Stereo B satellite recovery
28may15
28may15: stereob
10jun15: stereob
22jun16: stereob
28may15: recovery attempt
Taking the data:
We took data with the xband receiver while attempts were
made to wake up the satellite. The setup used was:
- jpl horizon's ephemeris used for tracking the satellite
- Here's how i arrived at the frequency setup used:
- The plan for tone recovery had dsn transmitting:
- start 7188.88600 MHz
- sweep down 13 KHz
- then sweep up 18 KHz
- sweep segments 1000Hz, sweep rate 100Hz/sec
- So they swept over 1khz for 10 secs, giving the
satellite a chance to lock
- they then sent the command sequence (assuming it had
locked). this took about 628 seconds
-
|
freq
range MHz
|
notes;
|
|
Min freq
|
max Freq
|
|
SatUplinkRcv
|
7188.873000
|
7188.891000 |
|
SatDwnLinkXmit
|
8446.205928
|
8446.227076 |
880/749 of rcv
|
aoRcv
|
8446.230365 |
8446.251513 |
avgdop @ 15:30utc
24437 Hz,blueshifted
|
|
cfr
MHz
|
bw
|
|
ao
Rcv cfr/bw
|
8446.240939 |
21148.
Hz
|
|
Ao Settings Used
|
8446.231359
|
4.0
MHz
|
4MHz bw, voltage
sampling
|
- Assumptions:
- they did uplink doppler so 7188873000 Hz is the value
rcved by the satellite.
- I took 4 MHz bw voltage. data.The sampling center was
about 8khz below the rcv center
- Mock spectrometers;
- 8bit time domain complex sampling at 4MHz, both
pols, clock set to 160MHz.
- used +10MHz offset if2, -10MHz offset mock digital mixer to
get rid of dc spike
- pdev file format, got 17 2Gb files.. about 34 Gbytes
of data for the 36 minutes we took data.
Making the images.
- I took 50 KHz bw about 8446.240939 Mhz... just in case..
- 2^20 length xform is .25 seconds or 4 Hz resolution
- avg 16 spectra --> 4 seconds of data
- the doppler was moving by about 1Hz/sec, so the signal would
smear over 1 4Hz freq bin in 4 seconds.
- We started at 15:12:44 utc and took data for 2170
seconds.
- if the receive signal started at 14:05 utc (email), we then
started on step 6.457 . 6Khz below the start freq
- 2170 secs is 3.455 628 second intervals. So we ended on
interval 9.93.. 9 khz below the start xmit freq.
the images show the dynamic spectrra for the two polarizations
image notes:
- Don't see any signal. I would expect it to be drifting to
lower frequency at about 1hz/second..
- the channel width is 4 Hz, the display channel width is 36 Hz
(i averaged by 9 channel)
- The vertical is 1 pixel/spectra.
- I also made 17 5KHz bandwidth images (giving 4Hz display
resolution).. still saw nothing.
- The signal should be seen:
- starting at 8446.238590 Mhz
- to
8446.233890 Mhz after 2170 secs (from the 1khz xmiter hops
each 628 seconds).
- the start receive time was only quoted to 1 minute...
- --> maybe next time...
processing: x101/150528/cmpsat.pro
10jun15 stereob recovery attempt
The setup was similar to the 28may15
attempt. The differences were:
- only took 2Mhz bandwidth data
- topocentric avg rcv freq: 8446.239778
- dopVel @ transit: -0.69587060 km/sec.
- dopFrqOffset @ transit: 0.019723861 Mhz (blue shifted).
- doppler drift was +3898 to -3898 Hz about the center rcv
frequency.
- center freq for 2Mhz band: 8446.140000 (wanted to get away
from DC, and first lo was only setting to multiples of KHz.
- started taking data:14:52;40 utc . ended at 17:27:00
Making the images.
- I took 60 KHz bw about 8446.239783 Mhz... just in case..
- 2^19 length xform is .25 seconds or 4 Hz resolution
- avg 16 spectra --> 4 seconds of data
- the doppler was moving by about 1Hz/sec, so the signal would
smear over 1 4Hz freq bin in 4 seconds.
the images show the dynamic spectra for the two polarizations
image notes:
- Don't see any signal. I would expect it to be drifting to
lower frequency at about 1hz/second..
- the channel width is 4 Hz, the display channel width is 44Hz
(i averaged by 11 channel)
- The vertical is 3 spectra/pix.. or 12 seconds/pixel.
this would smear the 12 hz in the vertical direction.
- I also made 11 5KHz bandwidth images, by 1 spectra vertical
resolution (giving 4Hz display resolution).. still saw
nothing.
processing: x101/150610/cmpsig.pro
22jun16 stereob recovery attempt
The setup was similar to the 10may15
attempt. The differences were:
- topocentric avg rcv freq: 8446.19150
- dopVel @ transit: -0.8520704 km/sec
- dopFrqOffset @ transit: -.023989 Mhz (blue shifted).
- doppler drift was +4000 to -4000 Hz about the center rcv
frequency (for the run)
- center freq for 2Mhz band: 8446.140000 (wanted to get away
from DC, and first lo was only setting to multiples of KHz.
- started taking data:14:24:35 utc . ended at 16:44:00.
- short gap 15:40 to 15:44 where data taking was stopped
(transmitted a tone to recheck frequencies).
Making the images.
- I took 60 KHz bw about 8446.19150 Mhz... just in case..
- 2^19 length xform is .25 seconds or 4 Hz resolution
- avg 16 spectra --> 4 seconds of data
- the doppler was moving by about 1Hz/sec, so the signal would
smear over 1 4Hz freq bin in 4 seconds.
the images show the dynamic spectra for the two polarizations
- 14:24 to 15:40 utc
- 15:44 to 16:44 utc
image notes:
- Don't see any signal. I would expect it to be drifting to
lower frequency at about 1hz/second..
- the channel width is 4 Hz, the display channel width is 44 Hz
(i averaged by 11 channel)
- The vertical is 2 spectra/pix.. or 8 seconds/pixel. this
would smear by 8 hz in the vertical direction.
- I also made 11 5 KHz bandwidth images, by 1 spectra vertical
resolution (giving 4Hz display resolution).. still saw
nothing.
processing: x101/160622/cmpsig.pro,
dispimg.pro
home_~phil