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Telescopes · Fixed · PSU

PSU Fixed Telescope

Historical fixed zenith-pointing telescope at Prince Sultan University: a fixed reflector that looks straight up and lets the Earth do the scanning.

Instrument

A fixed 5 m reflector pointing at the zenith

The project's first telescope generation, and the historical entry point to the whole data story.

Reflector
5 m parabolic reflector with approximately f/D = 0.35.
Feed
Choke-horn/feed and low-noise receiving chain.
Performance
Approximately 35 dBi gain and approximately 2.5° beamwidth.
Method
Fixed zenith transit-scan observations using Earth rotation.

Values as reported for the published fixed implementation (IEEE Antennas and Propagation Magazine, 2025). Station-specific details for PSU are to be added from the station record.

Learning entry point

How the fixed telescope works, step by step

This page is being prepared as the main historical learning path. Topics marked Planned are placeholders: their content is not written yet.

  • Zenith-pointing operationAvailable (summary)
    The reflector points straight up and never moves. The beam therefore stays on one band of sky, at the declination set by the site's latitude, while the Earth turns.
  • Drift-scan observingAvailable (summary)
    As the Earth rotates, the sky drifts through the beam: each fixed telescope maps one band of sky per day. Simple and robust, but the telescope cannot choose where to look. Read the fixed-to-moving story
  • SDR-based spectrum acquisitionPlanned
    How the software-defined receiver chain turns the received signal into a spectrum. Detailed PSU description to be added.
  • Averaged spectraPlanned
    How many short spectra are averaged into the recorded spectrum, and what the recorded file contains. Detail to be added from the station record.
  • Receiver / background response correctionPlanned
    How the receiver and background response were removed from the historical spectra, and what assumptions that involved. Detail to be added.
  • Sidereal time and Right Ascension processingExplainer ready · data awaiting ingestion
    How clock time on each spectrum becomes sidereal time and Right Ascension for a zenith-pointing drift instrument. Open Solar Time → Right Ascension
  • Limitations that motivated the moving telescopeAvailable (summary)
    A fixed telescope cannot repeat an observation on demand, map a chosen region, or point at a calibration source. These limits led to the steerable DISH222. Continue to the moving PSU telescope

Data

Data and archive for this station

Continue from the instrument to its recorded observations.

Live archiveRadio Telescope Data Explorer

Explore the telescope data

The historical observation archive is now available online. Open real observing sessions, inspect spectra, view time–frequency recordings and download the original archived files.

Open the Radio Telescope Data Explorer →

The Data Library catalogues this archive among the project's other datasets, and the PSU fixed archive page lays out the lineage from original spectra to a modern reprocessed archive.

Pointing and Observation

How a fixed station observes

Historical fixed system

In the published fixed implementation, the telescope points at zenith and Earth rotation carries sky regions through the beam. This supports transit-scan measurements without implying motorized tracking.

Telescope System

Radio signal chain

A practical path from the neutral hydrogen line to an interpreted spectrum.

  1. H I emission near 1.42 GHz
  2. 5 m parabolic reflector
  3. Choke-horn / feed
  4. Low-noise receiver chain
  5. Software-defined radio
  6. I/Q samples
  7. FFT
  8. Averaging and signal processing
  9. H I spectrum
  10. Scientific visualization

Instrument record

What is documented about the fixed stations

Generated from the project's instrument registry. Details that are not documented are listed as open questions rather than guessed.