GLOSSARY.

 

This is a simple ‘get you started’ glossary. A more advanced version can be found in part two of the book.....when hopefully...the reader will be more able to comprehend the terms used.

 

AFSK - Audio Frequency Shift Keying.

 

ALLIGATOR - ‘All mouth and no ears’...(self-explanatory).

 

ALTITUDE - The distance between the  satellite and the point

on the Earth's surface directly below it. Same as height.

 

AMSAT - The Amateur Satellite Corporation.

 

AOS - Acquisition of signal. - when the satellite comes  into range of your QTH.

 

APOGEE - The point in the satellite orbit when it is furthest

from the earth.

 

ATTITUDE - The way the satellite is orientated in space.

 

AZIMUTH - The ‘direction’ of the satellite in degrees in the

horizontal plane.

 

BEACON - The reference frequency of the satellite.

 

BIRD - Slang for ‘satellite’.

 

BPSK - Binary Phase Shift Keying.

 

DOPPLER - Change in frequency due to motion.

 

DOWNLINK -The frequency from the satellite to the groundstation.

 

EIRP - Effective Isotropic Radiated Power.

 

ELEVATION - The ‘direction’ of the satellite in degrees in the

vertical plane.

 

EPOCH - A specific date and time.

 

EQX - Equator crossing time.

 

FOOTPRINT  - The circle of radiation of the satellites antennas on the surface of the earth.

 

GEOSTATIONARY ORBIT -A special type of orbit where a satellite has a velocity such that when the earth rotates...the satellite appears to be 'fixed' in space. Used particularly for TV satellites where an antenna can remain fixed at a certain azimuth/elevation.

 

GROUND STATION -Term used for stations that communicate via  satellite.

 

INCLINATION - The ‘angle’ of an orbit in relation to a perpendicular line drawn from the equator.

One of the classic Kepler Elements

 

INVERTING TRANSPONDER - LSB on the Uplink gives USB on the Downlink. (Fully explained in the Procedure chapter).


KEPLERIAN ELEMENTS - Angles and distances used to determine the position of a  satellite in space.

 

LNA - Low Noise Amplifier.

 

LOS - Loss of signal. (When the satellite passes out of the ‘footprint’).

 

MOLNIYA ORBIT - Special type of high elliptical orbit.

(See Part 2...ORBITS).

 

NODE - Point where the ground track and equator intersect.

 

OSCAR - Acronym for: Orbiting Satellite Carrying Amateur Radio.

 

ORBITAL ELEMENTS - The same as KEPLERIAN elements.

 

PASS - The time the satellite is within view of your QTH.

 

PASSBAND - The band of frequencies the satellite operates in.

 

PERIGEE - The point in an orbit closest to the earth's surface.

 

PERIOD - The time taken for the satellite to make one complete revolution of the earth.

 

POLAR ORBIT -  An orbit that passes over (or close to) the North and South Pole.

 

RANGE CIRCLE - The area in which any station can communicate with   any  other station for a given satellite.

 

SAREX - Shuttle Amateur Radio Experiment.

 

SLANT RANGE - The shortest distance from the satellite's antennas to    the receiving antenna.

 

SUB SATELLITE POINT - The point on the earth's surface immediately    beneath the satellite.

 

TELEMETRY - Data sent from the satellite to the earth.

 

TLM - Abbreviation for Telemetry.

 

TRANSPONDER - Transmitter/receiver combination on board a satellite.

 

UOSAT - A  family of satellites built at the University of Surrey.

 

 UPLINK - The frequency from the ground station to the satellite.

 

WINDOW - Where two range circles overlap...allowing communications between stations within those circles

 

Go to Advanced Glossary

 

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