Friday 10. May - BlueBox Micro PCBs arrived
This is going to be a great weekend. Stay tuned for pictures of the PCB.
Today we did:
- Check that connectors and enclosure fits
- Solder two PCBs using the free stensil from PCB-Pool
- Test RX sensitivity (<-117 dBm) and TX power (so far better than 20 dBm - we expect 27 dBm after fine-adjusting).
- Live-test with AAUSAT3 in a good pass usin a small handheld monopole antenna - WE DID MANAGE TO RECEIVE MSG IN 9K6 FROM AAUSAT3!! (once again this would not be possible without FEC)
Tuesdag 07. May - ESTCube-1 in orbit
Big congratulations to the ESTCube-1 team, with a satellite well in orbit! ESTCube-1 on facebook
We're glad to have been able to help it a bit on the way ;)
Tuesdag 07. May - We have spotted Skimpy
We have lately been kindly asked if we could find Skimpy - a sailing yacht - passing the Pacific Ocean. Skimpy has some danes in the crew.
Skimpy is carrying a class B AIS transponder.
So we are happy to announce that we have now spotted Skimpy close to Galapagos.
Friday 03. May - BlueBox update
Monday 29. April - What a marvelous antenna
On 29. April 05:37 UTC Jean-Pierre Godet (F5YG) did receive AAUSAT3 on a small monopole antenna shown on the picture. We are a little impressed :-)
From his email:
This morning at last I listened the good one, pass of orbit nr 897 over western Europe and catched two easy to decode CW beacon frames with a lot of short packet frames between them.
In attachment, the sound file mp3 of the second CW frame received between 05:37:13 UTC and 05:37:23 UTC this morning on April Monday 29th (orbit number 897). Decoding by ears, that is easier for me than the encapsulated CSP packets : _._._ OZ3CUB B7.6 T34 +"
The first CW frame of this pass was received about five minutes earlier, between 05:32:15 and 05:32:25 UTC. See the two spectrograms, in attachment too. The small dots at 05:32:45 and 05:37:44 are two of the nine short packet frames between the two long CW ones.
The devices used are mainly homebrew, poorly hacked from scrap, from the receiver to the antenna which is a simple quarter-wave ground plane in the attic (see photo in attachmnent). So it means, receiving in these so basic conditions, that your bird is very healthy and doing a good job. Congratulation to all the staff involved in the sat project at AAU.
WE SAY THANKS A LOT
Some old beacons:
- http://space.aau.dk/aausat3/picts/sounds/1288385-aausat3-cw-beacon.mp3 (by Andrew Garratt)
Sunday 28. April 19:50 CEST - 500.000 AIS msg received on AIS2
1) Happy birthday to AAUSATII. 5 years in space, still going strong.
2) AIS2 has in total decoded 500000 msg. with correct crc.
Thursday 25. April 22:12 CEST - Updated AIS2 raw sample
First of all we would like to share this view of the first 1 MB of raw downloaded IF samples from the AIS2 SDR. The two IF for AIS ch. 1 and 2 is 175 kHz and 225 kHz. This plot contains about 370 ms of data, corresponding to 1 MB in the current file format. The data shows that we still have a bit of reconfiguration to do on our AGC. This will require a 52 B file upload, once we have verified the configuration on ground. This will most likely happen this weekend.
Next up, we are working on 3-4 important parts at the same time:
1) Improve AIS algorithm for computational time and enhanced Doppler correction This will hopefully increase the number of ships detected per day by more than a factor of two. We need to verify code, and upload about 70 kB of code. After 1-2 days we will know if the enhanced algorithm is working.
2) The BlueBox (our ground-station-in-a-box project) has turned to the USB-stick sized form factor, a.k.a. BlueBox Micro. We do hope that in a few months we can help radio amateurs (and others) to receive and decode data from our satellite, and other satellites as well. Supported: USB interface for simple VHF/UHF transceiver using FSK/MSK - for both RX and TX if you have a small YAGI or similar antenna! (additional LNA/PA is recommended for operation in low elevation).
3) Experiment: Use the AIS2 linux system to enhance the attitude control system. We expect that the AIS detection rate can be further enhanced by pointing the antenna null direction towards Europe. Further more we might be able to increase the average power generated by our solar panels, by pointing a corner adjacent to 3 sides containing solar panels towards the sun. (only 5 out of 6 sides contains solar panels). Today we have about 1 hour during the day and 1 hour during the night in the low power state to save power.
We will soon have a few plots from our demodulator, to show what kind of SNR we are decoding, so stay tuned until next time.
Thursday 18. April 19:28 CEST - AIS2 raw sample file 03.raw
Now it must be time for a small update on the AIS reception status. We have been downloading some small chunks of a raw sample file last week, to conclude that further fine-tuning in our gain control loop is needed to handle the large amount of transmissions from ships that change rapidly.
A new frontend configuration file was uploaded to AIS2 (total of 52 bytes) on April 14th 2013. The Flight Planner (FP) was then configured to start sampling and saving four raw AIS2 SDR samples during the following night, when the satellite will have Greenland in range.
So far we have downloaded about 450 kB of the raw file named 03.raw corresponding to approx. 150 ms (total size 4 MB equals about 1.2 sec.).
For a quick sneak-peek, take a look at the fft picture (all rights reserved). The IF bandwith is configured to 100 kHz, so we see a few maritime channels - including the two AIS channels. With a keen eye you will notice a small break between AIS transmission slots (not to be confused with the part in the beginning where the AGC (automatic gain control) it adjusting).
Wednesday 10. April 20:30 CET - Fun facts
A total of 119,719 packets with 7,959,128 data bytes have been successfully downloaded.
Our FEC has so far corrected 1,166,785 bits and 22,499 bytes
Maximum bits corrected in packet is 197
Maximum bytes corrected in packet is 16
RSSI of weakest packet received is -123 dBm
RSSI of strongest packet received is -72 dBm
Mean RSSI is -87 dBm
Monday 8. April 18:00 - Some stats on AIS
We have now been in space for 41 days and AAUSAT3 is just rocket stable.
The figure on the right shows number of AIS messages received by AIS2 AND downloaded to ground.
A few comments to the mission until today...
- After the first few days we did not get AIS data down
- Second interval(day 7-16) we did get AIS data down with a one day record of 13000
- Third phase (day 17-18) we did test our assisted AIS data downlink - nearly no data down
- Fourth and current phase - we get 9-10000 AIS messages down every day
It is the SDR AIS2 system that provide all this information.
A few facts:
- AIS2 is active approx 30% of the time every day
- and of these 30% it samples the AIS channels 3-10% of the time
So in 24 hour AIS2 receive and analyze maybe 15-30 minutes of the 24 hours. So it receives around 5-10 AIS messages/second world wide in average. But please have in mind this is very rough numbers.
Saturday 23. March 18:00 CET - Start downloading of raw AIS
Today the download of a raw sample from AIS2 started. AIS2 was told to save 1 second of unprocessed data, when it was approaching Aalborg. The data is approximately 4 MB, which we need to download through the spacelink.
Currently we are running 9600 bps on the link, and we are able to download around 20-25 kB of data in one pass.
The raw sample will give us an insight in how the AIS2 receiver is performing, the amount of doppler shift, and so forth.
Futhermore the latest beacon is now shown in the top of this page. A green box means that the system is powered on, and responding to a periodic "ping" from the EPS. Grey means that the system is deliberately powered off.
stay tuned and enjoy the weekend.
Thursday 21. March 10:00 CET - Gossip - North Western tracked
The famous North Western has been spotted 37.48 miles NW of Dutch Harbor (which is SW of Alaska).
Latest news at 18:20: The Northwestern is now 145.86 miles NW of Dutch Harbo
Monday 18. March 10:00 CET - Nanny came by
AAUSAT3 operators has in the morning had assistance from Nanny - a software extension which ease download of missing AIS packages by identifying missing sequence numbers. This makes filling gap in downloaded data a lot easier.
Uptime for our system is now 9 days :-)
Sunday 17. March 13:00 CET - staying at high speed
This morning it was decided to go up at 19200 baud again and stay there until further notice.
The speed advantage clearly overrule weak link periodes, but of course there are less energy in each bit.
Saturday 15. March 20:00 CET - going high speed
Saturday has been used to test high speed link: 19200 baud.
19200 baud is 8 times the link speed we did start with (2400).
At 19200 baud we can move approx 6 to 8 packages pr second each carrying 88 byte or around 500 to 700 Bytes/second.
- The first observations is that downlink seems better(read accepted) than uplink
- might be more sensible to fadings
- nice for machine gun mode in downlink :-)
At the end of the passes we did went back to 9600 because we have found this rock stable.
Some recording received from Tetsu(JA0CAW) - Japan. We say thanks a lot.
On the picture on the right you can see a recording of our CW beacon from AAUSAT3 on 16th March by Tetsu(JA0CAW). You are welcome to decode it :-)
Listen to it here
On these two picture - from a recording by Tetsu you can see our 19200 baud test
Friday 15. March 18:00 CET - Beyond LEOP
We are now ongoing to more regular operation on AAUSAT3:
We are still retrieving lot of AIS information from space and are looking forward to get some time to do some analysis. For now we still just want to record and get so much information as possible down.
- We do have enough power
- Temperatures inside is ok (30-50C)
- Tumbling are now in region of 0.1 degree/second
- We do still have side 6 (no solar cells) exposed towards sun with temporarely low energy production.
- We have a very sound link to ground (often 20-30dB above noise level)
- Our link is occasionally hit by fading due to dipole antennas and slow tumbling
- Our AIS systems are working very good
On the plot you can see energy production and observe some of the slow tumbling. The green curve is power from the solar cells and blue is voltage on battery pack. It is observed that battery pack voltage is stable even in periods with low production from solarcells.
- retrieved ADCS measurments
- 7.65V 45C
- 16:44 pass
- Batt: 7480mV EPS temp: 35 C PV power: 1960mW - good
The picture shows (in our MCC client) EPS(power system) sending a number of CSP packages to MCC(ground). There is signal strength (RSSI) as meaured by our Bluebox. But the most interesting part is the column marked FEC (Forward Error Correction) First number is number of bit corrected and the number after the / is additional bytes correct. It is observed that without FEC we would have lost all these 11 packages from space. But all are received correct.
So we just say (as said before) never never AX.25 any more :-)
Wednesday 13. March 12:00 CET - AAUSAT3 students win an award
The AAUSAT3 student team is in Copenhagen today to receive Teleprisen 2013.
The reward is given by Teleteknisk Selskab which is an organisation covering telecommunication and related areas.
The price is the honour and 15000 DKK
We are very happy and proud for the recognition of AAUSAT3 and all the students behind the project.
On the picture you can see Jeppe and Troels doing a pass of AAUSAT3 from Copenhagen airport on way home. (picture by Hans Peter). Our distributed Mission Control Client system only require a relative low bandwith connection, in this case we connected through our mobile phones using 3G.
Tuesday 12. March 21:10 CET - a good day
AIS2 has now passes a milestone: 100.000 AIS messages!!!
All in all a good day. We had i some passes observed periodes of fading. Might be due to slow tumbling (as seen on plot below there is a periode og 46.5 minutes on the power production from the solar cells).
On the picture you can see a quite large number of ships tracked in the northern hemispshere the last days - We think it reflect what you can do with a single unit cubesat :-)
Short for the afternoon:
- 20:02 Good pass - AIS2 now passed 100.000 AIS messages receieved :-)
- 7.96V PA temp 40-42C
- ADCS2 data downloaded
- Weak link i the end of the pass
- It's let to the flight planner to switch off ADCS2
- 18:22 Now close to download a 24 hour continous data from AIS2
- EPS charge log downloaded
- 7.96V PA temp 40C
- 16:44 Still at 437.425 MHz Spacecraft ok
- 7.96V PA(radio) temperature 43C
- Got 300 AIS2 packages downlinked
- Rest of pass weak because of fading - slow tumbling ?!
Tuesday 12. March 12:38 CET - A top view of AIS messages received
On the plot you can see where AIS messages (based on in the message embedded position) are received relative to AAUSAT3 position(AIS1 and AIS2 together). The circle is approx 5400 km in diameter. Red is where many ships are recieved and fainted blue i fewest. It seems that AIS messages are mostly received from ships just below(with the shortest distance between ship and satellite). You may also argue that front and back where Doppler shift is largest add difficulties to receive. But we need more analysis to state this clear so please only take these comments as first wild guesses.
AAUSAT3 is flying 8 degrees away from true geographical north. This can be seen in the picture.
The plot has kindly been made by the Danish Maritime Authority.
Tuesday 12. March 09:44 CET - All ok - getting more AIS2 down
- 01:29(5 deg) unmanned 8 minutes 8 beacons from 01:29 to 01:33 7.68V 2W from solar cells PA 48C - alles ok
- AIS1 and AIS2 running
- 03:04-03:16(14 deg) unmanned 14 min 13 beacons 7.72V 2W 46C on PA - alles ok
- 04:41-04:56(47 deg) manned 15 min 11 beacons 7.72V 47C
- AIS1 and AIS2on
- 1000 AIS packages from AIS2 unique list downloaded
Monday 11. March 20:14 CET - AAUSAT3 now on 437.425MHz
Now LEOP is coming to an end we have now changed AAUSAT3 to our given frequency 437.425 MHz
We apology for the inconvenience for all HAM people.
Our COM system onboard has now transmitted 30000 packages since reboot :-)
On the picture on right you can see our power production from our solar cells 130310 from approx 1700 to 2000. Large fading occur regular with 46.5 minutes spacing and the small fading in the top with approx same interval.
There is only solar cells on five sides. One side carry the antenna system and it was by purpose decided not to have solar cells on top of the antenna for having a better antenna system. This decision was right because we have very good link on communication - often we see downlink 30 dB above noise level - and our AIS systems receive many AIS packages.
So it seems that with 46.5 minute interval AAUSAT3 points antenna side towards the sun. And the dusk-dawn orbit dont give much reflection from ground (albedo) for the solar cells in the shadow.
So all in all the trade off has shown its right.
We do also see some very slow fading in our down link from time to time. We dare not to conclude 100% except that we (by purpose) are tumbling very slow as also argued above.
But still not 100% certainty - we will still investigate on these matters.
Sunday 10. March 17:08 CET - Class B transponders received
We have identified a number of class B transponders in our material.
Class B AIS transponders transmits with only 2W compared to the normal class A transponders which transmits with 12W and often better antennas.
This could be a VERY good news as SART transponders also transmit with 2W (but with weaker antenna).
On the picture is 168 class B transponders identified on AIS message no 18.
We have also tracked DAMSAs (S°fartsstyrelsens) test transponder in Thule (class A) - so we think we have passed test no 1 :-)
A few things was changed in AAUSAT3 during the last passes:
- Max voltage for charging on batteries has been changed from 7.6 to 7.7V.
- New MPPT algorithm has been activated for testing (to see if we can charge even better)
- Temperatures norminal: 35C to 44C range
The early morning passes was not manned and nothing new.
- We do still have slow fading in some passes
- Time for 100000 AIS packages received is coming closer
The MCC (mission control center server and clients ) has been through a major revision this weekend for adding more features like:
- automatic recognition of missing packages when downloadning data for easy re-download
- adding antenna and pass information so only one client is needed
- automatic generation of VDM packets based on downloaded AIS information
- advanced replay of sessions in past so we can re-create all passes from day and filter on communication (if we only want to see EPS information)
- and much more
If you are passing by Aalborg University come and have a look
So a nice weekend with hard working people at the University
- 22:47(6 deg) approx 1000 AIS packages downlinked
- 21:30 (19 deg) EPS log data from last two orbits and 1187 AIS packages downloaed
- 19:28(72 deg) 7.68V-7.6V PA Temp 31C 44C, fading/weak link in middle
- 16:50(2.9 deg) and 17:50(25 deg) New MPPT activated and AIS log data downloaded
Saturday 9. March 22:49 CET - Evening passes
In general everything is very ok. We have some very slow tumbling which we appreciate because we do only have solar cells on five sides.
A few things we will look at the coming week.
- We have some interfering PWM noise from our antenna rotor when AAUSAT3 is weak.
- Our elevator tower on the roof shadow the path in azimuth range [358-15] or so meaning we could get more data down if we were on the top.
- Start more detailed analys of data
21:41(13 degree) unmanned
- A few beacons received 7.5V on batteri radio temperature 38C
- Uptime +10H since WDRF (watchdog reset)
- AIS1 boot count 22, AIS2 boot count 20 - mainly due to EPS switch off at 7.4V
20:00(44 degree) lot of data down
- Downloaded EPS data from two orbits before MPPT was activated as well as two orbit after. Purpose: analyze MPPT.
- No big difference by first glance
- Downloaded AIS data
- Some problem with fading
- Some problem with PWM noise from rotor when receiving weak packages.
18:20(41 degree) data down. EPS have had a WDRF at 11:07 CET
- Retrieved charge log for last orbit for analysing the newly MPPT. Not a big difference
- EPS have had a WDRF(9. March 11:07 CET) so EPS log downloaded. Only a boot message in the log
- Downloaded 1842 AIS packages from AIS1. Ended when battery fall below 7.4V and EPS correctly switch off AIS1.
- EPS has now been changed to use MPPT based on dI/dV tracking
- AIS2 data downloaded. Now more than 20k packages
- AIS2 has now wrapped around for first time
Saturday 9. March 13:04 CET - Mission statement 2
WE HAVE A SOUND MISSION
AAUSAT3 seems to be in really good conditions. Since Monday 4. March when we got in contact after a few days without everything has been ok.
- AIS systems are tracking many ship
- Fundamental systems (EPS,COM,LOG, ADCS, FP) are performing
- EPS(power) Charge well. In situations where power consumption exceeds production systems are closed down and later restarted. Battery package voltage is 7.4->7.48V. Solar cell production peaks around 2.3W
- COM(radio) is now running at 9600 baud which has increased amount of data download. It has been observed up to 35 dB above noise floor. Bit errors in packages has been between and up to maybe 150 which is approximate max number of bit errors that can be corrected in one package
- LOG just logs
- ADCS has been able to stabilize very well.
- FP(flighplanner) has gone through a few but critical tests and it works well.
- Tumbling are under control
- Lot of science data has and are being downloaded on regular basis
- 9600 baud is now considered stable
The coming days will be used to final tests and analysis of the spacecraft for being able to state LEOP has been finalized with success.
Thanks to all HAM people that has been very helpful to us
Saturday 9. March 11:58 - Unmmaned morning passes
After 10 days with up and downs we are now targeting normal operation.
So all took Saturday morning off.
NO PROBLEMS OBSERVED
9th mar 2013 Time Battery Energy production Temperature Charging 03:04 7520 mV 2080 mW 40 deg 40 mA 03:06 7520 mV 2440 mW 41 deg 80 mA 04:46 7480 mV 40 mW 41 deg -180 mA 04:47 7480 mV 260 mW 41 deg -160 mA 04:47 7480 mV 560 mW 40 deg -150 mA 04:50 7520 mV 1720 mW 39 deg 10 mA 04:53 7520 mV 2060 mW 37 deg 30 mA 06:26 7520 mV 2200 mW 37 deg 50 mA 06:31 7520 mV 2180 mW 37 deg 60 mA 08:08 7560 mV 2400 mW 40 deg 50 mA 08:12 7560 mV 1980 mW 42 deg 60 mA
Friday 8. March 23:55 - Good download of AIS data
A VERY GOOD DAY.
Record many AIS data down in two passes, and everything seems to be ok.
All passes 9600 baud on radio. It seems it is without problems running this speed.
From Mike Rupprecht (dk3wn) we have received the picture below indicating we are not tumbling. Thanks a lot Mike.
- 22:13 (9 degree pass) Got AIS1 and AIS2 science data down.
- Good link, no fading, tumbling must be very low
- 20:30 (28 degree) Good link
- Got 3635 AIS packages down
- 7.48V on battery 1.8W production from solar cells
- AIS2 has now passed 50000 AIS packages correct received
- 19:10 (70 degree) Very very good link
- fading on last 4 degress of pass
- After pass 7.44V 42C on UHF PA
- Download 4489 AIS packages in one pass
- 17:15(15 degree)
- Battery 7.48V 39C on UHF PA
- Received 8 beacons during pass all with AAUSAT3 chargin
- 863 AIS packages downloaded
IN TOTAL FOR TWO PASSES TODAY DOWNLOADED 8124 AIS MESSAGES RECEIVED THE LAST 11 HOUR BEFORE THE PASSES.
The ships are plotted here:
Friday 8. March 10:44 - We can retrieve data at passes below 3 degrees
GETTING DATA DOWN UPON REQUEST WHEN PASSING NUUK - GREENLAND !!!
10000 SHIPS TRACKED THE FIRST 10 DAYS IN ORBIT
WE HAVE NOW TRACKED 10000 DIFFERENT SHIPS SINCE LAUNCH!!!
At 13:31 CET we have been in space for T+11 = 11 days
- 05:15 (77degr - high pass)
- Beacon OK, no reboots
- Requested and received ADCS1 log from launch and until now
- requested and recived 1371 AIS2 messages(including Greenland)
- Just a nice pass
- 06:55 (23 degr)
- ADCS2 sensor measurement started
- AIS2 data down. Newest as well picking a few which on sequence number which has bee missed until now
- ADCS2 measurement finalized and downloaded results
- Perfect link
- COM PA up to 50C (hot)
- No fading
- 08:38 (2.4 degr low pass)
- Beacon check 7.48V COM PA 38C - so I has cooled down since last pass
- Requested 40 AIS2 data packages. Did receive 34: At that time elevation was from 1 degr to 0.5 degree. AAUSAT3 was at that time passing Nuuk Greenland.
- 9k6 running good
- fadings in size of minutes (slooow tumbling) but in good periodes nearly no bit errors
See our live orbit path at n2yos realtime page
WHAT A MORNING :-)
Thursday 7.March - Ships at west coast of Greenland
Nuuk is located a third up in the picture
SO WE CAN TRACK SHIPS AROUND GREENLAND
Thursday 7. March 23:00 CET - T+10 days - now at 9k6
- operated 17:48 (25 degr) ,19:27 (72 degr), 21:07 (19 degr)
- see details below
- passive 22:50(6 degr) - observed but no operation carried out
- would like to see if 9k6 in speed is ok
- Battery voltage 7.44V Temperature 34C
- 10 beacons - no one in between missed :-)
- So 9k6 is just running ok
Following was carried out at the 17:47, 19:27 and 21:07 passes:
- Standard procedure: check beacon, temperatures, voltages - everything ok
- Log downloaded for all subsystems - all ok
- ADCS1 reconfigured for getting that last very slow tumbling
- Flightplanner tested. Asked to switch off AIS1 after 1 minute. Success
COM reconfigured from 4800 baud to 9600 baud.
- Worked very well - 0-2 bit errors in each package
- One packet (88Byte) download
- 4800 baud takes 20 msec(training) +88*8*3/4800 = 0.44 sec
- 9600 baud takes 20 msec(training) +88*8*3/9600 = 0.24 sec
- (multiply by 3 for forward error correction overhead)
With 4 AIS packages(short version) in a packet we can now dowload 16 AIS packages/second or 1000 AIS packages/minute.
A commment from Satlab this evening
AAUSAT3 currently testing spacelink at 9k6 - so far tested in one pass above Aalborg - WORKING!!!
We are very happy.
Maybe we will be able to download ALL the AIS data that we are receiving in space. The Software Defined AIS Receiver has received 36700 msg with correct CRC since launch (10 days).
Once we enable MPPT(in near future) on our EPS, it could/should be possible to leave SDR AIS ON 100% of the time !??
Also, the DSP algorithm implementation offers the option to decrease the processing time and hence increase the 'on air' sampling time - perhaps by a factor of 2-6 times! (translates directly to an increased detection rate of 2-6 times)
All we need to download is 1-4 MB of raw samples, to ensure that we can improve algorithm without reducing sensitivity.
So .. We will continue on 9600 baud the comming days
Another nice evening at Satlab
Thursday 7. March 09:13 CET - T+10 days - All under control
Following morning passes was manned:
- 04:10 CET (30 degr) AIS data downloaded for specific time intervals for spotting ships around Greenland
- AIS2 approx 23:15 and 00:50
- AIS1 approx 23:15
- Std telemetry beacons and house keeping downloaded
- 05:50 (65degr) Continued 04:10 pass - spotted 11 ships around Greenland
- 07:27 (14 degr) Continued 05:50 pass
- 00:56 (3.7 degr) Beacons recieved - healthy satellite 7.48V, 38C. Closest distance 2900 km.
- 02:31 (9.8 degr) Beacons reveived - healthy satellite 7.48V, 40C
In general very good communication link. Still impressed of beacons and communication with AAUSAT3 at distances beyond 2900 km
AAUSAT3 is healthy: 7.5V on batteries, 35-41C inside. Very slow tumbling- ADCS1 works !
A QUESTION: Why dont you track many ships around Europe?.
AN ANSWER: Receiving AIS from space is difficult in areas with many ships. Ships do coordinate their AIS transmissions with ships nearby - closer than approx 65km. From space we see ships within 2000 km of distance, so when passing Europe we receive AIS signals from ships maybe 1000 km away from each other and these transmissions interfere.
Dealing with these problems or interesting and will be addressed in the near future in the next phases of our AAUSAT3 mission.
Wednesday 6. March 09:24 CET - T+9days
FIRST SHIPS OBSERVED AROUND GREENLAND IN MATERIAL !
AAUSAT3 is very much in live. At 8:11 today key figures 2W 7.52V 40C uptime 3 days 16 hours
So conditions onboard our spacecraft seems quite stable.
Short about this morning
No operations - we were sleeping. Many beacons were received on the passes:
- 01:27-01:36 only 4.8 degr elevation (shortest distance 2816km) passing our shadow (lift tower on roof)
- 03:03-03_15 max 14 degr elevation (shortest distance 2088km)
- 04:40-04:55 max 47 degr elevation (shortest distance 1042km)
- 06:19-06:34 max 39 degr elevation (shortest distance 1176km)
- 08:02-08:07 max 7 degr elevation (shortest distance 2582km)
Shortest distances minimum is 780 km(when passing in a 90 degr pass just over our heads)
We are satisfied with reception of beacons when AAUSAT3 is more than 2800 km away
- ADCS data and log downloaded
- UHF log downloaded
- more than 2000 AIS frames downloaded over two passes
- very slow tumbling (less than 0.1Hz). We are working on it but as her is no problem we want to do additional measures and simulations before changing on ADCS1.
- packet bit error rates is in long periodes 0 and in blind spot up to 100 (we cand deal with up to 80). So again error corrective protocols is not nice but a need to have.
- and lot of beacons :-)
So we are slowly targeting normal operations :-)
Tuesday 5. March 09:57 CET - T+8days
Very early this morning we were in contact again.
We did receive beacon at 08:41 in a pass with a max elevation of 2.09 degree - not so bad ...
Only duty carried out was checkout on subsystem and attitude control.
AAUSAT3 seems to be in a good shape - 30-40C onboard and stable, 7.5V and up to 2.3W from solarpanels.
We can see that when in high mode AIS1 and AIS2 is on and draw (as exepected) more power than produced, so when batteries hits 7.4V there are turned gracefully off and again on at 7.6V.
This has happened once - so we are just smiling.
AAUSAT3 satellite number is 39087
Monday 4. March - T+7days - ALIVE
A beacon from 4th March 2013 - we are in contact again after 4 days silence.
You can see we that the latest two ships we have spotted has been outside marinetraffic range for 69 and 15 days. Not too bad ...
On the COM part you can see 67 bit errors in 15 bytes that was corrected by our protocols in one packet. Just 1 bit error had destroyed an AX.25 package. Not too bad for error corrective protocols...
A short summary for the evening passes
- ADCS1 had detumbled the spacecraft from a high tumble rate during the night
- AIS1 and AIS2 has been running much of the time, as they are configured to automatically turn on in high power mode (> 7.6 V)
- EPS is working (and charging up till 2.3W from solar cells)
- Temperature now in range 3-8C - which is good
- Very low bit error rate on downlink (more on this later)
Following was carried out
- New parameters for ADCS1 uploaded
- ADCS 1 turned on, magnetorquers turned on
- ADCS1 parameters saved to flash
- EPS configured so AIS1 and AIS2 on in high power mode and off in low power
- Beacon switched on
- COM still on 4800 bps
During early evening pass 17:46 we did receive beacon from AAUSAT3. Furthermore we had two way communication.
This is first contact since 28th February 06:26 Danish/CET time.
- We are running 4800 baud at 437.450 MHz for communication.
- CW and normal beacon are temporarily disabled but will be turned on at next pass
- We did loose one bottle of Champagne
A good pass
We are planning next pass
Friday 1. March - T+4days
Mission statement no 1
First of all the first days in orbit has been very successful and we have retrieved more data from space than we had dreamed of.
On late day 2 we did observe on our telemetry that AAUSAT3 were colder than calculated. This has one main impact charging of batteries. At battery voltage 7.0V AAUSAT3 is designed to go into safe mode and temporarily suspends communication. In this state AAUSAT3 use only 0.1 mA and has only focus on charging. We have observed it works because we have had been in safe mode once and back again to normal mode without problems. Now early on day 4 we did not observe any beacons at the 6:37 UTC pass which indicates it is again in safe mode.
During the first days we also conducted a number of ADCS optimizing experiments which has been verified by simulation. So we have a complete ADCS setup ready when AAUSAT3 hopefully will come back to normal state.
In the coming days we will continue analyzing on all the data retrieved from space. We do already now have some hypothesis concerning the situation and we will share it with you when we are approaching a confident conclusion. We do believe in sharing info and lessons learned with the cubesat community.
And again many many THANKS to HAM people all around the world for your invaluable help.
Daily reports further down on this page
Day 3 27th Feb - status before evening passes
We have been looking a little bit more on our received AIS messages. In the first 80 minutes we did recognize some DANISH SHIPS: Adrian Maersk south of Alaska and Thyra Torm south west of South Africa.
During the last 24 hours we have been monitoring AAUSAT3 for further commission of the spacecraft. We are now optimize our attitude control system. Our battery voltage is lower than expected (7.1-7.3V) so we are also running experiments in between each Aalborg pass to get it higher.
We are still very very happy with our results and are working at early morning and evening passes so we can take the next steps in our plan for operation.
The first beacon
The screenshot at right shows the first sign of life from AAUSAT3 in the form of a nominal beacon, received on a spectrum analyzer borrowed from Rohde & Schwarz. This particular beacon was not decodeable, but the beacon which followed shortly after was decoded correctly, and showed - as already told - that the satellite was in an excellent condition.
The waterfall plot shows time on the Y-axis and frequency on the X-axis. The lower read area is the received beacon. The red lines in the top is noise generated near our ground station ! The difference from the background noise to the saturated red color is approximately 5 dB. Downlink data are often received with 20 dB SNR.
Day 2 26th Feb - status after last evening pass 20:02 UTC
First pass in AAUSAT3 mission operated 100 percent remotely with no people physical present at MCC and radio facilities. It just worked - so a big success.
We have now fetched most of the data for the 80 minutes of the mission for AAUSAT3.
We have now retrieved 1225 AIS messages from AAUSAT3 from the first 80 minutes of operation. The AIS data is now safe on ground in Aalborg.
Click here for an explanation about why we see these ships and not others on the map below.
On the picture below you can see the 1225 ships detected during the very first 80 minutes of operation.
In addition to that all telemetry indicates everything is well onboard our spacecraft.
We have a lot of data and telemetry we will analyze the coming days.
One conclusion we already can give is (as said before) that error corrective protocols on the space link really improve quality of mission. We will come with more detailed info later.
So we are all very satisfied - and stay tuned the coming days.
Day 2 26th Feb - status for the morning passes
We did operate three morning passes today
After the successful first day we did change scope to do the first step of commission of AAUSAT3 instead of collection more AIS data.
Among other things following was investigated
- temperatures in all subsystems and structure including side panels
- condition of subsystems in general
In addition to that we did download the first 160 AIS packages of which you can see a world map plot below. We do still have up to 1000 AIS packages onboard the spacecraft and we will get them down in the near future.
General conclusion is AAUSAT3 is in very well shape and we will continue with the next steps in operation. This includes tuning of ADCS1 and planning of the AIS mission.
Day 2 - 26th Feb row call 02:50 UTC in MCC
Satlab manned again from 03:50 CET/danish time.
Our first observation this morning is that we have received beacons from all passes at our ground station in Aalborg.
This is very much beyond our expectations.
At the pass at (03:09UTC) this morning we had full contact.
Following was changed
- Beacon interval increased to 60 seconds
- COM changed to 4800 baud.
- Two way communication at 3000 km at 4800 baud
We can conclude that our COM system performs very good and that error corrective protocols is a must for satellite operations.
We receive error free packages but also many with one or a few bit errors which are corrected by the protocols.
We are now waiting for next pass at 06:25UTC
Status on Day 1 - after 8 hours and 20 minuttes in orbit
- AAUSAT3 IN VERY SUCESSFULL OPERATION FROM VERY BEGINNING
- AT FIRST PASS
- TELEMETRY DOWNLOADED SHOWING 800 SHIPS TRACKED
- UNTIL SECOND PASS MORE THAN 4000 OK AIS PACKAGES RECEIVED
- DETAILED INFO FOR FIRST 60 SHIPS DOWNLOADED TO GROUND
- AND MUCH MORE
Now we will take a few hours sleep and continue operation Tuesday 26. February 04:06
We have on first day obtained more results than we could dream of
25. feb 16:44 First pass
It's alive and we full two way communication at first pass !!
Below you can see telemetry and some of the ships tracked before we even got in contact. A real autonomous satellite :-)
AAUSAT3 has tracked nearly 900 different ships before we were in contact first time.
This is much much more than we had ever dreamed about :-)
Some ... of the ships tracked(2nd pass)
ISRO (launch provider) will stream rocket launch at http://www.isro.org/video-pslv-c20.aspx
from our livefeed
* 2013/03/04 19:21 Two way contact :-) * 2013/03/04 19:20 * 2013/02/25 18:05 Next pass: 18:19 * 2013/02/25 16:46 It seems we have a mission * 2013/02/25 16:45 Received 1181 AIS packages * 2013/02/25 16:44 WE ARE OK CHARGE IS OK * 2013/02/25 16:44 CONTACT 2 way communicatoin * 2013/02/25 16:29 12 min to first pass * 2013/02/25 15:24 Radio should now be on - AAUSAT3 is just north of Madagascar * 2013/02/25 15:05 The antennas should now be deployed, and we are waiting for the radio to power on * 2013/02/25 14:27 First beacons will be 15:00 so we hope for our foreign friends that are listening * 2013/02/25 14:26 Awaiting first pass at 16:44 * 2013/02/25 13:53 Star Beer * 2013/02/25 13:52 AAUSAT3 released and in orbit :-) * 2013/02/25 13:47 T+16m - Stage 4 is burning - next is deployment * 2013/02/25 13:47 T+16m - alles is okidoki * 2013/02/25 13:18 T-14min - still counting * 2013/02/25 13:13 T-20 - 20 minuttes to go * 2013/02/25 12:33 Service Tower Withdrawn * 2013/02/25 12:21 T-1.5 * 2013/02/25 09:32 New TLE due to slight delay. See space.aau.dk/aausat3 * 2013/02/25 09:29 Launch delayed to 13:31 * 2013/02/24 22:56 14:29 to go C ju 2morrow * 2013/02/23 19:27 Saturday rehersal over :-) * 2013/02/23 12:15 Dress rehersal.
25. Feb 11:57 (T-1h:30m) Mobile Service Tower withdrawn
The service tower is now withdrawn so launch are approaching.
25. Feb 10:25 Launch Status Check in India
At T-03:05 (3 hour and 3 minutes before launch) ISRO launch site report RDY TO GO
This means count down continues and everything is ok
So launch will be 13:31 danish/CET time
25 Feb 10:25 Launch Site Weather
Weather conditions at launch size is reported optimal.
25 Feb 09:23 CET New TLE available
Due to additional 5 minuttes delay to 13:31 CET a new TLE has been generated
AAUSAT3 1 30000U 13010D 13056.53765324 .00000000 00000-0 -11606-4 0 0011 2 30000 98.4714 245.1613 0004579 356.2524 218.6600 14.32690253000011
25. Feb 06:41 Launch has been shifted to 13:31
Last update from India is a slight 5 min delay
24. February Ready for launch
The last day before launch is over. We have been testing and testing and testing an everything seems to work.
Looking forward to see you all tomorrow :-)
23. February Dress Rehersal
It always a good idea to do some training. Today(Saturday) we are running a few passes acc. to our LEOP procedure.
21. February AAUSAT 3 - a complicated satellite
We have just found some metrics for AAUSAT3
- 7 microcontrollers (1 BF537 DSP, 1 Arm7, 5 AT90CAN128)
- 2 operating systems (freertos and Linux(BF537))
- 125.000 lines of C code all written in house by students
- 500 kbit/sec CANBUS serving all subsystems
- Our own developed fieldbus CSP(cubesat space protocol) (open source) that is also used for sat to ground communication.
- Our own designed and constructed alu(7075) frame made in one piece from a solid block.
AAUSAT3 is a pure AAU satellite. All is designed and constructed by AAU students. No foreign nor bought subsystems.
21. February Our rocket is ready
Our PSLV C20 rocket is now ready on the launch site.
Everything is ok according to our launch provider.
So we are testing our MCC (mission control center) to be ready for Monday.
A dress rehersal is scheduled for Saturday.
More info can be found at:
21. February A sneak view to our MCC
Our MCC (mission control center) is now ready for launch
So we are just waiting for the launch.
20. February Image Gallery and more detailed description
We are continuously building an image gallery of AAUSAT3, components etc
See here for more details about AAUSAT3.
See LaunchInformation page for ISRO's graphical tour up in space.
18. February First pass rehearsal
This evening, we tested our procedures for the first AAUSAT3 passes, on our qualification model (QM). After some thrilling moments, the antennas on QM unfolded correctly, and began transmitting beacons as expected.
Some simulated 10 min passes gave us important knowledge about how to handle different situations happening during the first critical minutes of contact to AAUSAT3.
15. February Radio Amateurs listening
We are very happy that people want to listen to our satellite :-) If you want to help us please email firstname.lastname@example.org
We will put you on our HAM people list
14. February 2013
Our new antenna has been tested this evening and it works fine :-)
It is operated from our Blue Box. We did track AAUSAT-II in a +60 degrees pass.
13. February 2013
SFL (Freddy) has just confirmed that charging of batteries has taken place in India at the launch site.
- 7.63V at start (So we have gone from 8.2V to 7.63V since September 2012 - that is ok)
- 8.19V after charging
0 Charging started at 1A current and ended with 0A :-)
So now we are more than ready
9. February 2013
It seems that ...
LAUNCH IS SCHEDULED FOR 25th FEBRUARY 2013
We will have live videostream from Chennai - India
- lift off 13:22 CET(danish time) by a PSLV rocket
- first weak pass from AAUSAT3 around 1630
- hopefully good passes at 1800 and 1930
Then next passes will be 12 hours later
In addition to that we hope that we will get our groundstation at Thule(Greenland) up and running
9. February - waiting
AAUSAT-II received by Omar Frits Eriksson
Our previous cubesat AAUSAT-II is still alive as you can see here:
Five years in space and still working :-)
We do have about 8.4V at the batteries and beacons are 20 dB above noise level :-)
8. February 2013
Follow us at twitter @aausat3
1. February 2013
AAUSAT3 is now in Chennai and awaits launch
19. January 2013
AAUSAT3 is today flying from Canada to India. It is a very low orbit (10km) and might be due to the fact it is onboard an airplane.
So launch are approaching.
21. Nov 2012 - Blue Box Ground Station
We are working hard on our Blue Box ground station. It is a small - with USB interface - radio for receiving communication from AAUSAT3. It is based on the same ADF radio chip as AAUSAT3.
If any body are interested in helping us we would be happy to hear from you. We have a limited number of Blue Boxes for you out there. We cant promise everybody to borrow one but let's us know and we will take a look on it. Our major preference is HAM people far away from Aalborg so we can extend the contact to AAUSAT3 - but any case please contact us.
More info here.
21. Nov 2012 - Launch delayed until ultimo January
Launch has been delayed to late January 2013 due to problems with the main payload.
26. Sep 2012 - AAUSAT3 has passed all tests
AAUSAT3 has in week 39 passed all tests at SFL in Toronto and is now ready for launch.
The picture shows one of the two vibration setup at Toronto. The test shall ensure mechanical stability and test robustness of antenna deployment system.
Tests are covers up to 10G and frequencies below 1 kHz.
Sep 2012 - At SFL Labs, Toronto
26. Sep 2012 - Tests are now completed
Last news from SFL from Troels and Jesper:
AAUSAT3 is now approved for launch :-) All tests went well and AAUSAT3 is integrated in our own POD.
So we are now waiting on launch.
25. Sep 2012 - At SFL Laboratory
Things are progressing as expected. Tests has up until now been successful on FM as well as QM. We hope that next news will be that FM is integrated in the POD(deployment unit)
24. Sep 2012 - Arrived Toronto SFL
Jesper and Troels on way to first working and testing day at SFL
23. Sep 2012 - Aalborg Airport inspecting cubesat box - PASSED :-)
- : Q: What's that ?
- : A: It's two satellites on way to launch
- : Reaction from security: oh ... well okay :-)
Conclusion: we are traveling to much with satellites :-)
(C) AAUSAT3 team - 2012 2013