SatChecker Ephemeris API Documentation

Overview

SatChecker is a satellite position prediction tool from the IAU CPS (IAU Centre for the Protection of the Dark and Quiet Sky from Satellite Constellation Interference) SatHub group. It uses TLEs (two-line element sets) from CelesTrak and Space-Track to provide predictions of satellite positions at a given time and location. It also provides additional information like range, on-sky velocity, and an “illuminated” flag for each prediction point.

SatChecker uses the TLE with the closest epoch date available to the date specified in the API parameters - currently available TLEs go back to July 2019. General TLE data is updated daily, and supplemental TLEs from CelesTrak are updated every 8 hours.

The SatChecker Tools API provides additional functionality for satellite name and ID lookup, as well as the ability to retrieve all available TLE data for a given satellite over a given date range. Satellites can be assigned temporary IDs after launch, and names are subject to change, so the Tools API can be used to keep track of these changes.

Support

For assistance with SatChecker, please open an issue on the GitHub repository, or email questions to sathub@cps.iau.org.