ISS Pass

A photo of the ISS pass last night. Just put my camera on a wheelie bin pointing up with a 10 second exposure and crossed my fingers! Of the 3 photos I took, one has ISS going through it.

The photo won't win any prizes, but its good to see what can be done with very simple equipment. If only it had been clear during the Perseids a few days back.

I got a couple of new RTL-SDR USB sticks last week and am currently roughly calibrating them (estimating the frequency offset error and will look at the noise figure to compare with my other USB sticks - although the latter is tricky due to the lack of equipment I have.)

Software Announcement!

The GroundStation software I've been working on for the last few months is now available from github here - below are a couple of screen shots of the realtime view of where the sats are and the pane on the right shows what frequency they are at (x-axis is frequency in MHz, y-axis is time in hours from now).

The second image show that I've select a part of the RF spectrum to capture (width determined by the fact its just a RTLSDR receiver).

When the times comes along, up pops an appropriate 'channel' which decode the signal (with real time Doppler corrections) - all by the magic of GnuRadio (and a fair amount of swearing!!). Its still pretty rough around the edges (and its very polyhedral....) but has got a fair amount of potential - so by the 10th rewrite it'll be great!

This week I also got my beagleboneblack running Debian and now happily streaming my RTLSDR dongle back to my desktop.

This looks like a very nice bit of kit, HackRF I look forward to getting mine.

Updates and things....

Here's the latest I've got from Aeneas from the pass today at around 13:45UTC:

AFSK1200: fm KE6YFA-1 to CQ-0 via TELEM-0 UI  pid=F0
4341455255531D0040020006190B0611391424050000001000F07500007013004900398341A5C5
AFSK1200: fm KE6YFA-1 to CQ-0 via TELEM-0 UI  pid=F0
4341455255531D0040020006190B0611392824050000001000F07500007013004900398341CEC4
AFSK1200: fm KE6YFA-1 to CQ-0 via TELEM-0 UI  pid=F0
4341455255531D0040020006190B06113A0024050000001000F07500007013004900398341C764
AFSK1200: fm KE6YFA-1 to CQ-0 via TELEM-0 UI  pid=F0
4341455255531D0040020006190B06113A1424050000001000F07500007013004900398341119C
AFSK1200: fm KE6YFA-1 to CQ-0 via TELEM-0 UI  pid=F0
4341455255531D0040020006190B06113A2824050000001000F075000070130049003983417A9D

And here's some from the pass yesterday (3rd Aug) at around 13:30UTC:

AFSK1200: fm KE6YFA-1 to CQ-0 via TELEM-0 UI  pid=F0
4341455255531D0040020006180B0511271424050000001000F075000070130049C0004D41AD4C
AFSK1200: fm KE6YFA-1 to CQ-0 via TELEM-0 UI  pid=F0
4341455255531D0040020006180B0511272824050000001000F075000070130049C0004D41C64D
AFSK1200: fm KE6YFA-1 to CQ-0 via TELEM-0 UI  pid=F0
4341455255531D0040020006180B0511280024050000001000F075000070130049C0004D410E83
AFSK1200: fm KE6YFA-1 to CQ-0 via TELEM-0 UI  pid=F0
4341455255531D0040020006180B0511281424050000001000F075000070130049C0004D41D87B

also STRaND-1 has been a strong signal (25-30dB above noise), but I've not yet sorted out the decode of it yet.

I've continued to work on my groundstation software and now have a working Doppler correction gnuradio block. I've made a bunch of improvements to the GUI and should have something pushed to github in the next month or two. One of the features I've added is a frequency against time plot which allows you to have multiple channels receiving different sats with different modes & Doppler corrections applied.

I'm still working on getting my beaglebone black working with my rtl-sdr receiver to make a PoE powered remote device - the main issue I'm having is updating the OS to be debian so I can easily put all of the dependencies - I know have a way forward with this - but not the time to do it!

Aeneas

From the pass that just occurred (20:25 GMT):

AFSK1200: fm KE6YFA-1 to CQ-0 via TELEM-0 UI  pid=F0
4341455255531D0040020006040B0617132808050000001000F07500007013004930C617423C83
AFSK1200: fm KE6YFA-1 to CQ-0 via TELEM-0 UI  pid=F0
4341455255531D0040020006040B0617140008050000001000F07500007013004930C6174285FE
AFSK1200: fm KE6YFA-1 to CQ-0 via TELEM-0 UI  pid=F0
4341455255531D0040020006040B0617141408050000001000F07500007013004930C617425306
AFSK1200: fm KE6YFA-1 to CQ-0 via TELEM-0 UI  pid=F0
4341455255531D0040020006040B0617142808050000001000F07500007013004930C617423807
AFSK1200: fm KE6YFA-1 to CQ-0 via TELEM-0 UI  pid=F0
4341455255531D0040020006040B0617150008050000001000F07500007013004930C61742E9C9
AFSK1200: fm KE6YFA-1 to CQ-0 via TELEM-0 UI  pid=F0
4341455255531D0040020006040B0617161408050000001000F07500007013004930C617428B68
AFSK1200: fm KE6YFA-1 to CQ-0 via TELEM-0 UI  pid=F0
4341455255531D0040020006040B0617162808050000001000F07500007013004930C61742E069

Testing with NOAA-19

I've got my software to the point where I can just click on a button and it will record (and perhaps decode) that pass. I have come to the conclusion that my Doppler corrector isn't good enough, so I'll have to re-engineer that. I don't support all the modes & modulations & baud rates that I need yet, but am working on it. Some, for example, APT I'm still having to do by hand. When the weather cools down, I'll start to design a much better Gnuradio backend which will allow me to construct & control flow graphs better than the GRC ones I'm currently employing. Anyway, to end on here's a pretty picture that I just decoded from NOAA-19 on my RTL-SDR dongle:

Todays progress

I've actually made a fair bit of progress on the software side of things. I can now kick off the GnuRadio bits'n'bobs as required from the GUI and then control them with XMLRPC. This allows me to do the Doppler corrections in real time - as you can see from the attached picture of the pass of ISS a few minutes ago. I'm having some issues with processes & zombies, bit hopefully I'll get to the problem that is causing me some robustness issues over the coming week.

Has anyone seen any recent TLEs for AENEAS?

Todays sats

I attempted listened to the following:

• HO-68 (09:50 GMT)
• CO-65 (10:05 GMT)
• FO-29 (10:30 GMT)
• CubeBug-1 (10:54 GMT) - Not heard
• ESTcube1 (11:27 GMT) - Not heard
• SO-50 (12:44 GMT)
• ITUpSAT (13:04 GMT)
• AENEAS (14:35 GMT)

The equipment was the same as last week. Times are approx AOS.

Started to restructure my software to start to allow me to do real time doppler corrections and then decode it - however its going to take a few more weeks of coding 'till I get something useful.

I ordered a comb generator from AMSAT-UK, which turned up yesterday. Hopefully this will allow me to quantify the drift I think I'm seeing in my RTLSDR (E4000) USB dongle. I started to assemble it but the SMD components have slowed me down.