Category Archives: AMATEUR-DSN

More confirmations of my ISEEE-3 detection

Space Collage:

According to our team “The frequency offset is ~18025 Hz on Spectravue, so it looks likely. He’s tuned to XB, so just seeing the very tip of the PM carrier.”

http://spacecollege.org/isee3/detecting-isee-3-with-a-8-foot-dish.html

Phil Karn KA9Q

“I calculate a C/N0 of -2.5 dB-Hz for you, depending on mod index. Seem right? That’s weak!”

https://twitter.com/ka9q/status/475739296708567041

Confirmation of my ISEE-3 detection from James Miller G3RUH

Dear Iban,

Thank you for the timestamp, qth etc, and the info about the Spectravue
header format.

I examined the file anyway and worked out that a “stereo” signal was I and Q,
16-bits each, LSB first.

I confirm the signal as you found.  I averaged small and large numbers of
FFTs.  This showed that the signal strength varied, between approximately
11 to 16 dB-Hz.  The spacecraft is spinning at about 3 rpm, so this may be
the reason.

Attached is a typical plot from my my own software.  This is not the strongest
signal display; the largest I found was a signal = -45.7 dB over the
noisefloor = -53.8 dB, or SNR = 8.1 dB.

With a bin bandwidth of 0.124 Hz, this equates to a CNR of 16.4 dB-Hz.

Congratulations!

73 de James G3RUH

ISEE-3 signal processed by G3RUH

ISEE-3 signal processed by G3RUH

ISEE-3 / ICE DETECTED !

Finally after four days of attempts I detected the ISEE-3 / ICE space probe :)

I used the LHCP channel that is at 2217.5MHz becuse I have a lot of noise in the RHCP channel.  I used a can feddhorn and a plexiglas depolarizer.

The signal is very weak and impossible to see without time integration.  The offset reported by the Arecibo guys of 7202Hz has been very important to locate the probe. In my case I’m getting the probe with a carrier offset of 6035Hz from 2217.5MHz.

Here the first detection:

ISEE-3 / ICE Dection

ISEE-3 / ICE Dection

After the detction, to confirm that I moved the dish 18deg, and the signal disappears:

ISEE-3 / ICE off center

ISEE-3 / ICE off center

To confirm again the signal I stoped the doppler compensation:

ISEE-3 / ICE no signal without the doppler compensation

ISEE-3 / ICE no signal without the doppler compensation

Finally I started to compensate the doppler again and the signal is acquired again:

ISEE-3 / ICE with doppler corrected

ISEE-3 / ICE with doppler corrected

To finally confirm at 100% a offline signal process without doppler compensation to see doppler signature. I used the amazing baudline autodrift option, it is a great feature to see signals with doppler:

ISEE-3 / ICE baudline autodrift

ISEE-3 / ICE baudline autodrift

Here the IQ recording from Spectravue without the doppler compensation used  in the baudline analysis. The sample rate is 8138 samples/sec:

www.eb3frn.net/files/Record1_20140607_151047_nodoppler.wav

73!

 

 

Detected GAIA spacecraft

Detected the GAIA spacecraft travelling to the L2 point.

Gaia Spacecraft

GAIA Spacecraft

ESA GAIA

ESA GAIA Mission

The frequency is 8465 MHz and for the moment don’t have ephemeris from the JPL/Horizons or spice kernels. For the moment using the ephems from GBOT getting a aprox RA and DEC and using my own tools for full tracking.

GAIA detection

GAIA detection

Gaia sidebands

GAIA sidebands

 

Successful reception of the Yutu landing

Yesterday the Chang’e3 spacecraft andt the Yutu rover was landing successfuly. I was start to track the moon since the 18:30 to the 22:30 UTC. And I was listen Yutu from the start of my window and the signal was over 15dB of SN at 1Hz of BW.  The frequency of the rover is 8462.08000MHz with the moon doppler of -0.6Hz/s of aprox. The signal was easy to listen in the earphones, and sounds like a some kind of morse.

For this event I was setup two receivers, as main a AOR AR5000 and Rfspace SDR14. As second receiver a rtl-sdr doongle with r820t tuner and baudline.

Yutu rover, using AR5000 + SDR14

Yutu rover, using AR5000 + SDR14

Yutu rover using rtlsdr + baudline

Yutu rover using rtl-sdr + baudline

The command line to use rtlsdr with baudline was:

rtl_fm -g 44 -d0 -f$1 -s 250000 -F -U | ./baudline.static -stdin -samplerate 250000 -channels 1 -session rtlsdr1chUSB0 -basefrequency $1

Yutu rover using rtlsdr + baudline

Yutu rover using rtlsdr + baudline

Now you can listen how sounds the data stream from Yutu. A short audio record of the signal demodulated:

Detecting Juno spaceprobe coming to Earth

This week he the enthusiasts os the space probes and the amateur-DSN are living a nice week dued the flyby of the Juno spacecraft. The flyby will be in the next October 9th.

Juno spacecraft

Juno spacecraft

When the spaceprobes are very near to the Earth to do a flyby, the low gain (LGA)and medium gain (MGA) antennas are used. As this antennas not are in the central axis of the probe and it is rotating continuosly, you can see the rotational movement in the screenshoot:

Juno received from EB3FRN station

Juno received from EB3FRN station

 

Ephemeris for planetery space probes

The next images, I’m comparing the data using my ephemeris in the upper side and Horizons ephemeris in the lower side. Remember that Horizons dont give data for planetary probes, and are using the data of the planet that is orbiting the planet.

Data for Mars Express

Data for Mars Express

As you can apreciate, in the upper side, the range calculated using SPICE and the mission kernels is smaller than the range of the MARS calculated by Horizons. Then the MEX space probe not is eclipsed by the planet and then detectatble for our stations in the earth! Check the difference of 60 KHz in the predicted frecuency and doppler too.

Data for Mars Reconnaissance Orbiter

Data for Mars Reconnaissance Orbiter

Now the inverse case, the MRO probe is more away from the earth, then the probe is eclipsed by the planet.

Another issue observed is a small position difference from JPL/Horizons to my ephemerris using SPICE. It happend, because JPL/Horizons uses TDB as time reference and I’m using UTC. Then, exists a difference of few secconds produced by the leap seconds.