Apr14: Aerostat returns

        The aerostat went off the air on 15dec11 when its tether broke. A new aerostat is now being brought online.

Setup:

• lband wide, linear polarization.
• mock spectrometer time domain sampling.
• two 5 Mhz bands
• cfr 1256.7
• cfr 1242
• 36 seconds of data was taken (3 12 second periods).

Processing:

• 256 channel spectra were computed (49.6 usecs) for the all the data
• total power was computed for 1.1 Mhz about each of the two radar frequencies.

• Page 1: total power vs time for the three 12 second rotations.
•  Each rotation has been offset for display.
• The y axis is units of Tsys (for the 1.1 Mhz total power).
• The blue dashed lines show the blanking in the AO direction
• the red blank lines show the blanking for the airport (or the airport radar).
• The peaks at 3 And 9 seconds are sidelobes that we saw in the old version of the aerostat
• Using the AO blanking as a reference, the period is actually 11.824 seconds
• Page 2: blowup showing AO blanking region
• The dashed blue lines are anchored on the first blanking region
• The blanked region varies by about 30 millisecs
• the radar blanks for 1.421 seconds when pointing at AO.

• Page 1: total power versus radar azimuth.
• Azimuth =0 when the radar points at AO
• Page 2: blowup when radar points at AO.
• The radar blanks 43.2 degrees (+/- 21.65 degrees about ao direction).

• Page 1: average spectra for the 36 seconds.
• Black is polA , red is polB
• Top: 1256.7 Mhz pulse
• bottom: 1241.7 Mhz pulse
• The vertical scale is in Tsys units.
• Page 2:
  
• Top: ipp Sequence
• The radar uses a 7 ipp sequence. the Ipps in order are:
  
• 3771.3,3504.0,3075.8,2808,4,2904.3,3289.9, then 3675.4 Useconds.
• Bottom: pulse sequence for the two frequencies.
• Black is 1256.7 Mhz, red is 1241.7
• Total power was computed using 5Mhz about each frequency.
• The time resolution was .2 useconds.
• Each pulse is about 160 usecs.
• 1256.7 Mhz comes first.

SUMMARY:

• The is operating again (22apr14)
• It was seen broadcasting on 1241.7 and 1256.7 Mhz.
• it has used (1261.25,1246.2)  (1256.5,1241.74) Mhz
• the blanking is currently centered  on ao and is what was being done with the previous aerostat.
• the ipps (in order) are:
• 3771.3,3504.0,3075.8,2808,4,2904.3,3289.9, then 3675.4 Useconds
• The pulse length is 160 usecs with 1256.7 followed by 1241.7
• The pulse shape is a bit spread out. my 1256.7 would be 1256.5 if i used only polA).