Showing posts with label Telemetry. Show all posts
Showing posts with label Telemetry. Show all posts

Friday, 28 August 2015

Upcoming YRARC General Meetings

The first meeting of the new season is on Tuesday, September 1st - before the Labour Day weekend. The meeting schedule for the year is:
  • September 1st - Dave VE3OOI on "Model Rocketry & Amateur Radio"
  • October 6th - Prof. Paul Delaney, Senior Lecturer in Physics and Astronomy, York University
  • November 3rd - Dave VE3KCL on balloon launches with a ham radio telemetry package on board.
  • December 1st - Christmas Social
  • January 5th - Mini flea market
  • February 2nd - TBD
  • March 1st - TBD
  • April 5th - TBD
  • May 3rd - TBD
  • June 7th - Barbecue and AGM
Club meetings are at Sharon Temperance Hall at 7:30 pm. 

Thursday, 27 August 2015

Splashdown - Flight S4 Descends into the Norwegian Sea

The first report came in this morning at 0430Z (00:30 EDT) with a single station LA9JO reporting until 0654 when it was joined by SM0EPX/RX2. Only once did we see as many as four stations reporting, with the last one at 1130Z (07:30 EDT) heard by OH3HTI and again by SM0EPX.



The last altitude reported was 1,120 metres, down from 8000 metres. The Flight S-4 status page estimates it ditched at 1135Z after a steady descent of 920 metres per minute, just about the time I was on the repeater telling Geoff VA3GS how well it was doing.

Looking forward to the next flight.

Wednesday, 26 August 2015

Not Quite Norway: The Balloon Wanders Westward

We pick up the story in Finland this morning, with the balloon travelling North from Estonia to somewhat West and North of Helsinki through the night. We will never know the exact path it took, as the electronics power down when it gets too dark to drive the solar cells.

From southern Finland it crossed the Gulf of Bothnia heading Northwest into Sweden, picking up speed to a still-slow 28 knots, which gradually reduced through the day until its final report at 1818Z (14:18 North American Eastern Daylight Time) where it was doing just half that speed.



Its final reported position for the day is at the foothills of the Scandinavian Mountains, perhaps 150km from Norway (I do wish the map had a scale). It is not a densely populated area but the last report has it right over a road which winds it way around lakes and through the mountain valleys, continuing on to Norway. It looks like it might be a spectacular drive. The mountains are not particularly steep and the balloon is some 20,000 feet above their highest peak.

The WSPR reporting site shows LB9YE continuing to hear the WSPR transmissions for 48 minutes after the last position report. It only seems to have heard the "main" WSPR transmission, not the secondary information that provides temperature, battery condition and the final two digits of the grid square. Those reports show the balloon moving from JP85 to JP75, which includes both Sweden and Norway. LB9YE is on the Norwegian West coast about 185km Southwest of the last reported position.

Earlier in the day I checked the web site to see who was hearing the reports. First the first hour or so of the day there were reports from New Zealand and Australia.The site can also display a map of the communication paths between stations. This one shows all stations hearing VE3KCL at around Noon today.



In spite of being wrong 2 days in a row about its forecast direction, the winds appear to want to take it off the West coast of Norway only to make a right turn and head back towards Russia. As this may well happen overnight we may not see that track due to lack of overnight position reports. It might also head to Greenland if it picks up a different wind but we'll definitely know if it does that.

The Flight S-4 Status Page is also providing comments on the flight and is worth checking out. It has posted some other interesting links recently.

The development of new weak signal protocols has spawned great new opportunities for low coast experimentation with some spectacular results.

Tuesday, 25 August 2015

Balloon Experiment in the Doldrums

Once again the balloon's systems are asleep right now. The last transmission was heard by 22 stations, including one each in Australia and New Zealand. Not bad for 16mw.

Not much distance was made today due to very light winds aloft, with the final report of the day at only 4 knots. It has almost crossed the Baltic Sea from Sweden (after passing over Stockholm) to Estonia, making the island of Hiiumaa, part of Estonia and off its West coast, South of Finland.

The slow speed is evident from the meandering track shown on the map. The sharp right turn on the left hand side of the map is from the first report of the day. The overnight flight is always shown as a straight line from the last report of the previous day because the intermediate points are unknown, but it is likely that it held a track further West than the line indicates. The zig-zagging during the daytime trip, especially East of Stockholm as it slowed to a crawl, is due to the lack of precision in position reporting, which is done with 6 character Maidenhead Grid Locators.


The last reported temperature on board was -10.8C. During the day it is often around 30C, which is clearly inside the insulated electronics package the ambient temperature is about -40C. Before the electronics go to sleep the temperature starts dropping with the setting Sun, and the altitude usually drops a couple of hundred metres as well. We also see the battery voltage dropping, nearing the point where it is too weak to support the radio transmissions and other powered activities.

The winds are forecast to continue to blow from the West but will not pick up much, so when (if) it wakes up tomorrow morning it probably won't have even crossed Estonia.

Monday, 24 August 2015

Balloon crosses into Europe

The VE3KCL s-4 balloon experiment woke up this morning just off the coast of France spent the day working Northeast across the country, passing over Luxembourg, Germany, and reported its position just across the Danish border on its final transmission of the day. 14 stations, all in Europe, received this final report.

During the previous night, the winds aloft changed from Southeast to Northeast and then slowed down, and by the end of the day it was only doing 44 knots compared to 68 knots earlier in the day. It was closing in on Odense Denmark by nightfall, where sunset was 20:32 local, or 1832Z, just 10 minutes before that final report.

Based on the forecast upper level winds in Europe, it appears that the balloon will continue North and then veer towards the West, which if so will cause it to cross the West coast of Norway before heading towards Iceland and further North from there. Based on a smaller scale upper level wind forecast we might see the balloon pass Northward off the East coast of Greenland before doing a right hand 180 degree turn and heading North to South across Russia. Then again it could find its way along a more Eastward course over Denmark where the winds diverge a bit and go straight to those Southerly winds in Russia without taking another tour of the North Atlantic. We should know by tomorrow morning.

Of course, anything could happen between now and then. Before getting ahead of ourselves we can just hope that the balloon wakes up in the morning. If it really does find its way that far North it might stay in the midnight Sun for a while, giving us more reports from which to track its progress.

This map shows the track from a little before it shut down last night to the latest report. Note the little zigzag on yesterday's path from the West. It is an artefact of the position reporting which is limited to the precision of a Maidenhead grid locator.

The segment just before it reaches the coast of France is a straight line. This is another artefact due to the lack of reporting through last night. A straight line was drawn between consecutive points, but it is more likely that it really took a curved path somewhat South of that line.

So far the balloons have reported for 3 days and 5 hours and covered a distance of 7,668 km (as the crow flies, I believe). If you want to check out the position in the morning, a map is available.

Sunday, 23 August 2015

Update - Balloon Flight S-4

The intrepid pair of party balloons were more than 1/2 way over the North Atlantic by Sunday evening, when transmissions ended due to darkness. The last reported position is between the Azores and Iceland, west of Ireland. Darkness arrived early with transmissions ceasing at 2030Z (16:30 EDT), over 2 hours earlier than the night before where it was just off the coast of Labrador.

All seems OK so far. Altitude and speed was 60 knots. 15 stations on both sides of the Atlantic reported its final transmission for the day. You can check the WSPR web site for signal reports, click "Specify Query Parameters" and enter VE3KCL in the call sign box. The current track will mean that it will make landfall over Northern Spain, and it may well do that before the Sun rises and we see the next transmission. If it does, it will be the first in the series to cross the Atlantic Ocean.


It could be transmitting again as early as 3:30 EDT Monday morning, assuming all is well.

Saturday, 22 August 2015

Another Balloon Experiment Takes Flight

It crossed the region a little further North than the last one, crossing St. John's Sideroad about half way between Yonge and Bayview travelling eastward. Also unlike the previous flight, which crossed the South shore of Lake Ontario and was over Delaware when it reached the Atlantic Ocean, this flight (number 4) has stayed North of the 401, at least so far.

Check out the status page for this new mission. The last one made it more than 1/2 way over the Atlantic. Maybe this one will make landfall over Europe. The battery doesn't stay charged overnight so a little after dark the transmitter goes quiet and we wait until it gets light and hope we hear from it again.

Here's a full size map of the flight track.

Previous posts about flight #3: part one, part two.


Monday, 3 August 2015

Balloon Experiment Update

The balloon (see yesterday's post) hasn't been heard from since 6:44 pm last night (2244Z). As it would have been night time over the mid-Atlantic by then, it is probably due to the discharge of its batteries. By now (1514Z) it should have picked up again, so hopefully it is just due to unfavourable propagation and not a failure of some kind.

The day before, it shut down a little later (but of course was further West with more sun) but picked up operation quite early, as you can see from two successive beacon reports. Note the timestamps on the left in UTC, and that the last report of the evening was at 2320 reported by Germany and the first report in the morning was at 1052 reported in Illinois.

 2015-08-02 10:52  VE3KCL  10.140129  -21  -3  GM66  +13  0.020  K9AN  EN50wc  3576  2222 
 2015-08-01 23:20  VE3KCL  10.140152  -26  0  JB24  +23  0.200  DL8HAF/P  JO53dm  14354  8919

Digression: As mentioned before the WSPR protocol has been hijacked to provide additional information. The reports with the power shown (correctly) as 0.020 (20 milliwatts) are well-formed WSPR reports. The others (like the second line above) re-use the fields like the transmitter power to convey other information. 20 milliwatts was all that was needed to communicate 23,500 km to New Zealand, which is over 1,000 km per milliwatt, assuming the speculation that it was long path is correct (otherwise a mere 16,500 km).

The map appears to show it wandering around in the same area at the end of its path. The web site doesn't mention this and has no indication that anything might be amiss.


Hopefully all is well. I will watch, and wait.

Sunday, 2 August 2015

Balloon Experiment Crosses York Region

Toronto Ham David Beverstein, VE3KCL, Launched a balloon experiment consisting of 2 foil balloons filled with Hydrogen with a payload of WSPR, JT9 and CW telemetry beacons from a bit Southwest of the intersection of Airport Road and Highway 89. The track across our region runs more or less along King Road from King City to Gormley although the precision of the track is limited to that of a 6 character grid square due to bandwidth limitations in the WSPR protocol and a low duty cycle of 12 minutes per beacon to conserve power. At the time of writing it is over the North Atlantic about 1/2 way to Europe at about the latitude of Kentucky and has reached an altitude of almost 8000 metres.

This "mission" page gives more details on the project, the telemetry and the progress of the mission, or check out the full size map.

The main source of telemetry is the WSPR protocol. There are a large number of receiving stations for WSPR which makes it ideal (other than the low bandwidth) for very weak beacons. These receiving stations relay the information received to the WSPR Network web site where anyone can see them on the map. The site will automatically take you to the 30m reports which is the band used by this mission. If you don't see it try extending the time period to greater than 10 minutes. You may see the report come from a strange place, like I did when I saw it over the Southern tip of India. I think this is because of some of the additional telemetry (like battery condition and altitude) that is overlaid on the grid locator field in the WSPR protocol (there is a full description of how this works on the mission page, including the link to the raw WSPR decodes from the balloon's transmitter. If you go to the links in the previous paragraph the extended protocol is properly decoded and the map will show the correct position.

In the last 12 hours (at time of writing) it has been picked up by 10 stations in North America and 1 in New Zealand. A quick review of the raw telemetry data shows that 64 stations have picked up the balloon so far, including VA3ROM and VA3XCD in Thunder Bay and Yarker (about 30km NW of Kingston) Ontario respectively. A large number of reports have been made by VE1VDM, who has an advantage by being further East than most of North America.

The mission site reports that the JT9 transmissions have been received. However the PSKReporter network does not report any transmissions received at the time of writing. There are far fewer receiving stations on PSKreporter 30m JT9 than on WSPR and probably more importantly WSPR can operate on a lower signal to noise ratio.

Anyway if you're up for it set yourself up for WSPR and see if you can receive its transmissions while it's still in the air.

Chris VE3NRT