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Glossary

This page explains the most common OrbitDeck and amateur-satellite terms in plain language.

AOS

AOS means acquisition of signal.

In simple terms: the moment a satellite pass starts and the satellite comes up over your horizon.

LOS

LOS means loss of signal.

In simple terms: the moment the pass ends and the satellite drops below your horizon.

TCA

TCA means time of closest approach.

In OrbitDeck, this is typically near the middle of the pass and often near the highest point.

Azimuth

Azimuth is the compass direction to the satellite.

  • is north
  • 90° is east
  • 180° is south
  • 270° is west

Elevation

Elevation is how high above the horizon the satellite is.

  • is on the horizon
  • 90° is straight overhead

Pass

A pass is one trip of a satellite across your sky while it is above your horizon.

Doppler

Doppler is the apparent shift in radio frequency caused by motion.

In practice:

  • a satellite coming toward you sounds or appears slightly higher in frequency
  • a satellite moving away appears slightly lower

OrbitDeck helps by showing recommended frequencies during the pass.

Rotator view

OrbitDeck screen centered on one active or upcoming pass.

Kiosk view

OrbitDeck dashboard screen for station status and pass summary information.

Lite view

OrbitDeck screen for phones and Pi Zero-class hardware.

Tracked satellites

In lite mode, these are the satellites OrbitDeck is allowed to spend time computing. Keeping the list small helps the app stay fast.

Frequency guidance

OrbitDeck tuning guidance for a pass.

AMSAT status

OrbitDeck comparison against recent reports from the AMSAT status site.