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Trilateration - Wikipedia, the free encyclopedia Trilateration is a method of determining the relative positions of objects using the geometry of triangles in a similar fashion as triangulation. Hyperbolic positioning systems such as DECCA use a variant of trilateration: what is being measured is the difference in distance from the subject to two synchronized reference stations (called master and slave), placing the subject (using an unsynchronized clock) on a hyperbolic curve on a nautical chart. The GPS satellite positioning system is also based on hyperbolic positioning, but in three dimensions: four satellites (orbital "reference stations") are commonly sufficient for obtaining a fix. en.wikipedia.org /wiki/Trilateration   (904 words)

LORAN Information - TextSheet.com   (Site not responding. Last check: 2007-11-04) Hyperbolic LORAN lines of position (LOP) are formed by measuring the difference in reception times of synchronized signals. As one example, the hyperbolic formed by one pair along with the ranges observed from either master or slave or both provided useful geometry for navigation in areas with only one usable hyperbolic was normally available. British hyperbolic systems were deployed and one, the Decca Navigation System, was often deployed by private firms in a portable form for such operations as oil exploration. www.xplosive.sferahost.com /encyclopedia/l/lo/loran.html   (1022 words)

Positioning GSM Telephones Another major limitation on positioning receivers is the phenomenon known as multipath, which refers to the common situation where a signal propagating from a transmitter to a receiver may travel via several paths including a direct (line of sight) and one or more reflected paths. Alternatively, the positioning receiver collocated with a BTS could measure the TOA relative to their own transmission cycle, and separate monitoring sites would provide the LSC with the timing offset of each BTS, thus allowing TDOAs and subsequently position to be calculated. The monitoring of position is a political issue, and the level of authority and legal steps required to monitor a person's or object's position without their permission or knowledge varies from country to country. www.comsoc.org /ci/private/1998/apr/Scott.html   (8815 words)

History of Satellite Navigation Since the positions of the satellites are known, either through previous publication or as part of the satellite's broadcast information, the user's position can be calculated. The DECCA system was a low-frequency hyperbolic navigation system covering much of western Europe, parts of Canada, the Persian Gulf and the Bay of Bengal. The user was able to calculate position to within a few hundred meters as long as the user knew his altitude and the satellite ephemeris. ares.redsword.com /gps/old/sum_pre.htm   (1020 words)

MedMark.org - Health and Medicine Directory Australian Global Positioning Systems Society - A free membership society to bring together the delegates, sponsors, and exhibitors for the Satellite Navigation Conference and to foster, develop, and assist the Global Positioning System disciplines.. The Global Positioning System: The History of GPS - The history and story of how the Global Positioning System evolved from the development of the world's most accurate timepieces, atomic clocks, by physicists looking into the nature of time. Hyperbolic Positioning Algorithm - An algorithm for obtaining an exact solution for the three dimensional location of a mobile given the locations of four fixed stations (like a GPS satellite or a base station in a cell) and the signal time of arrival (TOA) from the mobile to each station. www.medmark.org /odp.php?browse=/Science/Earth_Sciences/Geomatics/Global_Positioning_System   (874 words)

Open Directory Project > Science> Earth Sciences> Geomatics> Global Positioning System Australian Global Positioning Systems Society - - A free membership society to bring together the delegates, sponsors, and exhibitors for the Satellite Navigation Conference and to foster, develop, and assist the Global Positioning System disciplines. The Global Positioning System: The History of GPS - - The history and story of how the Global Positioning System evolved from the development of the world's most accurate timepieces, atomic clocks, by physicists looking into the nature of time. Hyperbolic Positioning Algorithm - - An algorithm for obtaining an exact solution for the three dimensional location of a mobile given the locations of four fixed stations (like a GPS satellite or a base station in a cell) and the signal time of arrival (TOA) from the mobile to each station. www.bie.no /products/phpodp/odp?browse=/Science/Earth_Sciences/Geomatics/Global_Positioning_System   (857 words)

GPS Concepts -- 3DSoftware.com The standard position for a hyperbola is rotated 45° (compared to the example above), and centered at the origin (not translated). That circle is small compared to the larger circles approaching the unknown position from the known positions. It calculates the error between its estimated position and actual position, and then broadcasts that error to the shipboard Loran receivers in the harbor. www.3dsoftware.com /Cartography/GPS   (2441 words)

Directory - Science: Earth Sciences: Geomatics: Global Positioning System Australian Global Positioning Systems Society  · cached · A free membership society to bring together the delegates, sponsors, and exhibitors for the Satellite Navigation Conference and to foster, develop, and assist the Global Positioning System disciplines. Hyperbolic Positioning Algorithm  · cached · An algorithm for obtaining an exact solution for the three dimensional location of a mobile given the locations of four fixed stations (like a GPS satellite or a base station in a cell) and the signal time of arrival (TOA) from the mobile to each station. The Global Positioning System: The History of GPS  · cached · The history and story of how the Global Positioning System evolved from the development of the world's most accurate timepieces, atomic clocks, by physicists looking into the nature of time. www.incywincy.com /default?p=27763   (826 words)

[No title]   (Site not responding. Last check: 2007-11-04) The Global Positioning System FAQ Version 9.001 - July 30, 1997 Additions, comments, and corrections should be sent to: Karen Nakamura, karen@gpsy.com This article is a collection of information, and pointers to other information sources, on the Navstar Global Positioning System (GPS), and related topics. The basic concept is that the reference station "knows" its position, and determines the difference between that known position and the position as determined by a GPS receiver. It also requires the receiver to be in a fixed position while taking a fix, or to be moving on a known course at a known speed. vancouver-webpages.com /peter/gpsfaq.txt   (4861 words)

Passive Detection and Localization of Transient Signals In order to determine the position of the animal in three dimensions, a given call must be detected on a minimum of four hydrophones. A three-dimensional hyperbolic positioning model [5] is used to determine the vocalizing animal’s location in X, Y, and Z as well as the time of emission of the call. When marine mammals were localized, their positions were relayed to the tagging vessel, which then endeavored to maneuver close enough to place a tag. web.mit.edu /seagrant/aqua/cfer/acoustics/exsum/jarvis/extended.html   (2789 words)

Library Reference Search : Science : Earth Sciences : Geomatics : Global Positioning System Directory   (Site not responding. Last check: 2007-11-04) The history and story of how the Global Positioning System evolved from the development of the world's most accurate timepieces, atomic clocks, by physicists looking into the nature of time. Objective is the development of a system for rapid and inexpensive monitoring of unstable slopes, such as pit walls, earth\rock slopes and dam walls using global satellite positioning technology. An algorithm for obtaining an exact solution for the three dimensional location of a mobile given the locations of four fixed stations (like a GPS satellite or a base station in a cell) and the signal time of arrival (TOA) from the mobile to each station. www.libraryreference.org /index.php?c=Science/Earth_Sciences/Geomatics/Global_Positioning_System   (663 words)

IUGG Swiss National Report If the position of three GPS antennae is known in a body frame, the determination of their position in an Earth-fixed coordinate sys-tem allows the determination of the attitude parameters. Its major goal is to investigate the feasibility of the Global Positioning System (GPS) as a remote sensing tool for the determination of tropospheric water vapor.These investigations include validation of the accuracy and temporal resolution of GPS meteorology by comparison with microwave water vapor radiometers (WWR) and radiosonde profiles. The position of this fictitious satellite may be computed using the position and velocity vectors of the actual satellite. www.p.igp.ethz.ch /iugg99/Section_1.html   (11462 words)

Geographic Information System Loran-C Coverage Modeling Early coverage charts assumed a user community with single chain receivers operating in the hyperbolic mode and are not adequate descriptors of coverage for the new generation of Loran-C receivers and the variety of user requirements. This is accomplished by the use of a table of known positions outside of the land conductivity boundaries. Position error at a given location is computed using the following operations where the weight matrix is formed from a column of TOA variances. www.colorado.edu /geography/gcraft/notes/gisloran/gisloran.html   (4742 words)

Development of Inverse Hyperbolic Positioning Using the GSM Cellular Telephone Network, 16-9222 Development of Inverse Hyperbolic Positioning Using the GSM Cellular Telephone Network, 16-9222 This capability provides an alternative to the Global Positioning System (GPS) for cases in which GPS technology is not appropriate. Each TDOA can be mapped to a hyperbolic contour on which the receiver must lie. www.swri.org /3pubs/IRD2002/16-9222.htm   (371 words)

Intro to GPS Apps - Disclaimers Global positioning systems are based on the concept of radio navigation. That is, using the characteristics of radio waves transmitted by a fixed point whose characteristics are known to determine the location of a radio receiver. It relies on the fact that all the points where the difference between radio signals from different stations is constant form a hyperbola. ares.redsword.com /GPS/apps/general/radionav_systems.htm   (1324 words)

DEVELOPMENT OF A CELLULAR TELEPHONE POSITIONING SYSTEM USING GPS TIME SYNCHRONIZATION AND A SUPER-RESOLUTION ALGORITHM   (Site not responding. Last check: 2007-11-04) The time of arrivals are differenced between the cell sites and hyperbolic trilateration is used to estimate the position of the cellular telephone. The simulations indicate that for an actual cellular network in Calgary, and for typical propagation losses and multipath effects, the system is able to estimate the horizontal position of a cellular telephone with an accuracy of 119 m (67%). Positioning accuracy is shown to be a function of received SNR, multipath, geometry, and calibration of system biases. www.geomatics.ucalgary.ca /research/GPSRes/Klukas.html   (510 words)

SAS group research projects - Positioning services for mobile terminals   (Site not responding. Last check: 2007-11-04) The study and implementation of positioning services for present and future generation cellular systems can be approached, in principle, by adding a GPS receiver to the mobile terminal. The user localization performances could be also improved with the use of multiple antennas in the base stations and/or the use of multi-user detection. The availability of a user positioning service may allow the implementation of further services and capabilities, such as user localization following an emergency call, location sensitive billing, fraud detection, improved power control systems. www.tlc-networks.polito.it /SAS/posit.html   (242 words)

Three Dimensional Hyperbolic Positioning and Synthesizable VHDL Code / GPS satellite   (Site not responding. Last check: 2007-11-04) This paper presents the detailed derivation of an algorithm for obtaining an exact solution for the three dimensional location of a mobile given the locations of four fixed stations (like a GPS satellite or a base station in a cell) and the signal time of arrival (TOA) from the mobile to each station. The input signals are the x, y, z positions of four GPS satellites i, j, k, l in meters, and the signal TOAs from the individual satellites to the mobile in nanoseconds. The z value representing the mobile position can be determined by using a fifth satellite, or checking if the value is in the horizon of the four satellites relative to earth. ralph.bucher.home.att.net /project.html   (1293 words)

GPS - Global Positioning System Science, Directory   (Site not responding. Last check: 2007-11-04) Australian Global Positioning Systems Society A free membership society to bring together the delegates, sponsors, and exhibitors for the Satellite Navigation Conference and to foster, develop, and assist the Global Positioning System disciplines. GPS Deformation Monitoring Objective is the development of a system for rapid and inexpensive monitoring of unstable slopes, such as pit walls, earth\rock slopes and dam walls using global satellite positioning technology. The Global Positioning System: The History of GPS The history and story of how the Global Positioning System evolved from the development of the world's most accurate timepieces, atomic clocks, by physicists looking into the nature of time. www.wacofdn.org /d2RjXzI3NzYz.aspx   (658 words)

Best GPS Thorough review: Links to related sites Global Positioning System: The Role of Atomic Clocks - learn how basic research into the nature of time and ways to measure time accurately contributed to development of GPS. GPS Time Series - measurements made with the Global Positioning System are sensitive enough to detect motion of the Earth's tectonic plates. USDA Forest Service Global Positioning System (GPS) Page - forestry related GPS mapping and GIS applications with emphasis on receiver operation under forest canopy and in backcountry/wildland environments for land management. www.gpsawards.com /links.htm   (1187 words)

(GCJ84D) HyperNav by binthair   (Site not responding. Last check: 2007-11-04) The Decca portable positioning system was used locally where higher accuracy was necessary. It is the intersection of two hyperbolic LOP's from different families that determines a position. The cache is also on another hyperbolic LOP where its distance from B minus its distance from C equals 1.947 kilometers. www.geocaching.com /seek/cache_details.aspx?wp=GCJ84D   (693 words)

Title page for ETD etd-05122003-161802 Many modern systems use a combination of these techniques because electrical detection is an older and proven technology and acoustic detection allows for the source to be located when several sensors are mounted to the exterior of the tank. This thesis presents the theoretical functionality and experimental validation of a band-limited OA sensor with a usable range of 100-300 kHz, which is consistent with the frequency content of an acoustic pulse caused by a PD event. It also presents a positioning system using the time difference of arrival (TDOA) of the acoustic pulse with respect to four sensors that is capable of reporting the three-dimensional position of a PD to within ±5cm on any axis. scholar.lib.vt.edu /theses/available/etd-05122003-161802   (422 words)

Links for marine electronics, fish finders and depth sounders, gps, loran, radar, radios, cell phones, satellite ... Global Utility Mapping Systems - Provide location mapping software, hardware and global positioning systems to broad range of industries for companies who require rapid response together with economical operations for their in field personnel. Kym GPS Mapping and Surveying - Mapping of European agriculture, farming and golf courses as well as worldwide surveying for forestry, roads,mineral exploration, pipe lines and quarrying. Positioning Resources - Software which allows users to take GIS maps out into the field and create accurate, geographically referenced records on the spot. www.fishinontario.com /links/electronic.shtml   (3677 words)

Norcom | Offline Software These data may then be collated to build a database of the position and depth of burial of an unknown pipeline or cable Facilitates Bathymetric editing of lateral and vertical positions within the acquired data. This is a general program for both online and offline Norcom4D which configures a plotting device allowing either real time positions or delivery of charted data to the plotter. www.norcom.demon.co.uk /offline.htm   (961 words)

Intellectual Responses to Globalisation Nor are new technologies sufficient reason for abandoning the social contract between a government and its citizens. It should be recognised that such hyperbolic positioning is merely part and parcel of the Riefenstahlian marketing strategies of big business and politics. Globalisation is inevitable in the sense that it has always existed, but people continue to have a weakness for utopian futures; a weakness that, at times, threatens to be a terminal addiction. www.milkbar.com.au /globalhistory/graham.htm   (4183 words)

sntp windows nt   (Site not responding. Last check: 2007-11-04) Hyperbolic Positioning Algorithm An algorithm for obtaining an exact solution for the three dimensional location of a mobile given the locations of four fixed stations (like a GPS satellite or a base station in a cell) and the signal time of arrival (TOA) from the mobile to each station. In answer to the question "Does anyone know the exact difference between GMT and UTC?" here are a few facts concerning Greenwich Mean Time, Universal Time, and the Royal Greenwich Observatory. http://www.gps-society.org/ A free membership society to bring together the delegates, sponsors, and exhibitors for the Satellite Navigation Conference and to foster, develop, and assist the Global Positioning System disciplines. www.timetools.co.uk /categories/sntp/sntp-windows-nt.htm   (216 words)

Marine Navigation   (Site not responding. Last check: 2007-11-04) In use with marine navigation, the Global Positioning System (GPS) can and will help the marine user with positioning, emergency management, modernization of navigational information, as well as many similar advantages for the U.S. Navy. The United States Coast Guard is responsible for the civilian marine capabilities of the Global Positioning System and the Differential Global Positioning System (DGPS). The DGPS differs from the GPS in that it is a radio navigation system that receives satellite-generated positioning information for GPS (www.dot.gov/dotinfo/uscg/hq/reserve/apr96/dgps.html). www.cs.virginia.edu /~jones/tmp352/projects98/group8/Marine.html   (443 words)

Norcom | 2nd Gen Software Offers guidance, position data logging and video overlay for up to 4 screens. Bathymetric editing of lateral and vertical positions, with tidal correction and user defined data format import/export functions. Checks the integrity of positioning system by cross referencing transits taken by aligning the legs of 3 or 4 legged ground based rigs. www.norcom.demon.co.uk /gen2.htm   (727 words)

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