On-Line Geodesy Resources
Geodesy & Astronomy

Contents

• What is Geodesy?
• General Information
• Geodesy Organizations
• On-Line Geodesy Software
• Geodesy Software

• Astronomy Organizations, Data & Ephemerides
• On-Line Astronomy Calculators
• Astronomy Software

General Information

• A Tutorial in Geodesy by Petr Vanicek
  • Online version
  • PDF File (1.7 MB)
• Geodetic Glossary by the U.S. National Geodetic Survey, Silver Spring, MD, September 2001, Revised June 3, 2009.
• The Geographer's Craft Project
  A teaching initiative by Kennith E. Foote at the University of Colorado at Boulder. Various authors provide course materials to improve the teaching of geographical techniques at the introductory level. Includes excellent notes introducing the concepts of GPS, coordinates systems and more. Although created at the University of Texas at Austin, the site was moved the University of Colorado at Boulder in 2000.
  • Global Positioning System Overview by Peter Dana
  • Coordinate Systems Overview by Peter Dana
  • Map Projections Overview by Peter Dana
  • Geodetic Datums Overview by Peter Dana
  • Error, Accuracy and Precision by Kenneth E. Foote and Donald J. Huebner
• Bob Burtchand's Links to Coordinates, Datums and Transformation Information
• The Science of Timekeeping by David W. Allen, Clifford C. Hodge and Neil Ashbyare, 1997 (one of Hewlett Packard's well-known Application Notes and an excellent reference on timekeeping).
• Time Scales (by Paul Schlyter)
• Canadian Very Long Baseline Interferometry. Information on VLBI in Canada.
• NIMA Earth Gravity Model (EGM96)
• The Unofficial Canadian Geodetic Networks Home Page (Password required)
• Canada's Vertical Datum (Password required)
• The US Geoid Page
• Tables of Contents in Geodesy. A searchable archive of the tables of contents of recent geodetic journals, by yours truly.

Geodesy Organizations

• International Association of Geodesy
  • IAG Commissions
    • Commission 1: Reference Frames
      • Sub-Commission 1.1 (SC 1.1): Coordination of Space Techniques
      • Sub-Commission 1.2 (SC 1.2): Global Reference Frames
      • Sub-Commission 1.3 (SC 1.3): Regional Reference Frames
      • Sub-Commission 1.4 (SC 1.4): Interaction Between Celestial and Terrestrial Reference Frames
    • Commission 2: Gravity Field
    • Commission 3: Earth Rotation and Geodynamics
    • Commission 4: Positioning and Applications
    • Intercommission Committee on Theory
  • IAG Services
    • International GPS Service (IGS)
    • International VLBI Service (IVS)
    • International Laser Ranging Service (ILRS)
    • International DORIS Service (IDS)
    • International Gravimetric Bureau (BGI)
    • International Geoid Service (IGeS)
    • International Center for Earth Tides (ICET)
    • International Earth Rotation and Reference Systems Service (IERS)
    • Permanent Service for Mean Sea Level (PSMSL)
    • Time Section of the International Bureau of Weights and Measures (BIPM)
    • International Bibliographic Service
  • Geodetic Data Centers
  • IAG Publications
    • Geodesists Handbook
    • IAG Travaux
    • IAG News
    • IAG Newsletters
    • National Reports
    • IAG Scientific Reports
    • Reports of Institutes
    • PhD Theses
  • Email addresses (of the officers, fellows and associates of the IAG)
• International Earth Rotation Service (IERS)
  • Science Background -- Information about Earth rotation, reference frames, and observation techniques in general.
  • Conventions
  • Earth Orientation Data -- including announcements of leap seconds and DUT1.
  • International Celestial Reference Frame (ICRF)
  • International Terrestrial Reference Frame (ITRF) -- Reference frame upon which recent versions of WGS84 (used by GPS) are based.
  • IERS Analysis Coordination and Combination Research Activities
  • Geophysical Fluids Data

• American Geophysical Union
• European Geophysical Society
• Canadian Geophysical Union

• Natural Resources Canada, Geodetic Survey Division
  • CDGPS - Real-Time Canada-Wide DGPS Service
  • CSRS Networks
  • CSRS Database (GPS data, gravity, coordinates)
  • GDCINFO (Gravity Data)
  • Online Applications
  • CSRS-PPP (Precise Point Positioning)
  • Mike Craymer's Canadian Geodetic Networks (password required)
  • Marc Veronneau's Canada's Vertical Datum (password required)
  • NRCan Directory of People and Services
  • Gov't Electronic Directory Services (gov't-wide directory)
• British Columbia Base Mapping & Geomatics Services Branch, Geo Spatial Reference Unit
  • BC Active Control System (BCACS)
  • BC Municipal Active Control System (BCACSm)
  • MAnagment of Survey Control Operations and Tasks (MASCOT)
  • GPS Training Courses
• Quebec Ressources naturelles et Faune
  • Positioning and reference Products
    • Le reseau geodesique du Quebec (Geodetic reference network of Quebec)
    • Les donnŽes GPS (GPS data for permanent sites)
    • SystŹme de gestion des informations gŽodŽsiques du QuŽbec (GEODEQ III) (Geodetic information management system of Quebec)
  • Geodetic reference tools

• U.S. National Geodetic Survey
• U.S. National Geospatial-Intelligence Agency (NGS, formerly NIMA), GEOINT Sciences Office
  • GPS Data (precise GPS ephemerides, EOPs)
  • WGS 84
    • World Geodetic Systems 1984: It's Definition and Relationships with Local Geodetic Systems
    • Implementation of the World Geodetic System 1984 (WGS 84) Reference Frame G1150
    • EGM96 (360 x 360) Earth Gravitation Model
    • WGS 84 (180 x 180) Earth Gravitational Model
    • EGM96 On-line Geoid Calculator
    • WGS 94 On-line Geoid Calculator
  • Coordinate Systems Analysis
    • Datum Transformations
    • Geographic Translator (GEOTRANS) Coordinate conversion and datum transformation software
    • On-line Geodetic Datum Reference Guide
  • Publications
• U.S. Naval Observatory

• Academic Sites for Geomatics Engineering
• University of New Brunswick Dept. of Geodesy & Geomatics Engineering
  • Geodesy Group
  • Other Research Groups
  • Departmental Publications
• University of Calgary Dept. of Geomatics Engineering
  • Research Groups
  • Publications

On-Line Geodesy Software

• Geodetic Survey Division's Online Applications
  • TRNOBS -- Transformation of Coordinates & Observations between NAD83(CSRS) and all official realizations of the International Terrestrial Reference Frame (ITRF) in North America
  • NTv2 -- National Transformation v2 Between NAD27 and NAD83 in Canada
  • GPS-HT -- GPS Height Transformation Between NAD83(CSRS) ellipsoidal heights and CGVD28 orthometric heights in Canada
  • CSRS-PPP -- Canadian Spatial Reference System Precise Point Positioning
  • INDIR -- Direct and Inverse Geodetic Computations
  • GSRUG -- Coordinate Conversions Between UTM and Ellipsoidal Coordinates
• US National Geodetic Survey On-Line Geodetic Tool Kit. A collection of on-line interactive software utilities for solving a variety of geodetic problems. The software can also be downloaded to run locally.
  • HTDP: Horizontal Time-Dependent Positioning
  • XYZ Coordinate Conversion
  • UTM Coordinate Conversions
  • US State Plane Coordinate Conversions
  • Computation of the Forward and Inverse Geodetic Problem
  • Geoid99 -- Transforms between NAD83 ellipsoidal heights and NAVD88 orthometric heights in the US
  • G99SSS -- Gravimetric geoid undulations with respect to ITRF97/GRS80
• Geoscience Australia Geodetic Calculation Methods. A collection of on-line interactive software utilities and MS Excel spreadsheets for solving different geodetic problems.
  • Great Circle Calculator (great circle distances from latitude and longitude)
  • Vincenty Direct Formula (latitude and longitude from distance and azimuth)
  • Vincenty Inverse Formula (distance and azimuth from latitude and longitude)
  • UTM to Latitude & Longitude
  • Latitude & Longitude to UTM
• Movable Type Scripts' Useful Scripts (includes JavaScript code)
  • Indirect Geodetic Problem (calculates distance, bearing and more between points using Haversine formula)
  • Direct Geodetic Problem (calculates distance between two points using Vincenty formula)
• Gazza's Geodetics Calculator for UTM Projections (convertes geodetic to UTM coordinates and computes direct & inverse problem for two points)
• Great Circle Calculator (Javascript to compute direct and inverse problem on an ellipsoid)
• Julian Day Converter (converts from calendar date and time to Julian date, and vice versa)
• SOPAC Online GPS Date Converter (from Scripps Orbit and Permanent Array Center). Converts between various date formats, including GPS week + day of week, year + day of year, decimal year, modified Julian date, year + month + day.
• See the GPS page for online GPS software

Geodesy Software

• Geodetic Survey Division's Software Products
  • TRNOBS -- Transformation of Coordinates & Observations between NAD83(CSRS) and all official realizations of the International Terrestrial Reference Frame (ITRF) in North America
  • NTv2 -- National Transformation v2 between NAD27 and NAD83 in Canada
  • GPS-H -- GPS Height Transformation Between NAD83(CSRS) ellipsoidal heights and CGVD28 orthometric heights in Canada
  • CSRS-PPP -- Canadian Spatial Reference System Precise Point Positioning
  • INDIR -- Direct and Inverse Geodetic Computations
  • GSRUG -- Coordinate Conversions Between UTM and Ellipsoidal Coordinates
• US National Geodetic Survey
  • NGS Geodetic Tool Kit. On-line interactive software utilities for solving a variety of geodetic problems. Most software can also be downloaded to run locally.
  • NGS PC Software Free geodetic software developed by NGS, including their 3D adjustment package ADJUST.
• GHOST 3D Adjustment Software. Home page and help for users of the GHOST adjustment software by the Geodetic Survey Division, Natural Resources Canada. Note: distribution of this software is restricted.
• Mike's Software Archive. A collection of some of some Fortran & MATLAB software programs and libraries from myself and others, including:
  • TRNOBS. Transforms GHOST and GeoLab data files between ITRF and NAD83(CSRS) reference frames. From yours truly.
  • DATES. Converts between different date formats, including year + month + day, year + day of year, year + decimal year, GPS week + seconds of week and Julian date. From yours truly.
  • DATUM. Determines the parameters of a seven parameter datum (similarity) transformation between two sets of coordinates on different datums. From Geodetic Survey Division, Natural Resources Canada.
  • gho_geo. Converts between GHOST and GeoLab format data files. From Geodetic Survey Division, Natural Resources Canada.
  • Geodetic Toolbox. Matlab functions for general problems in geodesy. Most popular download in Earth Sciences on the Matlab web site. From yours truly.
  • LSSA. Performs a Least Squares Spectral Analysis based on the the algorithm and software developed and described in "Least Squares Spectral Analysis Revisited" by D. Wells, P. Vanicek and S. Pagiatakas (Dept. of Surveying Engineering Technical Report No. 85, 1985).
  • UNB Geodetic Fortran Library. A collection of various geodetic subroutines and functions from the Department of Surveying Engineering, University of New Brunswick, circa 1980's.
  • Scientific Subroutine Package. Selected matrix subroutines and functions from IBM's original Scientific Subroutine Package, circa 1970's. It's hard to improve on some of these basic routines.
  • Mike's Fortran Archive. A collection of Fortran libraries for geodesy, statistics and miscellaneous utilities from myself and others.
  • Mike's MATLAB Toolbox Archive. A collection of MATLAB toolboxes for geodesy, GPS, statistics, plotting, maps, etc. from myself and others.
• GPS Deformation Network Analysis Software (from Mattia Crespi). Performs 1D, 2D, and 3D statistical analyses of GPS deformation networks, including the significance of coordinate differences from two repeated surveys of the same network, and displacement vectors with error and reliability ellipsoids.
• GeoCommunity -- Free Software (a directory of free software tools and utilities in geomatics)
  • Coordinate conversion utilities
  • GPS-related utilities
• Aviation Formulary (great circle navigation formulae for aviation)
• SOFA: Standards of Fundamental Astronomy A free software collection of constants, algorithms and procedures that implement standard models used in fundamental astronomy, from the International Astronomical Union.
• AUSLIG's Geodetic Calculation Methods. Geocentric Datum of Australia Technical Manual containing algorithms and MS Excel spreadsheets for a variety of geodetic computations, including coordinate conversions and computations on the ellipsoid.
• CUBA (City University Bundle Adjustment) A least-squares estimation package from Tim Short that can be used for photogrammetric, geodetic and combined adjustments. May no longer be available.
• EasyTrans. A comprehensive, easy to use, shareware program for coordinate conversions and transformations, available for Windows 95/98/NT, Linux and various flavours of Unix. From geoIma.
• MADTRAN. Converts between WGS84 and local datums. Designed for coordinates scaled from maps and charts. From National Imagery and Mapping Agency.
• Gencoord Converts geographical coordinates to UTM and reverse, and performs datum transformations. From MultiGIS.
• SeisSoft Coordinate transformation software (shareware), including Lat/Long-to-mapping plane conversions and datum transformations based on DMA values.
• MultiGIS. Converts geographical coordinates to UTM and reverse, and performs datum transformations.
• Free GPS software and processing services (see GPS section).
• GeoTimer Shareware Windows utility that converts dates and times between Gregorian, GPS and Modified Julian time scale. Also the time span between two time marks will be computed. From geoIma.

Astronomy Organizations, Data & Ephemerides

• Astronomy at Scince@NASA (general information on astronomy, including links to other astronomical resources)
• International Astronomical Union
  • Division I Fundamental Astronomy
  • Commission 4 Ephemerides
  • Where to Obtain Ephemerides
• US Naval Observatory (Astronomical almanacs, Earth orientation and time services)
  • Data Services
  • Astronomical Almanac Online
  • Julian Date Converter
  • GPS Timing Operations (provides information on GPS from a timing aspect, the status of the current GPS constellation, timing data files for individual GPS satellites and a section on GPS and GLONASS satellite visibility).
  • Computer Time Services (time synchronization, NTP, modem and voice time services)
• Jet Propulsion Laboratory's Solar System Dynamics Group
  • HORIZONS On-Line Solar System Data and Ephemeris Computation Service (provides access to key solar system data and flexible production of highly accurate ephemerides for solar system objects (24000+ asteroids and comets, 64 natural satellites, 9 planets, the Sun)
  • Planetary and Lunar Ephemerides (most accurate ephemerides available)
    • FTP archive
    • CD-ROM from William-Bell
• Bureau des longitudes, Institut de mecanique celeste
  • Ephemerides Server
• Astronomisches Rechen-Institut (ARI), University of Heidelberg
  • Catalogues and databases
  • FK6 star cataglue
  • Hipparcos Catalogue
• Astronomical Data Center (rather dated source of data)
  • Astrometric and Positioning Data
  • ACD Data on CD-ROM and FTP (includes AGK3, SAO, FK4 and FK5 star catalogues)

On-Line Astronomy Calculators

• USNO's Data Services
  • Azimuth & Altitude of the Sun & Other Objects (provides a table of the altitude and azimuth of the Sun, solar system objects & bright stars for given time and location; high precision version)
  • Celestial Navigation Data for Assumed Position and Time (provides all the astronomical information necessary to plot navigational lines of position from observations of the altitudes of celestial bodies)
  • Julian Day Converter (converts from calendar date and time to Julian date, and vice versa)
  • Astronomical Almanac Online
• JPL's Solar System Dynamics Online Tools
  • HORIZONS Ephemeris Generation (provides access to key solar system data and flexible production of highly accurate ephemerides for solar system objects, including 71000+ asteroids and comets, 91 natural satellites, 9 planets and the Sun)
  • Date/Time Converter (converts date/time in one of several different forms to all other forms, including Gregorian calendar date and time, Julian date, day of year, etc.)
• BDL's Ephemerides Server (provides real time calculations of the position of solar bodies using the official ephemerides worked out at the Bureau des longitudes following the recommendations of the International Astronomical Union)
• On-Line Astronomical Almanac (CGI-interface to JPL's DE200 planetary ephemerides)
• AUSLIG's Sun or Moon Position Computation (computes the astronomic azimuth and vertical angle of the Sun or Moon using AUSLIG's WINSMPOS program)

Astronomy Software

• UNSO Software Products
  • MICA: Multiyear Interactive Computer Almanac ($25 program that provides much of the information printed in the annual Astronomical Almanac but covers the period 1990-2005, available for both Mac and PC)
  • NOVAS: Naval Observatory Vector Astrometry Subroutines (a free integrated package of subroutines for the computation of a wide variety of common astrometric quantities and transformations, in Fortran and C)
• NavPac and Compact Data (provides simple and efficient methods for calculating the positions of the Sun, Moon, navigational planets and stars over several years to a consistent precision with the aid of a pocket calculator, personal computer or laptop; from Her Majesty's Nautical Almanac Office)
• SOFA: Standards of Fundamental Astronomy Libraries (a free software collection of constants, algorithms and procedures that implement standard models used in fundamental astronomy, from the International Astronomical Union)
• SPADE: Solar and Polaris Azimuth DEtermination (free DOS program from yours truly that provides astronomic azimuths of the Sun and Polaris without the use of tables, designed for use by land surveyors and geodesists.)
• William-Bell Astronomical Software Catalog