Stuart, GW7HPW, the RFM-22 guru from the $50sat team, has done some testing with LoRA and has flown a few pico balloons to compare max range with the RFM-22. LoRA shows a significant increase in usable range based on Stuart's testing. Howeve, it appears LEO satellite doppler may pose a problem with the standard hardware. Further testing would be required to make a final determination.
Howie AB2S
________________________________ From: AMSAT-BB amsat-bb-bounces@amsat.org on behalf of Ross Whenmouth ross@topwire.co.nz Sent: Tuesday, July 4, 2017 1:43 AM To: amsat-bb@amsat.org Subject: Re: [amsat-bb] Lora and other modes
Date: Mon, 3 Jul 2017 10:58:27 +0530 From: Ashhar Farhanfarhanbox@gmail.com
Is Lora a candidate for satellites? How well does it handle doppler? Given that it uses CSS(Chirp Spread Spectrum), it is claimed to be resilient to doppler shift.
Does anybody have any further details or knowledge?
Hi Ashhar,
LORA is/uses a proprietary protocol, however, it has already been reverse-engineered by software defined radio people, so ground stations could potentially use an SDR instead of a LORA chipset: https://myriadrf.org/blog/lora-modem-limesdr/ [https://www.bing.com/th?id=OVP.QKgyi09JbcuxzNA5wRTr8gEsDh&pid=Api]https://myriadrf.org/blog/lora-modem-limesdr/
LoRa modem with LimeSDR - Myriadhttps://myriadrf.org/blog/lora-modem-limesdr/ myriadrf.org LoRa is a chirp-based modulation format that can operate beneath the noise floor. Its robust, low power, and low rate -- and a candidate technology for connecting the ...
https://static1.squarespace.com/static/54cecce7e4b054df1848b5f9/t/57489e6e07... MATT KNIGHT // BASTILLE NETWORKS REVERSING LORAhttps://static1.squarespace.com/static/54cecce7e4b054df1848b5f9/t/57489e6e07eaa0105215dc6c/1464376943218/Reversing-Lora-Knight.pdf static1.squarespace.com reversing lora matt knight // bastille networks exploring next-generation wireless
I think that it might be interesting to try EME with an FM-chirp signal (one optimised for the task ie not LORA) as an alternative to JT65...
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