Re: Questions on Skymap Projection vs UNID matching

From: Bjoern Gimle@GlocalNet (Gimle@GlocalNet)
Date: Mon Aug 04 2008 - 14:13:31 UTC

  • Next message: Alberto Rango: "4641 SATOBS 02 - 03 AUG 2008."

    Stereographic is "always" most realistic, because it is a true projection
    around the center of the image, viewed from a point on the opposite
    side of the sphere.
    This means that great circles passing through the image center
    are straight lines at the correct angle, so you can use it at wide
    angle to trace meteor or LEO satellite tracks across the sky.
    BUT, Stereographic in SkyMap is sensitive to the F7/F7 setting
    AltAz/Equatorial - in AltAz THOSE track values are correct,
    but the stars only at the selected map time!
    
    Polar is "true" near the poles.
    Rectangular is good near the equator, and may help if
    you have a polar mount scope and know the directions.
    Stereographic then is true to your view in hand-held
    prismatic binoculars (and naked eye)
    
    /Björn
    
    ----- Original Message ----- 
    From: <chiayk1@singnet.com.sg>
    To: <seesat-l@satobs.org>
    Sent: Monday, August 04, 2008 3:51 AM
    Subject: Questions on Skymap Projection vs UNID matching
    
    
    Hi folks:
    
    
      In Rob's Skymap pro: Which map projection is 'closer' to the real view?
    Rectangular or Steoroegrahy.
    
      I was trying to ID a flasher last night and found that changing the map
    proj view had a big effect between matching the trajectory versus
    background stars ( distance from it).
    [This sat is suppose to be half the distance between two recognised stars
    but only one projection show it properly w.r.t stars.]
    
    
      Thanks
       rgds
       ykchia
    
    
    
    
    --------------------------------------------------------------------
    mail2web.com - What can On Demand Business Solutions do for you?
    http://link.mail2web.com/Business/SharePoint
    
    
    -------------------------------------------------------------------------
    Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive:
    http://www.satobs.org/seesat/seesatindex.html
    
    
    -------------------------------------------------------------------------
    Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive:  
    http://www.satobs.org/seesat/seesatindex.html
    



    This archive was generated by hypermail 2b29 : Mon Aug 04 2008 - 14:15:07 UTC