This is a sub-section of the "geometrically improved, color enhanced" version of the 360-degree panorama heretofore known as the "Gallery Pan," the first contiguous, uniform panorama taken by the Imager for Mars Pathfinder (IMP) over the course of Sols 8, 9, and 10. Different regions were imaged at different times over the three Martian days to acquire consistent lighting and shadow conditions for all areas of the panorama.
The IMP is a stereo imaging system that, in its fully deployed configuration, stands 1.8 meters above the Martian surface, and has a resolution of two millimeters at a range of two meters. In this geometrically improved version of the panorama, distortion due to a 2.5 degree tilt in the IMP camera mast has been removed, effectively flattening the horizon.
The IMP has color capability provided by 24 selectable filters -- twelve filters per "eye." Its red, green, and blue filters were used to take this image. The color was digitally balanced according to the color transmittance capability of a high-resolution TV at the Jet Propulsion Laboratory (JPL), and is dependent on that device. In this color enhanced version of the panorama, detail in surface features are brought out via changes to saturation and intensity, holding the original hue constant. A threshold was applied to avoid changes to the sky.
On the horizon the double "Twin Peaks" are visible, about 1- 2 kilometers away. The rock "Couch" is the dark, curved rock at right of Twin Peaks. A Lander petal is visible on the left, showing the fully deployed rear ramp, which rover Sojourner used to descend to the surface of Mars on July 5. Immediately to the left of the rear ramp is the rock "Barnacle Bill," which scientists found to be andesitic, possibly indicating that it is a volcanic rock (a true andesite) or a physical mixture of particles. Just beyond Barnacle Bill, rover tracks lead to Sojourner, shown using its Alpha Proton X-Ray Spectrometer (APXS) instrument to study the large rock "Yogi." Yogi, low in quartz content, appears to be more primitive than Barnacle Bill, and appears more like the common basalts found on Earth.
The tracks and circular pattern in the soil leading up to Yogi were part of Sojourner's soil mechanics experiments, in which varying amounts of pressure were applied to the wheels in order to determine physical properties of the soil. During its traverse to Yogi the rover stirred the soil and exposed material from several centimeters in depth. During one of the turns to deploy Sojourner's Alpha Proton X-Ray Spectrometer, the wheels dug particularly deeply and exposed white material. Spectra of this white material show it is virtually identical to the rock "Scooby Doo," and such white material may underlie much of the site. Deflated airbags are visible at the perimeter of the Lander petals.
Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The IMP was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.
Photojournal note: Sojourner spent 83 days of a planned seven-day mission exploring the Martian terrain, acquiring images, and taking chemical, atmospheric and other measurements. The final data transmission received from Pathfinder was at 10:23 UTC on September 27, 1997. Although mission managers tried to restore full communications during the following five months, the successful mission was terminated on March 10, 1998.
This image is a product of 3 data sets:
1 a color mosaic image of the "Gallery Panorama," 2 an image which indicates the distance to the nearest object at each pixel location, referred to as a range image, and 3 a digital image of a full-scale museum model of the MPF Lander.
The Gallery Pan image and the range image were projected onto a continuous cylindrical/perspective coordinate system spanning 360 degrees of azimuth. The range image was then treated as a displacement map with respect to a sphere's surface, and the color image mosaic was draped onto the inside of the sphere so that lines of constant azimuth radiate from the center and lines of constant elevation are concentric circles. The position of the camera is fixed at the sphere's center, while its viewing direction is in this case looking at the south pole of the sphere. This projection preserves the resolution of the original panorama.
The distortion visible near the edges of this image is due to the large field of view, as well as the limitation introduced by using cylindrically-projected images on the sphere—the effects of which are less apparent when smaller fields of view are used.
The center of the image consists of the museum model image, which has been geometrically warped to spatially register with the projected Gallery Pandata. The position of the camera was fixed above the model so that the IMPMast was roughly at Nadir.
The image has been rotated so that the main points of interest, which are the "Rock Garden," the rover Sojourner and the rock "Yogi," are visible arching across the upper hemisphere. In fixed Mars Surface coordinates, the top of the image looks out towards a point a few degrees north of West. Color has been enhanced to improve contrast in features, and is derived from IMP spectral filters 5, 9 and 0.