Farewell ARISSat-1

There has been no official announcement yet, but it appears that plucky satellite ARISSat-1 finally de-orbited early this morning.

The last frame of received telemetry on ARISSATTLM site hasn’t changed since 06:02:14 UTC.

The DK3WN SatBlog posted the last report and some of the last heard voice telemetry earlier this morning. There is a post on the Yahoo FUNCube group from Konstantin RN3ZF claiming a very intermittent later contact at around 08:42, with links to some IQ wav files.

Several users on twitter have also reported no further contact with ARISSat-1, I monitored an pass myself earlier and got nothing.

I will miss it, I have enjoyed experimenting and receiving transmissions and I have learned a lot more about amateur satellites. It prompted me to join AMSAT-UK and am looking forward to having a go with the other satellites out there and the FUNCube project which will be launching later in the year.

Update, AMSAT-UK have confirmed ARISSat-1 is now silent key

First FCD experiments

I was feeling shattered after a hectic Christmas and being back at work, so it was nice with the New Year break to have a chance to recover. I have spent the weekend around the house and so had a good chance to try out my FUNCube Dongle (FCD) to do some proper satellite reception!

First off I spent a while calibrated my dongle using the excellent user guides available on the yahoo group, and getting to grips with the excellent but somewhat daunting SDR-Radio application. 

I fired up another of my ancient laptops a Sony Vaio, with XP and a pitiful 512MB of RAM. It is a nice machine, with an excellent large display but is a little underpowered. However undeterred with the prospect of some timely satellite passes I installed the necessary software and set off to the summerhouse at the top of the garden with my YAGI and a warm coat.

NOAA Weather Satellites

As I posted about back in October I was hoping if I did get an SDR radio to capture some of the APT images broadcast by the NOAA polar orbiting weather satellites. (Noaa 15, 18 and 19 are currently active)

The SDR-Radio application has the facility to decode the noaa images directly and along with it’s built in satellite prediction and doppler correction features it was fairly easy to get some decent images. The huge advantage of the SDR system is being able to alter the bandwidth to accommodate the 34KHz deviation required (as you can see in the image above)

The image above was captured on 31st December at 13:26 GMT from NOAA-19 on 137.100MHz, the left image is the IR, the right being the visible image. If you click to enlarge you can clearly see Spain and the Balearic Islands at the bottom, the UK and most of Northern Europe is covered in dense cloud and is rapidly going into shadow. There is some noise, caused in part by pager transmissions and some course manual doppler correction.

ARISSat-1

As I posted before Christmas this little satellite is still going strong but it’s time is very short as reaches the atmosphere. I have been able to receive four afternoon passes in the last two days

As you can see from the image shows, the FCD makes the entire ARISSat-1 2 meter downlink band plan available. The slight slope shows the doppler effect.

On the left you can clearly see the Morse code beacon and the BPSK telemetry segment and the right the FM voice and SSTV transmission. I am really really pleased to have successfully managed to decode some telemetry frames before she meets her fiery death. The decode was done after the passes by processing the recorded IQ wav file. I probably have just one more day to have a chance to try to decode some live telemetry and hopefully forward it via the internet to ARISS.
It goes without saying I have some excellent audio and decoded a couple of SSTV images too.

I love my new toy!

ARISSAT-1 nears the end

ARISSat-1 the satellite that has given me some pleasure over the last few months is approaching it’s fiery death, it looks like it might make it to the New Year just. http://www.southgatearc.org/news/december2011/arissat1_decay_date.htm

It is a real pity that at the moment the orbit mean I have no chance of capturing anything from it before it’s demise. All the passes over the UK are when in shadow and due to the battery failure it is silent.

Thanks ARISSat-1 you have been fun.

 

ARISSat-1 – The results just keep getting better

As I mentioned in yesterdays post, this weekend saw a couple of well timed passes of ARISSat-1, today had two which seemed to offer the possibility of decent results.

So the setup again was I’d have the PRO2006 in the spare room on the loft mounted discone to capture any SSTV images and the Yagi with the Alinco DJ-X10 in the garden to capture the CW beacon. The first pass yielded rubbish results from both setups, the beacon was very faint (I suspect I haven’t got something quite right for receiving the SSB/CW modes) but as I lost signal at the end of the pass I switched the Alinco to FM on 145.950MHz and got a really strong signal!

The decision was made! For the second pass I decided not to bother with the beacon and get a FM capture with the Alinco.. well glad I did got a cracking full 5 minutes of voice and three sstv images, including a beautiful one of the blue marble!

The normal PRO2006 setup yielded nothing worthy of including here!

Arissat1 1311111140 by nerdsville

 

ARISSat-1 Morse beacon

This weekend there are a couple of excellent daytime flybys of ARISSat-1 predicted, passing very high in the sky.  Up till now I have been concentrating on the FM transmission on 145.950MHz which carries the voice messages, voice telemetry and the SSTV. The other signals from the satellite use SSB and CW modulation.

So this morning I left the loft discone and my Realistic PRO2006 with MMSSTV in the spare bedroom waiting for the pass while I took the borrowed Alinco DJ-X10, which has SSB capability, outside and using the Yagi antenna I built up last weekend had a go at getting some of the CW beacon on 145.919MHz

I got a decent signal as you can hear below, and using CWGet managed to decode some of the telemetry and the identification, but the high noise and doppler effect did cause some problems.

Arissat1 cw beacon by nerdsville

While I was doing this the SSTV system caught a lovely image

Can not wait till tomorrow for two almost overhead passes in the morning and then time to watch the Grand Prix!

Satellite experiments with the YAGI

There were a couple of reasonable passes of the ARISSat-1 satellite predicted this afternoon so I decided to try out the nice new InnovAntennas 4 element 144MHz LFA Yagi which my brother won in the prize draw at this years National Hamfest.

Well this is how it arrived, a big cardboard tube that has been sitting in my workshop since October.

Taking everything out the box, lots of metal work, but no instructions!

It was fairly logical to put together, but wasn’t absolutely sure how the folded dipole element went together and the u-shaped end pieces slotted in with no apparent fixings to hold them in place (I assume they are missing along with the instructions) There was also a piece that fitted under the antenna. I am no expert on antenna design so checked the InnovAntenna website but it was no help, lots of graphs and radiation patterns but and not one images of the actual antenna to look at! Looking at a small picture on the Waters and Stanton blog I made a guess as to how it should be put together.

I connected up a bit of coax, and screwed it a short wooden post I had. The end pieces of the folded dipole slipped in and seemed to be fairly secure but probably not brilliant electrically, so will need to secure them properly if I ever use this in anger.

It is lightweight and easy to move about, so I was ready to get going

The satellite passes are from west to east and to the south of my location. So would have to do this at the end of the garden to minimise obstuctions from houses and trees. I would be well away from my normal computer and scanner in the spare bedroom! I decided to use my Realistic PRO-26 hand-held scanner, which is a good performer and has a relatively clean unprocessed audio output (can decode pagers and ascars quite well with it)

I used an old Pentium III laptop running Windows 2000 to capture the audio. I didn’t attempt any decoding of the SSTV directly just captured the wav files so I could edit and process them later. The laptop has dead batteries but could be powered from the summerhouse mains and so with a few extension cables I could have a relatively clear view of the sky and have access to the scanner to adjust levels and could monitor the audio from the laptop!

I experimented with the first pass, at around 13:30 UTC and got a decent signal eventually, but it took a bit of trial and error as the polarisation seems to change during the pass. For the second at 15:14 UTC I set up the camera to record my efforts! The audio in the video is just being picked up by the microphone on the camera so has a lot of background noise, but as you can hear it was at times a fairly strong signal! I had my usual unattended setup going in the spare bedroom and got nothing on either pass!

I have uploaded the two audio files of each pass to Soundcloud

ARISSat1 0611111330 by nerdsville
 
ARISSat1 0611111514 by nerdsville

Here are the images decoded from the audio.. slight sync problems which I suspect is the underpowered laptop – I did have it capturing at 44.8KHz, 32 bit resolution, which was probably an overkill in hindsight!
 



But on the whole it was a fun way to spend the afternoon with some nice results.

ARISSat-1 Still Transmitting

ARISSat-1 is getting nearer the atmosphere but is still functional and the orbital passes have moved back into daylight over the UK so set up the gear again this week to try to get some more SSTV images. Results have been a bit poor, but did get the back end of a very nice image this afternoon clearly showing some cloud formations in the atmosphere.


Now got an excuse this weekend to try out the nice new yagi that we won in the prize draw at the Hamfest at the start of the October that is still sitting in the box! It sounds pretty good. http://blog.wsplc.com/?p=431

Oh and as I threatened too I have joined AMSAT-UK, now just saving up for my FunCube Dongle.