US (Umbrella Start) is a shell script, available on FOURIER and GAUSS, that starts Umbrella (Umbrla), UPoint (Umbrella pointing), Dop (Doppler-velocity corrections, etc.), and WatchThis (traffic lights). US should be all that's needed to start radio-astronomy observing at Haystack. Instructions for using US, either locally or remotely, are available on paper or on the Web.

UPoint accepts pointing information from Umbrla and sends pointing commands to the antenna-pointing servo. Starting with either planetary ephemerides or right ascension (RA) and declination (Dec) epoch 1950 or J2000, UPoint calculates precession, nutation, and annual aberration (corrections to RA and Dec to give apparent coordinates), local sidereal time, hour angle, and azimuth and elevation corrected for atmospheric refraction (from surface meteorology) and for telescope-specific pointing errors. These are recalculated each second of time and updated for the servo using linear interpolation each tenth second. UPoint also calculates the Doppler velocity (derivative of the distance from source to Haystack) and writes commands for the deformable subreflector.

Dop converts Doppler velocities from UPoint to frequency offsets and sends them to the local-oscillator-reference frequency (LORF) or directly to the LO and monitors operation of these devices. Dop also sends commands (from UPoint) to the deformable subreflector.

WatchThis (traffic lights) is a monitoring program with information about the operation of the system and the programs above. A writeup for WatchThis and a list of frequently asked questions (FAQ) is available.