Last updated: 16 June 2026
Using AstroSat
AstroSat is a free set of tools for astrophotographers: a satellite-trail forecaster and a coordinate converter. By using the site you accept these terms. If you don't agree with them, please don't use it.
Forecasts are estimates, not guarantees
This is the important part. AstroSat predicts satellite passes from public orbital element sets propagated with the standard SGP4 model, and it estimates brightness from published photometry models. All of that carries real uncertainty: element sets age between updates, satellites manoeuvre without warning, and apparent brightness depends on conditions we can't fully model. Treat the output as a well-informed estimate to plan around, not a certainty. In particular, AstroSat deliberately does not predict specular flares (the brief mirror-glints off a satellite's surfaces), because that depends on orientation data operators don't publish. Don't rely on a forecast as your only basis for a decision you can't undo.
Provided "as is"
AstroSat is provided as is, without warranties of any kind, express or implied, including fitness for a particular purpose. We don't promise the service will be uninterrupted, error-free, or available at any given time.
Limitation of liability
To the extent the law allows, we aren't liable for any loss arising from your use of, or inability to use, AstroSat, including a missed or ruined imaging session, wasted travel, or reliance on a forecast that didn't pan out. (Nothing here excludes rights that can't be excluded under applicable law, such as certain Australian Consumer Law guarantees.)
Your account
If you create an account, you're responsible for keeping your password and access secure, and for activity under your account. Use an email address you actually control, since it's how password resets reach you.
Acceptable use
Please don't attempt to break, overload, scrape, or abuse the service, interfere with other people's use of it, or use it for anything unlawful.
Changes
We may update the tools or these terms over time; the current version always lives on this page.
Governing law
These terms are governed by the laws of Tasmania, Australia.
Contact
Questions? Email hello@astrosat.org.