Look Angle
The azimuth and elevation angles at which a ground-station antenna must be pointed to establish a line-of-sight radio path to a given satellite.
Full Definition
Look angle comprises two angular parameters — azimuth and elevation — that define the direction in which a ground-station antenna must be oriented to point at a specific satellite. Azimuth is measured clockwise from true north in the horizontal plane; elevation is measured upward from the local horizontal. Look angles are computed from the ground station's geographic coordinates and the satellite's orbital position (longitude for a geostationary satellite, or current ephemeris for a non-geostationary satellite). Low elevation angles (below 5°) are associated with longer atmospheric path lengths, greater rain-fade and scintillation risks, and potential terrestrial interference, and they must be flagged in system design documents. Editors should render 'look angle' as two words when used as a noun.
Usage
Usage note: Two words as a noun; hyphenated as a compound modifier ('look-angle constraints'). Always specify whether azimuth and elevation are referenced to true north or magnetic north, and whether elevation is geometric or refraction-corrected.
In Context
- "The look angles for the 28.5°E orbital position from the London site are approximately 26° elevation and 143° azimuth." — Site Survey Report
- "At a look angle of only 4° elevation, the Ka-band link is particularly vulnerable to rain attenuation and tropospheric scintillation." — Link Performance Analysis