26mar14: swarm A 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

- 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

- 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.

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

The processing was:

- 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

I used the predict program (and some idl software) to plot the satellite pass around 8:00 utc on 26mar14

The plots show the az, source za, and range computed using this setup (.ps) (.pdf):

- 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.

processing:x101/140326/430sat.pro, cmpsatorb.pro

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