Re: Strobes

Waphead@aol.com
Thu, 30 Sep 1999 23:01:41 EDT 

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Hello!
     I've been following this discussion with great interest.  I'm fairly new 
to this list, but have been actively observing satellites since I wrote a 
program in college to predict the overflights of Salyut 7.   Currently I fly 
B-52's and here's my input:

<<  Could the plane have flown all the way across the field of
 the photo in between strobe flashes? The distance between the lines
 is the wingtip to wingtip distance. What is that? Say, 50 meters?
 How fast was the plane going? Say, 500 km/hr -> 138 m/s? So the plane
 could move about 3 times the spacing between the lines per second.
 How often does the strobe blink? Once every 1.5 seconds? So do the
 lines extend in length more than 5 times their spacing? (I couldn't
 see anything on the image posted on the web.) I certainly do recall
 flights where they left the strobe off, for whatever reason.
  >>

     The N-S passes could have been two aircraft refueling.  Given the 
proximity of Pope, Cherry Point, Shaw, and Charleston there is the potential 
for a lot of military traffic.  AR202 is aligned almost exactly N-S but would 
be too far East.  AR601 and AR602 are closer in azimuth to be in the field of 
view but may be too far South to match the observed elevation.  
     When aircraft refuel at night, strobes and anti-collision beacons are 
turned off.  Position lights on the receiver aircraft are set to dim.  This 
protects night vision and lowers the distraction level for the pilots and the 
boom operator.  Typical speeds are about 400 KTAS or 644 km/hr.  A formation 
of C-5's, C-17's, C-141's, or KC-10's may have overflown the area while 
aligning themselves for one of the nearby air refuleing tracks.
     Additionally, the Gamecock MOA is another possible source of military 
aircraft lights and is directly over the photographers position.  Possible 
civilian sources would be from jet routes J109, J121, J79 (close, but not 
N-S) however, J4 could be a good match for the E-W pass.
     I'll do some more research on the azimuths and elevations of the 
surrounding routes (as observed from the photographers position) tomorrow at 
work.
Shawn

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Date: Thu, 30 Sep 1999 17:08:59 -0500 (CDT)
From: "Joseph A. Dellinger" <jdellinger@amoco.com>
To: SeeSat-L@blackadder.lmsal.com
Subject: Strobes
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	Could the plane have flown all the way across the field of
the photo in between strobe flashes? The distance between the lines
is the wingtip to wingtip distance. What is that? Say, 50 meters?
How fast was the plane going? Say, 500 km/hr -> 138 m/s? So the plane
could move about 3 times the spacing between the lines per second.
How often does the strobe blink? Once every 1.5 seconds? So do the
lines extend in length more than 5 times their spacing? (I couldn't
see anything on the image posted on the web.) I certainly do recall
flights where they left the strobe off, for whatever reason.


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