Known issue

Brage and Vale telescopes often picks up significant radio frequency interference (RFI). Work in progress to fix these issues.

Support & documentation

Contact

If you have any questions or run into problems, please first read the User's manual and experiment instructions below. If you still need help, contact us at salsa.onsala@gmail.com.

We'd also love to hear from anyone using SALSA — what you observed, what worked, what surprised you. Same address. Knowing how the telescopes are being used helps us prioritise the time we put into keeping them running.

User's manual

The user's manual describes how to operate the SALSA telescope — scheduling observations, pointing, recording spectra, and downloading data.

Read the User's manual →

Experiments

Step-by-step lab guides covering the scientific background, observing procedure, and data analysis for each experiment.

Mapping the Milky Way with the 21 cm hydrogen line

Observe neutral hydrogen across the Milky Way, measure Doppler-shifted 21 cm emission, derive the rotation curve, and reconstruct the positions of the spiral arms.

GNSS satellite signal spectra

Receive and compare radio signals from GPS, Galileo, GLONASS, and BeiDou satellites, and see how their different modulation schemes produce distinct spectral shapes.

Measuring the SALSA antenna beam

Use the Sun as a bright radio source to map the beam pattern of the SALSA antenna, measure its angular resolution, and compare the result to theoretical predictions for a circular aperture.

Planning tools

Target visibility — for a galactic, equatorial, or Sun target on a given date, see when it is above the horizon at the SALSA site (Onsala, Sweden) so you can pick a booking window where it is actually observable. Open the visibility planner.

Alternative analysis tools

The observation archive page has built-in baseline-subtraction and Gaussian-fitting tools that cover most analysis workflows. The tools below are kept around for users who prefer to work in their own environment with the FITS files SALSA exports.

  • SalsaSpectrum (MATLAB class) — a MATLAB toolbox for analysing SALSA FITS files. Useful when you want to process many spectra programmatically or stay inside an existing MATLAB workflow. Source: SalsaSpectrum.m (right-click → Save Link As). Documentation: SalsaSpectrum_documentation.pdf. The class has been adapted (version 2.3, see the header comment) to work with FITS files written by the current SALSA control software; for archival files from the previous control system use the older version 2.2 from the historical varenius/salsa repository.
  • SalsaTS — a third-party browser-based analysis tool. Runs entirely in the browser, no installation: appolloford.github.io/salsa-ts. Maintained outside SALSA, so feature support and FITS-format compatibility may differ from the built-in tools.
  • Google Sheets — for quick visual inspection of an exported CSV without installing anything: see the short Google Sheets guide.

Publications

  • A popular science description of SALSA was published by Cathy Horellou and Daniel Johansson in the Swedish magazine Populär astronomi in 2008. PDF (in Swedish).
  • SALSA was mentioned in the article A Radio Astronomical Star Party for those "On The Verge", describing a star party in Onsala, Sweden in 2012. Published in CAPjournal (issue 13, 2013) by Eva Wirström and Robert Cumming. PDF.
  • Thomas Hobiger, Rüdiger Haas and Eskil Varenius describe using the two SALSA telescopes as an educational interferometer demonstrator in Hard and Software Tools for the Education of Geodetic VLBI, published in the IVS 2016 General Meeting Proceedings (NASA/CP-2016-219016, pp. 234–238). PDF.

Technical specifications

For hardware details — signal chain, rotor protocol, LNA measurements, and component references — see the Technical specifications page.