Test target

A test target (for spacecraft) or calibration target is a common feature on interplanetary landing craft such as the Viking Lander and Mars Exploration Rovers.[1]

The target is usually a visible marker or plate on the exterior of the vehicle within sight of the lander's imaging system (usually a CCD camera). The target possesses samples of primary colors and a grey scale.[2] The camera uses this much like a photographer would use a chip chart on Earth; the color samples allow the camera to compensate for white balance and contrast. The target provides a visual reference as well, so that the initial orientation of the camera can be fixed.[2]

On the Mars Exploration Rovers, the target was designed in the shape of a sundial mounted on the rover deck with colored blocks in the corners for color calibration.[3]

References

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  1. ^ Kinch, Kjartan; Hilverda, Mark; Madsen, Morten Bo; Bell, Jim (14 December 2020). "Calibrating Mars". The Planetary Society. Retrieved 3 June 2025. Every NASA surface mission ever sent to Mars has had a calibration target.
  2. ^ a b "Mars-Bound NASA Rover Carries Coin for Camera Checkup". JPL. NASA. 7 February 2012. Retrieved 3 June 2025.
  3. ^ "Mars Exploration Rovers Science Instruments | Calibration Targets". NASA. 22 March 2024. Retrieved 3 June 2025.