectified digital image product enables users to take advantage of the properties of current photoimagery as a source of geographic information. The product and accompanying standard were implemented in spring 1991. The digital orthophotos will be quadrangle based and cast on the Universal Transverse Mercator projection and will extend beyond the 3.75-minute or 7.5-minute quadrangle area at least 300 meters to form a rectangle. The overedge may be used for mosaicking with adjacent digital orthophotos. To provide maximum information content and utility to the user, metadata (header) records exist at the beginning of the digital orthophoto file. Header information includes the photographic source type, date, instrumentation used to create the digital orthophoto, and information relating to the DEM that was used in the rectification process. Additional header information is included on transformation constants from the 1927 and 1983 North American Datums to the orthophoto internal file coordinates to enable the user to register overlays on either datum. The quadrangle corners in both datums are also imprinted on the image. Flexibility has been built into the digital orthophoto format for future enhancements, such as the provision to include the corresponding digital elevation model elevations used to rectify the orthophoto. The digital orthophoto conforms to National Map Accuracy Standards and provides valuable mapping data that can be used as a tool for timely revision of standard map products, for land use and land cover studies, and as a digital layer in a geographic information system.
Georeferencing the historical cadastral map sheets of Hungary
NASA Astrophysics Data System (ADS)
Timár, Gábor; Biszak, Sándor
2010-05-01
In the historical Hungary, as a part of the Habsburg Empire, the first preserved and systematic cadastral survey was carried out between 1856 and 1859. Interestingly enough, this cadastral mapping, which was called in Hungary as 'Provisional' was surveyed simultaneously with the Stable Cadastre in the Austrian regions of the Empire. By the commission of the State Archives of Hungary, the Hungarian company Arcanum Ltd. scanned over 46,000 cadastral sheets of the Provisional Cadastre, mostly covering the present-day Hungary but also some copies covering parts of the present-day Croatia, Slovakia and Austria. The base ellipsoid was the Zach-Oriani hybrid (a=6376130 m; f=1/310). The fundamental point of the geodetic datum was the eastern pillar of the later destroyed astronomical observatory on the Gellérthegy, Budapest and the abridging Molodensky parameters from this datum to WGS84 are: dX=+1763 m; dY=+282 m; dZ=+568 m. The Cassini projection can be used for GIS integration with a projection center at the Gellérthegy with longitude=19d 3m 5.55s east of Greenwich; latitude=49d 29m 15.97s. The sheets were rectified by the calculated coordinates at the corner points. With the above given projection and datum parameters, the cadastral mosaic, based on the individual sheets and the digitized borders of the administrative units, is presented in any modern coordinate systems in GIS. Using this feature, the product is published as a DVD series by old counties as well as the distribution in the Internet.
,
2002-01-01
The National Elevation Dataset (NED) is a new raster product assembled by the U.S. Geological Survey. NED is designed to provide National elevation data in a seamless form with a consistent datum, elevation unit, and projection. Data corrections were made in the NED assembly process to minimize artifacts, perform edge matching, and fill sliver areas of missing data. NED has a resolution of one arc-second (approximately 30 meters) for the conterminous United States, Hawaii, Puerto Rico and the island territories and a resolution of two arc-seconds for Alaska. NED data sources have a variety of elevation units, horizontal datums, and map projections. In the NED assembly process the elevation values are converted to decimal meters as a consistent unit of measure, NAD83 is consistently used as horizontal datum, and all the data are recast in a geographic projection. Older DEM's produced by methods that are now obsolete have been filtered during the NED assembly process to minimize artifacts that are commonly found in data produced by these methods. Artifact removal greatly improves the quality of the slope, shaded-relief, and synthetic drainage information that can be derived from the elevation data. Figure 2 illustrates the results of this artifact removal filtering. NED processing also includes steps to adjust values where adjacent DEM's do not match well, and to fill sliver areas of missing data between DEM's. These processing steps ensure that NED has no void areas and artificial discontinuities have been minimized. The artifact removal filtering process does not eliminate all of the artifacts. In areas where the only available DEM is produced by older methods, then "striping" may still occur.
Estimation of shoreline position and change using airborne topographic lidar data
Stockdon, H.F.; Sallenger, A.H.; List, J.H.; Holman, R.A.
2002-01-01
A method has been developed for estimating shoreline position from airborne scanning laser data. This technique allows rapid estimation of objective, GPS-based shoreline positions over hundreds of kilometers of coast, essential for the assessment of large-scale coastal behavior. Shoreline position, defined as the cross-shore position of a vertical shoreline datum, is found by fitting a function to cross-shore profiles of laser altimetry data located in a vertical range around the datum and then evaluating the function at the specified datum. Error bars on horizontal position are directly calculated as the 95% confidence interval on the mean value based on the Student's t distribution of the errors of the regression. The technique was tested using lidar data collected with NASA's Airborne Topographic Mapper (ATM) in September 1997 on the Outer Banks of North Carolina. Estimated lidar-based shoreline position was compared to shoreline position as measured by a ground-based GPS vehicle survey system. The two methods agreed closely with a root mean square difference of 2.9 m. The mean 95% confidence interval for shoreline position was ?? 1.4 m. The technique has been applied to a study of shoreline change on Assateague Island, Maryland/Virginia, where three ATM data sets were used to assess the statistics of large-scale shoreline change caused by a major 'northeaster' winter storm. The accuracy of both the lidar system and the technique described provides measures of shoreline position and change that are ideal for studying storm-scale variability over large spatial scales.
Publications - RDF 2014-20 | Alaska Division of Geological & Geophysical
Tidal Datum Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to Geologic Hazards in Download golovin-lidar-las-index Shapefile 71.0 K Metadata - Read me Keywords Coastal; Coastal and River
Publications - MP 133 v. 2 | Alaska Division of Geological & Geophysical
Tidal Datum Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to Geologic Hazards in Maps; Alaska, State of; Aleutian Arc; Aleutian Islands; Coastal and River; Coastal and River Hazards
Publications - PIR 2001-3D | Alaska Division of Geological & Geophysical
Tidal Datum Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to Geologic Hazards in Shapefile 1.4 M Metadata - Read me Keywords Coastal and River; Coastal and River Hazards; Construction
Publications - RI 2000-1D | Alaska Division of Geological & Geophysical
Tidal Datum Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to Geologic Hazards in - Read me Keywords Arctic National Wildlife Refuge; Aufeis; Brooks Range; Coastal and River; Coastal and
Federal Register 2010, 2011, 2012, 2013, 2014
2011-09-02
.... ACTION: Availability of revised North American Datum of 1927 (NAD 27) Outer Continental Shelf Official...: Notice is hereby given that effective with this publication, the following NAD 27-based Outer Continental...
33 CFR 100.719 - Annual Suncoast Offshore Challenge; Gulf of Mexico, Sarasota, FL.
Code of Federal Regulations, 2010 CFR
2010-07-01
... datum: NAD 1983. (b) Special local regulations. (1) No anchoring will be permitted seaward of the...: NAD 1983. (4) Big Sarasota Pass will be closed to all inbound and outbound vessel traffic, other than...
NASA Astrophysics Data System (ADS)
Grombein, Thomas; Seitz, Kurt; Heck, Bernhard
2017-03-01
National height reference systems have conventionally been linked to the local mean sea level, observed at individual tide gauges. Due to variations in the sea surface topography, the reference levels of these systems are inconsistent, causing height datum offsets of up to ±1-2 m. For the unification of height systems, a satellite-based method is presented that utilizes global geopotential models (GGMs) derived from ESA's satellite mission Gravity field and steady-state Ocean Circulation Explorer (GOCE). In this context, height datum offsets are estimated within a least squares adjustment by comparing the GGM information with measured GNSS/leveling data. While the GNSS/leveling data comprises the full spectral information, GOCE GGMs are restricted to long wavelengths according to the maximum degree of their spherical harmonic representation. To provide accurate height datum offsets, it is indispensable to account for the remaining signal above this maximum degree, known as the omission error of the GGM. Therefore, a combination of the GOCE information with the high-resolution Earth Gravitational Model 2008 (EGM2008) is performed. The main contribution of this paper is to analyze the benefit, when high-frequency topography-implied gravity signals are additionally used to reduce the remaining omission error of EGM2008. In terms of a spectral extension, a new method is proposed that does not rely on an assumed spectral consistency of topographic heights and implied gravity as is the case for the residual terrain modeling (RTM) technique. In the first step of this new approach, gravity forward modeling based on tesseroid mass bodies is performed according to the Rock-Water-Ice (RWI) approach. In a second step, the resulting full spectral RWI-based topographic potential values are reduced by the effect of the topographic gravity field model RWI_TOPO_2015, thus, removing the long to medium wavelengths. By using the latest GOCE GGMs, the impact of topography-implied gravity signals on the estimation of height datum offsets is analyzed in detail for representative GNSS/leveling data sets in Germany, Austria, and Brazil. Besides considerable changes in the estimated offset of up to 3 cm, the conducted analyses show that significant improvements of 30-40% can be achieved in terms of a reduced standard deviation and range of the least squares adjusted residuals.
Schrader, T.P.
2007-01-01
The Cockfield Formation of Claiborne Group and the Wilcox Group contain aquifers that provide sources of ground water in southern and northeastern Arkansas. In 2000, about 9.9 million gallons per day was withdrawn from the Cockfield Formation of Claiborne Group and about 22.2 million gallons per day was withdrawn from the Wilcox Group. Major withdrawals from the aquifers were for industrial and public water supplies. A study was conducted by the U.S. Geological Survey in cooperation with the Arkansas Natural Resources Commission and the Arkansas Geological Survey to determine the water level associated with the aquifers in the Cockfield Formation of Claiborne Group and the Wilcox Group in southern and northeastern Arkansas. During February and March 2006, 56 water-level measurements were made in wells completed in the Cockfield aquifer and 59 water-level measurements were made in wells completed in the Wilcox aquifer, 16 in southwestern and 43 in northeastern Arkansas. This report presents the results as potentiometric-surface maps and as long-term water-level hydrographs. The regional direction of ground-water flow in the Cockfield Formation of Claiborne Group generally is towards the east and southeast, away from the outcrop, except in areas of intense ground-water withdrawals, such as western Drew County, southeastern Lincoln County, southwestern Calhoun County, and near Crossett in Ashley County. There are three cones of depression indicated by relatively low water-level altitudes in southeastern Lincoln County, southwestern Calhoun County, and near Crossett in Ashley County. The lowest water-level altitude measured was 44 feet above the National Geodetic Vertical Datum of 1929 in Lincoln County; the highest water-level altitude measured was 346 feet above the National Geodetic Vertical Datum of 1929 in Columbia County at the outcrop area. Hydrographs from 40 wells with historical water levels from 1986 to 2006 were evaluated using linear regression to calculate the annual rise or decline. Calhoun and Cleveland Counties have mean annual rises from 0.01 to 0.07 feet per year. Arkansas, Ashley, Bradley, Chicot, Columbia, Drew, Lincoln, and Union Counties have mean annual declines from 0.4 to 0.55 feet per year. Desha County has a mean annual decline of about 1.35 feet per year. The direction of ground-water flow in the southwestern study area of the Wilcox Group generally is south and east. The lowest water-level altitude measured in southwestern Arkansas was 147 feet above the National Geodetic Vertical Datum of 1929 near the Ouachita River in Clark County; the highest water-level altitude measured was 397 feet above the National Geodetic Vertical Datum of 1929 in the outcrop area of Hempstead County. The direction of ground-water flow in the northeastern study area of the Wilcox Group generally is south and east. The lowest water-level altitude measured in northeastern Arkansas was 120 feet above the National Geodetic Vertical Datum of 1929 near West Memphis in Crittenden County; the highest water-level altitude measured was 368 feet above the National Geodetic Vertical Datum of 1929 on Crowleys Ridge in Clay County. Hydrographs from 28 wells with historical water levels from 1986 to 2006 were evaluated using linear regression to calculate the annual rise or decline. All 28 wells showed an annual decline from 1986 to 2006. Craighead, Greene, Mississippi, and Poinsett Counties have mean annual declines from 0.27 to 1.00 feet per year. Crittenden, Lee, and St. Francis Counties have mean annual declines from 1.39 to 1.64 feet per year.
33 CFR 165.158 - Safety Zone: Patchogue Grand Prix, Patchogue Bay, Patchogue, NY.
Code of Federal Regulations, 2011 CFR
2011-07-01
... American Datum 1983. (b) Definitions. The following definitions apply to this section: Designated on-scene... zone on VHF-16 or via phone at (203) 468-4401. (d) Enforcement period. This rule will be enforced from...
33 CFR 165.158 - Safety Zone: Patchogue Grand Prix, Patchogue Bay, Patchogue, NY.
Code of Federal Regulations, 2010 CFR
2010-07-01
... American Datum 1983. (b) Definitions. The following definitions apply to this section: Designated on-scene... zone on VHF-16 or via phone at (203) 468-4401. (d) Enforcement period. This rule will be enforced from...
Using functional data analysis to analyze ecological series data
Background/Question/MethodsA frequent goal in ecology is to understand the relationships among biological organisms and their environment. Most field data are collected as scalar measurements, such that observations are recorded as a collection of datums. The observations are t...
ERIC Educational Resources Information Center
White, Owen Roberts
1985-01-01
The author reviews systems providing objective guidelines to facilitate ongoing, daily instructional decisions, focusing on those which utilize the sensitive datum and uniform charting procedures of precision teaching. Potential users are warned that the special education teacher must remain a critical and vigilant analyst of the learning process.…
NASA Astrophysics Data System (ADS)
Childers, V. A.; Diehl, T. M.; Roman, D. R.; Smith, D. A.
2009-05-01
The mission of NOAA's National Geodetic Survey (NGS) is to "define, maintain and provide access to the National Spatial Reference System" (NSRS). NAVD 88 (North American Vertical Datum of 1988) provides the vertical reference for the NSRS. However, comparisons of NAVD 88 with the Gravity Recovery and Climate Experiment (GRACE) satellite gravity data have demonstrated significant problems with the vertical reference, with an average difference between the two of 0.98 m and std dev of 0.37m. As repairing NAVD 88 through a massive leveling effort is impractical, our approach will be to establish a gravimetric geoid as the vertical reference. The linchpin in NGS's effort is the Gravity for the Redefinition of the American Vertical Datum (GRAV- D) program, which will ultimately incorporate satellite, airborne and terrestrial gravity data to build the 1-2 cm geoid that the U.S. surveying public is demanding. The program involves both an airborne component, for measuring a "baseline" gravity field, and a relative and absolute terrestrial program, for monitoring time variations of the gravity field. The GRAV-D aerogravity program commenced with a survey based from Anchorage, AK in the summer of 2008, additionally in support of NOAA's Hydropalooza program. Starting in October, the GRAV-D team has undertaken a concerted effort to survey Puerto Rico/US Virgin Islands, and then the Gulf Coast for the US Army Corps of Engineers. Gulf operations were from New Orleans, Lake Charles, and Austin, TX. This survey provides a continuous airborne field measurement at 10 km line spacing from the GA/AL state line to the Mexican border. We will present the results of these data collection efforts and outline the plans for the GRAV- D program during the remainder of 2009.
76 FR 62329 - Proposed Flood Elevation Determinations
Federal Register 2010, 2011, 2012, 2013, 2014
2011-10-07
...] Communities affected elevation * * Elevation in meters (MSL) Effective Modified Anne Arundel County, Maryland... + 8 + 10 Unincorporated Areas of Crain Highway. Anne Arundel County. Approximately 400 feet None + 105... American Vertical Datum. [caret] Mean Sea Level, rounded to the nearest 0.1 meter. * * BFEs to be changed...
76 FR 9714 - Proposed Flood Elevation Determinations
Federal Register 2010, 2011, 2012, 2013, 2014
2011-02-22
..., FEMA published in the Federal Register a proposed rule that included an erroneous Base Flood Elevation... as 355 feet, referenced to the North American Vertical Datum of 1988. DATES: Comments pertaining to... (FEMA) publishes proposed determinations of Base (1% annual-chance) Flood Elevations (BFEs) and modified...
33 CFR 165.159 - Safety Zone: New York Air Show at Jones Beach State Park, Wantagh, NY.
Code of Federal Regulations, 2011 CFR
2011-07-01
... Datum 1983. (b) Definitions. The following definition applies to this section: Designated On-scene... by contacting them on VHF-16 or by a request to the Captain of the Port Long Island Sound via phone...
76 FR 22064 - Safety Zone; Michigan Bankers Association Fireworks, Lake Huron, Mackinac Island, MI
Federal Register 2010, 2011, 2012, 2013, 2014
2011-04-20
...-foot radius from the fireworks launch site, approximately 460 yards south of Biddle Point, at position... 460 yards south of Biddle Point, at position 45[deg]50'32.82'' N, 084[deg]37'03.18'' W: [DATUM: NAD 83...
Code of Federal Regulations, 2014 CFR
2014-07-01
..., or local agencies. Table 1 to § 165.1123 [All coordinates referenced use datum NAD 83] 1. San Diego.... Big Bay Boom Fourth of July Fireworks Sponsor Port of San Diego. Event Description Fireworks Display...
33 CFR 100.905 - Door County Triathlon; Door County, WI.
Code of Federal Regulations, 2010 CFR
2010-07-01
... in position 45°00′46″ N, 087°20′30″ W. (DATUM: NAD 83). (b) Special Local Regulations. The...; Door County, WI. (a) Regulated Area. A regulated area is established to include all waters of Green Bay...
33 CFR 147.831 - Holstein Truss Spar safety zone.
Code of Federal Regulations, 2010 CFR
2010-07-01
...) Description. Holstein, Green Canyon 645 (GC 645), located at position 27°19′17″ N, 90°32′08″ W. The area... coordinates are based upon North American Datum 1983. (b) Regulation. No vessel may enter or remain in this...
Moore, Christopher R.; West, Allen; LeCompte, Malcolm A.; Brooks, Mark J.; Daniel, I. Randolph; Goodyear, Albert C.; Ferguson, Terry A.; Ivester, Andrew H.; Feathers, James K.; Kennett, James P.; Tankersley, Kenneth B.; Adedeji, A. Victor; Bunch, Ted E.
2017-01-01
Previously, a large platinum (Pt) anomaly was reported in the Greenland ice sheet at the Younger Dryas boundary (YDB) (12,800 Cal B.P.). In order to evaluate its geographic extent, fire-assay and inductively coupled plasma mass spectrometry (FA and ICP-MS) elemental analyses were performed on 11 widely separated archaeological bulk sedimentary sequences. We document discovery of a distinct Pt anomaly spread widely across North America and dating to the Younger Dryas (YD) onset. The apparent synchroneity of this widespread YDB Pt anomaly is consistent with Greenland Ice Sheet Project 2 (GISP2) data that indicated atmospheric input of platinum-rich dust. We expect the Pt anomaly to serve as a widely-distributed time marker horizon (datum) for identification and correlation of the onset of the YD climatic episode at 12,800 Cal B.P. This Pt datum will facilitate the dating and correlating of archaeological, paleontological, and paleoenvironmental data between sequences, especially those with limited age control. PMID:28276513
NASA Astrophysics Data System (ADS)
Moore, Christopher R.; West, Allen; Lecompte, Malcolm A.; Brooks, Mark J.; Daniel, I. Randolph; Goodyear, Albert C.; Ferguson, Terry A.; Ivester, Andrew H.; Feathers, James K.; Kennett, James P.; Tankersley, Kenneth B.; Adedeji, A. Victor; Bunch, Ted E.
2017-03-01
Previously, a large platinum (Pt) anomaly was reported in the Greenland ice sheet at the Younger Dryas boundary (YDB) (12,800 Cal B.P.). In order to evaluate its geographic extent, fire-assay and inductively coupled plasma mass spectrometry (FA and ICP-MS) elemental analyses were performed on 11 widely separated archaeological bulk sedimentary sequences. We document discovery of a distinct Pt anomaly spread widely across North America and dating to the Younger Dryas (YD) onset. The apparent synchroneity of this widespread YDB Pt anomaly is consistent with Greenland Ice Sheet Project 2 (GISP2) data that indicated atmospheric input of platinum-rich dust. We expect the Pt anomaly to serve as a widely-distributed time marker horizon (datum) for identification and correlation of the onset of the YD climatic episode at 12,800 Cal B.P. This Pt datum will facilitate the dating and correlating of archaeological, paleontological, and paleoenvironmental data between sequences, especially those with limited age control.
Himmelstoss, Emily A.; Kratzmann, Meredith G.; Thieler, E. Robert
2017-07-18
Long-term rates of shoreline change for the Gulf of Mexico and Southeast Atlantic regions of the United States have been updated as part of the U.S. Geological Survey’s National Assessment of Shoreline Change project. Additional shoreline position data were used to compute rates where the previous rate-of-change assessment only included four shoreline positions at a given location. The long-term shoreline change rates also incorporate the proxy-datum bias correction to account for the unidirectional onshore bias of the proxy-based high water line shorelines relative to the datum-based mean high water shorelines. The calculation of uncertainty associated with the long-term average rates has also been updated to match refined methods used in other study regions of the National Assessment project. The average rates reported here have a reduced amount of uncertainty relative to those presented in the previous assessments for these two regions.
NASA Astrophysics Data System (ADS)
Soare, R. J.; Conway, S. J.; Godin, E.; Osinski, G.; Hawkswell, J.; Bina, A.
2017-12-01
Expansive assemblages of low/high centred (ice-wedge) polygons and (polygonised) flat-floored thermokarst-basins (alases) are ubiquitous on Earth where the permafrost is continuous, metres to decametres-thick and ice rich, i.e. the Tuktoyaktuk Coastlands of northern Canada and the Yamal Peninsula of eastern Russia. These assemblages are geological bellwethers of transient and on occasion, long-term rises of sub-aerial and thaw-generating mean temperatures, for two principal reasons. First, high-centred (ice-wedge) polygons evolve from low-centred (ice-wedge) polygons when ice wedges that have aggraded and uplift overlying sediments above the elevation datum at the polygon centres, degrade, by thaw, and induce the loss of elevation below that datum. Second, thermokarst terrain comprises sediments whose pore volume is exceeded by the presence of water ice. A thermokarst basin (an alas) forms if and only when this ice undergoes thermal destabilisation and where thaw-generated meltwater is lost by evaporation or drainage. Spatially-associated and morphologically-similar assemblages of polygons and basins are commonplace throughout the mid-latitudes of eastern Utopia Planitia (UP), Mars. Under current conditions of extreme aridity, low atmospheric-pressure and frigid mean-temperatures, the widespread formation of ice-rich terrain by freeze-thaw cycling, let alone of near-surface ice-wedges and/or thermokarst basins, seems implausible. Against this environmental backdrop, sublimation seemingly stands alone in being able to revise ice-rich landscapes. However, multiple strands of data point to the possible periglacial-assemblages (PPAs) being youthful but not current in their formation. First, the sub-regional and dark-toned terrain incised by the PPAs is cratered more densely than would be expected. Second, the PPAs reside at a lower relative and absolute elevation than a light-toned and region-wide latitude-dependent mantle that is generally thought to be very recent in origin. These strands and others point to a earlier period in the geological history of UP, perhaps in conjunction with shifts in obliquity and eccentricity, when liquid-water would have been stable enough to sustain freeze-thaw cycling, wet periglacial processes and, derivatively, the development of the PPAs.
76 FR 56724 - Proposed Flood Elevation Determinations
Federal Register 2010, 2011, 2012, 2013, 2014
2011-09-14
.../town/county Source of flooding Location ** ground [caret] Elevation in meters (MSL) Existing Modified... Datum. Depth in feet above ground. [caret] Mean Sea Level, rounded to the nearest 0.1 meter. ** BFEs to... upstream of Cradduck Road None +876 Oklahoma Unincorporated Areas of Town Branch Approximately 400 feet...
47 CFR 101.1415 - Partitioning and disaggregation.
Code of Federal Regulations, 2012 CFR
2012-10-01
... American Datum (NAD83). (d) Unjust enrichment. 12 GHz licensees that received a bidding credit and... SERVICES FIXED MICROWAVE SERVICES Multichannel Video Distribution and Data Service Rules for the 12.2-12.7 GHz Band § 101.1415 Partitioning and disaggregation. (a) MVDDS licensees are permitted to partition...
47 CFR 101.1415 - Partitioning and disaggregation.
Code of Federal Regulations, 2013 CFR
2013-10-01
... American Datum (NAD83). (d) Unjust enrichment. 12 GHz licensees that received a bidding credit and... SERVICES FIXED MICROWAVE SERVICES Multichannel Video Distribution and Data Service Rules for the 12.2-12.7 GHz Band § 101.1415 Partitioning and disaggregation. (a) MVDDS licensees are permitted to partition...
47 CFR 101.1415 - Partitioning and disaggregation.
Code of Federal Regulations, 2014 CFR
2014-10-01
... American Datum (NAD83). (d) Unjust enrichment. 12 GHz licensees that received a bidding credit and... SERVICES FIXED MICROWAVE SERVICES Multichannel Video Distribution and Data Service Rules for the 12.2-12.7 GHz Band § 101.1415 Partitioning and disaggregation. (a) MVDDS licensees are permitted to partition...
47 CFR 101.1415 - Partitioning and disaggregation.
Code of Federal Regulations, 2011 CFR
2011-10-01
... American Datum (NAD83). (d) Unjust enrichment. 12 GHz licensees that received a bidding credit and... SERVICES FIXED MICROWAVE SERVICES Multichannel Video Distribution and Data Service Rules for the 12.2-12.7 GHz Band § 101.1415 Partitioning and disaggregation. (a) MVDDS licensees are permitted to partition...
Publications - GMC 233 | Alaska Division of Geological & Geophysical
Tidal Datum Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to Geologic Hazards in geologic field program in Lower Cook Inlet, Alaska Authors: Roberts, Chuck, Coastal Science Laboratories publication sales page for more information. Bibliographic Reference Roberts, Chuck, Coastal Science
33 CFR 100.906 - Grand Haven Coast Guard Festival Waterski Show, Grand Haven, MI.
Code of Federal Regulations, 2011 CFR
2011-07-01
..., DEPARTMENT OF HOMELAND SECURITY REGATTAS AND MARINE PARADES SAFETY OF LIFE ON NAVIGABLE WATERS § 100.906...″ N, 086°14′17″ W; then back to the point of origin. (DATUM: NAD 83). (b) Special Local Regulations...
14 CFR 171.263 - Localizer automatic monitor system.
Code of Federal Regulations, 2012 CFR
2012-01-01
... (CONTINUED) NAVIGATIONAL FACILITIES NON-FEDERAL NAVIGATION FACILITIES Interim Standard Microwave Landing... provide an automatic monitor system that transmits a warning to designated local and remote control points... centerline equivalent to more than 0.015 DDM at the ISMLS reference datum. (2) For localizers in which the...
14 CFR 171.263 - Localizer automatic monitor system.
Code of Federal Regulations, 2014 CFR
2014-01-01
... (CONTINUED) NAVIGATIONAL FACILITIES NON-FEDERAL NAVIGATION FACILITIES Interim Standard Microwave Landing... provide an automatic monitor system that transmits a warning to designated local and remote control points... centerline equivalent to more than 0.015 DDM at the ISMLS reference datum. (2) For localizers in which the...
14 CFR 171.263 - Localizer automatic monitor system.
Code of Federal Regulations, 2010 CFR
2010-01-01
... (CONTINUED) NAVIGATIONAL FACILITIES NON-FEDERAL NAVIGATION FACILITIES Interim Standard Microwave Landing... provide an automatic monitor system that transmits a warning to designated local and remote control points... centerline equivalent to more than 0.015 DDM at the ISMLS reference datum. (2) For localizers in which the...
14 CFR 171.263 - Localizer automatic monitor system.
Code of Federal Regulations, 2011 CFR
2011-01-01
... (CONTINUED) NAVIGATIONAL FACILITIES NON-FEDERAL NAVIGATION FACILITIES Interim Standard Microwave Landing... provide an automatic monitor system that transmits a warning to designated local and remote control points... centerline equivalent to more than 0.015 DDM at the ISMLS reference datum. (2) For localizers in which the...
14 CFR 171.263 - Localizer automatic monitor system.
Code of Federal Regulations, 2013 CFR
2013-01-01
... (CONTINUED) NAVIGATIONAL FACILITIES NON-FEDERAL NAVIGATION FACILITIES Interim Standard Microwave Landing... provide an automatic monitor system that transmits a warning to designated local and remote control points... centerline equivalent to more than 0.015 DDM at the ISMLS reference datum. (2) For localizers in which the...
77 FR 45262 - Final Flood Elevation Determinations
Federal Register 2010, 2011, 2012, 2013, 2014
2012-07-31
... upstream of the upstream Grundy County, Village side of the Dresden of Channahon. Island Lock and Dam.... Just downstream of the +507 Dresden Island Lock and Dam. * National Geodetic Vertical Datum. + North... available for inspection at the North Moreland Township Municipal Building, 15 Municipal Lane, Dallas, PA...
Multipackaging of Data At Source
ERIC Educational Resources Information Center
Bernier, Charles L.
1972-01-01
Techniques, media, and systems for making organized data available exist, but have not been used extensively enough. Reasons for failure to use these are explored and recommendations made for extraction by authors at time of writing, centralized organization, and publication through existing organization. Datum signatures are described. (50…
Effect of the Earth's inner structure on the gravity in definitions of height systems
NASA Astrophysics Data System (ADS)
Tenzer, Robert; Foroughi, Ismael; Pitoňák, Martin; Šprlák, Michal
2017-04-01
In context of the vertical datum unification, the geoid-to-quasi-geoid separation has been of significant interest in recent years, because most of existing local vertical datums are realized in the system of either normal or orthometric heights. Nevertheless, the normal-orthometric heights are still used in many other countries where the normal gravity values along leveling lines were adopted instead of the observed gravity. Whereas the conversion between the orthometric and normal heights is defined by means of the mean gravity disturbances (i.e. differences between the mean values of the actual and normal gravity) along the plumbline within the topography, differences between the normal and normal-orthometric heights can be described by means of the surface gravity disturbances. Since the normal gravity field does not reflect the topographic masses and actual mass density distribution inside the Earth, the definition of gravity represents a principal aspect for a realization of particular vertical datum. To address this issue in this study, we investigate effects of the Earth's inner density structure on the surface and mean gravity disturbances, and discuss their impact on the vertical datum realization. These two gravity field quantities are computed globally with a spectral resolution complete to a spherical harmonic degree 2160 using the global gravity, terrain, ice-thickness, inland bathymetry and crustal structure models. Our results reveal that both, the surface and mean gravity disturbances mostly comprise the gravitational signal of topography and masses distributed below the geoid surface. Moreover, in polar areas, a significant contribution comes from large glaciers. In contrast, the contributions of anomalous density distribution within the topography attributed to major lakes, sediments and bedrock density variations are much less pronounced. We also demonstrate that the mean gravity disturbances within the topography are significantly modified compared to the corresponding surface values mainly due to topographic elevation and terrain geometry as well as the presence of large glaciers in polar regions. Changes of the vertical gravity gradient within the topography attributed to the masses distributed below the geoid (dominated mainly by the isostatic signature and the long-wavelength gravitational signature of deep mantle density heterogeneities) are, on the other hand, relatively small. Despite differences between the normal and normal-orthometric heights could directly be assessed from the surface gravity disturbances only when taken along leveling lines with information about the spirit leveling height differences, our results indicate that differences between these two height systems can be significant.
Unification of height systems in the frame of GGOS
NASA Astrophysics Data System (ADS)
Sánchez, Laura
2015-04-01
Most of the existing vertical reference systems do not fulfil the accuracy requirements of modern Geodesy. They refer to local sea surface levels, are stationary (do not consider variations in time), realize different physical height types (orthometric, normal, normal-orthometric, etc.), and their combination in a global frame presents uncertainties at the metre level. To provide a precise geodetic infrastructure for monitoring the Earth system, the Global Geodetic Observing System (GGOS) of the International Association of Geodesy (IAG), promotes the standardization of the height systems worldwide. The main purpose is to establish a global gravity field-related vertical reference system that (1) supports a highly-precise (at cm-level) combination of physical and geometric heights worldwide, (2) allows the unification of all existing local height datums, and (3) guarantees vertical coordinates with global consistency (the same accuracy everywhere) and long-term stability (the same order of accuracy at any time). Under this umbrella, the present contribution concentrates on the definition and realization of a conventional global vertical reference system; the standardization of the geodetic data referring to the existing height systems; and the formulation of appropriate strategies for the precise transformation of the local height datums into the global vertical reference system. The proposed vertical reference system is based on two components: a geometric component consisting of ellipsoidal heights as coordinates and a level ellipsoid as the reference surface, and a physical component comprising geopotential numbers as coordinates and an equipotential surface defined by a conventional W0 value as the reference surface. The definition of the physical component is based on potential parameters in order to provide reference to any type of physical heights (normal, orthometric, etc.). The conversion of geopotential numbers into metric heights and the modelling of the reference surface (geoid or quasigeoid determination) are considered as steps of the realization. The vertical datum unification strategy is based on (1) the physical connection of height datums to determine their discrepancies, (2) joint analysis of satellite altimetry and tide gauge records to determine time variations of sea level at reference tide gauges, (3) combination of geometrical and physical heights in a well-distributed and high-precise reference frame to estimate the relationship between the individual vertical levels and the global one, and (4) analysis of GNSS time series at reference tide gauges to separate crustal movements from sea level changes. The final vertical transformation parameters are provided by the common adjustment of the observation equations derived from these methods.
2×2 systems of conservation laws with L data
NASA Astrophysics Data System (ADS)
Bianchini, Stefano; Colombo, Rinaldo M.; Monti, Francesca
Consider a hyperbolic system of conservation laws with genuinely nonlinear characteristic fields. We extend the classical Glimm-Lax (1970) result [13, Theorem 5.1] proving the existence of solutions for L initial datum, relaxing the assumptions taken therein on the geometry of the shock-rarefaction curves.
75 FR 31368 - Proposed Flood Elevation Determinations
Federal Register 2010, 2011, 2012, 2013, 2014
2010-06-03
... referenced ground [caret] Communities affected elevation Elevation in meters (MSL) Effective Modified Santa.... Depth in feet above ground. [caret] Mean Sea Level, rounded to the nearest 0.1 meter. ** BFEs to be... Vertical Datum. Depth in feet above ground. [caret] Mean Sea Level, rounded to the nearest 0.1 meter...
77 FR 21476 - Final Flood Elevation Determinations
Federal Register 2010, 2011, 2012, 2013, 2014
2012-04-10
... Communities affected elevation above ground [caret] Elevation in meters (MSL) Modified Randolph County... Vertical Datum. Depth in feet above ground. [caret] Mean Sea Level, rounded to the nearest 0.1 meter.... [caret] Mean Sea Level, rounded to the nearest 0.1 meter. ADDRESSES City of Beebe Maps are available for...
76 FR 39011 - Final Flood Elevation Determinations
Federal Register 2010, 2011, 2012, 2013, 2014
2011-07-05
... Communities affected elevation above ground [caret] Elevation in meters (MSL) Modified Rio Grande County... Unincorporated Areas of the Rio Grande, Rio Grande County. approximately 400 feet north of U.S. Route 160... Vertical Datum. Depth in feet above ground. [caret] Mean Sea Level, rounded to the nearest 0.1 meter...
77 FR 20999 - Final Flood Elevation Determinations
Federal Register 2010, 2011, 2012, 2013, 2014
2012-04-09
... set forth below: * Elevation in feet (NGVD) + Elevation in feet (NAVD) Depth in feet Flooding source(s..., and Incorporated Areas Docket No.: FEMA-B-1100 Mississippi River Approximately 11.2 miles +585 City of.... Approximately 12.8 miles +594 upstream of State Highway 136. * National Geodetic Vertical Datum. + North...
77 FR 73324 - Final Flood Elevation Determinations
Federal Register 2010, 2011, 2012, 2013, 2014
2012-12-10
.... Depth in feet above ground. [caret] Mean Sea Level, rounded to the nearest 0.1 meter. [[Page 73326.... + North American Vertical Datum. Depth in feet above ground. [caret] Mean Sea Level, rounded to the... Sea Level, rounded to the nearest 0.1 meter. ADDRESSES City of Walnut Ridge Maps are available for...
Research on the aircraft level measurement by laser tracker
NASA Astrophysics Data System (ADS)
Ye, Xiaowen; Tang, Wuzhong; Cao, Chun
2014-09-01
The measuring principle of laser tracking system was introduced. The aircraft level measurement was completed by establish the measurement datum mark, select public sites, set up the aircraft coordinate system and transfer stations. Laser tracking measurement technology improved the work efficiency and ensured the installation precision of key components.
Staff - Jacquelyn R. Overbeck | Alaska Division of Geological & Geophysical
Tidal Datum Portal Climate and Cryosphere Hazards Coastal Hazards Program Guide to Geologic Hazards in main content Jacquelyn R. Overbeck Jacquelyn R. Overbeck Geomorphology, coastal hazards, remote sensing University, Environmental Science Projects and/or Research Interests As the project manager for the Coastal
The Individual Human Being: A Sometime Variable For an Educational Rationale
ERIC Educational Resources Information Center
Butler, E. D.; Cozy, Joseph
1973-01-01
Authors believe that the function of education should be the practice of freedom, and also that for this to become reality it is imperative that the cornerstone of such a conception of education be the original datum of education, the individual human being. (Authors/GB)
The Statement: Foundation of Foucault's Historical Criticism.
ERIC Educational Resources Information Center
Blair, Carole
1987-01-01
Presents an overview of Michel Foucault's approach to the study of historical systems of thought, arguing that Foucault's view of historical criticism and language-in-use have much to offer rhetorical theory and criticism. Discusses the nature of discourse for Foucault and examines the characteristics of the fundamental discursive datum, the…
Religious Affiliation and the Fertility of Married Couples.
ERIC Educational Resources Information Center
Mosher, William D.; Hendershot, Gerry E.
1984-01-01
Used data from two National Surveys of Family Growth (N=14,000) to estimate the fertility of married couples by religious group. Results are presented in terms of religious and racial differences, controlling for age, education and residence, and indicate that religious affiliation continues to be an indispensable datum. (JAC)
Federal Register 2010, 2011, 2012, 2013, 2014
2013-10-25
... boundary determinations, coastal engineering, storm warnings and hazard mitigation, emergency management... shoreline depiction may need to be updated on the next regularly scheduled chart edition. Although... Web site ( http://www.tidesandcurrents.noaa.gov ) or contact the Center for Operational Oceanographic...
15 CFR Appendix II to Subpart P of... - Existing Management Areas Boundary Coordinates
Code of Federal Regulations, 2014 CFR
2014-01-01
....43.8′ N 81 deg.48.6′ W. Key West National Wildlife Refuge [Based on the North American Datum of 1983... COMMERCE OCEAN AND COASTAL RESOURCE MANAGEMENT NATIONAL MARINE SANCTUARY PROGRAM REGULATIONS Florida Keys... Administration Key Largo-Management Area [Based on differential Global Positioning Systems data] Point Latitude...
15 CFR Appendix II to Subpart P of... - Existing Management Areas Boundary Coordinates
Code of Federal Regulations, 2011 CFR
2011-01-01
....43.8′ N 81 deg.48.6′ W. Key West National Wildlife Refuge [Based on the North American Datum of 1983... COMMERCE OCEAN AND COASTAL RESOURCE MANAGEMENT NATIONAL MARINE SANCTUARY PROGRAM REGULATIONS Florida Keys... Administration Key Largo-Management Area [Based on differential Global Positioning Systems data] Point Latitude...
15 CFR Appendix II to Subpart P of... - Existing Management Areas Boundary Coordinates
Code of Federal Regulations, 2010 CFR
2010-01-01
....43.8′ N 81 deg.48.6′ W. Key West National Wildlife Refuge [Based on the North American Datum of 1983... COMMERCE OCEAN AND COASTAL RESOURCE MANAGEMENT NATIONAL MARINE SANCTUARY PROGRAM REGULATIONS Florida Keys... Administration Key Largo-Management Area [Based on differential Global Positioning Systems data] Point Latitude...
15 CFR Appendix II to Subpart P of... - Existing Management Areas Boundary Coordinates
Code of Federal Regulations, 2013 CFR
2013-01-01
....43.8′ N 81 deg.48.6′ W. Key West National Wildlife Refuge [Based on the North American Datum of 1983... COMMERCE OCEAN AND COASTAL RESOURCE MANAGEMENT NATIONAL MARINE SANCTUARY PROGRAM REGULATIONS Florida Keys... Administration Key Largo-Management Area [Based on differential Global Positioning Systems data] Point Latitude...
15 CFR Appendix II to Subpart P of... - Existing Management Areas Boundary Coordinates
Code of Federal Regulations, 2012 CFR
2012-01-01
....43.8′ N 81 deg.48.6′ W. Key West National Wildlife Refuge [Based on the North American Datum of 1983... COMMERCE OCEAN AND COASTAL RESOURCE MANAGEMENT NATIONAL MARINE SANCTUARY PROGRAM REGULATIONS Florida Keys... Administration Key Largo-Management Area [Based on differential Global Positioning Systems data] Point Latitude...
33 CFR 110.230 - Anchorages, Captain of the Port Puget Sound Zone, WA.
Code of Federal Regulations, 2013 CFR
2013-07-01
... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Anchorages, Captain of the Port... HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.230 Anchorages, Captain of the Port Puget Sound Zone, WA. (a) Anchorage grounds. All coordinates are expressed in North American Datum...
33 CFR 110.230 - Anchorages, Captain of the Port Puget Sound Zone, WA.
Code of Federal Regulations, 2014 CFR
2014-07-01
... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Anchorages, Captain of the Port... HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.230 Anchorages, Captain of the Port Puget Sound Zone, WA. (a) Anchorage grounds. All coordinates are expressed in North American Datum...
The importance of archiving baseline wilderness data
David N. Cole
2007-01-01
Baseline wilderness data are of considerable importance for several reasons. One of the primary values of wilderness is as a reference that contrasts with those lands where humans dominate the landscape. Leopold (1941) called wilderness "a base-datum of normality, a picture of how healthy land maintains itself." To realize this value, baseline data on...
77 FR 66555 - Final Flood Elevation Determinations
Federal Register 2010, 2011, 2012, 2013, 2014
2012-11-06
.... [caret] Mean Sea Level, rounded to the nearest 0.1 meter. ADDRESSES City of Chiefland Maps are available... American Vertical Datum. Depth in feet above ground. [caret] Mean Sea Level, rounded to the nearest 0.1... feet above ground. [caret] Mean Sea Level, rounded to the nearest 0.1 meter. ADDRESSES City of...
75 FR 31347 - Proposed Flood Elevation Determinations
Federal Register 2010, 2011, 2012, 2013, 2014
2010-06-03
... Datum. [caret] Mean Sea Level, rounded to the nearest 0.1 meter. ** BFEs to be changed include the... in feet above ground. [caret] Mean Sea Level, rounded to the nearest 0.1 meter. ** BFEs to be changed... in feet above ground. [caret] Mean Sea Level, rounded to the nearest 0.1 meter. ** BFEs to be changed...
77 FR 41685 - Drawbridge Operation Regulation; Willamette River, Portland, OR
Federal Register 2010, 2011, 2012, 2013, 2014
2012-07-16
... deviation is necessary to accommodate Portland's Big Float event. This deviation allows the bridge to remain... of the Big Float event. The Hawthorne Bridge crosses the Willamette River at mile 13.1 and provides 49 feet of vertical clearance above Columbia River Datum 0.0 while in the closed position. Vessels...
44 CFR 65.6 - Revision of base flood elevation determinations.
Code of Federal Regulations, 2010 CFR
2010-10-01
... when discharges change as a result of the use of an alternative methodology or data for computing flood... land use regulation. (ii) It must be well-documented including source codes and user's manuals. (iii... projects that may effect map changes when they are completed. (4) The datum and date of releveling of...
78 FR 12598 - Safety Zone; Seafair Blue Angels Air Show Performance, Seattle, WA
Federal Register 2010, 2011, 2012, 2013, 2014
2013-02-25
... Docket Management Facility in Room W12-140 on the ground floor of the Department of Transportation West..., call or email ENS Nathaniel P. Clinger; Waterways Management Division, Coast Guard Sector Puget Sound... point of origin. [Datum: NAD 1983]'' However, the participating aircraft have a flight pattern that will...
Applications of Simulator Freeze to Carrier Glideslope Tracking Instruction.
1982-07-01
Showing Datum Bars and Meatball . .. .. .. ... .. ... .... 19 4 Freezes Per Trial Averaged Across Freeze Conditions and Across 4-Trial Blocks of Training...algorithm linearly increased the criterion in meatball units from 1.0 at 6000 feet from the ramp to 1.5 at the ramp. "Freezes" did not occur beyond 6000
Hazards of Colour Coding in Visual Approach Slope Indicators,
1981-12-01
the glideslope. The central spot (the ’ meatball ’) is displaced above or below the datum lights when the pilot views from above or below the...undershoot is increasing or decreasing, the step changes in intensity may also be evident as a form of flash coding. Colour coding of the ’ meatball " in
77 FR 53141 - Drawbridge Operation Regulation; Columbia River, Vancouver, WA
Federal Register 2010, 2011, 2012, 2013, 2014
2012-08-31
... lift-spans. This deviation allows height-restricted lifts which will reduce the vertical clearance... which cross the Columbia River at mile 106.5 only be required to lift to a reduced height of 130 feet above Columbia River Datum for a 30 day period. The height restricted lifts are necessary to facilitate...
Federal Register 2010, 2011, 2012, 2013, 2014
2013-01-28
... Hydroelectric Dam, LLC; Notice of Preliminary Permit Application Accepted for Filing and Soliciting Comments, Motions To Intervene, and Competing Applications On October 19, 2012, Ceresco Hydroelectric Dam, LLC... feet National Geodetic Vertical Datum; (2) a dam comprised of (a) a 126- foot-wide, 13-foot-high...
33 CFR 165.805 - Security Zones; Calcasieu River and Ship Channel, Louisiana.
Code of Federal Regulations, 2012 CFR
2012-07-01
... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Security Zones; Calcasieu River... § 165.805 Security Zones; Calcasieu River and Ship Channel, Louisiana. (a) Location. (1) The following areas are designated as fixed security zones (all coordinates are based upon North American Datum of...
33 CFR 165.805 - Security Zones; Calcasieu River and Ship Channel, Louisiana.
Code of Federal Regulations, 2013 CFR
2013-07-01
... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Security Zones; Calcasieu River... § 165.805 Security Zones; Calcasieu River and Ship Channel, Louisiana. (a) Location. (1) The following areas are designated as fixed security zones (all coordinates are based upon North American Datum of...
33 CFR 165.805 - Security Zones; Calcasieu River and Ship Channel, Louisiana.
Code of Federal Regulations, 2014 CFR
2014-07-01
... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Security Zones; Calcasieu River... § 165.805 Security Zones; Calcasieu River and Ship Channel, Louisiana. (a) Location. (1) The following areas are designated as fixed security zones (all coordinates are based upon North American Datum of...
33 CFR 165.805 - Security Zones; Calcasieu River and Ship Channel, Louisiana.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Security Zones; Calcasieu River... § 165.805 Security Zones; Calcasieu River and Ship Channel, Louisiana. (a) Location. (1) The following areas are designated as fixed security zones (all coordinates are based upon North American Datum of...
Publications - MP 142 | Alaska Division of Geological & Geophysical Surveys
Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical Surveys Home Industry Reports AKGeology.info Rare Earth Elements WebGeochem Engineering Geology Alaska Tidal Datum
Publications - SR 70 | Alaska Division of Geological & Geophysical Surveys
Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical Surveys Home Industry Reports AKGeology.info Rare Earth Elements WebGeochem Engineering Geology Alaska Tidal Datum
Publications - MP 38 | Alaska Division of Geological & Geophysical Surveys
Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical Surveys Home Industry Reports AKGeology.info Rare Earth Elements WebGeochem Engineering Geology Alaska Tidal Datum
Publications - SR 45 | Alaska Division of Geological & Geophysical Surveys
Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical Surveys Home Industry Reports AKGeology.info Rare Earth Elements WebGeochem Engineering Geology Alaska Tidal Datum
Publications - MP 43 | Alaska Division of Geological & Geophysical Surveys
Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical Surveys Home Industry Reports AKGeology.info Rare Earth Elements WebGeochem Engineering Geology Alaska Tidal Datum
Publications - MP 149 | Alaska Division of Geological & Geophysical Surveys
Skip to content State of Alaska myAlaska My Government Resident Business in Alaska Visiting Alaska State Employees DGGS State of Alaska search Alaska Division of Geological & Geophysical Surveys Home Industry Reports AKGeology.info Rare Earth Elements WebGeochem Engineering Geology Alaska Tidal Datum
77 FR 62473 - Safety Zone, Seafair Blue Angels Air Show Performance, Seattle, WA
Federal Register 2010, 2011, 2012, 2013, 2014
2012-10-15
....1319 has been determined to be inadequate to accommodate the anticipated flight pattern of the Blue.... [Datum: NAD 1983]'' However, the participating aircraft have a flight pattern that will extend past the... summarize our analyses based on a number of these statutes or executive orders. 1. Regulatory Planning and...
33 CFR 165.708 - Safety/Security Zone; Charleston Harbor and Cooper River, Charleston, SC.
Code of Federal Regulations, 2010 CFR
2010-07-01
... Harbor and Cooper River, Charleston, SC. 165.708 Section 165.708 Navigation and Navigable Waters COAST... Guard District § 165.708 Safety/Security Zone; Charleston Harbor and Cooper River, Charleston, SC. (a... Cooper River. All coordinates referenced use datum: NAD 1983. (2) All waters within 100 yards of the...
What Future Teachers Believe about Democracy and Why It Is Important
ERIC Educational Resources Information Center
Zyngier, David
2016-01-01
This paper analyses pre-service education student perceptions and perspectives related to education for democracy in Australia. Using a critical pedagogical framework datum from an online survey, it presents both quantitative and qualitative responses of contrasting understandings of democracy. It begins by outlining the concepts of thick and thin…
Skull Size and Intelligence, and King Robert Bruce's IQ
ERIC Educational Resources Information Center
Deary, Ian J.; Ferguson, Karen J.; Bastin, Mark E.; Barrow, Geoffrey W. S.; Reid, Louise M.; Seckl, Jonathan R.; Wardlaw, Joanna M.; MacLullich, Alasdair M. J.
2007-01-01
An estimate of someone's IQ is a potentially informative personal datum. This study examines the association between external skull measurements and IQ scores, and uses the resulting regression equation to provide an estimate of the IQ of King Robert I of Scotland (Robert Bruce, 1274-1329). Participants were 48 relatively healthy Caucasian men…
ERIC Educational Resources Information Center
Ulucan, Hakki
2017-01-01
Study aims to examine the relationship between perceived job satisfaction levels and work-family conflicts of the physical education teachers. Research group consists of 154 volunteer physical education teachers that work full time in governmental institutions in Kirsehir city and its counties. To acquire the job satisfaction datum; the Minnesota…
On Distinguishing Competence from Performance in Studies of Human Communication.
ERIC Educational Resources Information Center
Sanders, Robert E.
Given that overt linguistic behavior is not an adequate or primary datum for linguistic theory and that linguistic theory cannot directly account for overt linguistic behavior, human language can be seen as an abstract system that relates (graphic or phonetic) surface representations of sentences and underlying grammatical forms and semantic…
What Are Data? Museum Data Bank Research Report Number 1.
ERIC Educational Resources Information Center
Vance, David
This paper describes the process of automatic extraction of implicit--global--data from explicit information by file inversion and threading. Each datum is the symbolic representation of a proposition, and as such has a number of movable parts corresponding to the ideal elements of the proposition represented; e.g., subject, predicate. A third…
Reliability Problems of the Datum: Solutions for Questionnaire Responses.
ERIC Educational Resources Information Center
Bastick, Tony
Questionnaires often ask for estimates, and these estimates are given with different reliabilities. It is difficult to know the different reliabilities of single estimates and to take these into account in subsequent analyses. This paper contains a practical example to show that not taking the reliability of different responses into account can…
On Management "Myth"-Information Systems.
ERIC Educational Resources Information Center
Mitroff, Ian I.; And Others
Management Myth-Information Systems (MMIS) are information systems which present information to a decision maker by means of stories. In MMIS a scientific datum by itself is not information, but is information if and only if it is tied to an appropriate story or myth that has meaning to the individual who needs the information, the organization in…
33 CFR 165.1122 - San Diego Bay, Mission Bay and their Approaches-Regulated navigation area.
Code of Federal Regulations, 2011 CFR
2011-07-01
... area. (a) Regulated navigation area. The following area is a regulated navigation area (RNA): All... coordinates reference 1983 North American Datum (NAD 83). (b) Definitions. As used in this section— COLREGS... means every description of watercraft or other artificial contrivance used, or capable of being used, as...
33 CFR 165.1122 - San Diego Bay, Mission Bay and their Approaches-Regulated navigation area.
Code of Federal Regulations, 2013 CFR
2013-07-01
... area. (a) Regulated navigation area. The following area is a regulated navigation area (RNA): All... coordinates reference 1983 North American Datum (NAD 83). (b) Definitions. As used in this section— COLREGS... means every description of watercraft or other artificial contrivance used, or capable of being used, as...
33 CFR 165.1122 - San Diego Bay, Mission Bay and their Approaches-Regulated navigation area.
Code of Federal Regulations, 2010 CFR
2010-07-01
... area. (a) Regulated navigation area. The following area is a regulated navigation area (RNA): All... coordinates reference 1983 North American Datum (NAD 83). (b) Definitions. As used in this section— COLREGS... means every description of watercraft or other artificial contrivance used, or capable of being used, as...
33 CFR 165.1122 - San Diego Bay, Mission Bay and their Approaches-Regulated navigation area.
Code of Federal Regulations, 2012 CFR
2012-07-01
... area. (a) Regulated navigation area. The following area is a regulated navigation area (RNA): All... coordinates reference 1983 North American Datum (NAD 83). (b) Definitions. As used in this section— COLREGS... means every description of watercraft or other artificial contrivance used, or capable of being used, as...
33 CFR 165.1122 - San Diego Bay, Mission Bay and their Approaches-Regulated navigation area.
Code of Federal Regulations, 2014 CFR
2014-07-01
... area. (a) Regulated navigation area. The following area is a regulated navigation area (RNA): All... coordinates reference 1983 North American Datum (NAD 83). (b) Definitions. As used in this section— COLREGS... means every description of watercraft or other artificial contrivance used, or capable of being used, as...
78 FR 19161 - Security Zones; Captain of the Port Detroit
Federal Register 2010, 2011, 2012, 2013, 2014
2013-03-29
... regarding our public dockets in the January 17, 2008, issue of the Federal Register (73 FR 3316). [[Page... Hall in downtown Detroit, MI. The NAIAS is the prime venue for introducing the world's most anticipated... and boarding. All geographic coordinates are North American Datum of 1983 (NAD 83). All persons and...
Future global SLR network evolution and its impact on the terrestrial reference frame
NASA Astrophysics Data System (ADS)
Kehm, Alexander; Bloßfeld, Mathis; Pavlis, Erricos C.; Seitz, Florian
2018-06-01
Satellite laser ranging (SLR) is an important technique that contributes to the determination of terrestrial geodetic reference frames, especially to the realization of the origin and the scale of global networks. One of the major limiting factors of SLR-derived reference frame realizations is the datum accuracy which significantly suffers from the current global SLR station distribution. In this paper, the impact of a potential future development of the SLR network on the estimated datum parameters is investigated. The current status of the SLR network is compared to a simulated potential future network featuring additional stations improving the global network geometry. In addition, possible technical advancements resulting in a higher amount of observations are taken into account as well. As a result, we find that the network improvement causes a decrease in the scatter of the network translation parameters of up to 24%, and up to 20% for the scale, whereas the technological improvement causes a reduction in the scatter of up to 27% for the translations and up to 49% for the scale. The Earth orientation parameters benefit by up to 15% from both effects.
GNSS Positioning by CORS and EGM2008 in Jilin Province, China
Wu, Qiong; Kang, Jingyu; Li, Shuwen; Zhen, Jianing; Li, Hongqing
2015-01-01
The Continuously Operating Reference Station (CORS) technique has been widely applied in land resource management, surveying, mapping, deformation monitoring, precise navigation, etc. This article analyzed the positioning method using EGM2008 and CORS of Jilin Province, China. The vertical transformation of EGM2008 from WGS84 to China’s CGCS2000 datum and the horizontal coordinate transformation from CGCS2000 to a triangulation coordinate system were discussed. The results indicated that a local geoid with respect to CGCS2000 can be transferred from EGM2008 with the same accuracy, and the geoid correction between CGCS2000 and WGS84 varied from 0.023 m to 0.111 m. The coordinate transformation method based on the curve surface approximation method indicated that the theoretical error was less than 0.09 m in the grid within 10° longitudinal and 5° latitudinal, and less than 0.3 m in large area and 0.1 m in small area in field validation. The method proposed in this article expanded the positioning result and its application for JLCORS and other CORS with local datum. PMID:26690150
NASA Technical Reports Server (NTRS)
Parker, T. J.; Gorsline, D. S.
1993-01-01
The use of photoclinometry and shadow measurements to determine the basin volume without linking the measurements to a global datum is described. Since the boundary, or shoreline, of the basin cannot be tied to the datum and typically has no useful local relative height to measure, what is needed is a number of measurements of the height of the paleoshorelines distributed across the basin. Photoclinometric profiles are being compiled from Viking Orbiter images of the Cydonia Mensae region, which includes images with high sun elevations, necessary to avoid shadows, and images with low sun elevations, to enable the use of shadow measurements as an independent check, at high resolution (40 to 100 m/pixel). Both asymmetric and symmetric photoclinometric profile models are being used, and the results cross checked with one another to minimize errors. An apron-height map, potentially a paleobathymetric map of part of the margin of Oceanus Borealis, can be compiled from this data to determine whether variations in apron height are consistent with a lacustrine interpretation.
GNSS Positioning by CORS and EGM2008 in Jilin Province, China.
Wu, Qiong; Kang, Jingyu; Li, Shuwen; Zhen, Jianing; Li, Hongqing
2015-12-04
The Continuously Operating Reference Station (CORS) technique has been widely applied in land resource management, surveying, mapping, deformation monitoring, precise navigation, etc. This article analyzed the positioning method using EGM2008 and CORS of Jilin Province, China. The vertical transformation of EGM2008 from WGS84 to China's CGCS2000 datum and the horizontal coordinate transformation from CGCS2000 to a triangulation coordinate system were discussed. The results indicated that a local geoid with respect to CGCS2000 can be transferred from EGM2008 with the same accuracy, and the geoid correction between CGCS2000 and WGS84 varied from 0.023 m to 0.111 m. The coordinate transformation method based on the curve surface approximation method indicated that the theoretical error was less than 0.09 m in the grid within 10° longitudinal and 5° latitudinal, and less than 0.3 m in large area and 0.1 m in small area in field validation. The method proposed in this article expanded the positioning result and its application for JLCORS and other CORS with local datum.
Method for laser-based two-dimensional navigation system in a structured environment
Boultinghouse, Karlan D.; Schoeneman, J. Lee; Tise, Bertice L.
1989-01-01
A low power, narrow laser beam, generated by a laser carried by a mobile vehicle, is rotated about a vertical reference axis as the vehicle navigates within a structured environment. At least three stationary retroreflector elements are located at known positions, preferably at the periphery of the structured environment, with one of the elements having a distinctive retroreflection. The projected rotating beam traverses each retroreflector in succession, and the corresponding retroreflections are received at the vehicle and focussed on a photoelectric cell to generate corresponding electrical signals. The signal caused by the distinctive retroreflection serves as an angle-measurement datum. An angle encoder coupled to the apparatus rotating the projected laser beam provides the angular separation from this datum of the lines connecting the mobile reference axis to successive retroreflectors. This real-time angular data is utilized with the known locations of the retroreflectors to trigonometrically compute using three point resection, the exact real-time location of the mobile reference axis (hence the navigating vehicle) vis-a-vis the structured environment, e.g., in terms of two-dimensional Cartesian coordinates associated with the environment.
Beck, David A.; Ryan, Roslyn; Veley, Ronald J.; Harper, Donald P.; Tanko, Daron J.
2006-01-01
The U.S. Geological Survey, in cooperation with Southern Nevada Water Authority and the Nevada Division of Water Resources, operates and maintains a surface-water monitoring network of 6 continuous-record stream-flow gaging stations and 11 partial-record stations in the Warm Springs area near Moapa, Nevada. Permanent land-surface bench marks were installed within the Warm Springs area by the Las Vegas Valley Water District, the Southern Nevada Water Authority, and the U.S. Geological Survey to determine water-surface elevations at all network monitoring sites. Vertical datum elevation and horizontal coordinates were established for all bench marks through a series of Differential Global Positioning System surveys. Optical theodolite surveys were made to transfer Differential Global Positioning System vertical datums to reference marks installed at each monitoring site. The surveys were completed in June 2004 and water-surface elevations were measured on August 17, 2004. Water-surface elevations ranged from 1,810.33 feet above North American Vertical Datum of 1988 at a stream-gaging station in the Pederson Springs area to 1,706.31 feet at a station on the Muddy River near Moapa. Discharge and water-quality data were compiled for the Warm Springs area and include data provided by the U.S. Geological Survey, Nevada Division of Water Resources, U.S. Fish and Wildlife Service, Moapa Valley Water District, Desert Research Institute, and Converse Consultants. Historical and current hydrologic data-collection networks primarily are related to changes in land- and water-use activities in the Warm Springs area. These changes include declines in ranching and agricultural use, the exportation of water to other areas of Moapa Valley, and the creation of a national wildlife refuge. Water-surface elevations, discharge, and water-quality data compiled for the Warm Springs area will help identify (1) effects of changing vegetation within the former agricultural lands, (2) effects of restoration activities in the wildlife refuge, and (3) potential impacts of ground-water withdrawals.
U.S.A. National Surface Rock Density Map - Part 2
NASA Astrophysics Data System (ADS)
Winester, D.
2016-12-01
A map of surface rock densities over the USA has been developed by the NOAA-National Geodetic Survey (NGS) as part of its Gravity for the Redefinition of the American Vertical Datum (GRAV-D) Program. GRAV-D is part of an international effort to generate a North American gravimetric geoid for use as the vertical datum reference surface. As a part of modeling process, it is necessary to eliminate from the observed gravity data the topographic and density effects of all masses above the geoid. However, the long-standing tradition in geoid modeling, which is to use an average rock density (e.g. 2.67 g/cm3), does not adequately represent the variety of lithologies in the USA. The U.S. Geological Survey has assembled a downloadable set of surface geologic formation maps (typically 1:100,000 to 1:500, 000 scale in NAD27) in GIS format. The lithologies were assigned densities typical of their rock type (Part 1) and these variety of densities were then rasterized and averaged over one arc-minute areas. All were then transformed into WGS84 datum. Thin layers of alluvium and some water bodies (interpreted to be less than 40 m thick) have been ignored in deference to underlying rocks. Deep alluvial basins have not been removed, since they represent significant fraction of local mass. The initial assumption for modeling densities will be that the surface rock densities extend down to the geoid. If this results in poor modeling, variable lithologies with depth can be attempted. Initial modeling will use elevations from the SRTM DEM. A map of CONUS densities is presented (denser lithologies are shown brighter). While a visual map at this scale does show detailed features, digital versions are available upon request. Also presented are some pitfalls of using source GIS maps digitized from variable reference sources, including the infamous `state line faults.'
Electrically Variable Resistive Memory Devices
NASA Technical Reports Server (NTRS)
Liu, Shangqing; Wu, Nai-Juan; Ignatiev, Alex; Charlson, E. J.
2010-01-01
Nonvolatile electronic memory devices that store data in the form of electrical- resistance values, and memory circuits based on such devices, have been invented. These devices and circuits exploit an electrically-variable-resistance phenomenon that occurs in thin films of certain oxides that exhibit the colossal magnetoresistive (CMR) effect. It is worth emphasizing that, as stated in the immediately preceding article, these devices function at room temperature and do not depend on externally applied magnetic fields. A device of this type is basically a thin film resistor: it consists of a thin film of a CMR material located between, and in contact with, two electrical conductors. The application of a short-duration, low-voltage current pulse via the terminals changes the electrical resistance of the film. The amount of the change in resistance depends on the size of the pulse. The direction of change (increase or decrease of resistance) depends on the polarity of the pulse. Hence, a datum can be written (or a prior datum overwritten) in the memory device by applying a pulse of size and polarity tailored to set the resistance at a value that represents a specific numerical value. To read the datum, one applies a smaller pulse - one that is large enough to enable accurate measurement of resistance, but small enough so as not to change the resistance. In writing, the resistance can be set to any value within the dynamic range of the CMR film. Typically, the value would be one of several discrete resistance values that represent logic levels or digits. Because the number of levels can exceed 2, a memory device of this type is not limited to binary data. Like other memory devices, devices of this type can be incorporated into a memory integrated circuit by laying them out on a substrate in rows and columns, along with row and column conductors for electrically addressing them individually or collectively.
Study on the position accuracy of a mechanical alignment system
NASA Astrophysics Data System (ADS)
Cai, Yimin
In this thesis, we investigated the precision level and established the baseline achieved by a mechanical alignment system using datums and reference surfaces. The factors which affect the accuracy of mechanical alignment system were studied and methodology was developed to suppress these factors so as to reach its full potential precision. In order to characterize the mechanical alignment system quantitatively, a new optical position monitoring system by using quadrant detectors has been developed in this thesis, it can monitor multi-dimensional degrees of mechanical workpieces in real time with high precision. We studied the noise factors inside the system and optimized the optical system. Based on the fact that one of the major limiting noise factors is the shifting of the laser beam, a noise cancellation technique has been developed successfully to suppress this noise, the feasibility of an ultra high resolution (<20 A) for displacement monitoring has been demonstrated. Using the optical position monitoring system, repeatability experiment of the mechanical alignment system has been conducted on different kinds of samples including steel, aluminum, glass and plastics with the same size 100mm x 130mm. The alignment accuracy was studied quantitatively rather than qualitatively before. In a controlled environment, the alignment precision can be improved 5 folds by securing the datum without other means of help. The alignment accuracy of an aluminum workpiece having reference surface by milling is about 3 times better than by shearing. Also we have found that sample material can have fairly significant effect on the alignment precision of the system. Contamination trapped between the datum and reference surfaces in mechanical alignment system can cause errors of registration or reduce the level of manufacturing precision. In the thesis, artificial and natural dust particles were used to simulate the real situations and their effects on system precision have been investigated. In this experiment, we discovered two effective cleaning processes.
Structure contour map of the greater Green River basin, Wyoming, Colorado, and Utah
Lickus, M.R.; Law, B.E.
1988-01-01
The Greater Green River basin of Wyoming, Colorado, and Utah contains five basins and associated major uplifts (fig. 1). Published structure maps of the region have commonly used the top of the Lower Cretaceous Dakota Sandstone as a structural datum (Petroleum Ownership Map Company (POMCO), 1984; Rocky Mountain Association of Geologists, 1972). However, because relatively few wells in this area penetrate the Dakota, the Dakota structural datum has to be constructed by projecting down from shallower wells. Extrapolating in this manner may produce errors in the map. The primary purpose of this report is to present a more reliable structure contour map of the Greater Green River basin based on datums that are penetrated by many wells. The final map shows the large- to small-scale structures present in the Greater Green River basin. The availability of subsurface control and the map scale determined whether or not a structural feature was included on the map. In general, large structures such as the Moxa arch, Pinedale anticline, and other large folds were placed on the map based solely on the structure contours. In comparison, smaller folds and some faults were placed on the map based on structure contours and other reports (Bader 1987; Bradley 1961; Love and Christiansen, 1985; McDonald, 1975; Roehler, 1979; Wyoming Geological Association Oil and Gas Symposium Committee, 1979). State geologic maps and other reports were used to position basin margin faults (Bryant, 1985; Gries, 1983a, b; Hansen 1986; Hintze, 1980; Love and Christiansen, 1985; Tweto, 1979, 1983). In addition, an interpreted east-west-trending regional seismic line by Garing and Tainter (1985), which shows the basin configuration in cross-section, was helpful in locating buried faults, such as the high-angle reverse or thrust fault along the west flank of the Rock Springs uplift.
GRAV-D for Puerto Rico and the U.S. Virgin Islands
NASA Astrophysics Data System (ADS)
Roman, D. R.; Li, X.; Smith, D. A.; Geoid; GRAV-D Teams
2013-05-01
NOAA's National Geodetic Survey began the Gravity for the Redefinition of the American Vertical Datum (GRAV-D) program in an effort to modernize and unify vertical datums in all states and territories. As a part of this program, NGS collected aerogravity profiles over the islands of Puerto Rico and the U.S. Virgin Islands in January 2009. A Citation II aircraft was equipped with an airborne gravimeter, GPS receiver, and a GPS/Inertial unit. Absolute gravity and GPS ties were made to multiple ground sites to ensure consistency in the results. The main survey covered a region of approximately 400 km by 500 km with flight altitudes of 10,668 m (35,000ft) and with 10 km track spacing. Cross-track profiles at 40 km spacing were also collected to establish an accuracy of 1.34 mGals RMSE. In addition to the high altitude flights, two more flights were made primarily over terrestrial areas at 1,524 m (5,000 ft) to obtain higher resolution information in these regions. There were no cross-ties established for these lower altitude flights. Additionally, terrestrial surveys were also conducted to better tie ground sites and to serve as control for later analysis for available but older terrestrial and marine gravity data in the region already held by NGS. The aerogravity data were analyzed and at least internally compared to obtain the optimal results before being published on the web. In this study, the aerogravity data were compared to available global gravity models derived from satellite missions (GRACE & GOCE) to evaluate their long wavelength character (e.g., potential biases and trends). The vetted satellite-aerogravity data were then combined and used to evaluate surface data (terrestrial and marine) in the region to remove any potential systematic effects. Finally, all these data were combined into a gravimetric geoid height model and evaluated with an eye to eventual use as a GNSS-accessed vertical datum.
Pierce, Kenneth L.; Cannon, Kenneth P.; Meyer, Grant A.; Trebesch, Matthew J.; Watts, Raymond D.
2002-01-01
The Yellowstone caldera, like many other later Quaternary calderas of the world, exhibits dramatic unrest. Between 1923 and 1985, the center of the Yellowstone caldera rose nearly one meter along an axis between its two resurgent domes (Pelton and Smith, 1979, Dzurisin and Yamashita, 1987). From 1985 until 1995-6, it subsided at about two cm/yr (Dzurisin and others, 1990). More recent radar interferometry studies show renewed inflation of the northeastern resurgent dome between 1995 and 1996; this inflation migrated to the southwestern resurgent dome from 1996 to 1997 (Wicks and others, 1998). We extend this record back in time using dated geomorphic evidence of postglacial Yellowstone Lake shorelines around the northern shore, and Yellowstone River levels in the outlet area. We date these shorelines using carbon isotopic and archeological methods. Following Meyer and Locke (1986) and Locke and Meyer (1994), we identify the modern shoreline as S1 (1.9 ? 0.3 m above the lake gage datum), map paleoshoreline terraces S2 to S6, and infer that the prominent shorelines were cut during intracaldera uplift episodes that produced rising water levels. Doming along the caldera axis reduces the gradient of the Yellowstone River from Le Hardys Rapids to the Yellowstone Lake outlet and ultimately causes an increase in lake level. The 1923-1985 doming is part of a longer uplift episode that has reduced the Yellowstone River gradient to a ?pool? with a drop of only 0.25 m over most of this 5 km reach. We also present new evidence that doming has caused submergence of some Holocene lake and river levels. Shoreline S5 is about 14 m above datum and estimated to be ~12.6 ka, because it post-dates a large hydrothermal explosion deposit from the Mary Bay area (MB-II) that occurred ~13 ka. S4 formed about 8 m above datum ~10.7 ka as dated by archeology and 14C, and was accompanied by offset on the Fishing Bridge fault. About 9.7 ka, the Yellowstone River eroded the ?S-meander?, followed by a ~5 m rise in lake level to S2. The lowest generally recognizable shoreline is S2. It is ~5 m above datum (3 m above S1) and is ~8 ka, as dated on both sides of the outlet. Yellowstone Lake and the river near Fishing Bridge were 5-6 m below their present level about 3-4 ka, as indicated by 14C ages from submerged beach deposits, drowned valleys, and submerged Yellowstone River gravels. Thus, the lake in the outlet region has been below or near its present level for about half the time since a 1 km-thick icecap melted from the Yellowstone Lake basin about 16 ka. The amplitude of two rises in lake and river level can be estimated based on the altitude of Le Hardys Rapids, indicators of former lake and river levels, and reconstruction of the river gradient from the outlet to Le Hardys Rapids. Both between ~9.5 ka and ~8.5 ka, and after ~3 ka, Le Hardys Rapids (LHR) was uplifted about 8 meters above the outlet, suggesting a cyclic deformation process. Older possible rises in lake level are suggested by locations where the ~10.7 ka S4 truncates older shorelines, and valleys truncated by the ~12.6 ka S5 shoreline. Using these controls, a plot of lake level through time shows 5-7 millennial-scale oscillations since 14.5 ka. Major cycles of inflation and deflation are thousands of years long. Le Hardys Rapids has twice been uplifted ~8 m relative to the lake outlet. These two locations span only the central 25% of the historic caldera doming, so that if we use historic doming as a model, total projected uplift would be ~32 m. This ?heavy breathing? of the central part of the Yellowstone caldera may reflect a combination of several possible processes: magmatic inflation, tectonic stretching and deflation, and hydrothermal fluid sealing and inflation followed by cracking of the seal, pressure release, and deflation. Over the entire postglacial period, subsidence has balanced or slightly exceeded uplift as shown by older shorelines that descend towards the caldera axis. We
GIS integration of the 1:75,000 Romanian topographic map series from the World War I
NASA Astrophysics Data System (ADS)
Timár, G.; Mugnier, C. J.
2009-04-01
During the WWI, the Kingdom of Romania developed a 1:75,000 topographic map series, covering not only the actual territory of the country (the former Danube Principalities and Dobrogea) but also Bessarabia (now the Republic of Moldova), which was under Russian rule. The map sheets were issued between 1914 and 1917. The whole map consists of two zones; Columns A-F are the western zone, while Columns G-Q are belonging to the eastern one. To integrate the scanned map sheets to a geographic information system (GIS), the parameters of the map projection and the geodetic datum should be defined as well as the sheet labelling system. The sheets have no grid lines indicated; most of them have latitude and longitude lines but some of them have no coordinate descriptions. The sheets, however, can be rectified using their four corners as virtual control points, and using the following grid and datum parameters: Eastern zone: • Projection type: Bonne. • Projection center: latitude=46d 30m; longitude=27d 20m 13.35s (from Greenwich). • Base ellipsoid: Bessel 1841 • Datum parameters (from local to WGS84): dX=+875 m; dY=-119 m; dZ=+313 m. • Sheet size: 40*40 kilometers, projection center is the NW corner of the 779 (Column L; Row VII) sheet. Western zone: • Projection type: Bonne. • Projection center: latitude=45d; longitude=26d 6m 41.18s (from Greenwich); • Base ellipsoid: Bessel 1841 • Datum parameters (from local to WGS84): dX=+793 m; dY=+364 m; dZ=+173 m. • Sheet size: 0.6*0.4 grad (new degrees), except Column F, which is wider to east to fill the territory to the zone boundary. In Columns E and F geographic coordinates are indicated in new degrees, with the prime meridian of Bucharest. Apart from the system of columns and rows, each sheet has its own label of three or four digit. The last two digit correspond to the column number (69 for Column A going up to 84 for Column Q) while the first digit(s) refer directly to row number (1-15). During the rectification process, the coordinates of the corners (the control points) should be defined in the respective Bonne zone projected coordinates. It can be done by simple additions in the eastern zone but it needs conversion from geographic to projected coordinates in the western one. The general accuracy of this geo-referencing method is up to 200 meters - this error is the same in the 1:75,000 series of the Habsburg Empire made from the 1880s.
Student Success Centers: Leading the Charge for Change at Community Colleges
ERIC Educational Resources Information Center
Smith, Caroline Altman; Baldwin, Christopher; Schmidt, Gretchen
2015-01-01
Ten years ago, community college presidents' most valued datum was the number of students enrolled, which drove the colleges' funding. Providing access to higher education for the millions of students without the time, money, or academic preparation to attend a traditional four-year college was (as it always had been) their top priority. Today, a…
The operation and maintenance of a crest-stage gaging station
Friday, John
1965-01-01
Rigid datum controls must be maintained at the gage site throughout the period of record. Physical changes of the site resulting from flood flows or manmade alterations must be evaluated. If a drainage structure such as a culvert is part of the site features, free-flow conditions must be maintained or obstructions carefully documented.
Federal Register 2010, 2011, 2012, 2013, 2014
2012-05-29
... temporary safety zones during Fourth of July Fireworks Displays on certain navigable waterways in Hilton... below. 1. Hilton Head Island, South Carolina. All waters within a 500 yard radius around the barge from... each safety zone. All coordinates are North American Datum 1983. [[Page 31496
Federal Register 2010, 2011, 2012, 2013, 2014
2011-07-21
... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Project No. 2662-012; Project No. 12968..., Federal Energy Regulatory Commission, 888 First Street, NE., Washington, DC 20426. The Commission's Rules... gravity-type ungated spillway section with a crest elevation of 75.38 feet local datum and 30-inch wooden...
47 CFR 101.31 - Temporary and conditional authorizations.
Code of Federal Regulations, 2010 CFR
2010-10-01
..., such as the continental United States. Sufficient data must be submitted to show the need for the... Dimensions=radius in kilometers Center-point Kitt Peak, Arizona 60 N31-57-22; W111-36-42 Big Pine, California... 160 N38-25-59; W79-50-24 Note: Coordinates are referenced to North American Datum 1983 (NAD83). (vii...
Code of Federal Regulations, 2011 CFR
2011-07-01
... of Tampa, Port of Saint Petersburg, Port Manatee, Rattlesnake, Old Port Tampa, Big Bend, Weedon..., Old Port Tampa, Big Bend, Weedon Island, and Crystal River, Florida. (a) Location. The following areas, denoted by coordinates fixed using the North American Datum of 1983 (World Geodetic System 1984), are...
Code of Federal Regulations, 2010 CFR
2010-07-01
... of Tampa, Port of Saint Petersburg, Port Manatee, Rattlesnake, Old Port Tampa, Big Bend, Weedon..., Old Port Tampa, Big Bend, Weedon Island, and Crystal River, Florida. (a) Location. The following areas, denoted by coordinates fixed using the North American Datum of 1983 (World Geodetic System 1984), are...
Company Decontamination Systems (Compagnieontsmettingssystemen)
1998-06-01
TNO-rapport Compagnieontsmettingssystemen PML 1998-AI08 TNO Prins Maurits Laboratorium Lange Kleiweg 137 Datum Postbus 45 2280 AA Rijswijk juni 1999...I8ECTED 4 TNO Prins Maurits Laboratorium is onderdeel _____ van de hoofdgroep TNO Defensieonderzoek waartoe verder behoren: TNO Fysisch en...Elektronisch Laboratorium Nederlandse Organisatie voor toegepast- TNO Technische Menskunde natuurwetenschappelijk onderzoek TNO TNO-rapport PML 1998-A108 2
. This shapefile was generated from a raster dataset with a 200 m resolution, in a UTM zone 12, datum WGS Sustainable Energy, LLC for the U.S. Department of Energy ("DOE"). The user is granted the right whatsoever, provided that this entire notice appears in all copies of the data. Further, the user of this
pacific_coast_90mwindspeed_off
UTM zone 11, datum WGS 84. The shapefile was generated from these raster datasets and then projected of Energy ("DOE"). The user is granted the right, without any fee or cost, to use, copy notice appears in all copies of the data. Further, the user of this data agrees to credit NREL in any
. This shapefile was generated from a raster dataset with a 200 m resolution, in a UTM zone 12, datum WGS , LLC for the U.S. Department of Energy ("DOE"). The user is granted the right, without any , provided that this entire notice appears in all copies of the data. Further, the user of this data agrees
Code of Federal Regulations, 2013 CFR
2013-07-01
... of Tampa, Port of Saint Petersburg, Port Manatee, Rattlesnake, Old Port Tampa, Big Bend, Weedon..., Old Port Tampa, Big Bend, Weedon Island, and Crystal River, Florida. (a) Location. The following areas, denoted by coordinates fixed using the North American Datum of 1983 (World Geodetic System 1984), are...
47 CFR 101.31 - Temporary and conditional authorizations.
Code of Federal Regulations, 2013 CFR
2013-10-01
..., such as the continental United States. Sufficient data must be submitted to show the need for the... region Dimensions=radius in kilometers Center-point Kitt Peak, Arizona 60 N31-57-22; W111-36-42 Big Pine..., West Virginia 160 N38-25-59; W79-50-24 Note: Coordinates are referenced to North American Datum 1983...
47 CFR 101.31 - Temporary and conditional authorizations.
Code of Federal Regulations, 2012 CFR
2012-10-01
..., such as the continental United States. Sufficient data must be submitted to show the need for the... region Dimensions=radius in kilometers Center-point Kitt Peak, Arizona 60 N31-57-22; W111-36-42 Big Pine..., West Virginia 160 N38-25-59; W79-50-24 Note: Coordinates are referenced to North American Datum 1983...
Code of Federal Regulations, 2014 CFR
2014-07-01
... of Tampa, Port of Saint Petersburg, Port Manatee, Rattlesnake, Old Port Tampa, Big Bend, Weedon..., Old Port Tampa, Big Bend, Weedon Island, and Crystal River, Florida. (a) Location. The following areas, denoted by coordinates fixed using the North American Datum of 1983 (World Geodetic System 1984), are...
Code of Federal Regulations, 2012 CFR
2012-07-01
... of Tampa, Port of Saint Petersburg, Port Manatee, Rattlesnake, Old Port Tampa, Big Bend, Weedon..., Old Port Tampa, Big Bend, Weedon Island, and Crystal River, Florida. (a) Location. The following areas, denoted by coordinates fixed using the North American Datum of 1983 (World Geodetic System 1984), are...
47 CFR 101.31 - Temporary and conditional authorizations.
Code of Federal Regulations, 2014 CFR
2014-10-01
..., such as the continental United States. Sufficient data must be submitted to show the need for the... region Dimensions=radius in kilometers Center-point Kitt Peak, Arizona 60 N31-57-22; W111-36-42 Big Pine..., West Virginia 160 N38-25-59; W79-50-24 Note: Coordinates are referenced to North American Datum 1983...
Federal Register 2010, 2011, 2012, 2013, 2014
2013-12-18
... reservoir for the Grand River Dam Authority's Markham Ferry Project No. 2183, for pumped storage operations.... Holway Reservoir (the upper reservoir), with a normal pool elevation between 850 feet and 865 feet National Geodetic Vertical Datum; (2) three rim dikes around the upper reservoir; (3) an 1,800-foot-long...
,
1999-01-01
The National Elevation Dataset (NED) is a new raster product assembled by the U.S. Geological Survey (USGS). The NED is designed to provide national elevation data in a seamless form with a consistent datum, elevation unit, and projection. Data corrections were made in the NED assembly process to minimize artifacts, permit edge matching, and fill sliver areas of missing data.
Federal Register 2010, 2011, 2012, 2013, 2014
2010-01-14
...-high, containing approximately 100 pump/turbine/ generator units having a total installed capacity of...,400 acre- feet at normal water surface elevation of +1,000 feet Project Datum; (2) a lower reservoir..., with a surface area of about 50 acres and volume of approximately 2,400 acre-feet at normal water...
A New Way to Teach (or Compute) Pearson's "r" without Reliance on Cross-Products
ERIC Educational Resources Information Center
Huck, Schuyler W.; Ren, Bixiang; Yang, Hongwei
2007-01-01
Many students have difficulty seeing the conceptual link between bivariate data displayed in a scatterplot and the statistical summary of the relationship, "r." This article shows how to teach (and compute) "r" such that each datum's direct and indirect influences are made apparent and used in a new formula for calculating Pearson's "r."
Code of Federal Regulations, 2013 CFR
2013-07-01
... the boundary of the RNA in this section. (c) Definitions. As used in this section: (1) Designated... Geodetic Datum (1984), are regulated navigation areas (RNAs). (1) Philippine Sea, Guam—All waters from the... of the COLREGS Demarcation as described in 33 CFR part 80. (3) Tanapag Harbor, Saipan—The waters from...
Code of Federal Regulations, 2012 CFR
2012-07-01
... the boundary of the RNA in this section. (c) Definitions. As used in this section: (1) Designated... Geodetic Datum (1984), are regulated navigation areas (RNAs). (1) Philippine Sea, Guam—All waters from the... of the COLREGS Demarcation as described in 33 CFR part 80. (3) Tanapag Harbor, Saipan—The waters from...
Code of Federal Regulations, 2011 CFR
2011-07-01
... the boundary of the RNA in this section. (c) Definitions. As used in this section: (1) Designated... Geodetic Datum (1984), are regulated navigation areas (RNAs). (1) Philippine Sea, Guam—All waters from the... of the COLREGS Demarcation as described in 33 CFR part 80. (3) Tanapag Harbor, Saipan—The waters from...
Code of Federal Regulations, 2014 CFR
2014-07-01
... the boundary of the RNA in this section. (c) Definitions. As used in this section: (1) Designated... Geodetic Datum (1984), are regulated navigation areas (RNAs). (1) Philippine Sea, Guam—All waters from the... of the COLREGS Demarcation as described in 33 CFR part 80. (3) Tanapag Harbor, Saipan—The waters from...
Code of Federal Regulations, 2010 CFR
2010-07-01
... the boundary of the RNA in this section. (c) Definitions. As used in this section: (1) Designated... Geodetic Datum (1984), are regulated navigation areas (RNAs). (1) Philippine Sea, Guam—All waters from the... of the COLREGS Demarcation as described in 33 CFR part 80. (3) Tanapag Harbor, Saipan—The waters from...
1986-12-01
established by the Federal Aviation Administration (FAA), take into account limitations of the navigational service available, and in some airspace the Air... Services (C&GS) of the National Ocean Service , National Oceanic and Atmospheric Administration (NOS/NOAA), are based on regional horizontal datums which...Electromagnetic Interference EMS Emergency Medical Service ERDA Energy Research & Development Administration (Now Department of Energy) F 3 Form, Fit, and
14 CFR Appendix C to Part 135 - Helicopter Flight Recorder Specifications
Code of Federal Regulations, 2011 CFR
2011-01-01
.... (see Table 1, TSO C51-a) 1 25 to 150 ft. Magnetic heading 360° ±5° 1 1°. Vertical acceleration −3g to +6g ±0.2g in addition to ±0.3g maximum datum 4 (or 1 per second where peaks, ref. to 1g are recorded...
14 CFR Appendix F to Part 91 - Helicopter Flight Recorder Specifications
Code of Federal Regulations, 2011 CFR
2011-01-01
...-a) 1 25 to 150 ft. Magnetic Heading 360° ±5° 1 1° Vertical Acceleration −3g to +6g ±0.2g in addition to ±0.3g maximum datum 4 (or 1 per second where peaks, ref. to 1g are recorded) 0.05g. Longitudinal...
47 CFR 101.31 - Temporary and conditional authorizations.
Code of Federal Regulations, 2011 CFR
2011-10-01
.... Sufficient data must be submitted to show the need for the proposed area of operation. (3) Operations in the...-point Kitt Peak, Arizona 60 N31-57-22; W111-36-42 Big Pine, California 60 N37-13-54; W118-16-34...-24 Note: Coordinates are referenced to North American Datum 1983 (NAD83). (vii) With respect to the...
Federal Register 2010, 2011, 2012, 2013, 2014
2013-07-10
... of Natural Resources on the East Fork White River in Lawrence County, Indiana. No federal lands are... Williams dam is currently owned by the Indiana Department of Natural Resources and impounds a 553-acre reservoir at a normal pool elevation of 472.2 North American Vertical Datum of 1988 (NAVD 88). In addition...
ERIC Educational Resources Information Center
Arslan, Yusuf
2016-01-01
In this study, it was tried to comprehend whether there occur any changes in behaviours of university students switching from classical cell phones to smartphones. The investigation was carried out according to quantitative research method. Questionnaire was employed as data collection tool. The datum of the study was limited with the information…
30 CFR 203.0 - What definitions apply to this part?
Code of Federal Regulations, 2010 CFR
2010-07-01
...., below the datum at mean sea level); (3) You drill to at least 18,000 feet TVD SS with a target reservoir... re-perforated at less than 15,000 feet TVD SS in the same reservoir is still a deep well... project to develop one or more oil or gas reservoirs located on one or more contiguous leases that have...
ERIC Educational Resources Information Center
Shah, Saeeda
2018-01-01
Islam underlines equality between women and men regarding their spiritual and intellectual potential. However, given interpretations of religious texts are often availed to suppress women in most Muslim societies, with serious implications for gender equality in the domestic and the professional spheres. This article draws on data from a study of…
33 CFR 100.904 - Celebrate Americafest, Green Bay, WI.
Code of Federal Regulations, 2010 CFR
2010-07-01
... Bridge at position 44°30′25″ N, 088°01′06″ W. (DATUM: NAD 83). (b) Special Local Regulations. The... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Celebrate Americafest, Green Bay..., Green Bay, WI. (a) Regulated Area. A regulated area is established to include all waters of the Fox...
ERIC Educational Resources Information Center
Breier, Mignonne
2010-01-01
While the role of financial considerations in higher education student dropout is being recognized increasingly, the dominant international literature fails to reflect the extent of socio-economic deprivation among students in countries where many people live below the poverty datum line. This article draws on a study of student retention and…
The Catalog: A Flexible Data Structure for Magnetic Tape.
ERIC Educational Resources Information Center
Kay, Martin; Ziehe, Theodore
This report outlines a generalized storage scheme for large files of highly structured data, or catalogs, and describes their realization on magnetic tape. Each datum, large or small, is assigned to one of a number of data classes of which a user may define any number. The over-all organization of a catalog is given by a map that imposes a tree…
Code of Federal Regulations, 2010 CFR
2010-07-01
... THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.420 Chicago River, Ill.; Sanitary... navigation. (2) Description of lock. Feet Clear length 600 Clear width 80 Depth over sills 1 24.4 1 This depth is below Chicago City Datum which is the zero of the gages mounted on the lock. The clear depth...
Code of Federal Regulations, 2011 CFR
2011-07-01
... THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION REGULATIONS § 207.420 Chicago River, Ill.; Sanitary... navigation. (2) Description of lock. Feet Clear length 600 Clear width 80 Depth over sills 1 24.4 1 This depth is below Chicago City Datum which is the zero of the gages mounted on the lock. The clear depth...
Hoffman, Scott A.; Roland, Mark A.; Schalk, Luther F.; Fulton, John W.
2013-01-01
The U.S. Geological Survey (USGS) conducted velocity, water-quality, and bathymetric surveys from spring 2010 to summer 2011 in the Grays Landing and Maxwell navigation pools of the Monongahela River, Pennsylvania, and selected tributaries in response to elevated levels of total dissolved solids (TDS) recorded in early September 2009. Velocity data were collected using an Acoustic Doppler Current Profiler. Water-quality surveys included the in-situ collection of specific-conductance, water-temperature, and turbidity data using a water-quality sonde. Additionally, discrete water samples were collected and analyzed for TDS, chloride, and sulfate. Bathymetric data were collected using an echo sounder, and the shoreline was delineated using a laser range finder and electronic compass. The data were geo-referenced using a differential global positioning system and navigational software. Horizontal (x, y) coordinates were referenced to the North American Datum of 1983. Depth (z) elevations were referenced to the North American Vertical Datum of 1988. The data are provided in electronic format (appendix 1) and may be downloaded and can be used in a geographic information system for cartographic display and data analysis.
C-band station coordinate determination for the GEOS-C altimeter calibration area
NASA Technical Reports Server (NTRS)
Krabill, W. B.; Klosko, S. M.
1974-01-01
Dynamical orbital techniques were employed to estimate the center-of-mass station coordinates of six C-band radars located in the designated primary GEOS-C radar altimeter calibration area. This work was performed in support of the planned GEOS-C mission (December, 1974 launch). The sites included Bermuda, Grand Turk, Antigua, Wallops Island (Virginia), and Merritt Island (Florida). Two sites were estimated independently at Wallops Island yielding better than 40 cm relative height recovery, with better than 10 cm and 1 m (relative) recovery for phi and gamma respectively. Error analysis and comparisons with other investigators indicate that better than 2 m relative recovery was achieved at all sites. The data used were exclusively that from the estimated sites and included 18 orbital arcs which were less than two orbital revolutions in length, having successive tracks over the area. The techniques employed here, given their independence of global tracking support, can be effectively employed to improve various geodetic datums by providing very long and accurate baselines. The C-band data taken on GEOS-C should be employed to improve such geodetic datums as the European-1950 using similar techniques.
Some aspects of the analysis of geodetic strain observations in kinematic models
NASA Astrophysics Data System (ADS)
Welsch, W. M.
1986-11-01
Frequently, deformation processes are analyzed in static models. In many cases, this procedure is justified, in particular if the deformation occurring is a singular event. If. however, the deformation is a continuous process, as is the case, for instance, with recent crustal movements, the analysis in kinematic models is more commensurate with the problem because the factor "time" is considered an essential part of the model. Some specialities have to be considered when analyzing geodetic strain observations in kinematic models. They are dealt with in this paper. After a brief derivation of the basic kinematic model and the kinematic strain model, the following subjects are treated: the adjustment of the pointwise velocity field and the derivation of strain-rate parameters; the fixing of the kinematic reference system as part of the geodetic datum; statistical tests of models by testing linear hypotheses; the invariance of kinematic strain-rate parameters with respect to transformations of the coordinate-system and the geodetic datum; the interpolation of strain rates by finite-element methods. After the representation of some advanced models for the description of secular and episodic kinematic processes, the data analysis in dynamic models is regarded as a further generalization of deformation analysis.
Moving to a Modernized Height Reference System in Canada: Rationale, Status and Plans
NASA Astrophysics Data System (ADS)
Veronneau, M.; Huang, J.
2007-05-01
A modern society depends on a common coordinate reference system through which geospatial information can be interrelated and exploited reliably. For height measurements this requires the ability to measure mean sea level elevations easily, accurately, and at the lowest possible cost. The current national reference system for elevations, the Canadian Geodetic Vertical Datum of 1928 (CGVD28), offers only partial geographic coverage of the Canadian territory and is affected by inaccuracies that are becoming more apparent as users move to space- based technologies such as GPS. Furthermore, the maintenance and expansion of the national vertical network using spirit-levelling, a costly, time consuming and labour intensive proposition, has only been minimally funded over the past decade. It is now generally accepted that the most sustainable alternative for the realization of a national vertical datum is a gravimetric geoid model. This approach defines the datum in relation to an ellipsoid, making it compatible with space-based technologies for positioning. While simplifying access to heights above mean sea level all across the Canadian territory, this approach imposes additional demands on the quality of the geoid model. These are being met by recent and upcoming space gravimetry missions that have and will be measuring the Earth`s gravity field with increasing and unprecedented accuracy. To maintain compatibility with the CGVD28 datum materialized at benchmarks, the current first-order levelling can be readjusted by constraining geoid heights at selected stations of the Canadian Base Network. The new reference would change CGVD28 heights of benchmarks by up to 1 m across Canada. However, local height differences between benchmarks would maintain a relative precision of a few cm or better. CGVD28 will co-exist with the new height reference as long as it will be required, but it will undoubtedly disappear as benchmarks are destroyed over time. The adoption of GNSS technologies for positioning should naturally move users to the new height reference and offer the possibility of transferring heights over longer distances, within the precision of the geoid model. This transition will also reduce user dependency on a dense network of benchmarks and offer the possibility for geodetic agencies to provide the reference frame with a reduced number of 3D control points. While the rationale for moving to a modernized height system is easily understood, the acceptance of the new system by users will only occur gradually as they adopt new technologies and procedures to access the height reference. A stakeholder consultation indicates user readiness and an implementation plan is starting to unfold. This presentation will look at the current state of the geoid model and control networks that will support the modernized height system. Results of the consultation and the recommendations regarding the roles and responsibilities of the various stakeholders involved in implementing the transition will also be reported.
Testing Younger Dryas ET Impact (YDB) Evidence at Hall’s Cave, Texas
NASA Astrophysics Data System (ADS)
Stafford, T. W.; Lundelius, E.; Kennett, J.; Kennett, D. J.; West, A.; Wolbach, W. S.
2009-12-01
Hall’s Cave, Kerrville County Texas, 167 km WSW of Austin, provides a unique opportunity for testing the presence of a chronostratigraphic datum (YDB layer) containing rare and exotic proxies, including nanodiamonds, aciniform soot, and magnetic spherules, the origins of which remain controversial, but possibly derive from a cosmic impact ~12,900 CAL BP. The karst-collapse cave in Cretaceous limestone on the Edwards Plateau contains ≥ 3.7 m of stratified clays grading to clayey silts recording continuous deposition from 16 ka RC yr to present. The cave’s small catchment area and mode of deposition were constant, and the stratigraphy is well dated based on 162 AMS 14C dates from individual vertebrate fossils, snails, charcoal, and sediment chemical fractions. The cave sequence contains an abundant small animal vertebrate fossil record, exhibiting biostratigraphic changes, and the timing of the late Pleistocene megafaunal extinction is consistent with that elsewhere in North America. At 151 cm below datum is the extremely sharp, smooth contact separating lower, dusky red (2.5YR3/2) clays below from overlying dark reddish brown (5YR3/3) clays (forming a 20-cm-thick dark layer) and dating to 13,000 CAL BP, at or close to the age of the YDB datum elsewhere. This appears to be the most distinctive lithologic change of the deglacial sequence. Sediments at or within 10 cm of this contact contain the local extinction of 4 species of bats, the local extinction of the prairie dog (Cynomys sp.) and perhaps other burrowing mammals in response to decrease in soil thickness, and the uppermost occurrence of 6 late Pleistocene megafaunal taxa that, although rare in the cave, do not extend younger than 12.9 ka. We collected and analyzed sediments at high resolution above and below the distinct lithologic contact at 151 cm. The red clays from 151 to 153 cm and immediately preceding the lithologic contact contain an abundance of nanodiamonds (5 different allotropes), aciniform soot at 2400 ppm, magnetic spherules, and carbon spherules, all of which we interpret as evidence for a unique chronostratigraphic marker (YDB) in the Western Hemisphere. Because the age of this horizon is ~ 13,000 CAL BP, we interpret the age of the event as the beginning of the Younger Dryas cooling. Regional soil erosion began ~15,000 CAL BP and continued until 7000 CAL BP, but dating suggests that there is no discontinuity or hiatus in deposition, and thus, the exotic materials in that layer are not considered to be erosional accumulations. Future analyses include sub-centimeter sampling over the YD boundary, quantification of nanodiamonds and other event-proxies within 1000 yr of the boundary and in sediments several 1000 years older and younger, continued refinement of the AMS 14C record to determine within 50 yr the location of 12,900 CAL BP datum and high resolution analysis of small animal biostratigraphy.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Walters, M.A.; Sternfeld, J.N.; Haizlip, J.R.
A high-temperature vapor-dominated reservoir underlies a portion of the Northwest Geysers area, Sonoma County, California. The high-temperature reservoir (HTR) is defined by flowing fluid temperatures exceeding 500º F, rock temperatures apparently exceeding 600º F and steam enthalpies of about 1320 BTU/lb. Steam from existing wells drilled in the Northwest Geysers is produced from both a “typical” Geysers reservoir and the HTR. In all cases, the HTR is in the lower portion of the wells and is overlain by a “typical” Geysers reservoir. Depth to the high-temperature reservoir is relatively uniform at about -5900 ft subsea. There are no identified lithologicmore » or mineralogic conditions that separate the HTR from the “typical” reservoir, although the two reservoirs are vertically distinct and can be located in most wells to within about 200 ft by the use of downhole temperature-depth measurements. Gas concentrations in steam from the HTR are higher (6 to 9 wt %) than from the “typical” Geysers reservoir (0.85 to 2.6 wt %). Steam from the HTR is enriched in chloride and the heavy isotopes of water relative to the “typical” reservoir. Available static and dynamic measurements show pressures are subhydrostatic in both reservoirs with no anomalous differences between the two: the HTR pressure being near 520 psia at sea level datum. The small observed differences in pressure between the reservoirs appear to vary along a steam density gradient. It is postulated that the Northwest Geysers area evolved more slowly toward vapor-dominated conditions than other parts of The Geysers field because of its poor connection with the surface. In this paper, a model is presented in which the boundary between the HTR and “typical” reservoir is a thermodynamic feature only, resulting from recent deep venting of a liquid-dominated system in which conduction is still an important component of heat transfer.« less
Theoretical and Experimental Study of Light Shift in a CPT-Based RB Vapor Cell Frequency Standard
2001-01-01
Questions and Answers ROBERT LUTWAK (Datum): When you servo the microwave power to eliminate the light shift, what do you servo to? To what are you...leveling that signal? MIA0 ZHU: Do you mean what I servo to o r where did I do the servo? LUTWAK : What is the error signal that determines the TR
Nearshore Sea Clutter Measurements from a Fixed Platform
2012-04-01
Water (MLL W) datum. 7. GPS Two differential GPS units, Magellan ProMark 3.0, were utilized to determine precise differences in position between the...8 Figure 8. (a) Trihedral configuration on the small boat and position of the GPS and IMU sensors. (b) Profile view of...SIO Miniature Directional Wave Buoys The Scripps Institution of Oceanography designs and manufactures GPS -based miniature directional wave buoys
2003-01-01
The approach being pursued, under this program structure, is to eliminate the use of physical surfaces on the component as datum. The use of physical...will eliminate /minimize fretting and low-cycle fatigue and the blade-disk interface. This optimum coating and/or coating process will be evaluated both...Utilizes MCLB infrastructure Avoids costs associated with existing APCS Biofiltration produces no secondary emissions Biofiltration is the most
NASA directory of observation station locations, volume 1
NASA Technical Reports Server (NTRS)
1971-01-01
Geodetic information is presented for NASA tracking stations and observation stations in the NASA geodetic satellites program. A geodetic data sheet is provided for each station, giving the position of the station and describing briefly how it was established. Geodetic positions and geocentric coordinates of these stations are tabulated on local or major geodetic datums, and on selected world geodetic systems when available information permits.
New Steering Strategies for the USNO Master Clocks
1999-12-01
1992. P. Koppang and R. Leland , “Linear quadratic stochastic control of atomic hydrogen masers,” IEEE Trans. Ultrason., Ferroelect., Freq. Contr...vol. 46, pp. 517-522, May 1999. P. Koppang and R. Leland , “Steering of frequency standards by the use of linear quadratic gaussian control theory...3lst Annual Precise Time and Time Interval (PTTI) Meeting NEWSTEERINGSTRATEGIESFOR THEUSNOMASTERCLOCKS Paul A. Koppang Datum, Inc. Beverly, MA
Lokalisatie Maskergelaatslekkage (Localization of Face-Seal Leak Sites)
2004-03-01
2004-A 12 TNO Prins Maurits Laboratorium Lokallisatie Maskergellaatslekkage DISTRIBUTION STATEMENT A Approved for Public Release Lange Kleiweg 137 Datum...1 /- O 9 TNO Prins Maurits Laboratorium is onderdeel van de hoofdgroep TNO Defensieonderzoek waartoe verder b~ehoren: TNO Fysisct en Elektronisch... Laboratorium Nedertandse Organisatie voor toegepast- TNO Te~chnische Menakunde natuurwetenschaDpeliik onderzoek TNO TNO Prn Ma rt LA. mu * s gg 2
Federal Register 2010, 2011, 2012, 2013, 2014
2012-07-23
... National Water Level Observation Network (NWLON) for bench marks designated 975 5371 A TIDAL (PID TV1513) (1.334 meters), located at La Puntilla, San Juan Puerto Rico, 975 2235 D (PID DN8624) (0.973 meters), located on Culebra Island, 975 2695 A (PID DN8535) (1.962 meters), located at Esperanza, Vieques Island...
45 CFR Appendix E to Part 1355 - Data Standards
Code of Federal Regulations, 2013 CFR
2013-10-01
... responses to the element, Sex of the Adoptive Child, is “1” for a male and “2” for a female, but the datum.... Element description 05 Date of most recent periodic, review. 06 Child's date of birth. 07 Child's sex. 08.... Element name 05 Child's date of birth. 06 Child's sex. 07 Child's race. 08 Is the child of Hispanic or...
45 CFR Appendix E to Part 1355 - Data Standards
Code of Federal Regulations, 2014 CFR
2014-10-01
... responses to the element, Sex of the Adoptive Child, is “1” for a male and “2” for a female, but the datum.... Element description 05 Date of most recent periodic, review. 06 Child's date of birth. 07 Child's sex. 08.... Element name 05 Child's date of birth. 06 Child's sex. 07 Child's race. 08 Is the child of Hispanic or...
45 CFR Appendix E to Part 1355 - Data Standards
Code of Federal Regulations, 2012 CFR
2012-10-01
... responses to the element, Sex of the Adoptive Child, is “1” for a male and “2” for a female, but the datum.... Element description 05 Date of most recent periodic, review. 06 Child's date of birth. 07 Child's sex. 08.... Element name 05 Child's date of birth. 06 Child's sex. 07 Child's race. 08 Is the child of Hispanic or...
Code of Federal Regulations, 2010 CFR
2010-07-01
... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Calumet River, Ill.; Thomas J. O... DEFENSE NAVIGATION REGULATIONS § 207.425 Calumet River, Ill.; Thomas J. O'Brien Lock and Controlling Works... Illinois Waterway, or when the lake level is below minus 2 feet, Chicago City Datum. (2) The elevation to...
33 CFR 165.506 - Safety Zones; Fireworks Displays in the Fifth Coast Guard District.
Code of Federal Regulations, 2013 CFR
2013-07-01
... Table to § 165.506 reference Datum NAD 1983. Table to § 165.506 No. Date Location Regulated area (a..., approximately 700 yards south of the waterfront at Southport, NC. 12. July 4th Big Foot Slough, Ocracoke, NC, Safety Zone All waters of Big Foot Slough within a 300 yard radius of the fireworks launch site in...
Code of Federal Regulations, 2012 CFR
2012-07-01
... Firework Events for the San Diego Captain of the Port Zone. 165.1123 Section 165.1123 Navigation and... Diego Captain of the Port Zone. (a) General. Safety zones are established for the events listed in Table..., or local agencies. Table 1 to § 165.1123 [All coordinates referenced use datum NAD 83.] 1. San Diego...
Code of Federal Regulations, 2013 CFR
2013-07-01
... Firework Events for the San Diego Captain of the Port Zone. 165.1123 Section 165.1123 Navigation and... Diego Captain of the Port Zone. (a) General. Safety zones are established for the events listed in Table..., or local agencies. Table 1 to § 165.1123 [All coordinates referenced use datum NAD 83.] 1. San Diego...
ERIC Educational Resources Information Center
Shukakidze, Berika
2013-01-01
The work is based on PISA 2009 International Assessment Study. Two counties were selected: a developed country, Estonia and a developing country, Azerbaijan. The following Datum was used for statistical analysis: students average scores in reading (162 schools, 4 600 students from Azerbaijan; 17 schools, 4 923 students from Estonia). The work is…
Code of Federal Regulations, 2011 CFR
2011-07-01
... Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE NAVIGATION... and the bottom of the lock chamber are −13.0 feet elevation, CofE datum, and usually provides a depth of water ranging from 14.0 feet at LLW to 19.4 feet at HHW, with greater depths during large floods...
Electronic Absolute Cartesian Autocollimator
NASA Technical Reports Server (NTRS)
Leviton, Douglas B.
2006-01-01
An electronic absolute Cartesian autocollimator performs the same basic optical function as does a conventional all-optical or a conventional electronic autocollimator but differs in the nature of its optical target and the manner in which the position of the image of the target is measured. The term absolute in the name of this apparatus reflects the nature of the position measurement, which, unlike in a conventional electronic autocollimator, is based absolutely on the position of the image rather than on an assumed proportionality between the position and the levels of processed analog electronic signals. The term Cartesian in the name of this apparatus reflects the nature of its optical target. Figure 1 depicts the electronic functional blocks of an electronic absolute Cartesian autocollimator along with its basic optical layout, which is the same as that of a conventional autocollimator. Referring first to the optical layout and functions only, this or any autocollimator is used to measure the compound angular deviation of a flat datum mirror with respect to the optical axis of the autocollimator itself. The optical components include an illuminated target, a beam splitter, an objective or collimating lens, and a viewer or detector (described in more detail below) at a viewing plane. The target and the viewing planes are focal planes of the lens. Target light reflected by the datum mirror is imaged on the viewing plane at unit magnification by the collimating lens. If the normal to the datum mirror is parallel to the optical axis of the autocollimator, then the target image is centered on the viewing plane. Any angular deviation of the normal from the optical axis manifests itself as a lateral displacement of the target image from the center. The magnitude of the displacement is proportional to the focal length and to the magnitude (assumed to be small) of the angular deviation. The direction of the displacement is perpendicular to the axis about which the mirror is slightly tilted. Hence, one can determine the amount and direction of tilt from the coordinates of the target image on the viewing plane.
Towards a Refined Realisation of the Terrestrial Reference System
NASA Astrophysics Data System (ADS)
Angermann, D.; Drewes, H.; Meisel, B.; Kruegel, M.; Tesmer, V.
2004-12-01
Global reference frames provide the framework for scientific investigations of the Earth's system (e.g. plate tectonics, sea level change, seasonal and secular loading signals, atmosphere dynamics, Earth orientation excitation), as well as for many practical applications (e.g. surveying and navigation). Today, space geodetic techniques allow to determine geodetic parameters (e.g. station positions, Earth rotation) with a precision of a few millimeters (or even better). However, this high accuracy is not reflected by current realisations of the terrestrial reference system. To fully exploit the potential of the space geodetic observations for investigations of various global and regional, short-term, seasonal and secular phenomena of the Earth's system, the reference frame must be realised with the highest accuracy, spatial and temporal consistency and stability over decades. Furthermore, future progress in Earth sciences will fundamentally depend on understanding the Earth as a system, into which the three areas of geodetic research (geometry/deformation, Earth rotation, gravity) are to be integrated. The presentation focusses on various aspects that must be considered for a refined realisation of the terrestrial reference system, such as the development of suitable methods for the combination of the contributing space geodetic observations, the realisation of the TRF datum and the parameterisation of site motions. For this purpose we investigated time series of station positions and datum parameters obtained from VLBI, SLR, GPS and DORIS solutions, and compared the results at co-location sites and with other studies. Furthermore, we present results obtained from a TRS realisation based on epoch (weekly/daily) normal equations with station positions and daily Earth Orientation Parameters (EOP) using five years (1999-2004) of VLBI, SLR, GPS and DORIS data. This refined approach has major advantages compared to past TRF realisations based on multi-year solutions with station positions at a given epoch and constant velocities, as for instance non-linear effects of site positions and datum parameters can be considered, and consistency between TRF and EOPs can be achieved. First results of this new approach are promising.
Kasmarek, Mark C.; Ramage, Jason K.; Johnson, Michaela R.
2016-10-07
Most of the land-surface subsidence in the Houston-Galveston region, Texas, has occurred as a direct result of groundwater withdrawals for municipal supply, commercial and industrial use, and irrigation that depressured and dewatered the Chicot and Evangeline aquifers, thereby causing compaction of the aquifer sediments, mostly in the fine-grained silt and clay layers. This report, prepared by the U.S. Geological Survey in cooperation with the Harris-Galveston Subsidence District, City of Houston, Fort Bend Subsidence District, Lone Star Groundwater Conservation District, and Brazoria County Groundwater Conservation District, is one in an annual series of reports depicting water-level altitudes and water-level changes in the Chicot, Evangeline, and Jasper aquifers and measured cumulative compaction of subsurface sediments in the Chicot and Evangeline aquifers in the Houston-Galveston region. The report contains regional-scale maps depicting approximate 2016 water-level altitudes (represented by measurements made during December 2015–March 2016) for the Chicot, Evangeline, and Jasper aquifers; maps depicting 1-year (2015–16) water-level changes for each aquifer; maps depicting approximate contoured 5-year (2011–16) water-level changes for each aquifer; maps depicting approximate contoured long-term (1990–2016 and 1977–2016) water-level changes for the Chicot and Evangeline aquifers; a map depicting approximate contoured long-term (2000–16) water-level changes for the Jasper aquifer; a map depicting locations of borehole-extensometer sites; and graphs depicting measured long-term cumulative compaction of subsurface sediments at the extensometers during 1973–2015. Tables listing the water-level data used to construct each water-level map for each aquifer and the measured long-term cumulative compaction data for each extensometer site are included. Graphs depicting water-level measurement data also are included; these graphs can be used to approximate changes in effective stress caused by changes in groundwater withdrawal from the Chicot and Evangeline aquifers.In 2016, water-level-altitude contours for the Chicot aquifer ranged from 200 feet (ft) below the vertical datum (North American Vertical Datum of 1988; hereinafter, datum) in a localized area in northwestern Harris County to 200 ft above datum in west-central Montgomery County. Water-level changes during 2015–16 in the Chicot aquifer ranged from a 39-ft decline to a 26-ft rise. Contoured 5-year and long-term changes in water-level altitudes of the Chicot aquifer ranged from a 30-ft decline to a 20-ft rise (2011–16), from a 140-ft decline to a 160-ft rise (1990–2016), and from a 120-ft decline to a 200-ft rise (1977–2016). In 2016, water-level-altitude contours for the Evangeline aquifer ranged from 250 ft below datum in three separate areas in south-central Montgomery County and extending into north-central Harris County, in west-central Harris County, and in southwestern Harris County to 200 ft above datum in southeastern Grimes and northwestern Montgomery Counties. Water-level changes during 2015–16 in the Evangeline aquifer ranged from a 65-ft decline to a 61-ft rise. Contoured 5-year and long-term changes in water-level altitudes of the Evangeline aquifer ranged from a 60-ft decline to a 40-ft rise (2011–16), from a 160-ft decline to a 160-ft rise (1990–2016), and from a 320-ft decline to a 240-ft rise (1977–2016). In 2016, water-level-altitude contours for the Jasper aquifer ranged from 200 ft below datum in south-central Montgomery County extending into north-central Harris County to 250 ft above datum in northwestern Montgomery County and extending into eastern Grimes County and southwestern Walker County. Water-level changes during 2015–16 in the Jasper aquifer ranged from a 38-ft decline to a 51-ft rise. Contoured 5-year and long-term changes in water-level altitudes of the Jasper aquifer ranged from a 60-ft decline to a 40-ft rise (2011–16) and from a 220-ft decline to a 20-ft decline (2000–16).Compaction of subsurface sediments (mostly in the fine-grained silt and clay layers) in the Chicot and Evangeline aquifers was recorded continuously by using 13 extensometers at 11 sites that were either activated or installed between 1973 and 1980. During the period of record beginning in 1973 (or later depending on activation or installation date) and ending in December 2015, measured cumulative compaction at the 13 extensometers ranged from 0.095 ft at the Texas City-Moses Lake extensometer to 3.666 ft at the Addicks extensometer. From January through December 2015, the Northeast, Southwest, Addicks, Johnson Space Center, and Clear Lake (deep) extensometers recorded net decreases in land-surface elevation, but the Lake Houston, East End, Texas City-Moses Lake, Baytown C–1 (shallow), Baytown C–2 (deep), Seabrook, Clear Lake (shallow), and Pasadena extensometers recorded net increases in land-surface elevation. For the 11 extensometer sites during the selected years 1988, 1998, 2008, 2012, and 2015, the smallest effective stress (20.12 pounds per square inch [psi]) was estimated at the Texas City-Moses Lake extensometer site and was produced by a measured water level of 46.42 ft below land-surface datum (blsd) in January 2008. The corresponding net compaction during 2007 at this site was 0.001 ft. The largest effective stress (174.86 psi) was estimated at the Addicks extensometer site and was produced by a measured water level of 403.38 ft blsd in January 1998. The corresponding net compaction at the Addicks site was 0.067 ft in 1997.The 2011 drought caused water-level declines in the aquifers that were documented by the water-level-measurement data collected in January 2012. During the 2011 drought, the 13 extensometers recorded varying amounts of compaction that ranged from a net compaction value of 0.002 ft recorded by the Texas City-Moses Lake extensometer to a net compaction value of 0.192 ft recorded by the Pasadena extensometer. Water-level data for 1988, 1998, 2008, 2012, and 2015 and the corresponding net compaction values recorded by the extensometers for 1987, 1997, 2007, 2011, and 2014 were used to illustrate the cause and effect relations between changes in water level caused by groundwater withdrawals and resulting changes in effective stress. Changes in effective stress are related to changes in land-surface elevations caused by compaction of the fine-grained sediments composing the Chicot and Evangeline aquifers.The rate of compaction varies from site to site because of differences in rates of groundwater withdrawal in the areas adjacent to each extensometer site; differences among sites in the ratios of sand, silt, and clay and their corresponding compressibilities; and previously established preconsolidation heads. It is not appropriate, therefore, to extrapolate or infer a rate of compaction for an adjacent area on the basis of the rate of compaction recorded by proximal extensometers.
Nelson, L.M.
1985-01-01
An unusually high oceanic tide on December 15, 1977, caused flooding of lowlying, nearshore parts of western Washington, including several areas in the Puget Sound region. At Seattle, the December 15 high tide of 14.8 feet above MLLW (mean lower low water datum; 8.55 feet above the National Geodetic Vertical Daltum of 1929, or NGVD) was 0.1 foot higher than the 100-year high tide. At Neah Bay, near the western end of the Straits of Juan de Fuca, however, the high tide of 8.77 feet MLLW (4.55 feet NGVD) on that date was 3.2 feet lower than the 100-year high tide. This study has identified the observed December 15 high-tide elevations at many locations in the Puget Sound region. The observed high tide then was much higher than predicted in most of the Puget Sound region, primarily as the result of a very low barametric pressure. Little damage from wind waves was reported. Elevation profiles for the predicted and observed high tides on December 15 and for several other selected tide levels indicate an increase in the maximum height in the inland direction, except near Port Angeles, and show abrupt changes in tidal elevations at three constrictions - Admiralty Inlet, Tacoma Narrows, and Deception Pass. (USGS)
Regional-scale analysis of subtidal rocky shore community
NASA Astrophysics Data System (ADS)
Derrien-Courtel, Sandrine; Le Gal, Aodren; Grall, Jacques
2013-12-01
The French monitoring network, REseau BENThique (REBENT), was launched by the Ministry of the Environment in 2003 following the 1999 Erika oil spill. REBENT aimed to acquire baseline knowledge of coastal benthic habitat distributions with a special focus on biological diversity. This study analyzed data from 38 subtidal rocky reef sites collected by a single diving team of marine biologists along the coast of Brittany from 2004 to 2010. At each site, the depth limits of the algal belts were determined between 0 and -40 m Chart Datum (CD); the flora and fauna compositions and abundances were sampled at -3 and -8 m CD. A total of 364 taxa (156 flora and 208 fauna), belonging to 12 phyla, were identified. The results showed that the depth limit and density of kelp beds increased as water turbidity decreased; moreover, several changes in community structure could be related to water turbidity and temperature. Thus, northern and southern Brittany showed strong differences in diversity and structure of the dominant kelp species ( Laminaria hyperborea and Saccorhiza polyschides). The results from this kelp habitat composition survey (dominant kelp species and indicator species) provided important information for local pressure assessments, like increases in turbidity. The data also provided a reference that could be useful for detecting changes in coastal water temperatures due to global warming.
2007-03-01
Sabel, ir. C.A.M. van Moll, Datum TNO Defensie en Veiligheid TNO Defensie en Veiligheid maart 2007 Auteur (s) Programmatitel Projecttitel prof. dr. D.G...parameters by means of bottom reflection loss data derived from ambient noise. Matched field inversion is an application of inverse theory . Addressing... theory . Because inverse theory estimates the best fitting model, the uncertainty of this estimate should be specified. These topics are not investigated
Conceptontwerp nieuwe slaapmatten (Concept Design of Sleeping Mattresses)
2008-11-01
Datum november 2008 Auteur (s) drs. P.A. Reffeltrath ing. M.G. Brandsma M.G.M. Weghorst Rubricering rapport Ongerubriceerd TK9 TNO-rapport...slaapmatten in combinatie met de gegevens van objectieve metingen. In theorie maakt het conceptontwerp het mogelijk om tegen minder gewicht en pakvolume...making a mattress that is lighter, has less packing volume, is more comfortable and more durable than the currently available mattresses. In theory
2007-12-03
and reference datums, in addition to other field positioning tasks. 3.5.3. Navigation Systems An Applanix 510 A/V POS system was co-mounted with...Cal and POS EO from Applanix Corp. lmageStation Suite from Z/1 Imaging Images: Camera and Data Recorder · I SAT Aerial Triangulation Software
Field precision machining technology of target chamber in ICF lasers
NASA Astrophysics Data System (ADS)
Xu, Yuanli; Wu, Wenkai; Shi, Sucun; Duan, Lin; Chen, Gang; Wang, Baoxu; Song, Yugang; Liu, Huilin; Zhu, Mingzhi
2016-10-01
In ICF lasers, many independent laser beams are required to be positioned on target with a very high degree of accuracy during a shot. The target chamber provides a precision platform and datum reference for final optics assembly and target collimation and location system. The target chamber consists of shell with welded flanges, reinforced concrete pedestal, and lateral support structure. The field precision machining technology of target chamber in ICF lasers have been developed based on ShenGuangIII (SGIII). The same center of the target chamber is adopted in the process of design, fabrication, and alignment. The technologies of beam collimation and datum reference transformation are developed for the fabrication, positioning and adjustment of target chamber. A supporting and rotating mechanism and a special drilling machine are developed to bore the holes of ports. An adjustment mechanism is designed to accurately position the target chamber. In order to ensure the collimation requirements of the beam leading and focusing and the target positioning, custom-machined spacers are used to accurately correct the alignment error of the ports. Finally, this paper describes the chamber center, orientation, and centering alignment error measurements of SGIII. The measurements show the field precision machining of SGIII target chamber meet its design requirement. These information can be used on similar systems.
NASA Astrophysics Data System (ADS)
Andritsanos, Vassilios D.; Vergos, George S.; Grigoriadis, Vassilios N.; Pagounis, Vassilios; Tziavos, Ilias N.
2014-05-01
The Elevation project, funded by the action "Archimedes III - Funding of research groups in T.E.I.", co-financed by the E.U. (European Social Fund) and national funds under the Operational Program "Education and Lifelong Learning 2007-2013" aims mainly to the validation of the Hellenic vertical datum. This validation is carried out over two areas under study, one in Central and another in Northern Greece. During the first stage of the validation process, satellite-only as well as combined satellite-terrestrial models of the Earth's geopotential are used. GOCE and GRACE satellite information is compared against recently measured GPS/Levelling observations at specific benchmarks of the vertical network in Attiki (Central Greece) and Thessaloniki (Northern Greece). A spectral enhancement approach is followed where, given the GOCE/GRACE GGM truncation degree, EGM2008 is used to fill-in the medium and high-frequency content along with RTM effects for the high and ultra high part. The second stage is based on the localization of possible blunders of the vertical network using the spectral information derived previously. The undoubted accuracy of the contemporary global models at the low frequency band leads to some initial conclusions about the consistency of the Hellenic vertical datum.
Application of carbon isotope stratigraphy to late miocene shallow marine sediments, new zealand.
Loutit, T S; Kennett, J P
1979-06-15
A distinct (0.5 per mil) carbon-13/carbon-12 isotopic shift in the light direction has been identified in a shallow marine sedimentary sequence of Late Miocene age at Blind River, New Zealand, and correlated with a similar shift in Late Miocene Deep Sea Drilling Project sequences throughout the Indo-Pacific. A dated piston core provides an age for the shift of 6.2 +/- 0.1 million years. Correlations based on the carbon isotopic change require a revision of the previously established magnetostratigraphy at Blind River. The carbon shift at Blind River occurs between 6.2 and 6.3 +/- 0.1 million years before present. A new chronology provides an age for the evolutionary first appearance datum of Globorotalia conomiozea at 6.1 +/- 0.1 million years, the beginning of a distinct latest Miocene cooling event associated with the Kapitean stage at 6.2 +/- 0.1 million years, and the beginning of a distinct shallowing of water depths at 6.1 +/- 0.1 million years. The Miocene-Pliocene boundary as recognized in New Zealand is now dated at 5.3 +/- 0.1 million years. Extension of carbon isotope stratigraphy to other shallow Late Miocene sequences should provide an important datum for international correlation of Late Miocene shallow and deep marine sequences.
Medalie, Laura; Olson, S.A.
2013-01-01
The U.S. Geological Survey, in cooperation with the Federal Emergency Management Agency, identified high-water marks after two floods in Vermont during 2011. Following a snowy winter, new monthly precipitation records were set in Burlington, Vermont, in April and May 2011, causing extensive flooding from April through June. The spring 2011 flooding resulted in a new record for stage (103.27 feet, referenced to the National Geodetic Vertical Datum of 1929) at the Lake Champlain at Burlington, Vt., gaging station (04294500). During August 28 and 29, 2011, tropical storm Irene delivered rainfall totals of 3 to more than 7 inches throughout Vermont, which resulted in extensive flooding and new streamflow records at nine streamgaging stations. Four presidential declarations of disaster were made following the 2011 flood events in Vermont. Thirty-nine high-water marks were identified and flagged to mark the highest levels of Lake Champlain from the May 2011 flooding, and 1,138 high-water marks were identified and flagged along Vermont rivers after flooding from tropical storm Irene in August 2011. Seventy-four percent of the high-water marks that were flagged were later found and surveyed to the North American Vertical Datum of 1988.
[Finite element analysis of stress changes of posterior spinal pedicle screw infixation].
Yan, Jia-Zhi; Wu, Zhi-Hong; Xu, Ri-Xin; Wang, Xue-Song; Xing, Ze-Jun; Zhao, Yu; Zhang, Jian-Guo; Shen, Jian-Xiong; Wang, Yi-Peng; Qiu, Gui-Xing
2009-01-06
To evaluate the mechanical response of L3-L4 segment after posterior interfixation with a transpedicle screw system. Spiral CT machine was used to conduct continuous parallel scan on the L3-L4 section of a 40-year-old healthy male Chinese. The image data thus obtained were introduced into MIMICS software to reconstruct the 2-D data into volume data and obtain 3-D models of every element.. Pro/3-D model construction software system was used to simulate the 3-D entity of L3-L4 fixed by screw robs through spinal pedicle via posterior approach that was introduced into the finite element software ABAQUS to construct a 3-D finite element model. The stress changes on the vertebrae and screw under the axial pressure of 0.5 mPa was analyzed. Under the evenly distributed pressure the displacement of the L4 model was 0.00125815 mm, with an error of only 0.8167% from the datum displacement. The convergence of the model was good. The stress of the fixed vertebral body, intervertebral disc, and internal fixators changed significantly. The stress concentration zone of the intervertebral disc turned from the posterolateral side to anterolateral side. The stress produced by the fixed vertebral bodies decreased significantly. Obvious stress concentration existed in the upper and lower sides of the base of screw and the fixed screw at the upper vertebral body bore greater stress than the lower vertebral body. Integration of computer aided device and finite element analysis can successfully stimulate the internal fixation of L3-IA visa posterior approach and observe the mechanic changes in the vertebral column more directly.
Kasmarek, Mark C.; Ramage, Jason K.
2017-08-16
Most of the land-surface subsidence in the Houston-Galveston region, Texas, has occurred as a direct result of groundwater withdrawals for municipal supply, commercial and industrial use, and irrigation that depressured and dewatered the Chicot and Evangeline aquifers, thereby causing compaction of the aquifer sediments, mostly in the fine-grained silt and clay layers. This report, prepared by the U.S. Geological Survey in cooperation with the Harris-Galveston Subsidence District, City of Houston, Fort Bend Subsidence District, Lone Star Groundwater Conservation District, and Brazoria County Groundwater Conservation District, is one in an annual series of reports depicting water-level altitudes and water-level changes in the Chicot, Evangeline, and Jasper aquifers and measured cumulative compaction of subsurface sediments in the Chicot and Evangeline aquifers in the Houston-Galveston region. This report contains regional-scale maps depicting approximate 2017 water-level altitudes (represented by measurements made during December 2016 through March 2017) and long-term water-level changes for the Chicot, Evangeline, and Jasper aquifers; a map depicting locations of borehole-extensometer (hereinafter referred to as “extensometer”) sites; and graphs depicting measured long-term cumulative compaction of subsurface sediments at the extensometers during 1973–2016.In 2017, water-level-altitude contours for the Chicot aquifer ranged from 200 feet (ft) below the North American Vertical Datum of 1988 (hereinafter referred to as “datum”) in two localized areas in southwestern and northwestern Harris County to 200 ft above datum in west-central Montgomery County. The largest water-level-altitude decline (120 ft) depicted by the 1977–2017 water-level-change contours for the Chicot aquifer was in northwestern Harris County. A broad area where water-level altitudes declined in the Chicot aquifer extends from northwestern, north-central, and southwestern Harris County across parts of north-central, eastern, and south-central Fort Bend County into southeastern Waller County. Adjacent to the areas where water levels declined was a broad area where water levels rose in central, eastern, and southeastern Harris County, most of Galveston County, eastern and northernmost Brazoria County, and northeastern Fort Bend County. The largest rise (200 ft) in water-level altitudes in the Chicot aquifer from 1977 to 2017 was in southeastern Harris County.The water-level-altitude contours for the Evangeline aquifer in 2017 indicated two areas where the water-level altitudes were 250 ft below datum—one area extending from south-central Montgomery County into north-central Harris County and another area in western Harris County. Water-level altitudes in the Evangeline aquifer ranged from 50 to 200 ft below datum throughout most of Harris County in 2017. In Montgomery County, water-level altitudes in the Evangeline aquifer in 2017 ranged from the aforementioned area where they were 250 ft below datum to an area where they were 200 ft above datum in the northwestern part of the county. The 1977–2017 water-level-change contours for the Evangeline aquifer depict a broad area where water-level altitudes declined in north-central Harris and south-central Montgomery Counties, extending through north-central, northwestern, and southwestern Harris County into western Liberty, southeastern and northeastern Waller, and northeastern and east-central Fort Bend Counties. The largest water-level-altitude decline (280 ft) was in north-central Harris and south-central Montgomery Counties. Water-level altitudes rose in a broad area from central, east-central, and southern Harris County extending into the northernmost part of Brazoria County, the northernmost part of Galveston County, and the southwestern area of Liberty County. The largest rise in water-level altitudes in the Evangeline aquifer from 1977 to 2017 (240 ft) was in southeastern Harris County.Water-level-altitude contours for the Jasper aquifer in 2017 ranged from 200 ft below datum in three isolated areas of south-central Montgomery County (the westernmost of these areas extended slightly into north-central Harris County) to 250 ft above datum in extreme northwestern Montgomery County, northeastern Grimes County, and southwestern Walker County. The 2000–17 water-level-change contours for the Jasper aquifer depict water-level declines in a broad area throughout most of Montgomery County and in parts of Waller, Grimes, and Harris Counties, with the largest decline (220 ft) in an isolated area in south-central Montgomery County.Compaction of subsurface sediments (mostly in the fine-grained silt and clay layers) in the Chicot and Evangeline aquifers was recorded continuously by using 13 extensometers at 11 sites that were either activated or installed between 1973 and 1980. During the period of record beginning in 1973 (or later depending on activation or installation date) and ending in late November or December 2016, measured cumulative compaction at the 13 extensometers ranged from 0.096 ft at the Texas City-Moses Lake extensometer to 3.700 ft at the Addicks extensometer. From January through late November or December 2016, the Addicks, Lake Houston, Southwest, and Northeast extensometers recorded net decreases in land-surface elevation, but the Baytown C–1 (shallow), Baytown C–2 (deep), Clear Lake (shallow), Clear Lake (deep), East End, Johnson Space Center, Pasadena, Seabrook, and Texas City-Moses Lake extensometers recorded net increases in land-surface elevation.The rate of compaction varies from site to site because of differences in rates of groundwater withdrawal in the areas adjacent to each extensometer site; differences among sites in the ratios of sand, silt, and clay and their corresponding compressibilities; and previously established preconsolidation heads. It is not appropriate, therefore, to extrapolate or infer a rate of compaction for an adjacent area on the basis of the rate of compaction recorded by proximal extensometers.
Geoid Determination Using GOCE-Based Models in Turkey
NASA Astrophysics Data System (ADS)
Serkan Işık, Mustafa; Erol, Bihter
2016-04-01
The maintenance of the vertical datum in tectonically active regions such as Turkey become more of an issue. The distortions in the vertical datum due to geodynamic phenomena necessitate the realization of geoid based vertical datum. The height modernization studies for transition to a "geoid based vertical datum definition" providing practical use of GNSS technologies to obtain orthometric heights in Turkey has accelerated rapidly in recent years and hence in the content of these efforts on-going projects contribute to improvement of quality and quantity of terrestrial gravity dataset as well as selection of the optimal computation algorithm to reach a precise geoid model in the territory. In this manner the assessment of the different methodologies with varying input parameters and referred models is obviously essential to in order to clarify the advantages of the algorithms in terms of providing an optimal combination of different data sets in regional geoid modeling. The performance of recently published GOCE-GRACE gravity field models show significant improvements in the medium frequency. This study investigates the contribution of the recently released Geopotential models with the contribution of GOCE and GRACE missions to the gravimetric geoid modeling specifically from Least squares modification of Stokes' (LSMS) formula point of view in Turkey territory. The algorithm developed by Royal Institute of Technology (KTH) that adopt the least squares modification of Stokes' kernel in order for providing an optimum combination of spherical harmonic expansion model and terrestrial gravity data and hence claims to optimize the drawbacks, may stem from the handicaps (such as low accuracy, sparse distribution etc.) of the terrestrial gravity data in the results. The additive corrective terms in order to account for downward continuation effect, atmospheric effect and ellipsoidal effect are proposed as the superiorities of this algorithm comparing to the conventional Remove-Restore method. The assessments of the geoid models are done at the homogeneously distributed thirty National Network points in Turkey. The positional accuracy of GNSS/Levelling points (belong the Turkey National Fundamental GNSS Network-TUTGA) are reported as ±1.0 cm in horizontal and ±1.5 cm in vertical components. The orthometric heights of these benchmarks are computed via adjustment of the Turkish National Vertical Control Network (TUDKA). All releases of direct (DIR), time-wise (TIM), space-wise (SPW) and Gravity Observation Combination (GOCO) models are evaluated using spectral enhancement method (SEM). DIR R5, TIM R5 and GOCO05S models, which show the best agreements with the GNSS/Levelling data, are included within the study and their performance are compared with EGM2008 model. In conclusion the GOCE gravity field models performs in the level very close to EGM2008 performance, when the same truncation degree of models are considered. The overall results reveal that the gravimetric geoid model which is computed using DIR R5 model provides the best performance having ±24.1 cm (without de-trending), though there is no significant improvement related with the contribution of GOCE gravity field models to the regional geoid determination based on LSMS approach in Turkey territory.
Mean Tide Level Data in the PSMSL Mean Sea Level Dataset
NASA Astrophysics Data System (ADS)
Matthews, Andrew; Bradshaw, Elizabeth; Gordon, Kathy; Jevrejeva, Svetlana; Rickards, Lesley; Tamisiea, Mark; Williams, Simon; Woodworth, Philip
2016-04-01
The Permanent Service for Mean Sea Level (PSMSL) is the internationally recognised global sea level data bank for long term sea level change information from tide gauges. Established in 1933, the PSMSL continues to be responsible for the collection, publication, analysis and interpretation of sea level data. The PSMSL operates under the auspices of the International Council for Science (ICSU), is a regular member of the ICSU World Data System and is associated with the International Association for the Physical Sciences of the Oceans (IAPSO) and the International Association of Geodesy (IAG). The PSMSL continues to work closely with other members of the sea level community through the Intergovernmental Oceanographic Commission's Global Sea Level Observing System (GLOSS). Currently, the PSMSL data bank holds over 67,000 station-years of monthly and annual mean sea level data from over 2250 tide gauge stations. Data from each site are quality controlled and, wherever possible, reduced to a common datum, whose stability is monitored through a network of geodetic benchmarks. PSMSL also distributes a data bank of measurements taken from in-situ ocean bottom pressure recorders. Most of the records in the main PSMSL dataset indicate mean sea level (MSL), derived from high-frequency tide gauge data, with sampling typically once per hour or higher. However, some of the older data is based on mean tide level (MTL), which is obtained from measurements taken at high and low tide only. While usually very close, MSL and MTL can occasionally differ by many centimetres, particularly in shallow water locations. As a result, care must be taken when using long sea level records that contain periods of MTL data. Previously, periods during which the values indicated MTL rather than MSL were noted in the documentation, and sometimes suggested corrections were supplied. However, these comments were easy to miss, particularly in large scale studies that used multiple stations from across a wide area. Therefore, the PSMSL have decided to begin applying a correction to all mixed MTL/MSL records in its datum-controlled RLR dataset, where a suitable correction is available. These corrections will be clearly flagged, allowing users of PSMSL data to quickly identify these values and ignore these data, or apply a different correction. Here we describe the corrections applied to the PSMSL dataset, how users can find MTL data and the corrections made, and some caveats and warnings that need to be considered.
33 CFR 165.1401 - Apra Harbor, Guam-safety zones.
Code of Federal Regulations, 2011 CFR
2011-07-01
... zones. (a) The following is designated as Safety Zone A—The waters of the Pacific Ocean and Apra Outer...′47″ N and 144°39′01.9″ E. Based on World Geodetic System 1984 Datum) (b) The following is designated... the center of Naval Wharf Kilo. (Located at 13°26′43″ N, 144°37′46.7″ E. Based on World Geodetic...
33 CFR 165.1401 - Apra Harbor, Guam-safety zones.
Code of Federal Regulations, 2014 CFR
2014-07-01
... zones. (a) The following is designated as Safety Zone A—The waters of the Pacific Ocean and Apra Outer...′47″ N and 144°39′01.9″ E. Based on World Geodetic System 1984 Datum) (b) The following is designated... the center of Naval Wharf Kilo. (Located at 13°26′43″ N, 144°37′46.7″ E. Based on World Geodetic...
33 CFR 165.1401 - Apra Harbor, Guam-safety zones.
Code of Federal Regulations, 2012 CFR
2012-07-01
... zones. (a) The following is designated as Safety Zone A—The waters of the Pacific Ocean and Apra Outer...′47″ N and 144°39′01.9″ E. Based on World Geodetic System 1984 Datum) (b) The following is designated... the center of Naval Wharf Kilo. (Located at 13°26′43″ N, 144°37′46.7″ E. Based on World Geodetic...
33 CFR 165.1401 - Apra Harbor, Guam-safety zones.
Code of Federal Regulations, 2010 CFR
2010-07-01
... zones. (a) The following is designated as Safety Zone A—The waters of the Pacific Ocean and Apra Outer...′47″ N and 144°39′01.9″ E. Based on World Geodetic System 1984 Datum) (b) The following is designated... the center of Naval Wharf Kilo. (Located at 13°26′43″ N, 144°37′46.7″ E. Based on World Geodetic...
33 CFR 165.1401 - Apra Harbor, Guam-safety zones.
Code of Federal Regulations, 2013 CFR
2013-07-01
... zones. (a) The following is designated as Safety Zone A—The waters of the Pacific Ocean and Apra Outer...′47″ N and 144°39′01.9″ E. Based on World Geodetic System 1984 Datum) (b) The following is designated... the center of Naval Wharf Kilo. (Located at 13°26′43″ N, 144°37′46.7″ E. Based on World Geodetic...
Vienna Fortran - A Language Specification. Version 1.1
1992-03-01
other computer archi- tectures is the fact that the memory is physically distributed among the processors; the time required to access a non-local...datum may be an order of magnitude higher than the time taken to access locally stored data. This has important consequences for program efficiency. In...machine in many aspects. It is tedious, time -consuming and error prone. It has led to particularly slow software development cycles and, in consequence
Surf Zone Currents. Volume I. State of Knowledge.
1982-09-01
elevation above an arbitrary datum a angle between wave crest and bottom contour a angle between wave crest and the shoreline . ab angle between breaking...b- Note that neglecting wave setup, refraction and for small ab , equation (74) reduces to that employed by Longuet-Higgins (eq. 48). These researchers...28. As ab o (Note that ab = o means theory reduces to original order (zero order) solution given by Longuet-Higgins, 1970, the triangular solution is
Cultural Diversity in Military Teams: Which Factors Influence Effectiveness?
2008-12-01
TNO-DV2008A513 Opdrachtnummer Datum december 2008 Auteur (s) dr. I.M. Wetzer dr. D.A. van Hemert Rubricering rapport Ongerubriceerd TM0...been reported. Based on Allport’s (1954) intergroup contact theory , positive effects of intercultural contact may occur under certain conditions...diversity on perceived team effectiveness, but only at the 11-30% level. In contrast, social identity theory would lead one to expect negative effects of
Job Oriented Training ’Lessons Learned’
2008-11-01
Job Oriented Training ’Lessons Learned’ Job Oriented Training (JOT), een vorm van trainen waarbij de cursist zelfstandig, zonder theorie vooraf...39 77 lnfo-DenV@tno.nl TNO-rapportnummer TNO-DV 2008 A447 Opdrachtnummer Datum november 2008 Auteur (s) drs. H.E. Stubbe dr. A.H. van der...onderlinge discussie over achterliggende overwegingen te stimuleren. Zij hebben op dat moment nog geen theorie aangeboden gekregen en zijn niet op de hoogte
Operational Ocean Modelling with the Harvard Ocean Prediction System
2008-11-01
tno.nl TNO-rapportnummer TNO-DV2008 A417 Opdrachtnummer Datum november 2008 Auteur (s) dr. F.P.A. Lam dr. ir. M.W. Schouten dr. L.A. te Raa...area of theory and implementation of numerical schemes and parameterizations, ocean models have grown from experimental tools to full-blown ocean...sound propagation through mesoscale features using 3-D coupled mode theory , Thesis, Naval Postgraduate School, Monterey, USA. 1992. [9] Robinson
2005-12-01
helicopter geophysical survey performed by US Army Engineering Support Center, Huntsville (USAESCH) and Oak Ridge National Laboratory ( ORNL ) over areas...Array Detection System NAD North American Datum ORAGS Oak Ridge Airborne Geophysical System ORNL Oak Ridge National Laboratory RMS Root...used by ORNL in 1999 for.....................5 Figure 2.4 ORAGS-Hammerhead airborne magnetometer system used at Badlands Bombing Range in FY2000
Atmospheric Propagation of High Energy Lasers: Modeling, Simulation, Tracking, and Control
2008-04-29
the North American Aerospace Defense Command (NORAD) SGP4 /SDP4 orbital propagator and study on energy transfer to orbital assets. • Implementation of...scenarios which include orbital assets. We have incorporated into SHaRE the North American Aerospace Defense Command (NORAD) SGP4 (for near-earth... TLE ) datum. This allows us to investigate the energy characteristics of a ground based laser to an orbital asset. We have conducted a study using
NASA Astrophysics Data System (ADS)
Borrelli, M.; Mague, S. T.; Smith, T. L.
2015-12-01
A new method of mapping storm-tide (inundation) pathways and linking those data with tidal elevations in real-time for local managers is being developed. Separate, ongoing studies in two coastal towns in Massachusetts have demonstrated the strengths of this method. High-resolution lidar datasets are imported into 3D data visualization software and water levels are raised incrementally from the highest spring tide of the year to the storm of record +1 m. This range was identified to include 'nuisance flooding' as well as present and future inundation pathways not yet observed by local authorities caused by storms superimposed on projected sea level rise. Potential storm-tide pathways are identified using Lidar data but are then verified with extensive fieldwork using RTK-GPS instruments (tested vertical accuracy of 4.9 cm at 95%) to overcome the vertical uncertainty associated with Lidar data. The fieldwork serves two purposes, first is to field check the lidar data with the highest resolution instrument available and, second to verify and document the presence or absence of a storm-tide pathway. Having developed the map of storm tide pathways within a GIS environment referenced to a geodetic datum (NAVD88), a tide gauge or staff is installed in the town's harbor or other sheltered coastal area and the elevations of all storm tide pathways are then referenced to the local tidal datum. The benefit here is three-fold. First, local officials can use the high-resolution data set that is tied to a local tidal datum to autonomously monitor predicted storm surges and be prepared for inundation at sites prior to flooding. Second, storm-tide pathways that have heretofore never been inundated can be identified and steps can be taken to remove or minimize flooding hazards. Finally, identification of present and future storm tide pathways can be used to prioritize and budget proactive solutions in response to increases in chronic, nuisance and more frequent flooding associated with sea level rise and climate change. This method does not rely on costly numerical models that are often too coarsely gridded to be of use on a street-by-street basis. Lidar data are publicly available in many coastal areas and can be used with little training to new or already existing local or regional GIS staff.
NASA Astrophysics Data System (ADS)
Koenig, Daniel
2018-02-01
Applying a one-step integrated process, i.e. by simultaneously processing all data and determining all satellite orbits involved, a Terrestrial Reference Frame (TRF) consisting of a geometric as well as a dynamic part has been determined at the observation level using the EPOS-OC software of Deutsches GeoForschungsZentrum. The satellite systems involved comprise the Global Positioning System (GPS) as well as the twin GRACE spacecrafts. Applying a novel approach, the inherent datum defect has been overcome empirically. In order not to rely on theoretical assumptions this is done by carrying out the TRF estimation based on simulated observations and using the associated satellite orbits as background truth. The datum defect is identified here as the total of all three translations as well as the rotation about the z-axis of the ground station network leading to a rank-deficient estimation problem. To rectify this singularity, datum constraints comprising no-net translation (NNT) conditions in x, y, and z as well as a no-net rotation (NNR) condition about the z-axis are imposed. Thus minimally constrained, the TRF solution covers a time span of roughly a year with daily resolution. For the geometric part the focus is put on Helmert transformations between the a priori and the estimated sets of ground station positions, and the dynamic part is represented by gravity field coefficients of degree one and two. The results of a reference solution reveal the TRF parameters to be estimated reliably with high precision. Moreover, carrying out a comparable two-step approach using the same data and models leads to parameters and observational residuals of worse quality. A validation w.r.t. external sources shows the dynamic origin to coincide at a level of 5 mm or better in x and y, and mostly better than 15 mm in z. Comparing the derived GPS orbits to IGS final orbits as well as analysing the SLR residuals for the GRACE satellites reveals an orbit quality on the few cm level. Additional TRF test solutions demonstrate that K-Band Range-Rate observations between both GRACE spacecrafts are crucial for accurately estimating the dynamic frame's orientation, and reveal the importance of the NNT- and NNR-conditions imposed for estimating the components of the dynamic geocenter.
Kress, Wade H.; Sebree, Sonja K.; Littin, Gregory R.; Drain, Michael A.; Kling, Michael E.
2005-01-01
The U.S. Geological Survey, in cooperation with The Central Nebraska Public Power and Irrigation District, conducted a study that used bathymetric and topographic surveying in conjunction with Geographical Information Systems techniques to determine the 2003 physical shape, current storage capacity, and the changes in storage capacity of Lake McConaughy that have occurred over the past 62 years. By combining the bathymetric and topographic survey data, the current surface area of Lake McConaughy was determined to be 30,413.0 acres, with a volume of 1,756,300 acre-feet at the lake conservation-pool elevation of 3,266.4 feet above North American Vertical Datum of 1988 (3,265.0 feet above Central datum). To determine the changes in storage of Lake McConaughy, the 2003 survey Digital Elevation Model (DEM) was compared to a preconstruction DEM compiled from historical contour maps. This comparison showed an increase in elevation at the dam site due to the installation of Kingsley Dam. Immediately to the west of the Kingsley Dam is an area of decline where a borrow pit for Kingsley Dam was excavated. The comparison of the preconstruction survey to the 2003 survey also was used to estimate the gross storage capacity reduction that occurred between 1941 and 2002. The results of this comparison indicate a gross storage capacity reduction of approximately 42,372 acre-feet, at the lake conservation-pool elevation of 3,266.4 feet in NAVD 88 (3,265.0 feet in Central datum). By comparing preconstruction and 2003 survey data and subtracting the Kingsley Dam and borrow pit, the total estimated net volume of sediment deposited over the past 62 years is 53,347,124 cubic yards, at an annual average rate of 860,437 cubic yards per year. The approximate decrease in the net storage capacity occurring over the past 62 years is 33,066 acre-feet, at an annual average decrease of approximately 533 acre-feet per year, which has resulted in a 1.8 percent decrease in storage capacity of Lake McConaughy. The lake has accumulated most of the sediment in the original river channel and in the west end of the delta area on the upstream end of the lake.
West Flank Coso, CA FORGE 3D temperature model
Doug Blankenship
2016-03-01
x,y,z data of the 3D temperature model for the West Flank Coso FORGE site. Model grid spacing is 250m. The temperature model for the Coso geothermal field used over 100 geothermal production sized wells and intermediate-depth temperature holes. At the near surface of this model, two boundary temperatures were assumed: (1) areas with surface manifestations, including fumaroles along the northeast striking normal faults and northwest striking dextral faults with the hydrothermal field, a temperature of ~104˚C was applied to datum at +1066 meters above sea level elevation, and (2) a near-surface temperature at about 10 meters depth, of 20˚C was applied below the diurnal and annual conductive temperature perturbations. These assumptions were based on heat flow studies conducted at the CVF and for the Mojave Desert. On the edges of the hydrothermal system, a 73˚C/km (4˚F/100’) temperature gradient contour was established using conductive gradient data from shallow and intermediate-depth temperature holes. This contour was continued to all elevation datums between the 20˚C surface and -1520 meters below mean sea level. Because the West Flank is outside of the geothermal field footprint, during Phase 1, the three wells inside the FORGE site were incorporated into the preexisting temperature model. To ensure a complete model was built based on all the available data sets, measured bottom-hole temperature gradients in certain wells were downward extrapolated to the next deepest elevation datum (or a maximum of about 25% of the well depth where conductive gradients are evident in the lower portions of the wells). After assuring that the margins of the geothermal field were going to be adequately modelled, the data was contoured using the Kriging method algorithm. Although the extrapolated temperatures and boundary conditions are not rigorous, the calculated temperatures are anticipated to be within ~6˚C (20˚F), or one contour interval, of the observed data within the Coso geothermal field. Based on a lack of temperature data west of 74-2TCH, the edges of this model still seem to have an effect on West Flank modeled temperatures.
Hunter, Shelby L.; Ashworth, Chad E.; Smith, S. Jerrod
2017-09-26
In February 2017, the Grand River Dam Authority filed to relicense the Pensacola Hydroelectric Project with the Federal Energy Regulatory Commission. The predominant feature of the Pensacola Hydroelectric Project is Pensacola Dam, which impounds Grand Lake O’ the Cherokees (locally called Grand Lake) in northeastern Oklahoma. Identification of information gaps and assessment of project effects on stakeholders are central aspects of the Federal Energy Regulatory Commission relicensing process. Some upstream stakeholders have expressed concerns about the dynamics of sedimentation and flood flows in the transition zone between major rivers and Grand Lake O’ the Cherokees. To relicense the Pensacola Hydroelectric Project with the Federal Energy Regulatory Commission, the hydraulic models for these rivers require high-resolution bathymetric data along the river channels. In support of the Federal Energy Regulatory Commission relicensing process, the U.S. Geological Survey, in cooperation with the Grand River Dam Authority, performed bathymetric surveys of (1) the Neosho River from the Oklahoma border to the U.S. Highway 60 bridge at Twin Bridges State Park, (2) the Spring River from the Oklahoma border to the U.S. Highway 60 bridge at Twin Bridges State Park, and (3) the Elk River from Noel, Missouri, to the Oklahoma State Highway 10 bridge near Grove, Oklahoma. The Neosho River and Spring River bathymetric surveys were performed from October 26 to December 14, 2016; the Elk River bathymetric survey was performed from February 27 to March 21, 2017. Only areas inundated during those periods were surveyed.The bathymetric surveys covered a total distance of about 76 river miles and a total area of about 5 square miles. Greater than 1.4 million bathymetric-survey data points were used in the computation and interpolation of bathymetric-survey digital elevation models and derived contours at 1-foot (ft) intervals. The minimum bathymetric-survey elevation of the Neosho River was 709.18 ft above North American Vertical Datum of 1988, which corresponds to a maximum depth of 34.22 ft. The minimum bathymetric-survey elevation of the Spring River was 714.18 ft above North American Vertical Datum of 1988, which corresponds to a maximum depth of 29.22 ft. The minimum bathymetric-survey elevation of the Elk River was 715.62 ft above North American Vertical Datum of 1988, which corresponds to a maximum depth of 27.78 ft.
The Effect of a Previously-Generated Hypothesis on Hypothesis Generation Performance.
1980-08-05
distinction 17I -’ai S between availability and accessibility has been made by Tulving and Pearlstone (1966). A datum may be present in memory, but may...1977. Thorndyke, P.W. The role of inference in discourse comprehension. Journal of Verbal Learning and Verbal Behavior, 1976, 15, 437-446. Tulving ...E. and Pearlstone , Z. Availability versus accessibility of infor- mation in memory for words. Journal of Verbal Learning and Verbal Behavior, 1966, 5
Self-weight effect in the measurement of the volume of silicon spheres
NASA Astrophysics Data System (ADS)
Mari, D.; Massa, E.; Kuramoto, N.; Mana, G.
2018-04-01
The volume of 28Si spheres about 94 mm in diameter is an input datum for the determination of the Avogadro constant. We report a finite element analysis of the self-weight effect on the volume determination via optical interferometric measurements of the sphere diameters. The self-weight expansion or shrinkage of the equatorial diameters, which ranges from -31 pm to +180 pm, depends on the southern latitude of the supports.
Descriptions of selected digital spatial data for Ravenna Army Ammunition Plant, Ohio
Schalk, C.W.; Darner, R.A.
1998-01-01
Digital spatial data of Ravenna Army Ammunition Plant (RVAAP), in northeastern Ohio, were compiled or generated from existing maps for U.S. Army Industrial Operations Command. The data are in the Ohio north state-plane coordinate system (North American Datum of 1983) in an ARC/INFO geographic information system format. The data comprise 15 layers, which include boundaries, topography, and natural and cultural features. An additional layer comprises scanned and rectified aerial photographs of RVAAP.
Tussenrapportage Validatie Onderwijsvernieuwingen (Validation Assistant in Instructional Design)
2007-05-01
validatie onderwij svemieuwingen D)atum mei 2007 Auteur (s) drs. J.P. van Meer drs. G,J. Veldhuis dr. M.L. van Ernmerik M.G. van Schaik Rubricering...als doel om nog beter is het van belang dat het maken van keuzes Auteur (s) passende adviezen te kunnen genereren. binnen een moeilijk grijpbaar...benaderd door de theorie achter de onderwijsconcepten te toetsen aan het oordeel van de expert. Er zijn echter beperkingen in deze opzet denkbaar die
2008-09-01
bijvoorbeeld de toekomstige uitzendgebieden in zich heeft. De praktijk gaat hierbij vooraf aan de theorie , de benodigde theoretische kennis wordt niet vooraf...rapportnummer TNO-DV 2008 A340 Opdrachtnummer Datum September 2008 Auteur (s) dr. A.H. van der Hulst ir. T.J. Muller maj C.L. Roos Rubricering rapport...Oriented Training toegepast. Dit betekent in essentie dat de leerlingen vanaf dag een, integrale missies uitvoeren en niet eerst de theorie wordt
2008-07-01
die binmen defensie tot aanzien van de effecten van JOT onderwijs met het nieuwe leren terug te dan toe in gebruik waren bij het theorie - voeren is op...problemen in de uitvoerings- onderwijs; toepassing van JOT impliceerde Grondslag praktijk van datzeltde regulier onderwijs. dat er geen theorie meer...het rechte eind Opdrachtnummer Datum PROGRAMMA PROJECT juli 2008 Program mabegeleider Projectbegeleider Auteur (s) IkolP.M.. Bonen,dr. A.H. van der
Archaeological Test Sampling of Sites within the La Quinta Flood Control Channel Easement,
1980-03-01
J L CRAIB MAR 80UNCLASSIFIED DACW@9-80-M-0975 F/G 5/6 NL | EmhhhhhhommhhlmEEIE hhhhhl I E5Ehhhhhhhhlh IIllfllfflfflffllfllf U-IIIIII a J 12 !EM imi.I...ima ii~ti -- I .u 1111125 11114 111116 MICROCOPY RESOLUTION TEST CHART NATIONAL BUR.AU OF STANDARDS-1963- A K- Lo’ • ~ ~ ~ ~ ~ ~ ~ ~ e 4e...66 REFERENCES CITED ............................................... 71 APPENDIX A - Triangulation Points for Site Datum Stakes ........ 73
Assessment of the Water Levels and Currents at the Mississippi Bight During Hurricane Katrina.
NASA Astrophysics Data System (ADS)
Nwankwo, U. C.; Howden, S. D.; Dodd, D.; Wells, D. E.
2017-12-01
In an effort to extend the length of GPS baselines further offshore, the Hydrographic Science Research Center at the University of Southern Mississippi deployed a buoy which had a survey grade GPS receiver, an ADPC and a motion sensor unit in the Mississippi Bight in late 2004. The GPS data were initially processed using the Post Processed Kinematic technique with data from a nearby GPS base station on Horn Island. This processing technique discontinued when the storm (Hurricane Katrina) destroyed the base station in late August of 2005. However, since then a stand-alone positioning technique termed Precise Point Positioning (PPP) matured and allowed for the reprocessing of the buoy GPS data throughout Katrina. The processed GPS data were corrected for buoy angular motions using Tait Bryan transformation model. Tidal datums (Epoch 1983-2001) were transferred from the National Oceanic and Atmospheric Administration (NOAA) National Water Level at Waveland, Mississippi (Station ID 8747766) to the buoy using the Modified Range Ratio method. The maximum water level during the storm was found to be about 3.578m, relative to the transferred Mean Sea Level datum. The storm surge built over more than 24 hours, but fell back to normal levels in less than 3 hours. The maximum speed of the current with respect to the seafloor was recorded to be about 4knots towards the southeast as the storm surge moved back offshore.
NASA Astrophysics Data System (ADS)
Pueyo, Emilio L.; Muñoz, Arsenio; Laplana, César; Parés, Josep M.
2016-11-01
The Villarroya Basin in Northern Spain contains one of the classic Villafranchian localities of Europe and allows about 100 m of sediments to be explored by magnetostratigraphic techniques. Besides, the occurrence of some other macro- and micro-mammifera fossils becomes Villarroya in one of the most important Villafranchian localities of Southern Europe. Therefore, we have sampled two sections (one contains the classic locality) to shed some light on its chronostratigraphy. Detailed stepwise demagnetization has revealed primary and reliable directions (carried by magnetite and hematite) in more than 250 samples and allows us building a robust local polarity scale. The correlation with the geologic time scale locates the local sequence along the Gauss and Matuyama chrons. A Réunion chron (C2r.1n) equivalent age (2.128-2.148 Ma) is here proposed for the Villarroya fossil locality since it is clearly located above the Gauss/Matuyama boundary (very well defined in the magnetostratigraphic section) and displays normal polarity. This correlation implies a new age assignment for the classic paleontological fossil locality of Villarroya and a Last Appearance Datum of Hipparion sensu lato in Western Europe significantly younger than previously established. Taking into account this new dating, the Hipparion and Equus horses could have coexisted in Europe up to the complete extinction of Hipparion in early Matuyama times.
Miller, J.F.; Ethington, Raymond L.; Evans, K.R.; Holmer, L.E.; Loch, James D.; Popov, L.E.; Repetski, J.E.; Ripperdan, R.L.; Taylor, John F.
2006-01-01
We propose a candidate for the Global Standard Stratotype-section and Point (GSSP) for the base of the highest stage of the Furongian Series of the Cambrian System. The section is at Lawson Cove in the Ibex area of Millard County, Utah, USA. The marker horizon is the first appearance datum (FAD) of the conodont Cordylodus andresi Viira et Sergeyeva in Kaljo et al. [Kaljo, D., Borovko, N., Heinsalu, H., Khazanovich, K., Mens, K., Popov, L., Sergeyeva, S., Sobolevskaya, R., Viira, V., 1986. The Cambrian-Ordovician boundary in the Baltic-Ladoga clint area (North Estonia and Leningrad Region, USSR). Eesti NSV Teaduste Akadeemia Toimetised. Geologia 35, 97-108]. At this section and elsewhere this horizon also is the FAD of the trilobite Eurekia apopsis (Winston et Nicholls, 1967). This conodont characterizes the base of the Cordylodus proavus Zone, which has been recognized in many parts of the world. This trilobite characterizes the base of the Eurekia apopsis Zone, which has been recognized in many parts of North America. The proposed boundary is 46.7 m above the base of the Lava Dam Member of the Notch Peak Formation at the Lawson Cove section. Brachiopods, sequence stratigraphy, and carbon-isotope geochemistry are other tools that characterize this horizon and allow it to be recognized in other areas. ?? 2006 Nanjing Institute of Geology and Palaeontology, CAS.
Mariano, John; Grauch, V.J.
1988-01-01
Aeromagnetic anomalies are produced by variations in the strength and direction of the magnetic field of rocks that include magnetic minerals, commonly magnetite. Patterns of anomalies on aeromagnetic maps can reveal structures - for example, faults which have juxtaposed magnetic rocks against non-magnetic rocks, or areas of alteration where magnetic minerals have been destroyed by hydrothermal activity. Tectonic features of regional extent may not become apparent until a number of aeromagnetic surveys have been compiled and plotted at the same scale. Commonly the compilation involves piecing together data from surveys that were flown at different times with widely disparate flight specifications and data reduction procedures. The data may be compiled into a composite map, where all the pieces are plotted onto one map without regard to the difference in flight elevation and datum, or they may be compiled into a merged map, where all survey data are analytically reduced to a common flight elevation and datum, and then digitally merged at the survey boundaries. The composite map retains the original resolution of all the survey data, but computer methods to enhance regional features crossing the survey boundaries may not be applied. On the other hand, computer methods can be applied to the merged data, but the accuracy of the data may be slightly diminished.
Rydlund, Jr., Paul H.; Densmore, Brenda K.
2012-01-01
Geodetic surveys have evolved through the years to the use of survey-grade (centimeter level) global positioning to perpetuate and post-process vertical datum. The U.S. Geological Survey (USGS) uses Global Navigation Satellite Systems (GNSS) technology to monitor natural hazards, ensure geospatial control for climate and land use change, and gather data necessary for investigative studies related to water, the environment, energy, and ecosystems. Vertical datum is fundamental to a variety of these integrated earth sciences. Essentially GNSS surveys provide a three-dimensional position x, y, and z as a function of the North American Datum of 1983 ellipsoid and the most current hybrid geoid model. A GNSS survey may be approached with post-processed positioning for static observations related to a single point or network, or involve real-time corrections to provide positioning "on-the-fly." Field equipment required to facilitate GNSS surveys range from a single receiver, with a power source for static positioning, to an additional receiver or network communicated by radio or cellular for real-time positioning. A real-time approach in its most common form may be described as a roving receiver augmented by a single-base station receiver, known as a single-base real-time (RT) survey. More efficient real-time methods involving a Real-Time Network (RTN) permit the use of only one roving receiver that is augmented to a network of fixed receivers commonly known as Continually Operating Reference Stations (CORS). A post-processed approach in its most common form involves static data collection at a single point. Data are most commonly post-processed through a universally accepted utility maintained by the National Geodetic Survey (NGS), known as the Online Position User Service (OPUS). More complex post-processed methods involve static observations among a network of additional receivers collecting static data at known benchmarks. Both classifications provide users flexibility regarding efficiency and quality of data collection. Quality assurance of survey-grade global positioning is often overlooked or not understood and perceived uncertainties can be misleading. GNSS users can benefit from a blueprint of data collection standards used to ensure consistency among USGS mission areas. A classification of GNSS survey qualities provide the user with the ability to choose from the highest quality survey used to establish objective points with low uncertainties, identified as a Level I, to a GNSS survey for general topographic control without quality assurance, identified as a Level IV. A Level I survey is strictly limited to post-processed methods, whereas Level II, Level III, and Level IV surveys integrate variations of a RT approach. Among these classifications, techniques involving blunder checks and redundancy are important, and planning that involves the assessment of the overall satellite configuration, as well as terrestrial and space weather, are necessary to ensure an efficient and quality campaign. Although quality indicators and uncertainties are identified in post-processed methods using CORS, the accuracy of a GNSS survey is most effectively expressed as a comparison to a local benchmark that has a high degree of confidence. Real-time and post-processed methods should incorporate these "trusted" benchmarks as a check during any campaign. Global positioning surveys are expected to change rapidly in the future. The expansion of continuously operating reference stations, combined with newly available satellite signals, and enhancements to the conterminous geoid, are all sufficient indicators for substantial growth in real-time positioning and quality thereof.
NASA Astrophysics Data System (ADS)
Kacimov, A. R.; Obnosov, Yu. V.
2017-03-01
The Russian engineer Kornev in his 1935 book raised perspectives of subsurface "negative pressure" irrigation, which have been overlooked in modern soil science. Kornev's autoirrigation utilizes wicking of a vacuumed water from a porous pipe into a dry adjacent soil. We link Kornev's technology with a slightly modified Philip (1984)'s analytical solutions for unsaturated flow from a 2-D cylindrical pipe in an infinite domain. Two Darcian flows are considered and connected through continuity of pressure along the pipe-soil contact. The first fragment is a thin porous pipe wall in which water seeps at tension saturation; the hydraulic head is a harmonic function varying purely radially across the wall. The Thiem solution in this fragment gives the boundary condition for azimuthally varying suction pressure in the second fragment, ambient soil, making the exterior of the pipe. The constant head, rather than Philip's isobaricity boundary condition, along the external wall slightly modifies Philip's formulae for the Kirchhoff potential and pressure head in the soil fragment. Flow characteristics (magnitudes of the Darcian velocity, total flow rate, and flow net) are explicitly expressed through series of Macdonald's functions. For a given pipe's external diameter, wall thickness, position of the pipe above a free water datum in the supply tank, saturated conductivities of the wall and soil, and soil's sorptive number, a nonlinear equation with respect to the total discharge from the pipe is obtained and solved by a computer algebra routine. Efficiency of irrigation is evaluated by computation of the moisture content within selected zones surrounding the porous pipe.
Mars synthetic topographic mapping
Wu, S.S.C.
1978-01-01
Topographic contour maps of Mars are compiled by the synthesis of data acquired from various scientific experiments of the Mariner 9 mission, including S-band radio-occulation, the ultraviolet spectrometer (UVS), the infrared radiometer (IRR), the infrared interferometer spectrometer (IRIS) and television imagery, as well as Earth-based radar information collected at Goldstone, Haystack, and Arecibo Observatories. The entire planet is mapped at scales of 1:25,000,000 and 1:25,000,000 using Mercator, Lambert, and polar stereographic map projections. For the computation of map projections, a biaxial spheroid figure is adopted. The semimajor and semiminor axes are 3393.4 and 3375.7 km, respectively, with a polar flattening of 0.0052. For the computation of elevations, a topographic datum is defined by a gravity field described in terms of spherical harmonics of fourth order and fourth degree combined with a 6.1-mbar occulation pressure surface. This areoid can be approximated by a triaxial ellipsoid with semimajor axes of A = 3394.6 km and B = 3393.3 km and a semiminor axis of C = 3376.3 km. The semimajor axis A intersects the Martian surface at longitude 105??W. The dynamic flattening of Mars is 0.00525. The contour intercal of the maps is 1 km. For some prominent features where overlapping pictures from Mariner 9 are available, local contour maps at relatively larger scales were also compiled by photogrammetric methods on stereo plotters. ?? 1978.
Naval War College Review. Volume 61, Number 2, Spring 2008
2008-01-01
However, for ships operating in the tramp trade in search of cargo on the spot market, transparency is problematic. Vessel position is a source of...commercial High Speed Vehicles. We have tried out the HSVs in a variety of exercises and real operations. Their wave-piercing catamaran hulls have helped to... a datum that independent shipping in World War II moved 250 nautical miles a day or more.11 On land an army maneuvering at operational speed against
Terrain Referenced Navigation Using SIFT Features in LiDAR Range-Based Data
2014-12-26
14 2.5 Geocentric and geodetic representation of the same point on Earth’s surface. . . 16 2.6 Difference between datum provided ellipsoid height h and...also called a geocentric system, in that its origin is coincident with the calculated center of the earth. 8 2.1.3.2 Local Navigation Frame. The local...utilizing them. 2.2.1.1 Ellipsoid Earth Models. While geocentric ECEF coordinates are useful to describe a point on or inside the earth they can be cumbersome
Concept Map Value Propagation for Tactical Intelligence
2007-06-01
meaningful diagrams: KMap, SmartDraw , MindGenius, and so on. However, CmapTools is the package we are using for this project. The software , produced by the...Cmap, driven by expected variability in the value of a datum and cost to get a new value. We use the CmapTools software developed with DoD support at... software developed with DoD support at the Institute of Human and Machine Cognition as a structural basis for creating and assessing tactical Cmaps. The
1994-09-01
titel DETECTIE VAN LANDMIJNEN EN MIJNENVELDEN OP AFSTAND, een overzicht van de technieken auteur (s) Drs. J.S. Groot, Ir. Y.H.L. Janssen datum september...functions based on set theory . The fundamental theory is developed in the sixties. This theory was applicable to binary images (black-and-white images...held at TNO-FEL. Various subjects related to fusion techniques: Dempster Shafer theory , Bayesian inference, Kalman filtering, fuzzy logic. [A15], [B4
2008-10-01
DV2008A176 Opdrachtnummer Datum October 2008 Auteur (s) dr. R. van Vossen B.A.J. Quesson dr.ir. J.C. Sabel Rubricering rapport Ongerubriceerd TH9...TNO report | TNO-DV 2008 A176 4/44 Summary This report presents an overview of the theory and implementation of interferometric SAS processing at TNO... theory in software has been tested on two types of data, simulated and measured. Chapter 3 presents results obtained with simulated data; Chapter 4
Analysing Operational Effects (Het analyseren van operationele effecten)
2007-09-01
Programmanummer Projectnummer Datum V215 032.10 177 september 2007 Program maplanning Projectplanning Auteur (s)drs. M. Duistermaat Start 1 maart 2003 Start 1...called an effect, and when do we call it a task. In theory , an effect is formulated as ’to have accomplished a change in the situation’. and a task is...determining strategies for the mission. In the current chapter, we look at the different ways of utilization of the framework: in theory (the operational
2008-07-01
SimSCORM Opdrachtnummer Trainingsconcepten voor Defensie Datum Programmanummer Projectnummer juli 2008 V406 032.13224 Auteur (s) ir H.L.H. de Penning...simulators can provide learners with powerful and realistic learning environments: whereas e-learning systems provide them with interactive, mostly theory ...practice and theory , in both learning and evaluation, is becoming increasingly important. From a learner’s point of view, a powerful learning environment
Visual Technology Research Simulator (VTRS) Human Performance Research: Phase III.
1981-11-01
you will intercept the glideslope and a centered meatball at approximately 4500 feet from the ramp. When the meatball approaches centerball you are to...this system with two horizontal bars (to represent the datum bars) and a moving dot (referred to as the ball or the meatball ). The system is...At two balls low the meatball starts to flash. Plus or minus two balls is the maximum effective range of the system. The ball will be lost off the top
1966-01-01
Geodetic leveling by the U.S. Geological Survey provides a framework of accurate elevations for topographic mapping. Elevations are referred to the Sea Level Datum of 1929. Lines of leveling may be run either with automatic or with precise spirit levels, by either the center-wire or the three-wire method. For future use, the surveys are monumented with bench marks, using standard metal tablets or other marking devices. The elevations are adjusted by least squares or other suitable method and are published in lists of control.
The Research of Paper Datum Mmanagement Information System
NASA Astrophysics Data System (ADS)
Zhigang, Ji; Gaifang, Niu; Lingxi, Liu
Now, paper management is becoming an important work in many colleges and universities, and the digitization of paper management is a significant constituent part of the information of college management. We have studied a universal framework of comprehensive management system spanning departments and geographical positions by taking the opportunity of the developing of the paper management system. The framework provides support for setting up large complicated distributed application fleetly, efficiently, expansively and safely, and it is a new project to realize the standardization of paper information management.
47 CFR 90.741 - Urban areas for Phase I nationwide systems.
Code of Federal Regulations, 2010 CFR
2010-10-01
...″ Indianapolis, Indiana 39°46′07.2″ 86°09′46.0″ New Orleans, Louisiana 29°56′53.7″ 90°04′10.3″ Portland, Oregon... referenced to North American Datum 1983 (NAD83)). Table Urban area North latitude West longitude New York, New York-Northeastern New Jersey 40°45′06.4″ 73°59′37.5″ Los Angeles-Long Beach, California 34°03′15.0...
Archaeological Survey of the Lewisville Lake Shoreline, Denton County, Texas
1990-01-01
the Denton All newly recorded and relocated sites were County Historical Society, the Willis Library at the flagged, plotted on a U.S. Geological Survey...USGS) University of North Texas, the Denton County 7.5’ topographic map and given a site tag and datum Courthouse, and the Barker Library in Austin...Description: Site 41 DN4 is located on a high upland appear to be of Mexican and Mississippian types. This ridge and adjacent slopes at the 90-degree bend
Singularities of the quad curl problem
NASA Astrophysics Data System (ADS)
Nicaise, Serge
2018-04-01
We consider the quad curl problem in smooth and non smooth domains of the space. We first give an augmented variational formulation equivalent to the one from [25] if the datum is divergence free. We describe the singularities of the variational space which correspond to the ones of the Maxwell system with perfectly conducting boundary conditions. The edge and corner singularities of the solution of the corresponding boundary value problem with smooth data are also characterized. We finally obtain some regularity results of the variational solution.
New standards for reducing gravity data: The North American gravity database
Hinze, W. J.; Aiken, C.; Brozena, J.; Coakley, B.; Dater, D.; Flanagan, G.; Forsberg, R.; Hildenbrand, T.; Keller, Gordon R.; Kellogg, J.; Kucks, R.; Li, X.; Mainville, A.; Morin, R.; Pilkington, M.; Plouff, D.; Ravat, D.; Roman, D.; Urrutia-Fucugauchi, J.; Veronneau, M.; Webring, M.; Winester, D.
2005-01-01
The North American gravity database as well as databases from Canada, Mexico, and the United States are being revised to improve their coverage, versatility, and accuracy. An important part of this effort is revising procedures for calculating gravity anomalies, taking into account our enhanced computational power, improved terrain databases and datums, and increased interest in more accurately defining long-wavelength anomaly components. Users of the databases may note minor differences between previous and revised database values as a result of these procedures. Generally, the differences do not impact the interpretation of local anomalies but do improve regional anomaly studies. The most striking revision is the use of the internationally accepted terrestrial ellipsoid for the height datum of gravity stations rather than the conventionally used geoid or sea level. Principal facts of gravity observations and anomalies based on both revised and previous procedures together with germane metadata will be available on an interactive Web-based data system as well as from national agencies and data centers. The use of the revised procedures is encouraged for gravity data reduction because of the widespread use of the global positioning system in gravity fieldwork and the need for increased accuracy and precision of anomalies and consistency with North American and national databases. Anomalies based on the revised standards should be preceded by the adjective "ellipsoidal" to differentiate anomalies calculated using heights with respect to the ellipsoid from those based on conventional elevations referenced to the geoid. ?? 2005 Society of Exploration Geophysicists. All rights reserved.
NASA Astrophysics Data System (ADS)
Izham, Mohamad Yusoff; Muhamad Uznir, Ujang; Alias, Abdul Rahman; Ayob, Katimon; Wan Ruslan, Ismail
2011-04-01
Existing 2D data structures are often insufficient for analysing the dynamism of saturation excess overland flow (SEOF) within a basin. Moreover, all stream networks and soil surface structures in GIS must be preserved within appropriate projection plane fitting techniques known as georeferencing. Inclusion of 3D volumetric structure of the current soft geo-objects simulation model would offer a substantial effort towards representing 3D soft geo-objects of SEOF dynamically within a basin by visualising saturated flow and overland flow volume. This research attempts to visualise the influence of a georeference system towards the dynamism of overland flow coverage and total overland flow volume generated from the SEOF process using VSG data structure. The data structure is driven by Green-Ampt methods and the Topographic Wetness Index (TWI). VSGs are analysed by focusing on spatial object preservation techniques of the conformal-based Malaysian Rectified Skew Orthomorphic (MRSO) and the equidistant-based Cassini-Soldner projection plane under the existing geodetic Malaysian Revised Triangulation 1948 (MRT48) and the newly implemented Geocentric Datum for Malaysia (GDM2000) datum. The simulated result visualises deformation of SEOF coverage under different georeference systems via its projection planes, which delineate dissimilar computation of SEOF areas and overland flow volumes. The integration of Georeference, 3D GIS and the saturation excess mechanism provides unifying evidence towards successful landslide and flood disaster management through envisioning the streamflow generating process (mainly SEOF) in a 3D environment.
Experiments in Reconstructing Twentieth-Century Sea Levels
NASA Technical Reports Server (NTRS)
Ray, Richard D.; Douglas, Bruce C.
2011-01-01
One approach to reconstructing historical sea level from the relatively sparse tide-gauge network is to employ Empirical Orthogonal Functions (EOFs) as interpolatory spatial basis functions. The EOFs are determined from independent global data, generally sea-surface heights from either satellite altimetry or a numerical ocean model. The problem is revisited here for sea level since 1900. A new approach to handling the tide-gauge datum problem by direct solution offers possible advantages over the method of integrating sea-level differences, with the potential of eventually adjusting datums into the global terrestrial reference frame. The resulting time series of global mean sea levels appears fairly insensitive to the adopted set of EOFs. In contrast, charts of regional sea level anomalies and trends are very sensitive to the adopted set of EOFs, especially for the sparser network of gauges in the early 20th century. The reconstructions appear especially suspect before 1950 in the tropical Pacific. While this limits some applications of the sea-level reconstructions, the sensitivity does appear adequately captured by formal uncertainties. All our solutions show regional trends over the past five decades to be fairly uniform throughout the global ocean, in contrast to trends observed over the shorter altimeter era. Consistent with several previous estimates, the global sea-level rise since 1900 is 1.70 +/- 0.26 mm/yr. The global trend since 1995 exceeds 3 mm/yr which is consistent with altimeter measurements, but this large trend was possibly also reached between 1935 and 1950.
User's manual for computer program BASEPLOT
Sanders, Curtis L.
2002-01-01
The checking and reviewing of daily records of streamflow within the U.S. Geological Survey is traditionally accomplished by hand-plotting and mentally collating tables of data. The process is time consuming, difficult to standardize, and subject to errors in computation, data entry, and logic. In addition, the presentation of flow data on the internet requires more timely and accurate computation of daily flow records. BASEPLOT was developed for checking and review of primary streamflow records within the U.S. Geological Survey. Use of BASEPLOT enables users to (1) provide efficiencies during the record checking and review process, (2) improve quality control, (3) achieve uniformity of checking and review techniques of simple stage-discharge relations, and (4) provide a tool for teaching streamflow computation techniques. The BASEPLOT program produces tables of quality control checks and produces plots of rating curves and discharge measurements; variable shift (V-shift) diagrams; and V-shifts converted to stage-discharge plots, using data stored in the U.S. Geological Survey Automatic Data Processing System database. In addition, the program plots unit-value hydrographs that show unit-value stages, shifts, and datum corrections; input shifts, datum corrections, and effective dates; discharge measurements; effective dates for rating tables; and numeric quality control checks. Checklist/tutorial forms are provided for reviewers to ensure completeness of review and standardize the review process. The program was written for the U.S. Geological Survey SUN computer using the Statistical Analysis System (SAS) software produced by SAS Institute, Incorporated.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wolery, Thomas J.; Jove Colon, Carlos F.
Chemical thermodynamic data remain a keystone for geochemical modeling and reactive transport simulation as applied to an increasing number of applications in the earth sciences, as well as applications in other areas including metallurgy, material science, and industrial process design. The last century has seen the development of a large body of thermodynamic data and a number of major compilations. The past several decades have seen the development of thermodynamic databases in digital form designed to support computer calculations. However, problems with thermodynamic data appear to be persistent. One problem pertains to the use of inconsistent primary key reference data.more » Such data pertain to elemental reference forms and key, stoichiometrically simple chemical species including metal oxides, CO 2, water, and aqueous species such as Na + and Cl -. A consistent set of primary key data (standard Gibbs energies, standard enthalpies, and standard entropies for key chemical species) for 298.15K and 1 bar pressure is essential. Thermochemical convention is to define the standard Gibbs energy and the standard enthalpy of an individual chemical species in terms of formation from reference forms of the constituent chemical elements. We propose a formal concept of “links” to the elemental reference forms. This concept involves a documented understanding of all reactions and calculations leading to values for a formation property (standard Gibbs energy or enthalpy). A valid link consists of two parts: (a) the path of reactions and corrections and (b) the associated data, which are key data. Such a link differs from a bare “key” or “reference” datum in that it requires additional information. Some or all of its associated data may also be key data. In evaluating a reported thermodynamic datum, one should identify the links to the chemical elements, a process which can be time-consuming and which may lead to a dead end (an incomplete link). The use of two or more inconsistent links to the same elemental reference form in a thermodynamic database will result in an inconsistency in the database. Thus, in constructing a database, it is important to establish a set of reliable links (generally resulting in a set of primary reference data) and then correct all data adopted subsequently for consistency with that set. Recommended values of key data have not been constant through history. We review some of this history through the lens of major compilations and other influential reports, and note a number of problem areas. Finally, we illustrate the concepts developed in this paper by applying them to some key species of geochemical interest, including liquid water; quartz and aqueous silica; and gibbsite, corundum, and the aqueous aluminum ion.« less
NASA Astrophysics Data System (ADS)
Wolery, Thomas J.; Jové Colón, Carlos F.
2017-09-01
Chemical thermodynamic data remain a keystone for geochemical modeling and reactive transport simulation as applied to an increasing number of applications in the earth sciences, as well as applications in other areas including metallurgy, material science, and industrial process design. The last century has seen the development of a large body of thermodynamic data and a number of major compilations. The past several decades have seen the development of thermodynamic databases in digital form designed to support computer calculations. However, problems with thermodynamic data appear to be persistent. One problem pertains to the use of inconsistent primary key reference data. Such data pertain to elemental reference forms and key, stoichiometrically simple chemical species including metal oxides, CO2, water, and aqueous species such as Na+ and Cl-. A consistent set of primary key data (standard Gibbs energies, standard enthalpies, and standard entropies for key chemical species) for 298.15 K and 1 bar pressure is essential. Thermochemical convention is to define the standard Gibbs energy and the standard enthalpy of an individual chemical species in terms of formation from reference forms of the constituent chemical elements. We propose a formal concept of "links" to the elemental reference forms. This concept involves a documented understanding of all reactions and calculations leading to values for a formation property (standard Gibbs energy or enthalpy). A valid link consists of two parts: (a) the path of reactions and corrections and (b) the associated data, which are key data. Such a link differs from a bare "key" or "reference" datum in that it requires additional information. Some or all of its associated data may also be key data. In evaluating a reported thermodynamic datum, one should identify the links to the chemical elements, a process which can be time-consuming and which may lead to a dead end (an incomplete link). The use of two or more inconsistent links to the same elemental reference form in a thermodynamic database will result in an inconsistency in the database. Thus, in constructing a database, it is important to establish a set of reliable links (generally resulting in a set of primary reference data) and then correct all data adopted subsequently for consistency with that set. Recommended values of key data have not been constant through history. We review some of this history through the lens of major compilations and other influential reports, and note a number of problem areas. Finally, we illustrate the concepts developed in this paper by applying them to some key species of geochemical interest, including liquid water; quartz and aqueous silica; and gibbsite, corundum, and the aqueous aluminum ion.
Wolery, Thomas J.; Jove Colon, Carlos F.
2016-09-26
Chemical thermodynamic data remain a keystone for geochemical modeling and reactive transport simulation as applied to an increasing number of applications in the earth sciences, as well as applications in other areas including metallurgy, material science, and industrial process design. The last century has seen the development of a large body of thermodynamic data and a number of major compilations. The past several decades have seen the development of thermodynamic databases in digital form designed to support computer calculations. However, problems with thermodynamic data appear to be persistent. One problem pertains to the use of inconsistent primary key reference data.more » Such data pertain to elemental reference forms and key, stoichiometrically simple chemical species including metal oxides, CO 2, water, and aqueous species such as Na + and Cl -. A consistent set of primary key data (standard Gibbs energies, standard enthalpies, and standard entropies for key chemical species) for 298.15K and 1 bar pressure is essential. Thermochemical convention is to define the standard Gibbs energy and the standard enthalpy of an individual chemical species in terms of formation from reference forms of the constituent chemical elements. We propose a formal concept of “links” to the elemental reference forms. This concept involves a documented understanding of all reactions and calculations leading to values for a formation property (standard Gibbs energy or enthalpy). A valid link consists of two parts: (a) the path of reactions and corrections and (b) the associated data, which are key data. Such a link differs from a bare “key” or “reference” datum in that it requires additional information. Some or all of its associated data may also be key data. In evaluating a reported thermodynamic datum, one should identify the links to the chemical elements, a process which can be time-consuming and which may lead to a dead end (an incomplete link). The use of two or more inconsistent links to the same elemental reference form in a thermodynamic database will result in an inconsistency in the database. Thus, in constructing a database, it is important to establish a set of reliable links (generally resulting in a set of primary reference data) and then correct all data adopted subsequently for consistency with that set. Recommended values of key data have not been constant through history. We review some of this history through the lens of major compilations and other influential reports, and note a number of problem areas. Finally, we illustrate the concepts developed in this paper by applying them to some key species of geochemical interest, including liquid water; quartz and aqueous silica; and gibbsite, corundum, and the aqueous aluminum ion.« less
An information theoretic approach of designing sparse kernel adaptive filters.
Liu, Weifeng; Park, Il; Principe, José C
2009-12-01
This paper discusses an information theoretic approach of designing sparse kernel adaptive filters. To determine useful data to be learned and remove redundant ones, a subjective information measure called surprise is introduced. Surprise captures the amount of information a datum contains which is transferable to a learning system. Based on this concept, we propose a systematic sparsification scheme, which can drastically reduce the time and space complexity without harming the performance of kernel adaptive filters. Nonlinear regression, short term chaotic time-series prediction, and long term time-series forecasting examples are presented.
About the Modeling of Radio Source Time Series as Linear Splines
NASA Astrophysics Data System (ADS)
Karbon, Maria; Heinkelmann, Robert; Mora-Diaz, Julian; Xu, Minghui; Nilsson, Tobias; Schuh, Harald
2016-12-01
Many of the time series of radio sources observed in geodetic VLBI show variations, caused mainly by changes in source structure. However, until now it has been common practice to consider source positions as invariant, or to exclude known misbehaving sources from the datum conditions. This may lead to a degradation of the estimated parameters, as unmodeled apparent source position variations can propagate to the other parameters through the least squares adjustment. In this paper we will introduce an automated algorithm capable of parameterizing the radio source coordinates as linear splines.
National geodetic satellite program, part 2
NASA Technical Reports Server (NTRS)
Schmid, H.
1977-01-01
Satellite geodesy and the creation of worldwide geodetic reference systems is discussed. The geometric description of the surface and the analytical description of the gravity field of the earth by means of worldwide reference systems, with the aid of satellite geodesy, are presented. A triangulation method based on photogrammetric principles is described in detail. Results are derived in the form of three dimensional models. These mathematical models represent the frame of reference into which one can fit the existing geodetic results from the various local datums, as well as future measurements.
2008-10-01
346 35 39 77 lnfo-DenV@tno nl Datum oktober 2008 Auteur (s) dr. ir. MM..I. Houben J.A. Verhave Rubricering rapport Ongerubriceerd Vastgesteld... Auteur (s) dr. ir. M.M.J. Houben J.A. Verhave Rubricering rapport Ongerubriceerd TNO-rapport | TNO-DV 2008 A395 4/19 Summary Sound exposure level...ontwikkeld om de geluidsexpositie van CEPs te bepalen (TNO-project 032.13072, rapport TNO-DV 2008 A054) [1], In theorie kan het totale
2007-04-01
inzetbaarheid van teams: ontwikkeling van een model van teamfunctioneren als module voor SCOPE Datumn april 2007 Auteur (s) R. de B~ruin C’. Vervvijs A.J...Datum april 2007 Programmaleider Projectleider Auteur (s) dr. W.A. Lotens, TNO Defensie en A.]. van Vijet, TNO Defensie en R. de Bruin Veiligheid...Deelnemers verwachten wel, in lijn met de theorie , dat een lage cohesie samenhangt met een lage effectiviteit. Een hoge cohesie, daarentegen, zou
2006-12-01
ante implementatietoetsing van beleid Een methodiek gebaseerd op synergie tussen risicomnanagemnent en verandermanagemnent Datuni december 2006 Auteur (s...te analyseren. Het de resultaten van de interviews gebruikct bij de theorie van risicomanagement en project Verandermanagernent bij de de ontwikkehing...Opdrachtnummer Hoewel expliciet is gekeken naar voorbeelden van risico’s bij Datum december 2006 Auteur (s) PROGRAMMA PR03ECT drs. R.C.T. de Haas drs
2007-09-01
Verboom Auteur TNO-rapport I TNO-DV 2007 A315 BijIage A I 1I7 A Berekening thermische explosiekubus A.1 Inleiding De theorie van een thermische...Responsie van verschillende munitieartikelen bij opwarming en brand Datum scptember 2007 Auteur (s) ir.J.H.G. Scholtes ir. V. Verboorn R Ubricering rapport O...mabegeleider Projectbegeleider Setembr20 Ltkol I Paap, G.B. Cornelisse, spebr20 DMO/DWS&B/Ressort Lucht- DS/CLAS/St-CLAS/Dir OPOST Auteur (s) systeen
New Orleans, LA, District: Report of the Secretary of the Army on Civil Works Activities for FY 2011
2011-01-01
side slopes, and protective vegetation. The sandfill berm slopes from an elevation of 8.5 feet, NGVD, at the toe of the dune 150 feet gulfward to an...and vegetated dune constructive with a geotextile tube core extending the length of Grand Isle’s gulf shore and a jetty to stabilize the western end...of the island at Caminada Pass. The dune has a 10-foot-wide crown at an elevation of 13.5 feet, National Geodetic Vertical Datum (NGVD), 1 on 5
Prototype Evaluation of Sluiceway Aeration System Libby Dam, Kootenai River, Montana.
1984-03-01
VICKSBURG MS H DRA.. R G MCGEE UNCLASSIFIED MAR 84 WES/TR/HL-84-2 F/G 13/13 NL- DE E-EullEI EEEEEIIIENEIII II I IE EEIImmiEmhihhhEEEI mEEmhEEihhEEm 1j...report of findings was published * All elevations ( el ) cited herein are in feet referred to the National Geodetic Vertical Datum (NGVD). 6 r.W (Hart...1981). Data derived from the test program were used as criteria for de - sign of a more efficient air vent system. 6. The resulting modification to the
Potentiometric surface of the Catahoula aquifer in central Louisiana, 2013
Fendick, Jr., Robert B.; Carter, Kayla
2015-12-09
The potentiometric surface of the Catahoula aquifer was constructed by using the altitude of water levels measured at 29 wells during the period May through September 2013. The altitude of water levels ranged from 0.02 ft above the National Geodetic Vertical Datum of 1929 (NGVD 29) in well Co-51 to 238 ft above NGVD 29 in well Na-317. Groundwater movement in the Catahoula aquifer is generally to the southeast and towards discharge areas beneath the Sabine, Red, Little, and Tensas River Valleys.
zorder-lib: Library API for Z-Order Memory Layout
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nowell, Lucy; Edward W. Bethel
2015-04-01
This document describes the motivation for, elements of, and use of the zorder-lib, a library API that implements organization of and access to data in memory using either a-order (also known as "row-major" order) or z-order memory layouts. The primary motivation for this work is to improve the performance of many types of data- intensive codes by increasing both spatial and temporal locality of memory accesses. The basic idea is that the cost associated with accessing a datum is less when it is nearby in either space or time.
Trajectory Simulation Model for a Side- Thruster Guided MLRS-Type Vehicle
1999-05-01
km halen . Voor de toekomst heeft men behoefte aan een dracht van ongeveer 60 km. Het is de doelstelling van opdracht A95KL410 om kennis en inzicht...G.M.H.J.L. Gadiot Datum mei 1999 Opdrachtnr. A95KL410 Rapportnr. PML 1998-A80 Figuur M.I.- Lancering van een M26-raket vanaf een MLRS ’launcher’. De...Koninklijke Nederlandse Landmacht (KL) heeft het ’Multiple Launcher Rocket System’ (MLRS) in gebruik. Met de huidige uitrusting kan men een dracht van 30
Geographical Information Extraction With Remote Sensing. Part I - Main Report.
1998-08-01
Oude Waalsdorperweg 63 Date P0 Box 96864 2509 JG The Hague August 1998 The Netherlands Author(s) Phone +31 70 374 00 00 Dr A.C. van den Broek Fax +31 70...328 09 61 M. van Persie H.H.S. Noorbergen Dr G.J. Rijckenberg SSponsor HWO-COfHWO-KL N E R Project officer J. Rogge Affiliation KIN/IA - i All...Main report Auteur(s) Dr. A.C. van den Broek, Ir. M. van Persie, Ing. H.H.S. Noorberg~en, Dr. G.J. Rijkenberg Datum augustus 1998 Opdrachtnr
Training with Simulated Team Members (Trainen met Gesimuleerde Teamieden).
1997-11-13
TEAMTAKEN 9 2.1 Teams 9 2.2 Teamtaken 10 2.3 De individuele deeltaken 11 2.4 De teamcomponent 11 2.5 Motivatie en attitudes 14 3 HET TRAINEN VAN TEAMS 15... 11 Fax 0346 35 39 77 datum 13 november 1997 Alle rechten voorbehouden. A oe a jb Miets uit deze uitgave mag worden vermenigvuldigd en/of openbaar...13 November 1997 7. NUMBER OF PAGES 8. NUMBER OF REFERENCES 9 . TYPE OF REPORT AND DATES COVERED 35 64 Interim 10. TITLE AND SUBTITLE Trainen met
Surface Gravity Data Contribution to the Puerto Rico and U.S. Virgin Islands Geoid Model
NASA Astrophysics Data System (ADS)
Li, X.; Gerhards, C.; Holmes, S. A.; Saleh, J.; Shaw, B.
2015-12-01
The Gravity for the Redefinition of the American Vertical Datum (GRAV-D) project provides updated local gravity field information for the XGEOID15 models. In particular, its airborne gravity data in the area of Puerto Rico and U.S. Virgin Islands (PRVI) made substantial improvements (~60%) on the precision of the geoid models at the local GNSS/Leveling bench marks in the target area. Fortunately, PRVI is free of the huge systematic error in the North American Vertical Datum of 1988 (NAVD88). Thus, the airborne contribution was evaluated more realistically. In addition, the airborne data picked up more detailed gravity field information in the medium wavelength band (spherical harmonic degree 200 to 600) that are largely beyond the resolution of the current satellite missions, especially along the nearby ocean trench areas. Under this circumstance (significant airborne contributions in the medium band), local surface gravity data need to be examined more carefully than before during merging with the satellite and airborne information for local geoid improvement, especially considering the well-known systematic problems in the NGS historical gravity holdings (Saleh et al 2013 JoG). Initial tests showed that it is very important to maintain high consistency between the surface data sets and the airborne enhanced reference model. In addition, a new aggregation method (Gerhards 2014, Inverse Problems) will also be tested to optimally combine the local surface data with the reference model. The data cleaning and combining procedures in the target area will be summarized here as reference for future applications.
A new morphology algorithm for shoreline extraction from DEM data
NASA Astrophysics Data System (ADS)
Yousef, Amr H.; Iftekharuddin, Khan; Karim, Mohammad
2013-03-01
Digital elevation models (DEMs) are a digital representation of elevations at regularly spaced points. They provide an accurate tool to extract the shoreline profiles. One of the emerging sources of creating them is light detection and ranging (LiDAR) that can capture a highly dense cloud points with high resolution that can reach 15 cm and 100 cm in the vertical and horizontal directions respectively in short periods of time. In this paper we present a multi-step morphological algorithm to extract shorelines locations from the DEM data and a predefined tidal datum. Unlike similar approaches, it utilizes Lowess nonparametric regression to estimate the missing values within the DEM file. Also, it will detect and eliminate the outliers and errors that result from waves, ships, etc by means of anomality test with neighborhood constrains. Because, there might be some significant broken regions such as branches and islands, it utilizes a constrained morphological open and close to reduce these artifacts that can affect the extracted shorelines. In addition, it eliminates docks, bridges and fishing piers along the extracted shorelines by means of Hough transform. Based on a specific tidal datum, the algorithm will segment the DEM data into water and land objects. Without sacrificing the accuracy and the spatial details of the extracted boundaries, the algorithm should smooth and extract the shoreline profiles by tracing the boundary pixels between the land and the water segments. For given tidal values, we qualitatively assess the visual quality of the extracted shorelines by superimposing them on the available aerial photographs.
NASA Astrophysics Data System (ADS)
Lin, Wei; Chen, Yu-hua; Wang, Ji-yuan; Gao, Hong-sheng; Wang, Ji-jun; Su, Rong-hua; Mao, Wei
2011-04-01
Detection probability is an important index to represent and estimate target viability, which provides basis for target recognition and decision-making. But it will expend a mass of time and manpower to obtain detection probability in reality. At the same time, due to the different interpretation of personnel practice knowledge and experience, a great difference will often exist in the datum obtained. By means of studying the relationship between image features and perception quantity based on psychology experiments, the probability model has been established, in which the process is as following.Firstly, four image features have been extracted and quantified, which affect directly detection. Four feature similarity degrees between target and background were defined. Secondly, the relationship between single image feature similarity degree and perception quantity was set up based on psychological principle, and psychological experiments of target interpretation were designed which includes about five hundred people for interpretation and two hundred images. In order to reduce image features correlativity, a lot of artificial synthesis images have been made which include images with single brightness feature difference, images with single chromaticity feature difference, images with single texture feature difference and images with single shape feature difference. By analyzing and fitting a mass of experiments datum, the model quantitys have been determined. Finally, by applying statistical decision theory and experimental results, the relationship between perception quantity with target detection probability has been found. With the verification of a great deal of target interpretation in practice, the target detection probability can be obtained by the model quickly and objectively.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Benedicto, A.; Labaume, P.; Seranne, M.
1995-08-01
Fault reconstruction techniques commonly assume horizontal pre-rift level datum to calculate fault geometry from hanging-wall geometry or viceversa. Example from Camargue basin shows that neglecting pre-rift relief may lead to important errors in calculating the fault and hanging-wall geometries, and the total extension. These errors have direct implications on reconstruction of the thermal history of basins. The Camargue basin results front NW-SE extension and rifting of the Gulf of Lion passive margin. More than 4000m of Oligo-Aquitanian syn-rift series unconformably overlie a crust previously thickened during Pyrenean orogeny. The half-graben basin is controlled by the SE-dipping listric Nimes basement faultmore » which generated a typical roll-over. As both fault and hanging-wall geometries are constrained, the pre-rift surface topography can be restored, using three reconstruction techniques. Either the constant-bed-length and constant-heave techniques produce a depression in the axis of the basin and a relief (1500m and 12(X)m respectively) atop the roll-over. The simple-shear (a=60{degrees}) technique generates a 1500m topography atop the roll-over, more coherent with regional data. Testing the hypothesis of a pre-rift horizontal datum leads to a roll-over 1400m too deep. Pre-rift surface elevation corresponds to the residual topography herited from the Pyrenean orogeny. Consequently, there has been some 1000m subsidence more than predicted by the syn-rift sedimentary record.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Essington, E.H.; Gilbert, R.O.; Wireman, D.L.
Blow-sand mounds or miniature sand dunes and mounds created by burrowing activities of animals were investigated by the Nevada Applied Ecology Group (NAEG) to determine the influence of mounds on plutonium, americium, and uranium distributions and inventories in areas of the Nevada Test Site and Tonopah Test Range. Those radioactive elements were added to the environment as a result of safety experiments of nuclear devices. Two studies were conducted. The first was to estimate the vertical distribution of americium in the blow-sand mounds and in the desert pavement surrounding the mounds. The second was to estimate the amount or concentrationmore » of the radioactive materials accumulated in the mound relative to the desert pavement. Five mound types were identified in which plutonium, americium, and uranium concentrations were measured: grass, shrub, complex, animal, and diffuse. The mount top (that portion above the surrounding land surface datum), the mound bottom (that portion below the mound to a depth of 5 cm below the surrounding land surface datum), and soil from the immediate area surrounding the mound were compared separately to determine if the radioactive elements had concentrated in the mounds. Results of the studies indicate that the mounds exhibit higher concentrations of plutonium, americium, and uranium than the immediate surrounding soil. The type of mound does not appear to have influenced the amount of the radioactive material found in the mound except for the animal mounds where the burrowing activities appear to have obliterated distribution patterns.« less
Limitations of correlation-based redatuming methods
NASA Astrophysics Data System (ADS)
Barrera P, D. F.; Schleicher, J.; van der Neut, J.
2017-12-01
Redatuming aims to correct seismic data for the consequences of an acquisition far from the target. That includes the effects of an irregular acquisition surface and of complex geological structures in the overburden such as strong lateral heterogeneities or layers with low or very high velocity. Interferometric techniques can be used to relocate sources to positions where only receivers are available and have been used to move acquisition geometries to the ocean bottom or transform data between surface-seismic and vertical seismic profiles. Even if no receivers are available at the new datum, the acquisition system can be relocated to any datum in the subsurface to which the propagation of waves can be modeled with sufficient accuracy. By correlating the modeled wavefield with seismic surface data, one can carry the seismic acquisition geometry from the surface closer to geologic horizons of interest. Specifically, we show the derivation and approximation of the one-sided seismic interferometry equation for surface-data redatuming, conveniently using Green’s theorem for the Helmholtz equation with density variation. Our numerical examples demonstrate that correlation-based single-boundary redatuming works perfectly in a homogeneous overburden. If the overburden is inhomogeneous, primary reflections from deeper interfaces are still repositioned with satisfactory accuracy. However, in this case artifacts are generated as a consequence of incorrectly redatumed overburden multiples. These artifacts get even worse if the complete wavefield is used instead of the direct wavefield. Therefore, we conclude that correlation-based interferometric redatuming of surface-seismic data should always be applied using direct waves only, which can be approximated with sufficient quality if a smooth velocity model for the overburden is available.
NASA Astrophysics Data System (ADS)
Alvarez, Gabriel O.
2018-05-01
Hydrocarbon exploration in Argentina started long before the IGM created a single, high-precision geodetic reference network for the whole country. Several geodetic surveys were conducted in every producing basin, which have ever since then supported well placement. Currently, every basin has a huge amount of information referenced to the so-called "local" geodetic systems, such as Chos Malal - Quiñi Huao in the Neuquén Basin, and Pampa del Castillo in the San Jorge Basin, which differ to a greater or lesser extent from the national Campo Inchauspe datum established by the IGM in 1969 as the official geodetic network. However, technology development over the last few years and the expansion of satellite positioning systems such as GPS resulted in a new world geodetic order. Argentina rapidly joined this new geodetic order through the implementation of a new national geodetic system by the IGM: POSGAR network, which replaced the old national Campo Inchauspe system. However, this only helped to worsen the data georeferencing issue for oil companies, as a third reference system was added to each basin. Now every basin has a local system, the national system until 1997 (Campo Inchauspe), and finally the newly created POSGAR network national satellite system, which is geocentric unlike the former two planimetric datums. The purpose of this paper is to identify and allocate geodetic systems of coordinates to historical wells, whose geodetic system is missing or has been erroneously allocated, by using currently available technological resources such as geographic information systems and high-resolution satellite imagery.
Effect of tip flange on tip leakage flow of small axial flow fans
NASA Astrophysics Data System (ADS)
Zhang, Li; Jin, Yingzi; Jin, Yuzhen
2014-02-01
Aerodynamic performance of an axial flow fan is closely related to its tip clearance leakage flow. In this paper, the hot-wire anemometer is used to measure the three dimensional mean velocity near the blade tips. Moreover, the filtered N-S equations with finite volume method and RNG k-ɛ turbulence model are adopted to carry out the steady simulation calculation of several fans that differ only in tip flange shape and number. The large eddy simulation and the FW-H noise models are adopted to carry out the unsteady numerical calculation and aerodynamic noise prediction. The results of simulation calculation agree roughly with that of tests, which proves the numerical calculation method is feasible.The effects of tip flange shapes and numbers on the blade tip vortex structure and the characteristics are analyzed. The results show that tip flange of the fan has a certain influence on the characteristics of the fan. The maximum efficiencies for the fans with tip flanges are shifted towards partial flow with respect to the design point of the datum fan. Furthermore, the noise characteristics for the fans with tip flanges have become more deteriorated than that for the datum fan. Tip flange contributes to forming tip vortex shedding and the effect of the half-cylinder tip flange on tip vortex shedding is obvious. There is a distinct relationship between the characteristics of the fan and tip vortex shedding. The research results provide the profitable reference for the internal flow mechanism of the performance optimization of small axial flow fans.
Schrader, T.P.; Jones, J.S.
2007-01-01
The U.S. Geological Survey in cooperation with the Arkansas Natural Resources Commission, the Arkansas Geological Commission, and the Louisiana Department of Transportation and Development has monitored water levels in the Sparta Sand of Claiborne Group and Memphis Sand of Claiborne Group since the 1920's. Ground-water withdrawals have increased while water levels have declined since monitoring was initiated. This report has been produced to describe ground-water levels in the aquifers in the Sparta Sand and Memphis Sand and provide information for the management of this valuable resource. The 2005 potentiometric-surface map of the aquifers in the Sparta Sand and Memphis Sand was constructed using water-level data collected in 333 wells in Arkansas and 120 wells in Louisiana during the spring of 2005. The highest water-level altitude measured in Arkansas was 327 feet above National Geodetic Vertical Datum of 1929 located in Grant County in the outcrop at the western boundary of the study area; the lowest water-level altitude was 189 feet below National Geodetic Vertical Datum of 1929 in Union County. The highest water-level altitude measured in Louisiana was 246 feet above National Geodetic Vertical Datum of 1929 located in Bossier Parish in the outcrop area near the western boundary of the study area; the lowest water-level altitude was 226 feet below National Geodetic Vertical Datum of 1929 in central Ouachita Parish. Three large depressions centered in Columbia, Jefferson, and Union Counties in Arkansas are the result of large withdrawals for industrial and public supplies. In Louisiana, three major pumping centers are in Ouachita, Jackson, and Lincoln Parishes. Water withdrawals from these major pumping centers primarily is used for industrial and public-supply purposes. Withdrawals from Ouachita and Lincoln Parishes and Union County, Arkansas, primarily for industrial purposes, have caused the resulting cones of depression to coalesce so that the -40 foot potentiometric contour encircles the three pumping centers. Seven smaller depressions are evident on the 2005 Sparta-Memphis potentiometric-surface map located in Webster and Winn Parishes, Louisiana, and Calhoun, Cleveland, western Columbia, Desha, and Lafayette Counties, Arkansas. The depression in Calhoun County initially was shown in the 1996-1997 potentiometric surface. The depression in Desha County initially was shown in the 1999 potentiometric surface. The depressions in Webster and Winn Parishes were shown as early as 1975. The depressions in Cleveland, western Columbia, and Lafayette Counties initially were shown in the 2003 potentiometric surface. A map of differences in water-level measurements between 2001 and 2005 was constructed using the difference between water-level measurements from 294 wells in Arkansas and 29 wells in Louisiana. The difference in water levels between 2001 and 2005 ranged from -30.1 to 44.6 feet. The largest rise of 44.6 feet in water level measured was in Union County in Arkansas. The largest decline of 30.1 feet in water level measured was in Columbia County in Arkansas. Areas with a general rise in water levels in Arkansas are shown in Arkansas, Columbia, Craighead, Jefferson, Prairie, and the western half of Union Counties. The area around west-central Union County had rises as much as 44.6 feet, with seven wells showing a rise of 20 feet or greater, which is an annual rise of 5 feet or greater. Areas in Arkansas with a general decline in water level are shown in western Bradley, eastern Calhoun, Cleveland, Cross, Desha, Drew, Lafayette, Lee, Lincoln, Lonoke, Poinsett, and the eastern half of Union Counties. In Louisiana, the water-level difference map showed a general rise in water levels in northern Claiborne, northern Webster, and northwestern Union Parishes mainly because of a decrease in industrial withdrawals in southern Arkansas, particularly Union County. Another rise in water level was indicated in western
NASA Technical Reports Server (NTRS)
Kraal, E. R.; Moore, J. M.; Howard, A. D.; Asphaug, E. A.
2005-01-01
Moore and Howard [1] reported the discovery of large alluvial fans in craters on Mars. Their initial survey from 0-30 S found that these fans clustered in three distinct regions and occurred at around the +1 km MOLA defined Mars datum. However, due to incomplete image coverage, Moore and Howard [1]could not conduct a comprehensive survey. They also recognized, though did not quantitatively address, gravity scaling issues. Here, we briefly discuss the identification of alluvial fans on Mars, then consider the general equations governing the deposition of alluvial fans and hypothesize a method for learning about grain size in alluvial fans on Mars.
Ponce, David A.
1997-01-01
Gravity data for the entire state of Nevada and adjacent parts of California, Utah, and Arizona are available on this CD-ROM. About 80,000 gravity stations were compiled primarily from the National Geophysical Data Center and the U.S. Geological Survey. Gravity data was reduced to the Geodetic Reference System of 1967 and adjusted to the Gravity Standardization Net 1971 gravity datum. Data were processed to complete Bouguer and isostatic gravity anomalies by applying standard gravity corrections including terrain and isostatic corrections. Selected principal fact references and a list of sources for data from the National Geophysical Data Center are included.
2008-11-01
F +31 15 284 39 91 info-DenV@tno.nl TNO-rapportnummer TNO-DV 2008 A357 Opdrachtnummer Datum november 2008 Auteur (s) ir. O.C. van der Jagt...een keramisch materiaal (ZrSiO.*). TNO-rapport | TNO-DV 2008 A357 32/44 K, 04 035 0.3 0 25 02 0 15 01 005 0 O a 0 X A • • Theory ...47] Molinari. A., et al., Modeling plastic shocks in periodic laminates with gradient plasticity theories . Journal of the Mechanics and Physics of
Nonlocal systems of balance laws in several space dimensions with applications to laser technology
NASA Astrophysics Data System (ADS)
Colombo, Rinaldo M.; Marcellini, Francesca
2015-12-01
For a class of systems of nonlinear and nonlocal balance laws in several space dimensions, we prove the local in time existence of solutions and their continuous dependence on the initial datum. The choice of this class is motivated by a new model devoted to the description of a metal plate being cut by a laser beam. Using realistic parameters, solutions to this model obtained through numerical integrations meet qualitative properties of real cuts. Moreover, the class of equations considered comprises a model describing the dynamics of solid particles along a conveyor belt.
A simple procedure for synthesizing Charpy impact energy transition curves from limited test data
DOE Office of Scientific and Technical Information (OSTI.GOV)
Rosenfeld, M.J.
1996-12-31
The importance of Charpy V-notch testing of pipe has been well established in the pipeline industry. Until now, it has been necessary to perform a number of tests in order to develop the toughness transition curve. A method is described which makes possible forecasting the full-scale toughness transition from a single subsize test datum to an acceptable degree of accuracy. This is potentially useful where historical test results or material samples available for testing are limited in quantity. Worked examples illustrating the use of the relationships are given.
Ultra-High-Density Ferroelectric Memories
NASA Technical Reports Server (NTRS)
Thakoor, Sarita
1995-01-01
Features include fast input and output via optical fibers. Memory devices of proposed type include thin ferroelectric films in which data stored in form of electric polarization. Assuming one datum stored in region as small as polarization domain, sizes of such domains impose upper limits on achievable storage densities. Limits approach 1 terabit/cm(Sup2) in all-optical versions of these ferroelectric memories and exceeds 1 gigabit/cm(Sup2) in optoelectronic versions. Memories expected to exhibit operational lives of about 10 years, input/output times of about 10 ns, and fatigue lives of about 10(Sup13) cycles.
Precise measurement of the half-life of the Fermi {beta} decay of {sup 26}Al{sup m}
DOE Office of Scientific and Technical Information (OSTI.GOV)
Scott, Rebecca J.; Thompson, Maxwell N.; Rassool, Roger P.
2011-08-15
State-of-the-art signal digitization and analysis techniques have been used to measure the half-life of the Fermi {beta} decay of {sup 26}Al{sup m}. The half-life was determined to be 6347.8 {+-} 2.5 ms. This new datum contributes to the experimental testing of the conserved-vector-current hypothesis and the required unitarity of the Cabibbo-Kobayashi-Maskawa matrix: two essential components of the standard model. Detailed discussion of the experimental techniques and data analysis and a thorough investigation of the statistical and systematic uncertainties are presented.
Coastal Digital Elevation Models (DEMs) for tsunami hazard assessment on the French coasts
NASA Astrophysics Data System (ADS)
Maspataud, Aurélie; Biscara, Laurie; Hébert, Hélène; Schmitt, Thierry; Créach, Ronan
2015-04-01
Building precise and up-to-date coastal DEMs is a prerequisite for accurate modeling and forecasting of hydrodynamic processes at local scale. Marine flooding, originating from tsunamis, storm surges or waves, is one of them. Some high resolution DEMs are being generated for multiple coast configurations (gulf, embayment, strait, estuary, harbor approaches, low-lying areas…) along French Atlantic and Channel coasts. This work is undertaken within the framework of the TANDEM project (Tsunamis in the Atlantic and the English ChaNnel: Definition of the Effects through numerical Modeling) (2014-2017). DEMs boundaries were defined considering the vicinity of French civil nuclear facilities, site effects considerations and potential tsunamigenic sources. Those were identified from available historical observations. Seamless integrated topographic and bathymetric coastal DEMs will be used by institutions taking part in the study to simulate expected wave height at regional and local scale on the French coasts, for a set of defined scenarii. The main tasks were (1) the development of a new capacity of production of DEM, (2) aiming at the release of high resolution and precision digital field models referred to vertical reference frameworks, that require (3) horizontal and vertical datum conversions (all source elevation data need to be transformed to a common datum), on the basis of (4) the building of (national and/or local) conversion grids of datum relationships based on known measurements. Challenges in coastal DEMs development deal with good practices throughout model development that can help minimizing uncertainties. This is particularly true as scattered elevation data with variable density, from multiple sources (national hydrographic services, state and local government agencies, research organizations and private engineering companies) and from many different types (paper fieldsheets to be digitized, single beam echo sounder, multibeam sonar, airborne laser bathymetric and topographic data, …) were gathered. Consequently, datasets were first assessed internally for both quality and accuracy and then externally with other to ensure consistency and gradual topographic/bathymetric transitioning along limits of the datasets. The heterogeneous ages of the input data also stress the importance of taking into account the temporal variability of bathymetric features, especially in the active areas (sandbanks, estuaries, channels). Locally, gaps between marine (hydrographic surveys) and terrestrial (topographic LIDAR) data have required the introduction of new methods and tools to solve interpolation. Through these activities the goal is to improve the production line and to enhance tools and procedures used for the improvement of processing, validation and qualification algorithms of bathymetric data, data collection work, automation of processing and integration process for conception of improved both bathymetric and topographic DEMs, merging data collected. This work is supported by a French ANR program in the frame of "Investissements d'Avenir", under the grant ANR-11-RSNR-00023-01.
NASA Astrophysics Data System (ADS)
Viglietti, Pia A.; Smith, Roger M. H.; Angielczyk, Kenneth D.; Kammerer, Christian F.; Fröbisch, Jörg; Rubidge, Bruce S.
2016-01-01
The Dicynodon Assemblage Zone (DiAZ) of South Africa's Karoo Basin is one of the eight biostratigraphic zones of the Beaufort Group. It spans the uppermost Permian strata (Balfour, Teekloof, and Normandien formations) and traditionally has been considered to terminate with the disappearance of Dicynodon lacerticeps at the Permo-Triassic Boundary. We demonstrate that the three index fossils currently used to define the Dicynodon Assemblage Zone (Dicynodon lacerticeps, Theriognathus microps, and Procynosuchus delaharpeae) have first appearance datums (FADs) below its traditionally recognized lower boundary and have ranges mostly restricted to the lower portion of the biozone, well below the Permo-Triassic Boundary. We propose re-establishing Daptocephalus leoniceps as an index fossil for this stratigraphic interval, and reinstating the name Daptocephalus Assemblage Zone (DaAZ) for this unit. Furthermore, the FAD of Lystrosaurus maccaigi in the uppermost reaches of the biozone calls for the establishment of a two-fold subdivision of the current Dicynodon Assemblage Zone. The biostratigraphic utility of Da. leoniceps and other South African dicynodontoids outside of the Karoo Basin is limited due to basinal endemism at the species level and varying temporal ranges of dicynodontoids globally. Therefore, we recommend their use only for correlation within the Karoo Basin at this time. Revision of the stratigraphic ranges of all late Permian tetrapods does not reveal a significant change in faunal diversity between the lower and upper DaAZ. However, the last appearance datums of the abundant taxa Di. lacerticeps, T. microps, P. delaharpeae, and Diictodon feliceps occur below the three extinction phases associated with the end-Permian mass extinction event. Due to northward attenuation of the strata, however, the stratigraphic position of the extinction phases may need to be reconsidered.
Aerial profiling of terrain to define stream-valley geometry: study report
Desai, Mukund; Drohan, William A.; Hursh, John W.; Mamon, Glenn; Youmans, Douglas G.
1976-01-01
A six-month engineering analysis was performed by The Charles Stark Draper Laboratory, Inc., at the request of the U. S. Geological Survey, to investigate the suitability of an airborne instrument package based on inertial techniques to serve as the datum for a laser altimeter in a system for aerial profiling of terrain to determine selected features of stream-valley geometry to an accuracy of ± 0.5 ft. in the vertical coordinate and ± 10 ft. in the horizontal coordinates. Feasible system configuration features a high performance inertial platform incorporating an integral laser tracker, pointing and ranging on retroreflectors on the ground, in order to provide the frequent updates needed to meet the accuracy requirements. In all environments except those of severe gravity gradients the nominal two- by twenty-mile survey area can be covered using three ground-surveyed retroreflectors, interspersed with several unlocated retroreflectors that are surveyed in by the airborne system along a longitudinal path within the river valley when the aircraft arrives over the site. Subsequent transverse profiling runs (traverses that may be spaced as close as one-quarter mile apart) are flown using, in turn, all retroreflectors as updating position references. Pointing and range information from the tracker are optimally combined with the on-board inertial measurements and available gravity data to provide position information and serve as the height datum for a terrain-clearance measuring laser altimeter. Data-logging means and operator display, as well as steering commands to the aircraft autopilot, are provided. The system configuration is capable of operating in single- or twin-engine aircraft including helecopters. It is recommended that work proceed into the design phase.
NASA Astrophysics Data System (ADS)
Rabah, Mostafa; Elmewafey, Mahmoud; Farahan, Magda H.
2016-06-01
A geodetic control network is the wire-frame or the skeleton on which continuous and consistent mapping, Geographic Information Systems (GIS), and surveys are based. Traditionally, geodetic control points are established as permanent physical monuments placed in the ground and precisely marked, located, and documented. With the development of satellite surveying methods and their availability and high degree of accuracy, a geodetic control network could be established by using GNSS and referred to an international terrestrial reference frame used as a three-dimensional geocentric reference system for a country. Based on this concept, in 1992, the Egypt Survey Authority (ESA) established two networks, namely High Accuracy Reference Network (HARN) and the National Agricultural Cadastral Network (NACN). To transfer the International Terrestrial Reference Frame to the HARN, the HARN was connected with four IGS stations. The processing results were 1:10,000,000 (Order A) for HARN and 1:1,000,000 (Order B) for NACN relative network accuracy standard between stations defined in ITRF1994 Epoch1996. Since 1996, ESA did not perform any updating or maintaining works for these networks. To see how non-performing maintenance degrading the values of the HARN and NACN, the available HARN and NACN stations in the Nile Delta were observed. The Processing of the tested part was done by CSRS-PPP Service based on utilizing Precise Point Positioning "PPP" and Trimble Business Center "TBC". The study shows the feasibility of Precise Point Positioning in updating the absolute positioning of the HARN network and its role in updating the reference frame (ITRF). The study also confirmed the necessity of the absent role of datum maintenance of Egypt networks.
Modeling the North American vertical datum of 1988 errors in the conterminous United States
NASA Astrophysics Data System (ADS)
Li, X.
2018-02-01
A large systematic difference (ranging from -20 cm to +130 cm) was found between NAVD 88 (North AmericanVertical Datum of 1988) and the pure gravimetric geoid models. This difference not only makes it very difficult to augment the local geoid model by directly using the vast NAVD 88 network with state-of-the-art technologies recently developed in geodesy, but also limits the ability of researchers to effectively demonstrate the geoid model improvements on the NAVD 88 network. Here, both conventional regression analyses based on various predefined basis functions such as polynomials, B-splines, and Legendre functions and the Latent Variable Analysis (LVA) such as the Factor Analysis (FA) are used to analyze the systematic difference. Besides giving a mathematical model, the regression results do not reveal a great deal about the physical reasons that caused the large differences in NAVD 88, which may be of interest to various researchers. Furthermore, there is still a significant amount of no-Gaussian signals left in the residuals of the conventional regression models. On the other side, the FA method not only provides a better not of the data, but also offers possible explanations of the error sources. Without requiring extra hypothesis tests on the model coefficients, the results from FA are more efficient in terms of capturing the systematic difference. Furthermore, without using a covariance model, a novel interpolating method based on the relationship between the loading matrix and the factor scores is developed for predictive purposes. The prediction error analysis shows that about 3-7 cm precision is expected in NAVD 88 after removing the systematic difference.
NASA Astrophysics Data System (ADS)
Rummel, R.
2012-12-01
With the gravity field and steady-state ocean circulation explorer (GOCE) (preferably combined with the gravity field and climate experiment (GRACE)) a new generation of geoid models will become available for use in height determination. These models will be globally consistent, accurate (
Alaska/Yukon Geoid Improvement by a Data-Driven Stokes's Kernel Modification Approach
NASA Astrophysics Data System (ADS)
Li, Xiaopeng; Roman, Daniel R.
2015-04-01
Geoid modeling over Alaska of USA and Yukon Canada being a trans-national issue faces a great challenge primarily due to the inhomogeneous surface gravity data (Saleh et al, 2013) and the dynamic geology (Freymueller et al, 2008) as well as its complex geological rheology. Previous study (Roman and Li 2014) used updated satellite models (Bruinsma et al 2013) and newly acquired aerogravity data from the GRAV-D project (Smith 2007) to capture the gravity field changes in the targeting areas primarily in the middle-to-long wavelength. In CONUS, the geoid model was largely improved. However, the precision of the resulted geoid model in Alaska was still in the decimeter level, 19cm at the 32 tide bench marks and 24cm on the 202 GPS/Leveling bench marks that gives a total of 23.8cm at all of these calibrated surface control points, where the datum bias was removed. Conventional kernel modification methods in this area (Li and Wang 2011) had limited effects on improving the precision of the geoid models. To compensate the geoid miss fits, a new Stokes's kernel modification method based on a data-driven technique is presented in this study. First, the method was tested on simulated data sets (Fig. 1), where the geoid errors have been reduced by 2 orders of magnitude (Fig 2). For the real data sets, some iteration steps are required to overcome the rank deficiency problem caused by the limited control data that are irregularly distributed in the target area. For instance, after 3 iterations, the standard deviation dropped about 2.7cm (Fig 3). Modification at other critical degrees can further minimize the geoid model miss fits caused either by the gravity error or the remaining datum error in the control points.
NASA Astrophysics Data System (ADS)
Theresa, D. M.; Vicki, C.; Dan, R.; Dru, S.
2008-12-01
The primary objective of the GRAV-D (Gravity for the Redefinition of the American Vertical Datum) project is to redefine the American vertical datum by using an improved gravimetric geoid. This will be partially accomplished through an extensive airborne gravity measurement campaign, focusing first on the land/water interface (and later on interior areas) of the US and its holdings. This airborne campaign is designed specifically to capture intermediate wavelength gravity information by flying at high altitudes (35,000 ft, ~10 km) with a 10 km line spacing. The intermediate wavelengths captured by airborne gravity data are complementary to ground and satellite gravity data. Combining the GRAV-D airborne gravity data with the Gravity Recovery and Climate Experiment (GRACE) satellite gravity field will allow existing terrestrial data sets to be corrected for bias and trend problems. Ultimately, all three types of data can then be merged into a single accurate representation of the gravity field. Typically, the airborne gravity data reduction process is used to produce free-air anomalies for geological/geophysical applications that require more limited accuracy and precision than do geodetic applications. Thus we re-examine long-standing data reduction simplifications and assumptions with an aim toward improving both the accuracy and precision of airborne gravity data before their inclusion into a gravimetric geoid. The data reduction process is tested on a 400 km x 500 km airborne gravity survey in southern Alaska (in the vicinity of Anchorage) collected in the summer of 2008 as part of the GRAV-D project. Potential improvements in processing come from examining the impacts of various GPS processing schemes on free-air gravity results and re-considering all assumptions in standard airborne gravity processing methods, especially those that might introduce bias into absolute gravity levels.
1981-03-19
on the design drawings appear to be from an arbitrary site datum. a. Drainage Area 0.49 square mile(1) b. Discharge at Dam Site ( cfs ) Maximum known...555 cfs ) meets the state’s "C" curve criteria. The report further notes that sufficient storage is provided between normal pool and emergency spillway...spillway, both located near the left abutment. The combined spillway capacity was estimated to be 6500 cfs , based on 6.8 feet of available freeboard
Bathymetry of the Hong and Luoc River Junction, Red River Delta, Vietnam, 2010
Kinzel, Paul J.; Nelson, Jonathan M.; Toan, Duong Duc; Thanh, Mung Dinh; Shimizu, Yasuyuki
2012-01-01
The U.S. Geological Survey, in collaboration with the Water Resources University in Hanoi, Vietnam, conducted a bathymetric survey of the junction of the Hong and Luoc Rivers. The survey was done to characterize the channel morphology of this delta distributary network and provide input for hydrodynamic and sediment transport models. The survey was carried out in December 2010 using a boat-mounted multibeam echo sounder integrated with a global positioning system. A bathymetric map of the Hong and Luoc River junction was produced which was referenced to the datum of the Trieu Duong tide gage on the Luoc River.
Design and realization of the optical and electron beam alignment system for the HUST-FEL oscillator
NASA Astrophysics Data System (ADS)
Fu, Q.; Tan, P.; Liu, K. F.; Qin, B.; Liu, X.
2018-06-01
A Free Electron Laser(FEL) oscillator with radiation wavelength at 30-100 μ m is under commissioning at Huazhong University of Science and Technology (HUST). This work presents the schematic design and realization procedures for the optical and beam alignment system in the HUST FEL facility. The optical cavity misalignment effects are analyzed with the code OPC + Genesis 1.3, and the tolerance of misalignment is proposed with the simulation result. Depending on undulator mechanical benchmarks, a laser indicating system has been built up as reference datum. The alignment of both optical axis and beam trajectory were achieved by this alignment system.
Determining Coastal Mean Dynamic Topography by Geodetic Methods
NASA Astrophysics Data System (ADS)
Huang, Jianliang
2017-11-01
In geodesy, coastal mean dynamic topography (MDT) was traditionally determined by spirit leveling technique. Advances in navigation satellite positioning (e.g., GPS) and geoid determination enable space-based leveling with an accuracy of about 3 cm at tide gauges. Recent CryoSat-2, a satellite altimetry mission with synthetic aperture radar (SAR) and SAR interferometric measurements, extends the space-based leveling to the coastal ocean with the same accuracy. However, barriers remain in applying the two space-based geodetic methods for MDT determination over the coastal ocean because current geoid modeling focuses primarily on land as a substitute to spirit leveling to realize the vertical datum.
Data-Dictionary-Editing Program
NASA Technical Reports Server (NTRS)
Cumming, A. P.
1989-01-01
Access to data-dictionary relations and attributes made more convenient. Data Dictionary Editor (DDE) application program provides more convenient read/write access to data-dictionary table ("descriptions table") via data screen using SMARTQUERY function keys. Provides three main advantages: (1) User works with table names and field names rather than with table numbers and field numbers, (2) Provides online access to definitions of data-dictionary keys, and (3) Provides displayed summary list that shows, for each datum, which data-dictionary entries currently exist for any specific relation or attribute. Computer program developed to give developers of data bases more convenient access to the OMNIBASE VAX/IDM data-dictionary relations and attributes.
Fröba, Andreas P; Kremer, Heiko; Leipertz, Alfred
2008-10-02
The density, refractive index, interfacial tension, and viscosity of ionic liquids (ILs) [EMIM][EtSO 4] (1-ethyl-3-methylimidazolium ethylsulfate), [EMIM][NTf 2] (1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide), [EMIM][N(CN) 2] (1-ethyl-3-methylimidazolium dicyanimide), and [OMA][NTf 2] (trioctylmethylammonium bis(trifluoromethylsulfonyl)imide) were studied in dependence on temperature at atmospheric pressure both by conventional techniques and by surface light scattering (SLS). A vibrating tube densimeter was used for the measurement of density at temperatures from (273.15 to 363.15) K and the results have an expanded uncertainty ( k = 2) of +/-0.02%. Using an Abbe refractometer, the refractive index was measured for temperatures between (283.15 and 313.15) K with an expanded uncertainty ( k = 2) of about +/-0.0005. The interfacial tension was obtained from the pendant drop technique at a temperature of 293.15 K with an expanded uncertainty ( k = 2) of +/-1%. For higher and lower temperatures, the interfacial tension was estimated by an adequate prediction scheme based on the datum at 293.15 K and the temperature dependence of density. For the ILs studied within this work, at a first order approximation, the quantity directly accessible by the SLS technique was the ratio of surface tension to dynamic viscosity. By combining the experimental results of the SLS technique with density and interfacial tension from conventional techniques, the dynamic viscosity could be obtained for temperatures between (273.15 and 333.15) K with an estimated expanded uncertainty ( k = 2) of less than +/-3%. The measured density, refractive index, and viscosity are represented by interpolating expressions with differences between the experimental and calculated values that are comparable with but always smaller than the expanded uncertainties ( k = 2). Besides a comparison with the literature, the influence of structural variations on the thermophysical properties of the ILs is discussed in detail. The viscosities mostly agree with values reported in the literature within the combined estimated expanded uncertainties ( k = 2) of the measurements while our density and interfacial tension data differ by more than +/-1% and +/-5%.
The morphology of the Martian surface
Carr, M.H.
1980-01-01
Most of the southern hemisphere of Mars is densely cratered and stands 1-3 km above the topographic datum. The northern hemisphere is more sparsely cratered and elevations are generally below the datum. A broad rise, the Tharsis bulge, centered at 14?? S, 101?? W, is 8000 km across and 10 km above the datum at its summit. The densely cratered terrain has two main components; very ancient crust, nearly saturated with large craters, and younger intercrater plains. In many areas the older unit is fractured and extensively dissected by small channels. The younger intercrater plains are distinctly layered in places and less dissected, less fractured, and less cratered. Both units probably date from very early in the planet's history. Cratered plains cover much of the northern hemisphere and are highly variegated. Those around the large volcanoes are covered with numerous volcanic flows whereas in other areas the plains are featureless except for craters and lunar mare-like ridges. Between 40?? N and 60?? N the plains are complex with various kinds of striped and patterned ground, low escarpments, and isolated irregularly shaped mesas. Their peculiar morphology has been attributed, in part, to the repeated deposition and removal of volatile-rich debris layers. Along the boundary between the northern plains and the densely cratered terrain to the south, the plains and cratered terrain complexly inter-finger. The old terrain forms the high ground and appears to have undergone mass wasting on a large scale. In several areas, particularly south of Chryse Planitia, the old, cratered surface has collapsed to form chaotic terrain. Large channels, tens of kilometers wide and hundreds of kilometers long, with numerous characteristics suggestive of catastrophic flooding, commonly emerge from the chaotic areas. Much of the area between 50?? W and 180?? W and 50?? N and 50?? S is cut by fractures radial to the center of the Tharsis bulge. The equatorial canyon system, Valles Marineris, is radial to the bulge and appears to have formed largely by faulting along the radial fractures, although it has also been extensively modified by various mass wasting and fluvial processes. Most but not all volcanoes are in the Tharsis and Elysium regions. The largest resemble terrestrial shield volcanoes except for scale; the edifices, flow features and calderas are all far larger than their terrestrial counterparts. Most impact craters on Mars are surrounded by layers of ejecta, each with a distil ridge. This unique morphology coupled with other surface characteristics suggests large amounts of ground ice. Layered deposits at both poles appear to be relatively young, volatile-rich, aeolian deposits. The north pole is also surrounded by a continuous belt of dunes several tens of kilometers across. In most other places, aeolian modification of the surface at a scale of several tens of meters appears slight despite annual global dust storms. ?? 1980 D. Reidel Publishing Co.
Home disadvantage in professional ice hockey.
Loignon, Andrew; Gayton, William F; Brown, Melissa; Steinroeder, William; Johnson, Carrie
2007-06-01
Occurrence of the home field disadvantage in professional ice hockey was examined by analyzing data on penalty shots from 1983-2004. This datum was used as it does not involve physical contact for only the player taking the penalty shot is involved in the outcome. As a result, inhibition of anxiety associated with physical contact should not occur, and diffusion of responsibility would not occur since only the shooter is involved. Analysis indicated the player who took the penalty shot did not make significantly fewer shots at home than in away games. The result did not support hypotheses about roles of physical contact and diffusion of responsibility in accounting for past failures to find the home disadvantage in professional ice hockey.
NASA Technical Reports Server (NTRS)
Li, Rongsheng (Inventor); Wu, Yeong-Wei Andy (Inventor); Hein, Douglas H. (Inventor)
2004-01-01
A method and apparatus for determining star tracker misalignments is disclosed. The method comprises the steps of defining a defining a reference frame for the star tracker assembly according to a boresight of the primary star tracker and a boresight of a second star tracker wherein the boresight of the primary star tracker and a plane spanned by the boresight of the primary star tracker and the boresight of the second star tracker at least partially define a datum for the reference frame for the star tracker assembly; and determining the misalignment of the at least one star tracker as a rotation of the defined reference frame.
Detailed gravimetric geoid for the United States.
NASA Technical Reports Server (NTRS)
Strange, W. E.; Vincent, S. F.; Berry, R. H.; Marsh, J. G.
1972-01-01
A detailed gravimetric geoid was computed for the United States using a combination of satellite-derived spherical harmonic coefficients and 1 by 1 deg mean gravity values from surface gravimetry. Comparisons of this geoid with astrogeodetic geoid data indicate that a precision of plus or minus 2 meters has been obtained. Translations only were used to convert the NAD astrogeodetic geoid heights to geocentric astrogeodetic heights. On the basis of the agreement between the geocentric astrogeodetic geoid heights and the gravimetric geoid heights, no evidence is found for rotation in the North American datum. The value of the zero-order undulation can vary by 10 to 20 meters, depending on which investigator's station positions are used to establish it.
NASA Astrophysics Data System (ADS)
Abellán-Nebot, J. V.; Liu, J.; Romero, F.
2009-11-01
The State Space modelling approach has been recently proposed as an engineering-driven technique for part quality prediction in Multistage Machining Processes (MMP). Current State Space models incorporate fixture and datum variations in the multi-stage variation propagation, without explicitly considering common operation variations such as machine-tool thermal distortions, cutting-tool wear, cutting-tool deflections, etc. This paper shows the limitations of the current State Space model through an experimental case study where the effect of the spindle thermal expansion, cutting-tool flank wear and locator errors are introduced. The paper also discusses the extension of the current State Space model to include operation variations and its potential benefits.
Construction Theory and Noise Analysis Method of Global CGCS2000 Coordinate Frame
NASA Astrophysics Data System (ADS)
Jiang, Z.; Wang, F.; Bai, J.; Li, Z.
2018-04-01
The definition, renewal and maintenance of geodetic datum has been international hot issue. In recent years, many countries have been studying and implementing modernization and renewal of local geodetic reference coordinate frame. Based on the precise result of continuous observation for recent 15 years from state CORS (continuously operating reference system) network and the mainland GNSS (Global Navigation Satellite System) network between 1999 and 2007, this paper studies the construction of mathematical model of the Global CGCS2000 frame, mainly analyzes the theory and algorithm of two-step method for Global CGCS2000 Coordinate Frame formulation. Finally, the noise characteristic of the coordinate time series are estimated quantitatively with the criterion of maximum likelihood estimation.
Annual maximum and minimum lake levels for Indiana, 1942-85
Fowler, Kathleen K.
1988-01-01
Indiana has many natural and manmade lakes. Lake-level data are available for 217 lakes. These data were collected during water years 1942-85 by use of staff gages and, more recently, continuous recorders. The period of record at each site ranges from 1 to 43 years. Data from the lake stations have been compiled, and maximum and minimum lake levels for each year of record are reported. In addition to annual maximum and minimum lake levels, each lake station is described by gage location, surface area, drainage area, period of record, datum of gage, gage type, established legal level, lake level control, inlets and outlets, and extremes for the period of record.
New and improved data products from the Permanent Service for Mean Sea Level (PSMSL)
NASA Astrophysics Data System (ADS)
Matthews, Andrew; Bradshaw, Elizabeth; Gordon, Kathy; Hibbert, Angela; Jevrejeva, Svetlana; Rickards, Lesley; Tamisiea, Mark; Williams, Simon
2015-04-01
The Permanent Service for Mean Sea Level (PSMSL) is the internationally recognised global sea level data bank for long term sea level change information from tide gauges. Established in 1933, the PSMSL continues to be responsible for the collection, publication, analysis and interpretation of sea level data. The PSMSL operates under the auspices of the International Council for Science (ICSU) and is one of the main data centres for both the International Association for the Physical Sciences of the Oceans (IAPSO) and the International Association of Geodesy (IAG). The PSMSL continues to work closely with other members of the sea level community through the Intergovernmental Oceanographic Commission's Global Sea Level Observing System (GLOSS). Currently, the PSMSL data bank for monthly and annual sea level data holds over 65,000 station-years of data from over 2200 stations. Data from each site are carefully quality controlled and, wherever possible, reduced to a common datum, whose stability is monitored through a network of geodetic benchmarks. Last year, the PSMSL also made available a data bank of measurements taken from in-situ ocean bottom pressure recorders from over 60 locations across the globe. Here, we present an overview of the data available at the PSMSL, and describe some of the ongoing work that aims to provide more information to users of our data. In particular, we describe the ongoing work with the Système d'Observation du Niveau des Eaux Littorales (SONEL) to use measurements from continuous GNSS records located near tide gauges to provide PSMSL data within a geocentric reference frame. We also highlight changes to the method used to present estimated sea level trends to account for seasonal cycles and autocorrelation in the data, and provide an estimate of the error of the trend.
Elevation of the March-April 2010 flood high water in selected river reaches in Rhode Island
Zarriello, Phillip J.; Bent, Gardner C.
2011-01-01
A series of widespread, large, low-pressure systems in southern New England in late February through late March 2010 resulted in record, or near record, rainfall and runoff. The total rainfall in the region during this period ranged from about 19 to 25 inches, which coupled with seasonal low evaporation, resulted in record or near record peak flows at 21 of 25 streamgages in Rhode Island and southeastern Massachusetts. The highest record peaks occurred in late March-early April and generally greatly exceeded the earlier March peaks that were near or exceeded the peak of record for 10 of the 25 streamgages. Determination of the flood-peak high-water elevation is a critical part of the recovery operations and post-flood analysis for improving future flood-hazard maps and flood-management practices. High-water marks (HWMs) were identified by the U.S. Geological Survey (USGS) from April 2-7, 2010, and by the U.S. Army Corps of Engineers (USACE) from April 3-7, 2010, in five major river basins including the Blackstone, Hunt, Moshassuck, Pawtuxet, and Woonasquatucket along the mainstems and in many tributaries. The USGS identified 276 HWMs at 137 sites. A site may have more than one HWM, typically upstream and downstream of a bridge. The USACE identified 144 HWMs at 127 sites. The HWMs identified by the USGS and USACE covered about 170 river miles, determined from the upstream and downstream HWMs. Elevation of HWMs were later determined to a standard vertical datum (NAVD 88) using the Global Navigation Satellite System and survey-grade Global Positioning System (GPS) receivers along with standard optical surveying equipment.
McCallum, Brian E.; McGee, Benton D.; Kimbrow, Dustin R.; Runner, Michael S.; Painter, Jaime A.; Frantz, Eric R.; Gotvald, Anthony J.
2012-01-01
The U.S. Geological Survey (USGS) deployed a temporary monitoring network of water-level and barometric pressure sensors at 127 locations along the gulf coast from Alabama to Louisiana to record the timing, areal extent, and magnitude of hurricane storm tide and coastal flooding generated by Hurricane Isaac. This deployment was undertaken as part of a coordinated federal emergency response as outlined by the Stafford Act under a directed mission assignment by the Federal Emergency Management Agency. Storm tide, as defined by National Oceanic and Atmospheric Administration (NOAA; National Oceanic and Atmospheric Administration, 2008), is the water-level rise generated by a combination of storm surge and astronomical tide during a coastal storm. Hurricane Isaac initially made landfall on the coast of Louisiana in Plaquemines Parish on August 28, 2012, as a Category 1 hurricane on the Saffir–Simpson Hurricane Wind Scale (National Weather Service, 1974) and then stalled over southern Louisiana for several days, causing prolonged storm-tide impacts. A total of 188 water-level and wave-height sensors were deployed at 127 locations during August 27–28 prior to landfall. More than 90 percent of the sensors and all high-water marks (HWMs) were recovered and surveyed to North American Vertical Datum of 1988 (NAVD 88) within 7 days of the Isaac landfall. Only a handful of sensors in the Plaquemines Parish area of Louisiana could not be retrieved until weeks later due to prolonged flooding in the area. Data collected from this event can be used to evaluate the performance of storm-tide models for maximum and incremental water level and flood extent and the site-specific effects of storm tide on natural and anthropogenic features of the environment.
Techniques for analyses of trends in GRUAN data
NASA Astrophysics Data System (ADS)
Bodeker, G. E.; Kremser, S.
2015-04-01
The Global Climate Observing System (GCOS) Reference Upper Air Network (GRUAN) provides reference quality RS92 radiosonde measurements of temperature, pressure and humidity. A key attribute of reference quality measurements, and hence GRUAN data, is that each datum has a well characterized and traceable estimate of the measurement uncertainty. The long-term homogeneity of the measurement records, and their well characterized uncertainties, make these data suitable for reliably detecting changes in global and regional climate on decadal time scales. Considerable effort is invested in GRUAN operations to (i) describe and analyse all sources of measurement uncertainty to the extent possible, (ii) quantify and synthesize the contribution of each source of uncertainty to the total measurement uncertainty, and (iii) verify that the evaluated net uncertainty is within the required target uncertainty. However, if the climate science community is not sufficiently well informed on how to capitalize on this added value, the significant investment in estimating meaningful measurement uncertainties is largely wasted. This paper presents and discusses the techniques that will need to be employed to reliably quantify long-term trends in GRUAN data records. A pedagogical approach is taken whereby numerical recipes for key parts of the trend analysis process are explored. The paper discusses the construction of linear least squares regression models for trend analysis, boot-strapping approaches to determine uncertainties in trends, dealing with the combined effects of autocorrelation in the data and measurement uncertainties in calculating the uncertainty on trends, best practice for determining seasonality in trends, how to deal with co-linear basis functions, and interpreting derived trends. Synthetic data sets are used to demonstrate these concepts which are then applied to a first analysis of temperature trends in RS92 radiosonde upper air soundings at the GRUAN site at Lindenberg, Germany (52.21° N, 14.12° E).
Techniques for analyses of trends in GRUAN data
NASA Astrophysics Data System (ADS)
Bodeker, G. E.; Kremser, S.
2014-12-01
The Global Climate Observing System (GCOS) Reference Upper Air Network (GRUAN) provides reference quality RS92 radiosonde measurements of temperature, pressure and humidity. A key attribute of reference quality measurements, and hence GRUAN data, is that each datum has a well characterised and traceable estimate of the measurement uncertainty. The long-term homogeneity of the measurement records, and their well characterised uncertainties, make these data suitable for reliably detecting changes in global and regional climate on decadal time scales. Considerable effort is invested in GRUAN operations to (i) describe and analyse all sources of measurement uncertainty to the extent possible, (ii) quantify and synthesize the contribution of each source of uncertainty to the total measurement uncertainty, and (iii) verify that the evaluated net uncertainty is within the required target uncertainty. However, if the climate science community is not sufficiently well informed on how to capitalize on this added value, the significant investment in estimating meaningful measurement uncertainties is largely wasted. This paper presents and discusses the techniques that will need to be employed to reliably quantify long-term trends in GRUAN data records. A pedagogical approach is taken whereby numerical recipes for key parts of the trend analysis process are explored. The paper discusses the construction of linear least squares regression models for trend analysis, boot-strapping approaches to determine uncertainties in trends, dealing with the combined effects of autocorrelation in the data and measurement uncertainties in calculating the uncertainty on trends, best practice for determining seasonality in trends, how to deal with co-linear basis functions, and interpreting derived trends. Synthetic data sets are used to demonstrate these concepts which are then applied to a first analysis of temperature trends in RS92 radiosonde upper air soundings at the GRUAN site at Lindenberg, Germany (52.21° N, 14.12° E).
NASA Technical Reports Server (NTRS)
Lucchitta, B. K.
1997-01-01
Recent studies of ice streams in Antarctica reveal a mechanism of basal motion that may apply to channels and valleys on Mars. The mechanism is sliding of the ice on deformable water-saturated till under high pore pressures. It has been suggested by Lucchitta that ice was present in outflow channels on Mars and gave them their distinctive morphology. This ice may have slid like Antarctic ice streams but on rubbly weathering products rather than till. However, to generate water under high pore pressures, elevated heatflow is needed to melt the base of the ice. Either volcanism or higher heatflow more than 2 b.y. ago could have raised the basal temperature. Regarding valley networks, higher heatflow 3 b.y. ago could have allowed sliding of ice-saturated overburden at a few hundred meters depth. If the original, pristine valleys were somewhat deeper than they are now, they could have formed by the same mechanism. Recent sounding of the seafloor in front of the Ross Ice Shelf in Antarctica reveals large persistent patterns of longitudinal megaflutes and drumlinoid forms, which bear remarkable resemblance to longitudinal grooves and highly elongated streamlined islands found on the floors of martian outflow channels. The flutes are interpreted to have formed at the base of ice streams during the last glacial advance. Additional similarities of Antarctic ice streams with martian outflow channels are apparent. Antarctic ice streams are 30 to 80 km wide and hundreds of kilometers long. Martian outflow channels have similar dimensions. Ice stream beds are below sea level. Carr determined that most common floor elevations of martian outflow channels lie below martian datum, which may have been close to or below past martian sea levels. The Antarctic ice stream bed gradient is flat and locally may go uphill, and surface slopes are exceptionally. Martian channels also have floor gradients that are shallow or go uphill locally and have low surface gradients. The depth to the bed in ice streams is 1 to 1.5 km. At bankful stage, the depth of the fluid in outflow channels was 1 to 2 km, according to the height of bordering scarps. The similarity between Antarctic ice streams and martian outflow channels suggests that ice may have flowed through and shaped the outflow channels, and that perhaps the mechanism of motion of Antarctic ice streams also operated in outflow channels. In addition, sliding on deformable rubble may explain the formation of small valley networks. The large Siple Coast Antarctic ice streams are thought to slide over longitudinally grooved, deforming till, where much of the movement is within the till. The till is saturated with water at high pore pressures that nearly supports all of the weight of the ice. The small differential between overburden pressure and pore pressure at the bed is more important than the volume of water, but water needs to be supplied to the till interface. For pore pressures to remain high, the ice streams have to act as a seal that blocks the flow of water through them, and the rock underneath has to be of low permeability to prevent the water from draining away.
NASA Astrophysics Data System (ADS)
Landing, Ed; Geyer, Gerd; Brasier, Martin D.; Bowring, Samuel A.
2013-08-01
Use of the first appearance datum (FAD) of a fossil to define a global chronostratigraphic unit's base can lead to intractable correlation and stability problems. FADs are diachronous—they reflect species' evolutionary history, dispersal, biofacies, preservation, collection, and taxonomy. The Cambrian Evolutionary Radiation is characterised by diachronous FADs, biofacies controls, and provincialism of taxa and ecological communities that confound a stable Lower Cambrian chronostratigraphy. Cambrian series and stage definitions require greater attention to assemblage zone successions and non-biostratigraphic, particularly carbon isotope, correlation techniques such as those that define the Ediacaran System base. A redefined, basal Cambrian Trichophycus pedum Assemblage Zone lies above the highest Ediacaran-type biotas (vendobionts, putative metazoans, and calcareous problematica such as Cloudina) and the basal Asteridium tornatum-Comasphaeridium velvetum Zone (acritarchs). This definition and the likely close correspondence of evolutionary origin and local FAD of T. pedum preserves the Fortune Head, Newfoundland, GSSP of the Cambrian base and allows the presence of sub-Cambrian, branched ichnofossils. The sub-Tommotian-equivalent base of Stage 2 (a suggested "Laolinian Stage") should be defined by the I'/L4/ZHUCE δ13C positive peak, bracketed by the lower ranges of Watsonella crosbyi and Aldanella attleborensis (molluscs) and the Skiagia ornata-Fimbrioglomerella membranacea Zone (acritarchs). The W. crosbyi and A. attleborensis FADs cannot define a Stage 2 base as they are diachronous even in the Newfoundland "type" W. crosbyi Zone. The Series 2 base cannot be based on a species' FAD owing to the provincialism of skeletalised metazoans in the Terreneuvian-Series 2 boundary interval and global heterochrony of the oldest trilobites. A Series 2 and Stage 3 (a suggested "Lenaldanian Series" and "Zhurinskyan Stage," new) GSSP base is proposed at the Siberian lower Atdabanian δ13C IV peak—which correlates into South China, Avalonia, and Morocco and assigns the oldest trilobites to the terminal Terreneuvian Series.
Advances and Best Practices in Airborne Gravimetry from the U.S. GRAV-D Project
NASA Astrophysics Data System (ADS)
Diehl, Theresa; Childers, Vicki; Preaux, Sandra; Holmes, Simon; Weil, Carly
2013-04-01
The Gravity for the Redefinition of the American Vertical Datum (GRAV-D) project, an official policy of the U.S. National Geodetic Survey as of 2007, is working to survey the entire U.S. and its holdings with high-altitude airborne gravimetry. The goal of the project is to provide a consistent, high-quality gravity dataset that will become the cornerstone of a new gravimetric geoid and national vertical datum in 2022. Over the last five years, the GRAV-D project has surveyed more than 25% of the country, accomplishing almost 500 flights on six different aircraft platforms and producing more than 3.7 Million square km of data thus far. This wealth of experience has led to advances in the collection, processing, and evaluation of high-altitude (20,000 - 35,000 ft) airborne gravity data. This presentation will highlight the most important practical and theoretical advances of the GRAV-D project, giving an introduction to each. Examples of innovation include: 1. Use of navigation grade inertial measurement unit data and precise lever arm measurements for positioning; 2. New quality control tests and software for near real-time analysis of data in the field; 3. Increased accuracy of gravity post-processing by reexamining assumptions and simplifications that were inconsistent with a goal of 1 mGal precision; and 4. Better final data evaluation through crossovers, additional statistics, and inclusion of airborne data into harmonic models that use EGM08 as a base model. The increases in data quality that resulted from implementation of the above advances (and others) will be shown with a case study of the GRAV-D 2008 southern Alaska survey near Anchorage, over Cook Inlet. The case study's statistics and comparisons to global models illustrate the impact that these advances have had on the final airborne gravity data quality. Finally, the presentation will summarize the best practices identified by the project from its last five years of experience.
NASA Astrophysics Data System (ADS)
Barbolini, Natasha; Rubidge, Bruce; Bamford, Marion K.
2018-04-01
The main Karoo Basin (MKB), internationally renowned for its wealth of fossil tetrapods, has been lithostratigraphically subdivided into three discrete regions: two (east and west) proximal facies adjacent to the Cape Fold Belt, and a distal facies, away from the Cape Fold Belt. Because of lithological differences between formations of the proximal and distal sectors of the MKB, it has been difficult to correlate time-equivalent lithostratigraphic units in the different sectors. Palynology provides a tool for refining stratigraphic correlations within the MKB, but only species with restricted ranges are biostratigraphically significant. Restricted-range palynomorph taxa from the Ecca and Beaufort groups indicate the following relationships: the lowermost Vryheid Formation palynoflora can be strongly correlated with that of the Prince Albert Formation, whereas the Whitehill-Collingham formations and No. 2 seam (Vryheid Formation), and the Ripon Formation and No. 4 seam (Vryheid Formation) can be tentatively linked using palynology. The lower-middle Normandien Formation in the north is chronologically equivalent to the Ripplemead member of the Balfour Formation in the south. Although the Ecca-Beaufort Group boundary is known to be diachronous, restricted-range palynomorphs cannot yet confirm that the uppermost Ecca Group in the northern part of the basin was deposited at the same time as the lower Beaufort Group in the south. This study demonstrates that despite diachronous ranges of some taxa, palynology is useful in correlating age-equivalent lithostratigraphic units in the proximal and distal sectors of the basin. A new First Appearance Datum (FAD) palynozonation for the Karoo is presented that is calibrated by the most recent radiometric dates for South Africa, Australia, and South America. The new zones are also correlated with Permian successions in Antarctica, Zambia, Botswana, and India. Future palynostratigraphic work in South Africa must take into account the ranges and FADs of these palynomorph taxa in order to make meaningful biostratigraphic correlations in the Karoo Basin and across Gondwana.