Posts Tagged ‘ssdv’
Moving Pictures! First dabbles in Amateur TV
August 6th, 2018 | 
Author: I am always keen to try something new and I've spent the last couple of weeks experimenting with some Amateur Television ATV and Digital ATV (warning this post is bit of ramble and information overload)
They say "a picture paints a thousand words"and I've always liked the idea of sending pictures via radio having dabbled with sending and receiving SSTV and SSDV, including pictures from High Altitude Balloons (HABs) like the Hamfest HAB flight I did back in 2015
But I've also been intrigued by "Fast scan TV" to transmit moving images. I've seen demonstrations at conferences and in online videos and joined the British Amateur Television Club BATC a few years ago but apart from reading the CQ-TV magazine I had not done anything mainly due to expense and investment I mistakenly thought I would need to make.
Recently I have seen mention of using easy and low cost equipment to get on the air on 5.6GHz (the 6 cm amateur band) using cheap modules intended to transmit “First Person Video” (FPV) back from drones.
These simple units can be used without any modifications to get on air. A number of operators have used them with high gain WiFi panel and/or dish antennas with a clear line of sight path to send pictures to stations using the same equipment over paths in excess of 50km, the current record is over 160km. Chris Leviston M0KPW has an excellent website describing his 5.6GHz system http://www.5-6ghz-atv.co.uk/ and there is more information at the BATC Wiki https://wiki.batc.org.uk/5.6_GHz
Inspired I ordered some kit from eBay a few weeks back, a receiver module and transmitter arrived quite quickly (no slow boat from China this time)
The equipment is powered by a 12V supply and input and output is a composite video signal and audio. It can be fed by a standard camera or video source but I dug out an old Raspberry Pi and soon had it generating and transmitting a test card with the required call sign overlay. The modules are channelised, the displayed 33 number is bank 3, channel 3 which is 5.665GHz selected by the BATC since it sits inside the amateur allocation,
Over the week I refined the Pi software, adding the Pi camera and various libraries in python to generate video with informational overlay, adding a GPS allowed calculation of the locator square when out portable. I have put it in a box (sorry no picture of that) and a switch to flip between live video and test card. I also had a bash at making some double biquad antennas. Regularly updating my twitter feed with various milestones (I recommend you follow me)
The satellite dish is inverted because they are offset so when the dish is vertical they are actually pointing around 20 degrees upward towards the TV satellite (in the UK). So for terrestrial use with low elevation they work better inverted. (see here for better description of offset dishes)
I did venture out but I chickened out setting up due to a combination of a surprisingly busy road, fly tipping and very hot conditions. Due to the the fly tipping in the lay-by I didn't want to be seen getting stuff out of car boot! especially as a few cars had slowed down as they passed.
Nevermind I have ordered couple of cheap high-gain mesh dish antennas so when they arrive I will get out again and arrange some skeds, hopefully roping in some of the radio club.
In addition to the 5.6GHz stuff I have also taken possession of an ADALM-PLUTO SDR from Analog Devices. It is inexpensive (£90/$100) and designed to allow educational experimenting in software defined radio. It is a SDR receiver and low-power transmitter. They had been in short supply but availability has improved.
Charles Brain G4GUO has added support for the device into the DATV Express software. I am hoping to use it for some experiments in RB-TV (Reduced bandwidth TV) so I can actually use my NoVs
I took the PLUTO along to the ATV workshop and was able to see it transmitting and being received by other peoples receivers. So last night I got out the two satellite receivers I have and with a little bit of persuasion with settings got some DVB-S DATV transmitted and received.
They say "a picture paints a thousand words"and I've always liked the idea of sending pictures via radio having dabbled with sending and receiving SSTV and SSDV, including pictures from High Altitude Balloons (HABs) like the Hamfest HAB flight I did back in 2015
But I've also been intrigued by "Fast scan TV" to transmit moving images. I've seen demonstrations at conferences and in online videos and joined the British Amateur Television Club BATC a few years ago but apart from reading the CQ-TV magazine I had not done anything mainly due to expense and investment I mistakenly thought I would need to make.
Recently I have seen mention of using easy and low cost equipment to get on the air on 5.6GHz (the 6 cm amateur band) using cheap modules intended to transmit “First Person Video” (FPV) back from drones.
These simple units can be used without any modifications to get on air. A number of operators have used them with high gain WiFi panel and/or dish antennas with a clear line of sight path to send pictures to stations using the same equipment over paths in excess of 50km, the current record is over 160km. Chris Leviston M0KPW has an excellent website describing his 5.6GHz system http://www.5-6ghz-atv.co.uk/ and there is more information at the BATC Wiki https://wiki.batc.org.uk/5.6_GHz
Inspired I ordered some kit from eBay a few weeks back, a receiver module and transmitter arrived quite quickly (no slow boat from China this time)
The equipment is powered by a 12V supply and input and output is a composite video signal and audio. It can be fed by a standard camera or video source but I dug out an old Raspberry Pi and soon had it generating and transmitting a test card with the required call sign overlay. The modules are channelised, the displayed 33 number is bank 3, channel 3 which is 5.665GHz selected by the BATC since it sits inside the amateur allocation,
Over the week I refined the Pi software, adding the Pi camera and various libraries in python to generate video with informational overlay, adding a GPS allowed calculation of the locator square when out portable. I have put it in a box (sorry no picture of that) and a switch to flip between live video and test card. I also had a bash at making some double biquad antennas. Regularly updating my twitter feed with various milestones (I recommend you follow me)
Pi sending live video via 5.6GHz with text overlay using pi camera and raspivid easy peasy.. pic.twitter.com/Fthfpbw0r0— Andrew Garratt M0NRD (@nerdsville) July 28, 2018
While browsing the BATC website for information I spotted that there was an ATV Academy workshop being organised by the Telford and District ARS, giving people the opportunity of finding out a bit more about ATV and people could bring along their equipment and projects for advice. So at the last minute I decided to go but because of the distance could only really go on the Saturday. But it was well worth it and a great day. I was made to feel welcome by everyone there and was able to show off my modest achievements on 5.6GHz and learned about the BATC Portsdown Transceiver and MiniTioune receiver projects, even buying the parts to build the receiver.Lol, wife looking suitably impressed by the Pi based image generator which flips between live feed and test card using switch pic.twitter.com/M6qnif5V0P— Andrew Garratt M0NRD (@nerdsville) August 3, 2018
The academy coincided with a BATC Activity weekend and they were going up to the summit of the nearby Long Mynd to operate on the Sunday. Since I wasn't there I had planned to go to a local high point to see if I could make contact with some of the other operators and stations and got the kit ready on a cheap lighting tripod. I was going to use an old portable satellite dish with one of my double biquads at the feed point.Having a great time learning all about ATV today, showing off my humble efforts pic.twitter.com/YTwEf7Sjdl— Andrew Garratt M0NRD (@nerdsville) August 4, 2018
Nevermind I have ordered couple of cheap high-gain mesh dish antennas so when they arrive I will get out again and arrange some skeds, hopefully roping in some of the radio club.
In addition to the 5.6GHz stuff I have also taken possession of an ADALM-PLUTO SDR from Analog Devices. It is inexpensive (£90/$100) and designed to allow educational experimenting in software defined radio. It is a SDR receiver and low-power transmitter. They had been in short supply but availability has improved.
Charles Brain G4GUO has added support for the device into the DATV Express software. I am hoping to use it for some experiments in RB-TV (Reduced bandwidth TV) so I can actually use my NoVs
I took the PLUTO along to the ATV workshop and was able to see it transmitting and being received by other peoples receivers. So last night I got out the two satellite receivers I have and with a little bit of persuasion with settings got some DVB-S DATV transmitted and received.
Anyway, that is enough for now.. but will try to keep the blog updated as I experiment some more, but follow my twitter account @nerdsville for realtime updates 73 AndrewBit of "shaky cam" but shows the ADALM-PLUTO transmitting across the shack using #DATVExpress being received by an old FTA satellite box. pic.twitter.com/souCJA9qBK— Andrew Garratt M0NRD (@nerdsville) August 5, 2018
Hamfest HAB Flight – Mission Debrief
The National Hamfest high altitude balloon flew on Saturday and Pinky Pig reached a maximum altitude of nearly 26km (25,927m / 96,873 feet) as pictured above.
The flight originally planned for Friday had to be postponed due to wind direction and restrictions but I had sort approval for both days and was able to fly on Saturday. The conditions were perfect on launch day, clear blue sky with little cloud and almost no wind. Flight prediction put it landing around 25km away.
Both payload trackers worked flawlessly, PINKY the high speed RTTY successfully sent SSDV as well as telemetry and the backup tracker PIGLET sent the slow speed RTTY telemetry. Trackers from all over the UK as well as France, Holland and Poland received data and uploaded data to the UKHAS website.
The received SSDV images can be seen at http://ssdv.habhub.org/PINKY
The flight path can be seen below
The flight can be seen visualised in Google Earth below and while the 26km altitude was impressive it was around 4km less than I'd planned.
The launch certainly created a great deal of interest at the Hamfest, on the Friday we setup the club tent for South Kesteven ARS with a tracking station and demonstrated the payloads to interested visitors. Stewart (M0SDM) used his Land Rover with a push up mast for a pair of collinear X-50s so we could receive and decode. The mast and the Land Rover generated just as much interest.
On the Saturday I was assisted by my brother David (M6GTD) and just before noon began filling the balloon watched by a large crowd, as can be seen on Dave's (M0TAZ) blog http://m0taz.co.uk/2015/09/national-hamfest-2015/
 |
| Picture by Dave M0TAZ |
Once filled to give the correct lift I sealed it off and checked everything was working then without a breath of wind slowly let the balloon rise, taking the weight of the payloads and once I was sure there were no aircraft flying nearby I let her go. The sky was clear and the balloon went up near vertically and could be seen for quite a long time as it ascended. Representatives of the RSGB and RadCom were in attendance to take photos and did a quick interview.
The tracking station was then full of people as the telemetry and pictures started to be received. It was great to see the huge interest in the balloon.
As the balloon started to near the planned maximum altitude I began to get ready to set off to recover it then suddenly I was told it had burst sooner than expected. I got a hurry up at which point the laptop and mobile connection decided to stop working! However I knew where to head off with my poor brother trying to sort it out as I drove.
Stewart telephoned and gave me directions of where the live prediction and tracking had put the landing spot. My wife also set off from home to come and assist. In the car we were receiving a signal but were struggling to decode and couldn't get on the internet to check the tracking.
I eventually pulled up near the landing zone, while trying to decode the weak signal another car pulled up with two radio amateurs who had been tracking the balloon. I was a little preoccupied and they eventually said they were off and wished us luck. I then realised we were the wrong side of the hill and turned around and drove up to the top and the signal strength increased.
Stewart had phoned to tell me to find the Viking way footpath, as we reached ground zero we saw the other amateurs car and they were setting off down the footpath! It was my flight I wanted to be the first to find it!
My wife then pulled up and was about to set off after them! Then I started getting successful decodes! With the new landing position in the GPS my wife raced off in hot pursuit as I sorted out the car and then followed her with my brother. It was a reasonable walk of around 800m and as we got near it became apparent the other team had been using the online tracker and had only got the last received position which had been sent from around 254m altitude. However the payload was still transmitting strongly and we were decoding it and it was reporting it was in fact at 115m altitude - they were therefore several hundred meters in the wrong direction.
Our accurate location gave us the edge and a quick hop up a bank into a stubble field and a 200m jog my brother spotted the parachute... we had found Pinky and Piglet and got there first!
I was surprised to find most of the balloon still attached, it hadn't so much burst as split in a single tear
The payloads had no damage, other than the antenna being bent by the landing
PIGLET had landed as planned and tested, I had put the battery pack at the top of the box the top heavy center of gravity causing it to roll on landing so the antenna would be upright. It was in a perfect orientation hence the strong signal.
The other chase team turned up and congratulated us then left... my apologies but I was in my own little happy place to be sociable. We then then had the obligatory team photograph before setting back to the Hamfest.
It has been an excellent experience and adventure. The pictures are better than I could have hoped for! Thanks to my understanding wife, my brother David and Stewart for setting up the antennas for the tracking station and manning it on his own while we went off to recover the payload.
Thanks to the organisers of the National Hamfest and Graham Boor (G8NWC) for asking me to do the flight and helping fund the venture and I hope it succeeded in publicising the event and the hobby.
I have now downloaded all the photographs from the onboard camera and they can been in my Flickr album at https://www.flickr.com/photos/nerdsville/sets/72157658732989849
Updated - I realised I didn't put the actual landing position on this post, so here it is
Hamfest HAB Flight – Mission Debrief
The National Hamfest high altitude balloon flew on Saturday and Pinky Pig reached a maximum altitude of nearly 26km (25,927m / 96,873 feet) as pictured above.
The flight originally planned for Friday had to be postponed due to wind direction and restrictions but I had sort approval for both days and was able to fly on Saturday. The conditions were perfect on launch day, clear blue sky with little cloud and almost no wind. Flight prediction put it landing around 25km away.
Both payload trackers worked flawlessly, PINKY the high speed RTTY successfully sent SSDV as well as telemetry and the backup tracker PIGLET sent the slow speed RTTY telemetry. Trackers from all over the UK as well as France, Holland and Poland received data and uploaded data to the UKHAS website.
The received SSDV images can be seen at http://ssdv.habhub.org/PINKY
The flight path can be seen below
The flight can be seen visualised in Google Earth below and while the 26km altitude was impressive it was around 4km less than I'd planned.
The launch certainly created a great deal of interest at the Hamfest, on the Friday we setup the club tent for South Kesteven ARS with a tracking station and demonstrated the payloads to interested visitors. Stewart (M0SDM) used his Land Rover with a push up mast for a pair of collinear X-50s so we could receive and decode. The mast and the Land Rover generated just as much interest.
On the Saturday I was assisted by my brother David (M6GTD) and just before noon began filling the balloon watched by a large crowd, as can be seen on Dave's (M0TAZ) blog http://m0taz.co.uk/2015/09/national-hamfest-2015/
|
| Picture by Dave M0TAZ |
Once filled to give the correct lift I sealed it off and checked everything was working then without a breath of wind slowly let the balloon rise, taking the weight of the payloads and once I was sure there were no aircraft flying nearby I let her go. The sky was clear and the balloon went up near vertically and could be seen for quite a long time as it ascended. Representatives of the RSGB and RadCom were in attendance to take photos and did a quick interview.
The tracking station was then full of people as the telemetry and pictures started to be received. It was great to see the huge interest in the balloon.
As the balloon started to near the planned maximum altitude I began to get ready to set off to recover it then suddenly I was told it had burst sooner than expected. I got a hurry up at which point the laptop and mobile connection decided to stop working! However I knew where to head off with my poor brother trying to sort it out as I drove.
Stewart telephoned and gave me directions of where the live prediction and tracking had put the landing spot. My wife also set off from home to come and assist. In the car we were receiving a signal but were struggling to decode and couldn't get on the internet to check the tracking.
I eventually pulled up near the landing zone, while trying to decode the weak signal another car pulled up with two radio amateurs who had been tracking the balloon. I was a little preoccupied and they eventually said they were off and wished us luck. I then realised we were the wrong side of the hill and turned around and drove up to the top and the signal strength increased.
Stewart had phoned to tell me to find the Viking way footpath, as we reached ground zero we saw the other amateurs car and they were setting off down the footpath! It was my flight I wanted to be the first to find it!
My wife then pulled up and was about to set off after them! Then I started getting successful decodes! With the new landing position in the GPS my wife raced off in hot pursuit as I sorted out the car and then followed her with my brother. It was a reasonable walk of around 800m and as we got near it became apparent the other team had been using the online tracker and had only got the last received position which had been sent from around 254m altitude. However the payload was still transmitting strongly and we were decoding it and it was reporting it was in fact at 115m altitude - they were therefore several hundred meters in the wrong direction.
Our accurate location gave us the edge and a quick hop up a bank into a stubble field and a 200m jog my brother spotted the parachute... we had found Pinky and Piglet and got there first!
I was surprised to find most of the balloon still attached, it hadn't so much burst as split in a single tear
The payloads had no damage, other than the antenna being bent by the landing
PIGLET had landed as planned and tested, I had put the battery pack at the top of the box the top heavy center of gravity causing it to roll on landing so the antenna would be upright. It was in a perfect orientation hence the strong signal.
The other chase team turned up and congratulated us then left... my apologies but I was in my own little happy place to be sociable. We then then had the obligatory team photograph before setting back to the Hamfest.
It has been an excellent experience and adventure. The pictures are better than I could have hoped for! Thanks to my understanding wife, my brother David and Stewart for setting up the antennas for the tracking station and manning it on his own while we went off to recover the payload.
Thanks to the organisers of the National Hamfest and Graham Boor (G8NWC) for asking me to do the flight and helping fund the venture and I hope it succeeded in publicising the event and the hobby.
I have now downloaded all the photographs from the onboard camera and they can been in my Flickr album at https://www.flickr.com/photos/nerdsville/sets/72157658732989849
Updated - I realised I didn't put the actual landing position on this post, so here it is
MADHEN Eggsplorer-1 – We’ve got the data!
Following the euphoria of the Eggsplorer-1 payload being found six weeks after launch washed up and retrieved from the beach in Terschelling, Netherlands it has been an agonising wait to see what the Dutch police would send back. My impatience got the better of me last week and I contacted them directly to be told that unfortunately due to the awful smell and condition of the box they had simply removed the memory card and had posted that back as requested.
More days past and I was beginning to think irony was going to play a cruel trick and the card after its fantastical journey would end up lost in the post. I shouldn't have been so pessimistic as it arrived today! Along with the card was a detailed map showing the final location and labels from the side of the box.
There was a nice note from the police.
The SD memory card seemed to have had survived more or less intact, though there was some corrosion on the contacts and crucially a small corner of the card was broken off.
The plan was to use the Win32 Disk Imager program to make a direct raw image of the card and work on that copy. I first used a small wad of wire wool to gently clean up the contacts
I was encouraged when I inserted the card into my Microsoft Windows laptop and it was detected, however my heart sank when any attempt to access it or use the imager program was met with an error. I gave it another gentle going over with the wire wool and thankfully was then able to make a image file, the next stage was to extract the precious data.
The card of course contained the Linux based Raspberry Pi file system and in order to access it on a Windows machine I used the freeware linux-reader from DiskInternals which allows access to Ext2/Ext3/Ext4, HFS and ReiserFS file systems within Windows.
It was a simple case of using the "mount image file" option and the partitions were then accessible and everything appeared intact, there were images on the card unfortunately not the "egg in space" image I wanted, just some nice "egg in the clouds" shots.
The telemetry log file confirmed the worst, the flight computer had indeed stopped/crashed at approx 2.5km up and no further images had been captured of the 31km accent into the stratosphere (confirmed by the backup tracker) I had hoped the transmission had stopped because of a fault in the antenna or the radio module board alas this wasn't the case.
On the day of the launch I did have problems with the payload not booting up. It had worked flawlessly under test the previous weeks and I had secured everything in the box ready for the flight. The day before the launch I had spotted there was another balloon going up in the UK at the same time and we had both opted for the same frequency. So at the eleventh hour I was forced to take out the SD card to change the configuration to prevent the transmission clash.
The launch day start up problem was the SD card. I had removed and reinserted it to get it to start up and secured it down with plenty of gaffa tape. Looking at the card now and the fact the broken corner is old damage I am convinced this is the reason for the failure as the card may well have become dislodged due to turbulence.
While slightly disappointed it is still a miracle I have any images at all and can only thank Jan and the Dutch Police again.
I have certainly learned a lot and hope the National Hamfest HAB that I and South Kesteven ARS are flying is more successful
MADHEN Eggsplorer-1 – We’ve got the data!
Following the euphoria of the Eggsplorer-1 payload being found six weeks after launch washed up and retrieved from the beach in Terschelling, Netherlands it has been an agonising wait to see what the Dutch police would send back. My impatience got the better of me last week and I contacted them directly to be told that unfortunately due to the awful smell and condition of the box they had simply removed the memory card and had posted that back as requested.
More days past and I was beginning to think irony was going to play a cruel trick and the card after its fantastical journey would end up lost in the post. I shouldn't have been so pessimistic as it arrived today! Along with the card was a detailed map showing the final location and labels from the side of the box.
There was a nice note from the police.
The SD memory card seemed to have had survived more or less intact, though there was some corrosion on the contacts and crucially a small corner of the card was broken off.
The plan was to use the Win32 Disk Imager program to make a direct raw image of the card and work on that copy. I first used a small wad of wire wool to gently clean up the contacts
I was encouraged when I inserted the card into my Microsoft Windows laptop and it was detected, however my heart sank when any attempt to access it or use the imager program was met with an error. I gave it another gentle going over with the wire wool and thankfully was then able to make a image file, the next stage was to extract the precious data.
The card of course contained the Linux based Raspberry Pi file system and in order to access it on a Windows machine I used the freeware linux-reader from DiskInternals which allows access to Ext2/Ext3/Ext4, HFS and ReiserFS file systems within Windows.
It was a simple case of using the "mount image file" option and the partitions were then accessible and everything appeared intact, there were images on the card unfortunately not the "egg in space" image I wanted, just some nice "egg in the clouds" shots.
The telemetry log file confirmed the worst, the flight computer had indeed stopped/crashed at approx 2.5km up and no further images had been captured of the 31km accent into the stratosphere (confirmed by the backup tracker) I had hoped the transmission had stopped because of a fault in the antenna or the radio module board alas this wasn't the case.
On the day of the launch I did have problems with the payload not booting up. It had worked flawlessly under test the previous weeks and I had secured everything in the box ready for the flight. The day before the launch I had spotted there was another balloon going up in the UK at the same time and we had both opted for the same frequency. So at the eleventh hour I was forced to take out the SD card to change the configuration to prevent the transmission clash.
The launch day start up problem was the SD card. I had removed and reinserted it to get it to start up and secured it down with plenty of gaffa tape. Looking at the card now and the fact the broken corner is old damage I am convinced this is the reason for the failure as the card may well have become dislodged due to turbulence.
While slightly disappointed it is still a miracle I have any images at all and can only thank Jan and the Dutch Police again.
I have certainly learned a lot and hope the National Hamfest HAB that I and South Kesteven ARS are flying is more successful
