The Mars Science Laboratory Curiosity rover Mastcam instruments: Preflight and in‐flight calibration, validation, and data archiving

Abstract

The NASA Curiosity rover Mast Camera (Mastcam) system is a pair of fixed-focal length, multispectral, color CCD imagers mounted~2 m above the surface on the rover's remote sensing mast, along with associated electronics and an onboard calibration target. The left Mastcam (M-34) has a 34 mm focal length, an instantaneous field of view (IFOV) of 0.22 mrad, and a FOV of 20°× 15°over the full 1648 × 1200 pixel span of its Kodak KAI-2020 CCD. The right Mastcam (M-100) has a 100 mm focal length, an IFOV of 0.074 mrad, and a FOV of 6.8°× 5.1°using the same detector. The cameras are separated by 24.2 cm on the mast, allowing stereo images to be obtained at the resolution of the M-34 camera. Each camera has an eight-position filter wheel, enabling it to take Bayer pattern red, green, and blue (RGB) "true color" images, multispectral images in nine additional bands spanning~400-1100 nm, and images of the Sun in two colors through neutral density-coated filters. An associated Digital Electronics Assembly provides command and data interfaces to the rover, 8 Gb of image storage per camera, 11 bit to 8 bit companding, JPEG compression, and acquisition of high-definition video. Here we describe the preflight and in-flight calibration of Mastcam images, the ways that they are being archived in the NASA Planetary Data System, and the ways that calibration refinements are being developed as the investigation progresses on Mars. We also provide some examples of data sets and analyses that help to validate the accuracy and precision of the calibration.Plain Language Summary We describe the calibration and archiving of the images being obtained from the Mastcam multispectral, stereoscopic imaging system on board the NASA Curiosity Mars rover. Calibration is critical to detailed scientific analysis of instrumental data, and in this paper we not only describe the details of the calibration process and the steps in our resulting data calibration pipeline but also present some examples of the kinds of scientific analyses and discoveries that this calibration has enabled.

Ancient Martian aeolian processes and palaeomorphology reconstructed from the Stimson formation on the lower slope of Aeolis Mons, Gale crater, Mars

“…Where grains share similar colours or are dust covered, the ability to resolve grains is diminished. Coverage obtained by the Mastcams limited by data volumes that can be stored onboard (8 Gb per camera) (Bell et al ., ) and bandwidth limitations associated with interplanetary communications. A full 360° azimuth × 80° elevation mosaic captured by the M100 camera is ca 6·6 Gb of data, which is 14 times larger than the typical daily data downlink capabilities.…”

“…The Mastcam instrument suite consists of two focusable cameras with a charge‐coupled device capable of acquiring full RGB colour images. The left Mastcam (Mastcam Left, or M34) has a fixed focal length of 34 mm and a 15° field of view; the right Mastcam (Mastcam Right, or M100) has a fixed focal length of 100 mm and field of view of 5° (Bell et al ., ; Malin et al ., ). The Mastcams are mounted on a pan‐tilt mast ca 1·9 m above the surface (Maki et al ., ; Warner et al ., ).…”

Mineral‐Filled Fractures as Indicators of Multigenerational Fluid Flow in the Pahrump Hills Member of the Murray Formation, Gale Crater, Mars

“…Mastcam consists of two cameras with different fixed focal lengths; the left Mastcam (M-34) has a 34-mm focal length and f/8 lens, creating a 15°field of view (FOV), and the right Mastcam (M-100) has a 100-mm focal length and f/10 lens, with a 5°FOV (Bell et al, 2017;Malin et al, 2017). Mastcam consists of two cameras with different fixed focal lengths; the left Mastcam (M-34) has a 34-mm focal length and f/8 lens, creating a 15°field of view (FOV), and the right Mastcam (M-100) has a 100-mm focal length and f/10 lens, with a 5°FOV (Bell et al, 2017;Malin et al, 2017).…”

The Mars Science Laboratory (MSL) Mast cameras and Descent imager: Investigation and instrument descriptions

“…Working in partnership with MSSS engineers, ATLO tests involving use of the Mastcams and MARDI aboard Curiosity were conducted thereafter in JPL facilities and, starting in July 2011, at NASA's Kennedy Space Center (KSC) in Florida. Major tests involving the cameras included integrated camera geometric calibration in December 2010 [ Maki et al ., ; Bell et al ., ] and rover system thermal/vacuum testing in a large environment chamber at JPL in March 2011 [ Novak et al ., ]. Final inspection and cleaning of the camera head optics by the MSSS team occurred in August 2011 at KSC.…”

“…This paper describes MSL Mastcam and MARDI (Figure ) investigation objectives, instrumentation, and MARDI calibration. Not covered here are the following: Mastcam calibration, presented by Bell et al []. Mastcam, MAHLI, and MARDI data and data products; these are archived with the National Aeronautics and Space Administration (NASA) Planetary Data System (PDS), and Malin et al [], Edgett et al [], and Bell et al [] described these products. Science results from the MARDI Entry, Descent, and Landing (EDL) and surface observations, and the science results from the use of the Mastcam throughout the surface mission. …”