Possible Explanation of RadarSat Flashing

Ted Molczan (molczan@neocom.ca)
Tue, 7 Nov 1995 19:10:41 -0500

Regarding Jeff Hunt's observation of flashes from Radarsat, I have received
a possible explanation from a friend who has a friend close to the Radarsat

Radarsat's radar panels began their deployment yesterday while it was above 
the horizon for the control centre at St. Hubert (near Montreal). The idea was 
that the deployment would self-start at St. Hubert AOS (5 degrees elevation) 
and they would monitor the deployment as it passed over until LOS.

Based on the latest elset, the satellite reached 5 deg elevation at St. Hubert
at 22:50 UTC on 6 Nov. Hunt's observation was 4 minutes later, at 22:55 UTC, 
so deployment was under way. I can easily imagine lots of bright glints as the
panels deployed.

Two other observers saw the object on passes several hours later, but saw no 
flashing. So it seems conceivable that Jeff Hunt observed transients glints
associated with antenna deployment.

Ted Molczan


For reference, here is part of Jeff Hunt's original message:

I Briefly observed RADARSAT (95059A) this evening (22:55 UTC 6 Nov) for the
first time in less than ideal conditions.  The sun was 10 deg. below the
horizon, the moon was full and there was a very high, thin scattered cloud
layer.  I needed my 7x50 binoculars to spot it.  At it's maximum altitude
it was located in the western sky with a calculated astronomical phase
angle of approximately 100 deg. which contributed to its poor reflectivity.
Perhaps my eyes were playing tricks with me but I believed I saw a
relatively high flash rate (several times a second).  I estimate the
brightness at 6 mag. for this pass.  Perhaps the 15 meter long radar
antenna contributes to that effect.  I hope others can verify this flashing