MAKE A MEME
View Large Image
| View Original: | Callisto_USGS_map.jpg (8452x7364) | |||
| Download: | Original | Medium | Small | Thumb |
| Courtesy of: | commons.wikimedia.org | More Like This | ||
| Keywords: Callisto USGS map.jpg LargeImage en Prepared on behalf of the Planetary Geology and Geophysics Program Solar System Exploration Division Office of Space Science National Aeronautics and Space Administration This sheet is one in a series of maps of the Galilean satellites of Jupiter at a nominal scale of 1 15 000 000 This series is based on data from the Galileo Orbiter Solid-State Imaging SSI camera and the cameras of the Voyager 1 and 2 spacecraft Mercator and Polar Stereographic projections used for this map of Callisto are based on a sphere having a radius of 2 409 3 km The scale is 1 8 388 000 at ±56° latitude for both projections Longitude increases to the west in accordance with the International Astronomical Union 1971 Seidelmann and others 2002 The geometric control network was computed at the RAND Corporation using RAND's most recent solution as of April 1999 Davies and Katayama 1981; Davies and others 1998 This process involved selecting control points on the individual images making pixel measurements of their locations using reseau locations to correct for geometric distortions and converting the measurements to millimeters in the focal plane These data are combined with the camera focal lengths and navigation solutions as input to photogrammetric triangulation software that solves for the best-fit sphere the coordinates of the control points the three orientation angles of the camera at each exposure right ascension declination and twist and an angle W0 which defines the orientation of Callisto in space W0-in this solution 259 51°-is the angle along the equator to the east between the 0° meridian and the equator's intersection with the celestial equator at the standard epoch J2000 0 This solution places the crater Saga at its defined longitude of 326° west Seidelmann and others 2002 This global map base uses the best image quality and moderate resolution coverage supplied by Galileo SSI and Voyager 1 and 2 Batson 1987; Becker and others 1998; Becker and others 1999; Becker and others 2001 The digital map was produced using Integrated Software for Imagers and Spectrometers ISIS Eliason 1997; Gaddis and others 1997; Torson and Becker 1997 The individual images were radiometrically calibrated and photometrically normalized using a Lunar-Lambert function with empirically derived values McEwen 1991; Kirk and others 2000 A linear correction based on the statistics of all overlapping areas was then applied to minimize image brightness variations The image data were selected on the basis of overall image quality reasonable original input resolution from 20 km/pixel for gap fill to as much as 150 m/pixel and availability of moderate emission/incidence angles for topography Although consistency was achieved where possible different filters were included for global image coverage as necessary clear for Voyager 1 and 2; clear and green 559 nm for Galileo SSI Individual images were projected to a Sinusoidal Equal-Area projection at an image resolution of 1 0 kilometer/pixel The final constructed Sinusoidal projection mosaic was then reprojected to the Mercator and Polar Stereographic projections included on this sheet The final mosaic was enhanced using commercial software Names on this sheet are approved by the International Astronomical Union Names have been applied for features clearly visible at the scale of this map; for a complete list of nomenclature for Callisto please see the Gazeteer of Planetary Nomenclature Font color was chosen only for readability http //geopubs wr usgs gov/i-map/i2770/ USGS 2002-05-01 File Callisto equatorial jpg File Callisto north pole jpg File Callisto south pole jpg Maps of Callisto PD-USGov | ||||
