P3D NASA Mars camera

[Michael _ Kaplan <mkaplan@xxxxxxxxxxx>]

Here are the details on the Mars Voyager stereo camera. These are 
available on the NASA website, along with a great photo of the camera
itself (not in 3D, unfortunately). Note that the base separation is 150
mm, which would exaggerate (or enhance) depth and reduce the perceived
size of objects. 

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The stereoscopic imager includes two imaging triplets, two fold mirrors
separated by 150 mm for stereo viewing, a 12-space filter wheel in each
path, and a fold prism to place the images side-by-side on the CCD focal
plane. Fused silica windows at each path entrance prevent dust intrusion.
the optical triplets are an f/10 design, stopped down to f/18 with 23-mm
effective focal lengths and a 14.4 degree field of view. The pixel
instantaneous field of view is one milliradian. The filter wheel four
pairs of atmospheric filters, two pairs of stereo filters, eleven
individual geologic filters (which, when combined with the two pairs of
stereo filters, result in thirteen distinct geologic filters) and one
diopter or close-up lens, designed to acquire images of magnetic,
wind-blown dust which adheres to a small magnet located on the IMP tip
plate. 

The focal plane consists of a CCD mounted at the foci of two optical paths
where it is bonded to a small printed wiring board, which in turn is
attached by a short flex cable to the preamplifier board. The CCD is a
front-illuminated frame transfer array with 23 micrometer square pixels. 
Its image section is divided into two square frames, one for each half of
the stereo FOV's. Each has 256x256 active elements. A 256x512 storage
section (identical to the imaging section) is located under a metal mask.
The imp focal plane and electronics are nearly identical copies of the
comparable subsystem employed in the Huygens Probe Descent Imaging
Spectroradiometer (DISR), using the Loral 512X512 CCD. 

Azimuth and elevation drives for the camera head are provided by stepper
motors with gear heads, providing a field of regard of 180 degrees in
azimuth and +83 degrees to -72 degrees in elevation, relative to lander
coordinates. The camera system is mounted at the top of a deployable mast,
a continuous longeron, open-lattice type provided by Able Manufacturing,
Inc. When deployed, the mast provides an elevation of 1.0 m above the
lander mounting surface. 

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Michael Kaplan
View*Productions
Publishers of "Bruce Goff: 3 Houses" in View-Master stereo
view@xxxxxxxx  


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