This page offers a brief introduction to utilizing a digital camera to track satellites.
The advantage of photos
Much like utilizing binoculars, the objective is ultimately to measure the precise location of a satellite at a specific time. Photos help create a permanent digital record that can be computer-processed for accuracy and automation.
By pointing your camera at the star pattern and taking a series of pictures, the satellite will appear as a short arc against a star background — which can be used for a precise position reference.
The camera electronics are more sensitive than your eyes, and even with a short exposure of a few seconds, you can see stars and satellites invisible to the unaided eye. Using free software, you can convert these images into formatted observation records which can be submitted to the TruSat catalog.
- Digital SLR camera (or another digital camera with shutter controls)
- 50-80mm lens
- A clear night shortly after sunset, or before sunrise.
To determine the best place and time to point your camera, see this explainer video on how to use the Heavens-Above website to predict visible satellite passes for your location:
You will need to experiment with your camera settings, such as setting exposure durations long enough to capture enough stars to serve as a position reference for any satellite arcs you may capture. A quick way to determine if your images are good for satellite tracking is to submit a picture to nova.astrometry.net. If the site is able to compute the precise direction of your camera, you are on your way to satellite observing!
Users who are getting started can use Windows programs like ObsReduce or IODEntry to assist converting the information in your picture into a formatted observation records which can be submitted to the TruSat catalog.
More advanced users familiar with compiling open source software can explore the STVID project, which can directly interface with some digital cameras, automatically detect, extract, and process observation entries from the images it creates. Amateur satellite observers use this software to allow one person to make 100’s of satellite observations in one night!
As we develop the TruSat roadmap, we hope to incorporate many of these tools and capabilities directly into TruSat.org