US Naval Academy LABsats Bob Bruninga, WB4APR AIAA JHU/APL Educational Seminar 10 Nov 2006.
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Transcript of US Naval Academy LABsats Bob Bruninga, WB4APR AIAA JHU/APL Educational Seminar 10 Nov 2006.
Digital Transponder
Telemetry system has 1200/9600 baud available
•STP Experiments can interface to serial ports here
•PCsat
SCIENCE
USNA-0203
USNA PCSAT2 on ISS
Launched Aug 2006, attached to ISS
1 Year of 3 Mbytes data per day
Supported Packet and Voice Relay
Returned Sept 2006
The comm channels can potentially draw from over 30,000 experimenters for easy assessment of loading and scaling issues.
Not only the sensors and users exist, but the global Internet collection and distribution system also exists from PCSAT1 & 2.
Our Satellites provide a low cost educational transponder supporting not only GPS position reporting but also remote WX stations and other data link experiments and other University and School Experiments.
Space User Baseline PCSAT validates our links
Vandegriff
SCIENCE
USNA-0203
PCSAT2 User Plot 18 Apr 06
See www.ariss.net
Global Internet Linked Ground Stations
All downlinks available live on web via Participating internet linked Ground Stations
www.ariss.net pcsat.aprs.org
SCIENCE
USNA-0203
Types of Labs• Antenna Labs: . . . . . . . . Link, Patterns, Gain, Beamwidth, SWR • Electrical Power sys: . . Solar Cells, batteries and Regulators • Transmitters: . . . . . . . . . TX power and antenna matching • Receivers: . . . . . . . . . . . Receiver sensitivity, selectivity and Bandwidth• Comms: . . . . . . . . . . . . . FSK, AFSK,PSK ; and TDMA and FDMA • Telemetry: . . . . . . . . . . . Signals, decoding, equations 5 channel A/D • Command / Control: . . . Using the 3 commandable ON/OFF circuits. • CPU and Experiments: . Aux serial port – processor, GPS, etc • GPS interface: . . . . . . . . Using a GPS input for position determination • Attitude Control: . . . . . . .Passive/active Magnetorquing & wheels. • Thermal Control: . . . . . . Absorbtivity, Emissivity, Conduction.
Antenna Tests
Uses small 2.4 GHz camera/transmitters
First observe dipole link (1000’)
Place dipole at dish focus and measure gain
Swing dish to see Beamwidth
Antenna Tests
Using PI network to match spacecraft antenna for best SWR
Using GPS signals to plot antenna pattern of GPS
Antenna Tests
RF LABsat model on rotor
Rotator and S/A to plot pattern
Dipole 1
Dipole 1
Antenna Phasing experiment
Demodulation - FSK
All Seven Student LABsats on the air
Sharing a single TDMA channel
Using FSK for demodulation
Demodulation - PSK
LABsat configured as HF to UHF linear transponder
Indoor LABsat RX
PSK-31 Waterfall Spectrum display on Student’s workstation
The comm channels can potentially draw from over 30,000 experimenters for easy assessment of loading and scaling issues.
Not only the sensors and users exist, but the global Internet collection and distribution system also exists from PCSAT1 & 2.
Our Satellites provide a low cost educational transponder supporting not only GPS position reporting but also remote WX stations and other data link experiments and other University and School Experiments.