The aerostat balloon radar

        The aerostat is a tethered balloon radar that flies above lajas puerto and is used for drug interdiction.

Aerostat radar specs

22apr14: aerostat returns to operation
15dec11: aerostat off the air.
23feb09: 1385 Mhz birdie in alfa from aerostat.
may05: Modeling the periods created by the aerostat radar.
08may05: aerostat compresses alfa when oh filterbank amps installed.
06oct04:Looking at the detected radar total power vs time


Aerostat radar specs:

The radar specs listed below were measured back in 1997-1999
transmitter L88-A (upgrade around 2002??)
rf frequencies (1261.25,1246.2)  (1256.5,1241.74) Mhz
Pulse len 160 usecs per frequency, 320 usec for a frequency pair (sequential in time)
7 ipp pulse sequence used [3771.,3504.,3076,2809.,2903.5,3289.,3676.]   Useconds
bandwidth 1.667 Mhz chirped
Dual Freq modes 1261 for 160 usecs followed by 1246. for 160 usec or
1256 for 160 usecs followed by 1241 for 160 usecs.
Rotation period Nominally 12 seconds. Measured back in 1999 to be 11.6 seconds (this may vary)
Blanking The radar is blanked for 42 degrees of azimuth (1.43 secs) centered on the arecibo direction.
The blanking level is set so that the main  lobe level after blanking is equal to the sidelobe level.
The radar is also blanked for 14.5  degrees (.48 secs) when it points at the san juan airport (or maybe the radar). This occurs 73.5 degrees (2.45 secs) after the start of the AO blanking.
Sidelobes There are sidelobes  (spillover ) at -108 and +115 degrees from the observatory direction
Location of tetherpoint 17:58:45 N  (AO: 18:20:39.44)
67:04:55 W (AO: 66:45:10.00)
The tether point location looks like it is not very accurate (no fractions).
distance to ao Probably less than 30 miles.
Misc The punta salinas radar also transmits at these freqeuncies (although it is not as strong)
Also see: 1997 report on radar frequencies.
tethered aerostat radar systems (FAA)
tethered aerostat radar systems (AF)