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  • Updating Locations for Observatory Codes

    Observatory codes are assigned to observatories that report astrometric observations of minor planets, comets or irregular natural satellites. The Minor Planet Center's listing of observatory codes is therefore not a complete listing of observatories worldwide.

    New codes are assigned on a regular basis, either as a result of new observers reporting observations or as a result of extracting observations from the old literature. See the Guide to Minor Body Astrometry for information on how to obtain an observatory code.

    Positions of observatories have been reported with respect to a number of geographical datums over the years. The bulk of positions for observatories operating in the 19th and early 20th centuries have been taken from the annual lists of observatory coordinates given in the Astronomical Ephemeris/ Nautical Almanac. Ideally, all positions should be reported with respect to the WGS84 datum. If you have previously reported coordinates for your site, you should remeasure its location using Google Earth and report the new measures.

    The current list of assigned codes is here.

    The KML file of observatory-code locations has been removed, following a request from some Spanish observers concerned about security at remote, unattended sites.

    What to Report

    When reporting updated coordinates for your site, be sure to include the following information:
    • Longitude (in sexagesimal form, to 0.1" or better, preferably 0.01")
    • Latitude (in sexagesimal form, to 0.1" or better, preferably 0.01")
    • Altitude (in meters)
    • Source for coordinates
      • If source is Google Earth, please simply state this.
      • If source is GPS, please state this and indicate whether the altitude is referred to the WGS84 ellipsoid or to mean sea level.
      • Use of other sources is strongly discouraged.
    • (Optionally) Height of instrument above ground (in meters)
    A convenient form in which to report the required information is:
    COM OC, xxx xx xx.xx E, xx xx xx.xx N, xxxx m, GoogleEarth
    COM OC, xxx xx xx.xx E, xx xx xx.xx S, xxxx m, GPS, MSL        ! GPS altitude referred to mean sea level
    COM OC, xxx xx xx.xx W, xx xx xx.xx N, xxxx m, GPS, ELL        ! GPS altitude referred to WGS84 ellipsoid
    COM OC, xxx xx xx.xx E, xx xx xx.xx N, xxxx m, 10 m, GoogleEarth  ! Telescope is 10 m above ground level
    where OC is the three-character observatory code.

    If your site has a webpage, you can report the URL in the same message as the updated coordinates. The format should be:

    URL OC http://...
    where OC is the three-character observatory code.

    Click here to report coordinates!

    Known Problems with the Observatory Code list

    A number of sites have previously only had low-precision coordinates reported. The observers at the sites listed below should report high-precision positions using Google Earth:
    484 174.75   0.753   -0.657   Happy Valley, Wellington
    495 357.66   0.598   +0.800   Altrincham
    497 359.30   0.626   +0.776   Ascot-Loudwater
    502   0.85   0.617   +0.783   Colchester
    588  11.25   0.715   +0.697   Eremo di Tizzano
    631  10.02   0.596   +0.800   Hamburg-Georgswerder
    792 288.30   0.753   +0.657   University of Rhode Island, Quonochontaug
    863 137.18   0.807   +0.588   Furukawa
    984 357.26   0.631   +0.774   Eastfield
    986 358.75   0.624   +0.779   Ascot
    989 357.69   0.600   +0.797   Wilfred Hall Observatory, Preston
    E21 151.5667 0.8838  -0.4665  Norma Rose Observatory, Leyburn
    E27 153.2667 0.8871  -0.4600  Thornlands
    Note that the quoted precision in the last two entries is not justified. The above list is not exhaustive and will be modified in the future as updates are received.

    Updated Coordinates

    If updated coordinates are reported, the details will appear in the on-line list of observatory codes after the next DOU MPEC is issued.

    Requests for Assistance

    Help is requested in identifying the locations of the following sites/instruments. With the information we have available, it is not possible for us to clearly identify these sites. For each site, we list the observatory code and name, followed by the approximate longitude and latitude, and finally the dome or building that needs identification.
    008 Algiers-Bouzareah      003 02.1     E  36 48.1     N   Need identification of observatory, before requesting particular dome.
    012 Uccle                  004 21 30    E  50 47 53    N   Need identification of what instruments are in what domes.
    065 Traunstein             012 38 24    E  47 52 26    N   Need location of observatory site
    066 Athens                 023 43 05.83 E  37 58 24.21 N   Need confirmation that identification is correct.
    109 Algiers-Kouba          003 04.3     E  36 44.3     N   Historical site, may be no trace left.
    556 Reintal                011 37.2     E  47 45.4     N   Need location of observatory
    589 Santa Lucia Stroncone  012 40 39.24 E  42 30 22.61 N   Dome-shaped feature, is this the observatory?
    Report coordinates here, noting the justification for the identification of the feature (e.g., "I work there", "I've observed there", "I live next door", etc.). Further entries will be made to this list in the future.


    The MPC has no connection with Google Earth, but is simply a satisfied user of the service.