Ham radio heads to the Moon DSLWP is a lunar formation flying mission led by Harbin Institute of Technology for low frequency radio astronomy, amateur radio and education It consists of a pair of 47 kg microsatellites, to be launched into a lunar transfer orbit UTC this Sunday evening, and finally enter a 300 x 9000km lunar elliptical orbit. Onboard each satellite, there are two VHF/UHF SDR transceivers to provide beacon, telemetry, telecommand, digital image downlink and a GMSK-JT4 repeater. Onboard transmitting power is about 2 W. Wei Mingchuan BG2BHC reports the first launch window will open at about 21:30 GMT Sunday May 20. The transmitters will be activated soon after separation. Satellite A will transmit 500 baud GMSK with 1/4 turbo code on 435.425 MHz and 250 baud GMSK with 1/2 turbo code and precoder on 436.425 MHz, and satellite B will transmit 500 baud GMSK with 1/4 turbo code on 435.400 MHz and 250 baud GMSK with 1/2 turbo code and precoder on 436.400 MHz, in every 5 minutes by default. Each transmittion will last about 16 seconds. Radio amateurs in South America will have the earliest chance to receive the signals from the satellites, then North America, Oceania, Asia, Europe and Africa. Harbin Institute of Technology Amateur Radio Club expects radio amateurs to join in this mission. We will prepare different QSL cards for different flight phase for amateurs successfully made QSO or received telemetry. Awards will also be given to the first 10 amateurs in each continent who successfully decoded the signals from the satellites, received the most number of packets, or received an image. Your participation will also help the team to get a better knowledge of the status of the satellites. An open source decoding software based on GNU Radio to work with RTL-SDR and USRP is provided. Not difficult to change the grc files to support other SDR receivers. A small proxy software will send the decoded data to a server for real-time display. Links for further information can be found at https://amsat-uk.org/2018/05/19/dslwp-satellites-lunar-orbit/ http://www.southgatearc.org/news/2018/may/ham-radio-heads-to-the-moon.htm
Great news ! But it is a little early in the morning for me to get my head around all the GMSK & half turbo code ! I'll wait till later on & read it all again ! Hi Hi P.S. China is going to the Dark Side of the Moon ! good luck .73 KI6PMD..
lets see here........ 2 watt transceiver moving in lunar orbit, 70 centimeter band, 2 moving and spinning planetary bodies 239,000 miles away, with a 16 second transmission burst. --- Guess I will need a bigger - MUCH BIGGER 70c array. Will not be holding my Breath for a QSL card...
About that "further information" link: http://www.southgatearc.org/news/2018/may/ham-radio-heads-to-the-moon.htm That is an exact duplicate of the posting here..
"Update May 21, 2018: After deployment signals from the DSLWP satellites were received by Edson Pereira PY2SDR, Nicolás Castro CD3NDC, Robert Mattaliano N6RFM and many other radio amateurs around the world." de Amstat-UK.org Now I'm confused, is or can it be heard with an SDR dongle? or are they just talking about RTL-SDR software? Does that elliptical orbit cause doppler? or because transmissions are only 16 seconds will Doppler be negligible. From the looks of the dish antenna, it has some gain. I seem to recall EME on 2 meters the path attenuation was like 70-90dB... then the moon isn't the greatest reflector. Given the EME distance is cut in half and the 2 watts at the moon, just what would be a reasonable antenna to start with.. Gain not manufacturer that is. Excuse my "old Fart" mentality.. 52 years is a long time in ham radio.
Satellite A will transmit 500 baud GMSK with 1/4 turbo code on 435.425 MHz and 250 baud GMSK with 1/2 turbo code and precoder on 436.425 MHz, and satellite B will transmit 500 baud GMSK with 1/4 turbo code on 435.400 MHz and 250 baud GMSK with 1/2 turbo code and precoder on 436.400 MHz, in every 5 minutes by default. Perfectly understandable - What ?
I wonder if one of those $29.95 chinese 2m/70cm hand held radios would do a good job of picking up the signals from whatever has been placed in moon orbit? Seriously, I am impressed at this achievement. Unfortunately for a 72 year old ham who limits his activities to CW rag-chewing on forty and sometimes 30 & 20 meters, the scope of modern communication technology has passed me by; but I don't care as long as my HW-101, HW-16 & HW-8 still work, I'm a happy camper!
That, of course, depends on the satellite's direction relative to your location when you try to receive it. It should be well above your horizon whenever the moon is, however. ("When the Moon's in the sky like a big pizza of pie...")
The Longjiang-2 satellite's footprint can be observed using N2YO.com by searching for NORAD # 43472 then clicking on "Footprint" on the map.
