Characteristics

Mechanical/Environmental

The SSI camera head and mechanical design are derived from the Imager for Mars Pathfinder (IMP) and the Mars Polar Lander SSI.

• Single camera head with 2 CCD detectors
• 15.1 cm stereo separation, 23.94 mrad toe-in per eye
• 3.042 m stereo crossing distance
• Mast mounted, elevation axis 793.5 mm above deck (deployed)
• Optic axis 12 mm above elevation axis
• 2-phase stepper motors for azimuth and elevation axes
• 355.4 degrees azimuth range of travel
• 184 degrees elevation range of travel (stowed to 89.6° above horizon)
• 0.288 degrees/step in azimuth and elevation
• Mass: Camera head and mast, 4.46 kg; electronics 0.91 kg
• Power dissipation: 4.2 W on/idle, 11.8 W imaging, 51.2 W peak
• Minimum operating temperature (electronics) -55 degrees C
• Uses JPEG and Rice compression

Optics

SSI optics are derived from the Imager for Mars Pathfinder (IMP) and the Mars Polar Lander SSI.

• Cooke triplet design
• Focal length = 49.98 mm, f/# = 20.2
• Optimal focus at 3.5 m, in focus from 2.0 m to infinity
• Diopter (filters R6 and R7) best focus at 1.2 m, in focus from 1 to 1.4 m
• IFOV = 0.236 mrad/pixel, FOV = 13.8 x 13.8 degrees
  • Left eye, 0.2376 mrad/pixel, 13.88 deg
  • Right eye, 0.2353 mrad/pixel, 13.74 deg
• Dual filter wheel with 12 positions per eye

(NAIF instrument kernels are available).

CCD

The SSI detects light with a Mars Exploration Rover spare Charge-Coupled Device.

• 1024 x 2048 Mitel (DALSA) frame transfer CCD
• 12 µm square pixels, 100% fill factor
• Full well capacity = 165 ke- (left), 188 ke- (right)
• System gain = 48.3 e-/DN (left), 50.3 e-/DN (right)
• System read noise = 18.7 e- (left), 24.1 e- (right)
• SNR > 200 at 50% full well
• Frame transfer time 5.12 ms
• Frame readout time 5.2 s
• Integration time 0-335 s in steps of 5.12 ms

Reflectance calibration target

SSI calibration targets use materials derived from Mars Pathfinder and Mars Exploration Rover designs, but in a configuration with magnets protecting some of the material.

• 3 targets on deck to allow shadowed and non-shadowed imaging
• Each is 52 mm diameter, 8 mm high, 45 g each
• 3 RTV disks per target with 20, 40, 60% reflectivity, protected by sweep magnets
• 3 RTV disks per target with 20, 40, 60% reflectivity, not protected by sweep magnets
• 3 pigmented RTV disks per target, protected by sweep magnets
• 3 pigmented RTV disks per target, not protected by sweep magnets
• 4 anti-static coated RTV disks per target