Step 1 · Telescopes
Three instrument generations appear in the project record. The earlier two are historical. DISH222 is the active telescope and the source of every dataset in the research archive.
Evolution
The project's first telescopes were fixed 5 m reflectors pointing straight up. As the Earth turns, a strip of sky at the site's declination drifts through the beam, so each telescope maps one band of sky per day. That design is simple and robust, and it was replicated at several Saudi universities and published in IEEE Antennas and Propagation Magazine (2025).
A fixed telescope cannot choose where to look. To map chosen regions of the Galactic plane, repeat observations and point at calibration sources, the project moved to motorised dishes that can steer in azimuth and elevation. DISH1 and DISH222 are the two steerable dishes in the record. Both were operated during August–September 2026, but only DISH222 has observations in the research archive, and it is now the active research telescope.
The Project Story and lecture slides 12–17 tell the engineering story in more detail.
DISH222
A conceptual overview for students. It explains the measurement, not how to operate the telescope.
DISH222 is a 5 m parabolic reflector on an azimuth/elevation mount. To observe a sky position, software converts its celestial coordinates (right ascension and declination, or Galactic longitude and latitude) into azimuth and elevation for the current time and site. A motor controller then drives the dish there, and the dish reports its position back. The observing software keeps scans above 30° elevation.
Radio waves collected by the dish reach the feed and a low-noise amplifier, then a HackRF One software-defined radio locked to an external 10 MHz reference. In the 26 Aug 2026 session the receiver was tuned to 1419.9 MHz with 2.4 MHz of bandwidth. The computer turns the sampled signal into 1024-channel spectra and averages many of them.
Only these averaged power spectra are stored, not the raw radio samples.
The beam is about 3° wide, so pointing errors of a degree matter. A Sun-based pointing calibration on 25 Aug 2026 reduced the residual error to about 1.1°. Later software added an automatic Sun cross-scan check, and comparing the observed ridge of Galactic H I with b = 0° provides an independent test.
Current role. DISH222 produces all data in the research archive and is the reference instrument for the calibration work described on the Calibration page. New, independently tested DISH222 software is being designed starting with offline analysis tools. The receiver's sample format and the motor-safety behaviour are to be verified independently before any new software controls the telescope.
Instrument record
Generated from the project's instrument registry. Only documented values are shown; details that are not yet documented are listed as open questions rather than guessed.