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Antenna Control

A dual-process antenna control server, ``antcon/antcli'' was created. The processes run in parallel sharing a SHM segment. This architecture effectively separates network communication (TCP server process ``antcli'') from antenna control and thus enhances the robustness of ``antcon.

Antenna control software utilizes USNO Novas C Library version 2.0 which enables it to track the Sun, the Moon, all planets, and extragalactic sources with J2000 coordinates. Older 1950 epoch coordinates are supported in compatibility mode. Planet tracking uses JPL DE405 ephemeris data for accurate planet, Sun, and Moon positions. Strict GPS-based UTC timing is ``fine-adjusted'' with current and predicted IERS timing data available at ``ftp://maia.usno.navy.mil/ser7''. This enables correct handling of UTC leap seconds.

Support for line observations in form of line frequency Doppler shift calculations was added along with tests of AOS spectral line software by Helsinki University group.



Ari Mujunen 2001-07-30