Today Mark VK5QI took the Balloon ATV transmitter out for a terrestrial test. He carried out line-of-sight testing of the DVB-S payload from BlackTop Hill to the AREG remote site near Tarlee – a distance of 54km!
First test – could he see the signal on the SDR up at the site (RTLSDR, Diamond X-50, no preamp)… yes!
Next, Mark dumped some samples with rtl_sdr, then transferred them back to his laptop. He processed them through leandvb – and got video!!! A bit of fading, but for an omni receiver with no preamp, this is a pretty damn good result!
… and here’s some of the raw video
The MER as reported by leandvb was around 8-11 dB, right on the edge of what is decodable. Still, with such a basic system, a good result!
Based on the path, it is estimated to give us a working range of about 150km from the balloon given a receiving station with 15dBi gain and a good low noise preamplifier.
Stay tuned for more information on how to receive and decode the Digital ATV signal and save the date – we hope to launch the transmitter into the stratosphere on Sunday March 7th. (We also plan on streaming the event on Youtube).
For those who missed it late last year here is a bit more information about the Balloon ATV payload and some minimum signal testing that was carried out.
This is a reminder that this Friday’s AREG meeting will be held at the Fulham Community Centre, Phelps Court, Fulham. Doors open at 7.15pm Central summer time with the presentation planned to start at 7.45pm.
Our guest speaker will be Mark VK5QI. He will introduce you to the new Digital ATV payload and what you need to be able to receive and decode it. More information on the presentation is available (here).
Members who can’t attend in person will be able to access the meeting via Zoom (a link will be sent on the members mailing list on Thursday). Non members will be able to watch the Youtube Livestream thanks to Hayden VK7HH and his HamRadio DX channel.
Project Horus began in 2010 as the brain child of a group of radio Amateurs here in Adelaide. Now, 11 years later, one of the ideas that has been discussed many times within the group is finally going to be attempted. A flight is tentatively planned for Sunday March 7th that will carry aloft our first ever digital ATV transmitter.
Live ATV from 30km+ altitude!
Adelaide from 100,000ft – Horus 12
How can you get involved?
So that as many people as possible can participate or at least attempt to receive the ATV pictures, the next meeting of AREG on Friday February 19th will feature a presentation and Q&A session with Mark VK5QI. He will take you though everything you need to know about how to receive and decode the ATV signal.
What system are we using?
For the first launch, we are going to use the following transmitter settings:
Transmit Frequency: 445 MHz
Modulation: DVB-S, QPSK, r=½ FEC
Symbol Rate: 1Msps
Video Resolution: 704×400
This will produce fairly low quality video, but will give the best chance for the payload to be received. Once we understand what the achievable signal-to-noise ratio (SNR) is for a typical flight, the symbol rate (and image quality) can be increased on future launches.
Receiving DVB-S Signals – Hardware
The most ideal way to receive signals from this payload is with a dedicated DVB-S receiver like the Minitiouner Express ( https://www.datv-express.com/ ), however it’s also very possible to receive it with Software Defined Radio receiver setups, such as the ubiquitous RTLSDR devices. You will also need a 70cm antenna with some gain, and a low-noise pre-amplifier.
While some DVB-S set-top boxes may tune down to 445 MHz, the very low bit-rates that we will be transmitting from the payload will likely be incompatible with them.
Suggested Software-Defined Radio Receivers
There’s a huge range of SDRs available which are fit-for-purpose in this application, provided you put a low-noise-figure preamp in front of them – ideally one with band-pass filtering. Examples include:
More detailed instructions and information will be posted to our website in coming days. Stay tuned!
Meeting Details
The main meeting will be held at the clubrooms, 1 Phelps Court, Fulham at the Fulham Community Centre. Doors will open from 7.15pm (ACDT) with proceedings starting at 7.45pm (ACDT) (0915z). For those unable to attend in person, we will have online options available too!
The meeting on February 19th will also be live streamed on YouTube thanks again to Hayden VK7HH and his HamRadioDX Channel.
For members unable to attend in meeting hall in person, there will be a members only Zoom channel available as well.
Thanks to all that helped track the flight today! The tiny payload travelled over 550km from the launch site in Adelaide, to land near a piggery just outside Bendigo. Hopefully it gets recovered soon!
I recorded the following callsigns decoding telemetry:
… also a special mention to N0CALL, who received 154 packets.
Thanks to all that setup the decoding software – one of the aims of this flight was to get more people setup to decode telemetry from these payloads, and get feedback from users to help improve it. There are a few groups in Melbourne that are planning on using the same kind of telemetry, so more listeners in VK3 able to decode will make their flights even safer.
73 and cheers,
Mark VK5QI
Tomorrow at ~9AM ACDT VK5QI is going to launch a lightweight (<40g) balloon with a 70cm 4FSK transmitter onboard. This is a test of some software updates to the 4FSK transmitter payload (a reprogrammed RS41) to improve the battery life. There will be ~30 second gaps between telemetry transmissions, with short ‘pips’ every 5 seconds so you know you are on the right frequency!
The transmit frequency is still subject to change but will most likely be 434.200 MHz. (Note that this is different to our usual Horus 4FSK frequency of 434.660 MHz – this is because there are a few 70cm repeaters in Melbourne with inputs near this range).
With a bit of luck this one should make it into VK3, and reach an altitude of ~23km or so. This should make it receivable from western Victoria, and likely from Melbourne too.
If you want to have a go receiving the telemetry from this flight, you’ll need a SSB-capable 70cm receiver (or a SDR), and my horus-GUI telemetry decoder software ( https://github.com/projecthorus/horus-gui ).
Note that this flight is going to head east *very* quickly, and may go out of range of Adelaide receivers during the flight. If you know anyone in VK3 who might be able to receive this please forward on this information!
UPDATE: Launch was a complete success! A full write-up will be coming in due course…
The next Project Horus launch is currently planned to fly on Sunday the 25th of August(weather permitting), with a planned launch time of 10AM. As usual, there’s always the chance the weather for the planned launch date may not be suitable, so if necessary, the backup launch date will be Sunday the 1st of September.
The launch site will be the usual Mt Barker High School Oval. Launch crews should be on-site around 9AM. If you haven’t attended one of our launches before, this is a great opportunity to come along and see what’s involved first-hand!
WiFi Pineapple Payload
WiFi Pineapple
This flight will be the first of hopefully many more payloads proposed and developed by AREG club members under the Project Horus Member Payload Launch Program. Derek VK5TCP’s payload is a WiFi Pineapple board – a WiFi penetration testing device developed by Hak5. The payload will be ‘war-ballooning‘ throughout the flight, recording the SSID of all WiFi access points it can receive signals from. It will also be broadcasting an open WiFi access point (‘VK5ARG’) on the 2.4 GHz band. The payload will be using a ~11 dBi patch antenna pointed directly downwards.
To encourage community participation in this launch, there are two challenges associated with this payload:
Get your Access Point SSID observed by the payload! – Set up a WiFi Access point connected to a high gain antenna pointed at the payload. After the flight we will publish a list of all SSID’s that were observed, and at what altitude they were spotted. For your best chance at being observed, beacon using the lower-speed 802.11b mode.
Recover the secret message! – Connect to the access point on the balloon while it is in flight and retrieve a secret message from a web server running on the payload. This will be a serious challenge to achieve, and will require the use of high-gain antennas on the ground. Our link budgeting suggests that the full 4W of allowable LIPD Class License EIRP will be required to connect to the payload. Amateur radio operators with an advanced license are permitted to use any power level up to the limits of their license conditions. The web server will be running on the IP address 172.16.42.1, and clients can either accept a DHCP lease, or use a static IP address between 172.16.42.150 and 172.16.42.200.
To have the highest chance of success, stations will need to be situated directly underneath the flight path, with antennas pointing upwards to the payload. A map of the predicted flight path will be posted closer to the launch date.
Wenet Imagery Payloads
Image received via the Wenet Payload
This flight will also fly a ‘Wenet’ high-speed imagery payload, as have been flown on many previous Horus launches. The centre frequencies for this transmission will be 441.200 MHz. This payload will be downlinking HD pictures throughout the flight, which will be available at this link:
Reception of the Wenet signal requires a RTLSDR and a Linux PC/Laptop. Instructions on how to set up the required software are available here.
Telemetry Payloads
As always, we’ll be flying the usual assortment of telemetry payloads, including:
Our usual 100 baud 7N2 RTTY telemetry on 434.650 MHz USB. This can be decoded using dl-fldigi, with a reception guide available here. Recent testing of dl-fldigi’s decode performance has found that the auto-configured RTTY receive bandwidth is too narrow, and can detrimentally impact decode performance (by up to 3dB!).To fix this, open dl-fldigi, and in the Configure menu, select Modems, and then go to the ‘RTTY’ tab. Drag the ‘Receive filter bandwidth’ slider to 200, then click ‘Save’. Note that this setting will be reset whenever you hit the ‘Auto-Configure’ button!
4FSK Telemetry decoder
The new 4FSK Binary telemetry will be transmitting on 434.660MHz USB. This uses a separate decoder, with setup instructions for this available here. This telemetry payload will soon become the primary method of tracking the flight – the RTTY payload is expected to be retired in a few launches time.
Tracking of the flight will be available on the HabHub Tracker, available at this link. (Note that other balloon launches will also be visible on this page, including the Bureau of Meteorology launches from Adelaide Airport).
Thanks to Mark VK5QI, AREG is pleased to announce a new service has been added to the VK5RWN Repeater site. Mark has been developing a RadioSonde automated receive system which allows all of the Bureau of Meteorology weather balloon data to be collected and be made available on the internet. The data is available via the SondeHub instance of the HabHub High Altitude Balloon Habitat platform. You can access it here:
What can you see? Where all the active weather balloons are right now!
If you’re located in South Australia and are considering going out to recover a sonde, or have recovered one, please use the Facebook Group or the mailing list to announce your intentions! This helps avoid disappointment if others are intending to recover the same sonde.
Want to learn more? Read on…..
For quite a while now I’ve been interested in tracking and recovering radiosondes. These are meteorological instruments regularly launched by weather balloon from many locations around the world. Here in South Australia the Bureau of Meteorology launches them from Adelaide Airport twice daily (2315 and 1115Z), along with a few other locations around the state.
A Vaisala RS41 radiosonde found with the help of the radiosonde_auto_rx tracking network!
Radiosondes transmit in the 400-403 MHz band (usually on either 400.5/401.5/402.5 MHz), and there is a range of software, both closed and open source available to decode their telemetry. Not being entirely happy with the existing offerings, I started work on my own software, which became radiosonde_auto_rx (or ‘auto_rx’ for short).
auto_rx runs on a Raspberry Pi (or any other Linux machine) and automatically scans for and decodes radiosonde signals. Telemetry is uploaded to APRS-IS and the Habhub tracker for mapping purposes, and can also be viewed locally via a web interface. Most of the common radiosonde models are supported, including the Vaisala RS41 which is launched here in Adelaide. There are currently 147auto_rx stations in operation worldwide (16 here in VK5), and so far (as of 2019-05-25 10Z) 19415 individual radiosondes have been logged.
So why do I bother doing this? Many radiosondes are (in part..) highly recyclable! The Vaisala RS41 contains a good quality GPS receiver, a micro-controller, and a radio transmitter – perfect for re-programming for use as a high-altitude balloon payload, as we have been doing on many recent Project Horus flights. In fact, the RS41 is the ‘reference platform’ for the new high-performance balloon telemetry system developed by David Rowe and I.
Chasing and recovering radiosondes is also great practice for Project Horus launches, with a few of the new Horus regulars starting out tracking radiosondes, and many others around VK5 regularly out chasing the BOM’s radiosonde launches. We use the same mapping software for both radiosonde and Horus chases.
To help improve tracking coverage, I proposed to install an auto_rx receiver station at one of AREG’s premier repeater sites, overlooking the Adelaide plains. Thanks to the generosity of AREG members in approving this proposal, the receiver was installed over the easter break. A big thanks to Ben VK5BB for assistance in fabricating an antenna bracket, and helping with the installation!
Hardware Details
The auto_rx receiver station installed in a rack at the site.
The auto_rx receiver hardware consists of a Raspberry Pi 3, with two RTLSDR v3 dongles attached, allowing simultaneous reception of 2 sondes. The incoming RF from the antenna is filtered through an interdigital filter (passband 400-403 MHz, stop-band attenuation > 90 dB) before being going through a preamplifier and splitter to the two dongles. The estimated system noise figure is about 5dB, mostly from the insertion loss of the filter. Given this is a very RF-noisy site (co-located DSTAR repeaters, and many commercial services on a tower a few hundred metres away), the higher noise figure is an acceptable tradeoff – without the filter the receivers would immediately overload!
All the equipment is mounted within a 2RU rack-mount chassis, with all power and network inputs heavily filtered to avoid coupling in unwanted RF. The total power draw of the unit is ~10W.
View from the antenna!
The antenna is an AEA co-linear (kindly donated to the project by Ivan VK5HS) mounted to the side of the repeater hut. Being ~450m above sea level, the antenna has direct line-of-sight to the Adelaide airport, and essentially anywhere to the west of Adelaide.
Receiver Performance
Receiving a radiosonde on the ground at Adelaide Airport
With such excellent line-of-sight, the station regularly receives signals from the Adelaide Airport radiosondes before they launch, and often even during the ground-test and calibration activities performed on the radiosonde within the Bureau of Meteorology building at the airport.
Also often visible are radiosonde launches from the Ceduna and Woomera receiving stations, which typically rise above the horizon when they reach ~10km altitude. Coverage to the east is not quite as good, being blocked by the Adelaide Hills, however radiosondes are regularly tracked down to ~1 degree elevation.
Would you like to know more?
More information on the radiosonde reception software is available on github at https://github.com/projecthorus/radiosonde_auto_rx .
A conference presentation delivered by myself and Michael Wheeler (VK3FUR) where we discuss the re-use of the Vaisala RS41 radiosondes is also available (see below)
You can track radiosondes launched from Adelaide Airport (and many other launch sites around the globe!) by visiting the Habitat Tracker at this link.
Thanks again to all those who helped make this possible!
AREG is once again involved with the University of South Australia’s Southern Hemisphere Space Studies Program this year, which is run by UniSA on behalf of the International Space University. The launch, which was scrubbed last week due to the predicted landing zone is now planned for this coming Saturday 9th Feburary, with liftoff planned for ~11AM. The weather is looking much better!
The current predictions look as follows:
Payload Plans
While some details are still to be worked out, it’s looking like the following payloads will be flying:
RTTY – 434.650 MHz
4FSK – 434.640 MHz
Wenet – 441.200 MHz (downward facing images)
Wenet #2 – 443.5 MHz (horizon-facing images)
There is still a chance the second Wenet payload will be dropped from the launch due to weight restrictions, so if you don’t see any signal on 443.5 MHz, that’s what’s happened!
As always, amateurs from across the state are encouraged to take part, by collecting the telemetry data and relaying it to HabHub on the Internet. This data is used to help fill in any missing data the chase teams fail to capture, which they can use to help maximize their landing zone prediction accuracy. In that way, everyone taking part is adding to the success of the mission.
Tracking details will be provided closer to the launch. Keep watching the AREG website for details!
AREG will be launching a high-altitude balloon for the International Space University’s South Hemisphere Space Studies program, conducted by the University of South Australia again this year. The planned launch date is Saturday the 2nd of February, with liftoff around 10-10:30AM. The launch site will be the usual Mt Barker High School Oval location.
UPDATE 2019-01-31: Due to poor launch-day weather, this launch has been re-scheduled to 11AM on Saturday the 9th of February.
Payload Plans
While some details are still to be worked out, it’s looking like the following payloads will be flying:
RTTY – 434.650 MHz
4FSK – 434.640 MHz
Wenet – 441.200 MHz (downward facing images)
There may be a second Wenet payload on 443.5 MHz capturing outward-facing imagery, though this is yet to be confirmed.
As always, amateurs from across the state are encouraged to take part, by collecting the telemetry data and relaying it to HabHub on the Internet. This data is used to help fill in any missing data the chase teams fail to capture, which they can use to help maximize their landing zone prediction accuracy. In that way, everyone taking part is adding to the success of the mission.
WENET PAYLOAD NEWS
There have been some updates made to the Wenet HD imaging payload and receiver software, however all changes are backwards compatible. If you have a functioning Wenet receiver system, you *do not need to update for this launch*.
Project Horus began in 2010 as the brain child of a group of radio Amateurs here in Adelaide. Now, 11 years later, one of the ideas that has been discussed many times within the group is finally going to be attempted. A flight is tentatively planned for Sunday March 7th that will carry aloft our first ever digital ATV transmitter.
AREG will be launching a high-altitude balloon for the International Space University’s South Hemisphere Space Studies program, conducted by the University of South Australia again this year. 