Re: accuracy of ISS / Venus transit track

From: Denis (
Date: Thu Jun 03 2004 - 20:52:11 EDT

  • Next message: Kevin Fetter: "RE: accuracy of ISS / Venus transit track"

    I am working on adding the track feature. I have some ideas but I am not 
    very successful so far. To produce an accurate track, I have to take 
    care of a lot more variables such as refraction, airmass, temperature, 
    oblateness and a few more. Fun to play with, sometimes!
    Thomas Fly wrote:
    > Thanks Denis- indeed most programs that are capable of searching for transits
    > are observer-oriented, and so don't produce ground tracks.
    > The angular size of Venus on June 8 will be about 58", and for a 63 elevation
    > transit of Venus, the 73 meter width of the main solar panels corresponds to
    > about 37" (if oriented perpendicular to the line of sight, as Mike Tyrrell and
    > Phil Masding's ISS VRML simulator suggests may nearly be the case, at least in
    > some places), or about 2/3 the size of Venus.
    > Your results therefore match mine basically to the size of the ISS itself, which
    > means that "improved" accuracy (except for using accurate values for the local
    > elevation above sea-level) may be quite pointless, since it's unlikely that the
    > TLE available on June 7 will be able to locate the ISS's center of mass to
    > better than 73 meters- or even anything particularly close to 73 meters...
    > I'll pass along the link to your program, for anyone that may be interested:
    > -------------------------------------------------------------------------
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