Hi All, Jonathan mentioned the following from the Heavens-Above website: > Satellite Details > Orbit: 683 x 690 km, 68.0° > ... > Intrinsic brightness (Mag): 3.6(at 1000km distance, 50% illuminated) > Maximum brightness (Mag): 1.9 (at perigee, 100% illuminated) Not to beat a dead horse, but these two brightness values are not self-consistent. If 3.6 is the intrinsic (aka standard) brightness at 1000km range, 90-degree phase), then the peak brightness at perigee and full-phase would be: 3.6 - 2.5*LOG(Pi/0.683^2) = 1.53 "50% illuminated" is a very misleading description since what is really meant is that the observer-to-satellite-to- sun form a 90 degree angle. In any case, 90-degree phase is not half as bright as full-phase; it's only 31.83% as bright (factor of 1/pi). This is the source of error in the maximum brightness calculation. Cheers, Rob ----------------------------------------------------------------- Unsubscribe from SeeSat-L by sending a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@lists.satellite.eu.org http://www2.satellite.eu.org/seesat/seesatindex.html
This archive was generated by hypermail 2b29 : Tue Apr 17 2001 - 17:32:32 PDT