22mar14: swarm B satellite overflight

• tle computation used:
• aoLat: 18.34
• aoLong: -66.75
• aoHght: .5 km
  
• The the telescope position was compute using:

• 15mar14 tle file
  
• 2014.03.22 20:21:50 (utc)
• wgs x,y,z 2667.289,-5975.017, 2165.614 km
• g_lat,g_long: 18.419, -65.944 deg , 516.381 km
  
• az,el,range: 83.999, el=79.813,(za=10.187) , range: 523.515 km
• it was recomputed using 24mar14 tle file for 20:21:50
  
• 24mar14: recomputed position for 22mar14,20:21:50
• lat: 19.18  (.761 deg higher)
  
• long:-65.97 ( .025 deg farther east)
  
• range=516.1 km

  datataking:

• ch pointing at: at 83.999 az , za=10.187 .. pointing model was added to these values.
• mracf 2 usec sampling 300 usec pulse, 2048 heights covering 150 to 764 km
• ipp - 10 milliseconds

    processing:

• read  20 seconds of data around the expected overpass
• compute power for each height sample

• horizontal direction : range (km)  300 meters resolution
• vertical scale (time hours utc) 1 second resolution (i averaged 100 ipps together after computing power)
• the dotted vertical line is the expected overpass time: 20:21:50
• You can see the weak stripe a little after this time starting at 523km
  
• The width is from the 300 usec transmitter pulse
• the stripe at 420 km may be another satellite?

• average the 150*2usec samples starting at height 523.5 km (this averages over the rf pulse length) for each ipp in the20 seconds around the overpass.
• Normalize to the rms value using ipps prior to the overpass
• Top: range 523 km power vs time
• The satellite appeared near 20:22:00 (this is accurate to 1 second).l
• Bottom: blowup of the satellite overpass
• The horizontal scale is  now seconds from measured overpass.
• The time resolution is 10 milliseconds.

26mar14: swarm A pass

    The pass was computed using the same 15mar14 tle file
The values computed to point the telescope were:

• date/time (utc):2014.03.26 8:05:20
  
• g_lat,g_long:(deg):  18.429 ,-66.832
• range:     471.416  km
• source az:-41.270
• el: 88.291   (za=1.709 deg)
• range:  471.114    km

• ipp=10 millisecs,gw=2 usecs, 2048 heights starting at 1000 usecs (150 to 760 km)
• for each ipp compute the power for each range sample
• average 100 ipps to give 1 sec resolution
• make an image of total power range vs time
• There are two echoes in the 30 minute image.. the are pretty far from the expected time..
  

• the horizontal axis is range in km
• the vertical scale is utc Hours
• the horizontal, vertical line show where we expected to find the satellite
• 
  

 Computing swarmA ao pass using predict and a tle file from 28mar14

• I told predict to compute at 1  second intervals.
• The * are the computed points
• the red dashed lines show the time for the 15mar14 tle computation
• the blue lines are the az,za  we actually used for the observation.
• the az is off by a lot, but the za=1.7deg decreases the error by sin(za)
• the za is off by about 13 degrees.

 home_~phil