[aprssig] 9600 Baud Packet Network?

Andrew Rich vk4tec at tech-software.net
Sun Jun 12 19:01:06 CDT 2016


Should have used easy radio19k2

-----------------------------
Sent from my iPhone
Andrew Rich
vk4tec at tech-software.net
www.tech-software.net
0419 738 223

> On 13 Jun 2016, at 06:01, Thomas Krahn via aprssig <aprssig at tapr.org> wrote:
> 
> For what it is worth:
> 
> We have launched a balloon yesterday from Berlin (Germany) with our Pecan Pico 7b camera tracker. While we still sent out 1k2 AFSK APRS telemetry and position packets, we also encapsulated compressed JPEG images from the onboard camera. and sent them down in custom experimental 9k5 GFSK packets in APRS style, but on a different 2m frequency (144.860 MHz). The packets were received with high sensitivity with Kenwood THD72 radios and with less success with RTL-SDR dongles. 9k6 over 100 miles was not a problem. We captured more than 300 pictures that can still be seen on http://ssdv.habhub.org/DK0TU (scroll down to image 16 for a nice picture of the historical Tempelhof airport). It takes about 2 minutes for a VGA sized picture to come down at 9k6 which is a great speed for a 50 grams tracker module (including batteries).
> 
> A 9k6 network would be definitely very helpful for such experiments and I'm sure this would give a new push for experimenting with imaging and other data transmissions that require a somewhat higher data rate. BTW our Pecan Pico 7b trackers are open hardware and open source. Feel free to use it if you want to build 9k6 trackers that can be received with Kenwood or Yaesu 9k6 APRS radios.
> 
> https://github.com/DL7AD/pecanpico7
> https://github.com/DL7AD/pecan-stm32f429
> https://github.com/DL7AD/aprs_ssdv_decoder
> 
> http://ssdv.habhub.org/DK0TU
> 
> At 1k2 AFSK we also tried to transmit low resolution images (one packet every 20 seconds) through regular APRS igates without a path (!) that were then tunneled through APRS-IS and then re-posted to habhub with a perl script. While this worked great (almost every picture without packet loss) this is definitely a high burden for the existing APRS network and in the future we only want to use this for long duration floaters when they're in very remote regions of the planet.
> 
> I really hope for a good 9k6 APRS network. It can definitely be done!
> 
> 73
> 
> Thomas
> KT5TK / DL4MDW
> 
> 
> 
> 
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> 
> 
>> On 06/12/2016 07:13 PM, Robert Bruninga via aprssig wrote:
>> > I once tried... a 320x240 SSTV-like image over packet.
>> >... it took over 15 minutes to send one image.
>> 
>> Agreed, but at 9600 baud it might take only 3 minutes.
>> 
> 
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