The Bridge - Issue 2, 2019 - 11

Feature

Amateur Radio Satellites
Low-earth orbiting (LEO) amateur radio satellites can provide
significant design experience in polarized antennas, automated
tracking, RF modem design and telemetry analysis. The Radio
Amateur Satellite Corporation (AMSAT, www.amsat.org) includes
world-wide organizations of volunteers that design, build, arrange
launches for and then operate satellites carrying amateur radio
payloads. The earliest attempts were the OSCAR series of satellites
beginning in 1961.
TUARC received confirmation of the reception of a telemetry
signal from OSCAR 6 in 1973 and received the QSL card in
Figure 1. Temple University's ECE capstone design projects, which
developed a microcomputer-based azimuth-elevation (az-el)
antenna tracking system and an automatic Doppler frequency shift
correction for PSK digital data communication for LEO satellites,
were awarded two successive Bendix Awards for IEEE Region 2.
Our other projects include the development of satellite PSK DSP
data modems and a complete refurbishing and qualification of the
az-el tracking, cross-polarized VHF/UHF Yagi antenna system at
the K3TU station. (A Yagi antenna is a type of directional antenna.)
However, a LEO
amateur radio
satellite station
can use an omnidirectional, circular
polarized antenna
that does not have
to be pointed to
track and a highFig. 1: QSL card of the reception of telemetry from
performance
the OSCAR 6 LEO satellite.
software-defined
radio (SDR) such as the FUNcube dongle (www.funcubedongle.
com). The FUNcubes are small LEO amateur radio satellites
for telemetry and linear transponder uplink and downlink for
SSB AM voice, CW with Morse code and digital data
(http://funcube.org.uk), see Figure 2.
Fig. 2: Internal view of the
FUNcube SDR for LEO
satellite reception.

ACRONYMS
AMBE
APRS

Advanced Multi-Band Excitation
Automatic Packet
Reporting System
AFSK
Audio Frequency Shift Keying
ARHAB Amateur Radio
High-Altitude Ballooning
CW
Continuous Wave
DSB AM Double Sideband
Amplitude Modulation
DSP
Digital Signal Processing
DVB-T Digital Video
Broadcasting-Terrestrial
EM
Electromagnetic
EME
Earth-Moon-Earth
FCC
Federal Communications
Commission
FEC
Forward Error Correction
FFT
Fast Fourier Transform
FM
Frequency Modulation
FSK
Frequency Shift Keying
HF
High Frequency: 1.8 to 30 MHz
LEO
Low Earth Orbiting
LIDAR Light Detection And Ranging
MFSK Multiple Frequency Shift Keying
MMIC Monolithic Microwave
Integrated Circuit
MT63 MultiTone digital modulation
OSCAR Orbiting Satellite Carrying
Amateur Radio
PSK
Phase Shift Keying
PSK31 Phase Shift Keying at 31 b/sec
QPSK31 Quadrature Phase Shift
Keying at 31 b/sec
QSL
Q-signal: I confirm receipt
of a transmission
RF
Radio Frequency
SDR
Software-Defined Radio
SHF
Super High Frequency:
3 to 30 GHz
SSB AM Single-Sideband
Amplitude Modulation
SSTV
Slow Scan Television
TNC
Terminal Node Controller
UAV
Unmanned Aerial Vehicle
UGV
Unmanned Ground Vehicle
UHF
Ultra High Frequency:
0.3 to 3 GHz
VHF
Very High Frequency:
30 to 300 MHz

HKN.ORG

11

http://www.amsat.org http://www.fcc.gov http://www.funcubedongle.com http://www.funcubedongle.com http://www.temple.edu/k3tu http://funcube.org.uk http://www.temple.edu/k3tu https://hkn.ieee.org/ https://hkn.ieee.org/

The Bridge - Issue 2, 2019

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