radio amateurs satellites ground stations
TRANSCRIPT
Radio Amateurs Satellites&
Ground Stations By Jean Marc Momplé (3B8DU)
Agenda
1) Radio Amateurs and stations
2) Radio Amateur satellites
3) Radio Amateurs Satellite Ground Stations
4) Brief about future MIR-SAT 1 Ground Station
By 3B8DU
What is Radio Amateur?A Radio Amateur, also known as a “HAM”, is a person which uses radio frequencies for the purposes of experimentation, self training, non-commercial exchange of messages, private recreation and emergency communication without any pecuniary interest.
A Radio Amateur must pass an competency examination, obtain a Licence issued by the regulatory authority (ICTA) which will assign him a “callsign” before he may operate his station.
Over the years Radio Amateurs have significantly and benevolently contributed to education, science, engineering and saved many lives in times of emergency.
There are about 3 million licenced Radio Amateur operators worldwide represented at the International Telecommunication Union (ITU) by their worldwide association the International Amateur Radio Union (IARU).
Many are actively involved satellites activities. By 3B8DU
By 3B8DU
Radio Amateur station
Transmitter
Receiver
Computer/s
Antennas/s
Radio/s
A typical Radio Amateur station consists of several components and as a minimum one radio and one antenna
By 3B8DU
Radio Amateur equipment
By 3B8DU
Software Define Radio (SDR) receiver
Receiving the strong signal of NO-AA 15 Weather Satellite on 14/07/2018
Using:
Radio Amateur satellite orbits
By 3B8DU
Elliptical Orbit
Apoapsis.
Periapsis
“Circular” Orbit
LEO Satellites:Low Earth Orbit satellites (up to 2000 Km altitude)
HEO Satellites:Highly Elliptical
Orbit satellites
OSCAR 1, the first satellite built by Radio Amateurs, was launched in 1961 only 4 years after the launch of Sputnik 1. Also, it was the first non-governmental spacecraft.
Since then Radio Amateurs have regularly send transponders in space to facilitate communication between themselves and deeply involved in space technologies.
Today, many Radio Amateurs are helping Universities by supporting them building their satellites and Ground Stations. More helping to collect telemetry from spacecraft's worldwide. By 3B8DU
Radio Amateur satellites
Launch mass 10.0 kilogramsDimensions 15.2 by 25.4 by 33 cm Apogee 474 KmPerigee 245 Km
By 3B8DU
OSCAR 7 (AO-7)
Constructed by the Radio Amateur Satellite Corporation (AMSAT) it was launched on November 15, 1974 and remained operational until a battery failure in 1981. Then after 21 years of apparent silence, the satellite was heard again on June 21, 2002, some 27 years after launch. It is still operational when in sunlight and still used by Radio Amateurs to communicate.
Launch mass: 28.8 kilogramsDimensions: 36.0cm x 42.4cm octahedronApogee 1,465 KmPerigee 1,447 Km
Mauritian Radio Amateurs have been
active on satellites since the time of
Oscar 7, in the beginning with with
“home brewed” equipment.
By 3B8DU
One of the most used elliptical orbit satellite was Oscar-13, launched on June 15 1988 on the first test flight of the Ariane 4 rocket, along with Panamsat and Meteosat P2. Eight and a half years later AO-13 re-entered and burned up, on December 5 1996. With its high apogee Oscar-13 gave global VHF, UHF and SHF radio coverage to thousands of Radio Amateur operators.
OSCAR 13 (AO-13)
Height: 1.35 m, Width: 2.0 m, Weight: 140 140 Kg (at launch), 90 Kg (after engine firings)Apogee 38,000 KmPerigee 720 Km
By 3B8DU
Fox-1D or OSCAR 92 (AO-92) was launched on the PSLV-C40 mission from Satish Dhawan Space Centre in Sriharikota, India on January 12, 2018. It carries a UHF/VHF FM transponder, L-Band Downshifter, a Virginia Tech Camera, and the University of Iowa’s High Energy Radiation CubeSat Instrument (HERCI).
Examples of CubeSats carrying amateur radio
CubeSat 10 x 10 cm
Many CubeSats are being launched carrying Radio Amateur transponders such as 3 Cubesat recently, namely Bhutan 1 of Bhutan, Maya-1 a Filipino project and UiTMSAT-1 of Malaysia.
All three where launched from the International Space Station on Friday 10 August 2018 by the Japan Aerospace Exploration Agency (JAXA) Kibo'srobotic arm and all 3 carry Amateur Radio Digipeaters.
By 3B8DU
Longjiang-1, callsign BJ1SM and Longjiang-2, callsignBJ1SN, carrying Radio Amateur transponders where launch on a Long March 4C rocket from Xichang, China on the 20th May 2018.
Unfortunately Longjiang-2 was lost following a trajectory correction on 21th May 2018.
DSLWP-B successfully entered elliptical lunar orbit some 400,000 from the earth and is now orbiting the moon since 25th May 2018 at 14:08 UTC.
About 40 Radio Amateurs around the world have been able to receive the signal from the moon orbit, this using relatively small ground stations, including 2 Mauritian 3B8FA and 3B8DU.
The Longjiang-2 has now officially received the designation of Lunar OSCAR 94 (AO-94).
Lunar transponder “the new frontier”
Sample of beacon DSLWP-B received
1) The ISS carries several Radio Amateur transponders such as FM repeaters and APRS Digipeater.
2) Various experiment using Radio Amateurs frequencies are carried out from the ISS.
3) Slow Scan TV broadcasting for special events, latest being 40th anniversary of man in space on 11-14 April 2018.
International Space Station (ISS)
By 3B8DU
Award obtained by 3B8FA
(Mauritian Radio Amateur) for
receiving SSTV picture from the
ISS
By 3B8DU
ARISS (Amateur Radio on the International Space Station) lets students worldwide experience the excitement of talking directly with the crew members of the ISS, inspiring
them to pursue interests in careers in science, technology, engineering and math.
International Space Station (ISS)
Note: Many astronauts, cosmonauts, spationauts and taikonauts are Radio Amateurs
Assuming one has a computer, several LEO satellites and CubeSat telemetry or images may be received. Above setup cost about Rs 3,000. The antenna may be built in a few hours from readily available material in hardware stores.
This setup may be used by students or radio enthusiasts to get acquainted with LEO satellites and space technology.
+ +Cheap SDR Rs 1,200
Receiving LEO Satellite with SDR
+Cheap LNA Rs 300
DYI Antenna Rs 1,000
All required software are FREE
By 3B8DU
By 3B8DU
Tracking Ground Station AntennasIn order to have better reception at low elevation, many Radio Amateur satellite Ground Station antennas are high gain directional ones, such as Yagi’s or Dish antennas which are automatically pointed towards the satellite with a computer controlled motor (Rotator).
High quality low noise amplifiers are also used.
10 GHz Rx 80 cm dishMotorised tracking
145 MHz
435 MHz
2.4 GHz 1.2 GHz
2.4 GHz 120 cm dish
Rotator
+
+
+
+
+A Semi-duplex radio + SDR
A duplex radio
OR
SDR
2-Way Communication set-up
+SDR for High
speed Telemetry
By 3B8DU
Decoding is all about software nowadays
Decoding XW-2F satellite and forwarding same to an open satellite Data-Warehouse
By 3B8DU
The MIR-SAT 1 main Ground Station will be located in Ebene Cybercity, at the MRC.
It will be able to operate on the followingfrequencies:
1) VHF: 144-146 MHz.2) UHF: 430-440 MHz.3) S-Band: 2.5 – 2.45 GHz.
Cross Yagis antennas will be used forVHF/UHF and a dish antenna for S-Band.
It will be capable of automatically tracking LEO satellites, send command to and receiving data from MIR-SAT 1. It will be also equipped to experiment high speed data communication with the satellite.
MIR-SAT 1 Ground Station
S-BandVHF
UHF
Typical LEO antenna systemwith S-band dish
By 3B8DU
End NoteMIR-SAT 1 is a great opportunity for capacity building in Mauritius.
Suggestion:
1) individuals or students may start to build their own receiving SDR Ground Station at home, costing not much, and decode existing LEO satellites;
2) universities may start projects around MIR-SAT 1 such asbuilding fully fledged ground stations from scratch. Thelearning would be tremendous for the students involved.
Eventually they may actively participate in the MIR-SAT 1 project by receiving telemetry and image from our 1st spacecraft and proving same to a central Data Warehouse for further analysis.
Radio Amateurs are committed to help as benevolent in such projects.
By 3B8DU
Portable & Mobile Amateur Station
Portable (Talkie)
3B8DU/P
Mobile 3B8DU/M
By 3B8DU
Built by the Japan Amateur Radio League (JARL), launched on 17 August, 1996. Thanks to its high altitude it has a relatively large footprint and does not require much power to access, 5 Watts into a 8 element Yagi antenna. It is still active, after over 21 years in orbit and still a very popular “Bird”.
Fuji-OSCAR 29 (FO-29)
Dimensions:44 x 47 cm sphere-like polyhedronWeight: 50 KgApogee 1,323 KmPerigee 800 Km
2 SSTV picture transmitted from the ISS this year and received by 3B8DU in Curepipe
Sample SSTV Pictures received from ISS
By 3B8DU
By 3B8DU
Amsat Fox series Online Decoder
By 3B8DU
Satellite Portable Ground StationOne local Radio Amateur, Francois (3B8GZ) is doing reliable 2-way voice contacts on Satellites with Reunion, South Africa, Madagascar and Kenya using simple gears.
A “home brew” antenna, 2 walkie-talkies and computer headset. All together costing less that Rs 4,000.
In the beginning it is not obvious where to point the antenna, however after a few satellite passes one acquires the required skill by listening at his own voice coming back from the bird.
Four Radio Amateur satellites have been successfully used with this set-up, namely AO-91, AO-92, FO-29 and SO-50.