Re: PAS 1R Seen

From: Björn Gimle (
Date: Fri Feb 03 2006 - 05:48:35 EST

  • Next message: Greg Roberts: "Obs 02 Feb 2006"

    If the solar concentrators are 45 degrees, a double reflection in those 
    would return back, ie cause flaring at 12h difference.
    But then there would be no effect on to the solar panel (no 
    concentration) since the first reflection would travel parallell to the 
    solar panel!
    When this was first discussed, I think 60 degrees was mentioned (and 
    looked correct on photos).
    In this case, a reflection concentrator-panel would return 60 deg = 4h 
    off the Anti-Sun RA, unless the concentrators are so wide they block the 
    indirect panel reflections. (Those would then be reflected back towards 
    the Sun by the second concentrator).
    Several observations by Ed and others confirm flaring 3-4h before and 
    after expected times.
    A concentrator-concentrator ray would be reflected back to the first 
    concentrator, then again towards the Sun.
    All the above assumes that the panels are aligned towards the Sun. A 
    15-degree misalignment would cause the rays to leave 30 degrees = +-2h 
    off the direction 8h / 12h / 16h to anti-Sun. For such a case, 45-degree 
    concentrators would also be meaningful!
    It also assumes that the concentrators act in the RA direction, ie that 
    the panels extend in the Earth axis direction!
    If they are stretched out in the equatorial plane instead, the 
    concentrators would compensate for declination pointing errors.
    And it would fit Kevin's obs at 12h off the anti-Sun, and at an 
    unexpected declination!
    ----- Original Message ----- 
    > I have observed PAS 1R and other boeing HS702 series geo sat, on 
    > different nights. It flared up
    > around an area, that has a difference of 12 hours R.A from the sun, 
    > are when the sat is at
    > oposition for the night, as I call it.
    > I have found that so far, only the boeing HS702 series that have the 
    > solar concentrators, flare
    > The things angled at roughly 45 degrees to the solar panel.
    Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive:

    This archive was generated by hypermail 2b29 : Fri Feb 03 2006 - 05:52:02 EST