Re: Ground track calculations

From: Marco Langbroek (marco.langbroek@wanadoo.nl)
Date: Thu Aug 31 2006 - 03:50:12 EDT

  • Next message: Russell Eberst: "2006AUG29-30.OBS"

    Bill Frost wrote:
    > Hi Tom,
    > 
    > Everyone has their favourite. Mine is Orbitron and by coincidence 
    [snip]
    > Here's the data from a few seconds ago:
    > 
    > CALIPSO
    > Lon	28.0621° W
    > Lat	49.1764° N
    
    Just a remark that when it concerns very accurrate geographic positions, the map 
    datum of the given coordinates becomes of concern.
    
    I believe the standard SGP routine used by most software provides coordinates in 
    WGS72 datum? GPS-es on the other hand and for example our Dutch topographic 
    maps, employ the WGS84 datum.
    
    The difference between WGS72 and WGS84 is not of much concern (it is a 
    difference of about 10 yards maximum) but for some other map datums, it can go 
    up to a few hundred yards.
    
    So when a few hundred yards matter, take note of the map datum used and convert 
    if necessary!
    
    - Marco
    
    
    -----
    Dr Marco Langbroek  -  SatTrackCam Leiden, Cospar 4353
    Leiden, the Netherlands. 52.15412 N,  4.49081 E (WGS84), +0 m ASL
    
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