Alpha Testing     

The first stage of product testing after the prototype 

development. The sequence is: conception, design, prototype, alpha testing, beta testing, and production.

The AMateur SATellite Corporation. A United States-

based non-profit organization committed to the development and encouragement of amateur satellite activity.

A signal that varies in a continuous manner (e.g., voice,

music, and voltage and currents that vary in a continuous manner). (See digital.)

When the satellite is at it's highest altitude.

Acronym for American Radio Relay League.

Also called Start-Stop transmission. Digital signals

which are sent as groups of a specified length with start and stop bit indicators at the beginning and end of each group. Usually used when time intervals between transmitted groups may be uneven. (See synchronous.)

Amateur packet radio protocol version of the X.25

protocol. Usually used in reference to the data link layer protocol in use by most amateur packet stations.

Also called CBBS, PBBS, Mailbox. Acronyrn for Bulletin

Board System. An automated computer system which can be controlled from a remote location. Usually capable of sending and receiving messages and files.

The fifth and usually final stage of product development

before general production and release. The sequence is: conception, design, prototype, alpha testing, beta testing, and production.

A technique in which a binary "1" is represented by a

positive pulse and a binary "0" is represented by a negative pulse. Bipolar keying is the system used by NRZI on amateur packet radio.

A discrete or discontinuous signal whose various states are

identified with specified values. (See analog)

A shift in frequency caused by satellite motion.

The frequency used to recieve a satellite.

A circular area where the satellite is line of sight.

Acronym for Frequency Shift Keying. A method of

frequency modulation in which the frequency varies.

A satellite in a Geosynchronous Orbit (35,680km)

A circuit designed for transmission in either direction on

two separate channels but not both directions simultaneously.

A satellite in a High Earth Orbit (> 20,000km)

The angle of the satellite where equator = ZERO.

The Japanese AMSAT affiliate.

A packet radio satellite designed by JAMSAT which

features a flying mailbox and digipeater capabilities. (See RUDAK, Pacsat.)

A satellite in a Low Earth Orbit (400 - 2000km)

(See BBS.)

Acronym for Minimum Shift Keying. A modulation

method similar to FSK in which the shift in hertz is equal to half the signaling rate in BPS.

The path a satellite travels around the earth.

Acronym for Orbital Satellite Carrying Amateur Radio.

A group of bits including data and control elements which

is transmitted as a whole. Technically, a packet is not formed until the network layer; however, many refer to frame transmissions on the data link layer as packets. (See frame.)

Contraction of PACket SATellite. A packet satellite

designed by AMSAT which will feature a flying mailbox similar to terrestrial BBSs. (See JAS-l, RUDAK.)

When the satellite is at it's lowest altitude.

Acronym for Phase Shift Keying. A method of transmitting

digital information in which the phase of the carrier is varied in accordance with the digital signal.

Operation over a single channel in one direction at a time.

Acronym for Terminal Node Controller. A device which

assembles and disassembles frames. Usually includes some form of a user interface and command set. May be implemented in hardware or software. Used in conjunction with a radio, modem, and terminal for packet radio applications. (See node, PAD, FAD, packet controller.)

The frequency used to transmit to a satellite.