This page has been created as part of a project to put planetary control networks on the web. This control network for asteroid 951 Gaspra originated from Merton Davies and Tim Colvin at the RAND Corporation and was provided to the USGS in 1995. The control network solution was originally performed with software developed at RAND, and documented by Colvin (1992). Each control network is essentially a set of photogrammetric solution (input and output) files. The input files consist of, aside from a priori information, measurements of common points (control points, sometimes called tie points) on images of a planetary body. The output files include the body coordinates of the control points in latitude, longitude, and radius, and revised orientation information (camera pointing) for the images. The primary use of such information is for the creation of image mosaics of the planetary body. However, these solutions can also provide fundamental data on the size and shape of the body, its rotation period, and the direction of its polar axis in space. The control point coordinates also usually serve as a coordinate reference frame that defines the fundamental coordinate reference system for the body in question. This network consists of 130 control points and incorporates 14 images from the Galileo SSI instrument (Davies et al., 1994). This release is comprised of data from original RAND control network solutions raw Galileo SSI images and file-format description files.
- USGS Astrogeology Science Center
- Added to Astropedia
- 13 April 2018
- 2 May 2018
Created as part of a project to put planetary geodesy control networks on the web. The 951 Gaspra Galileo control network data here was originally provided by Merton Davies and Tim Colvin of the RAND Corporation. Funds were provided for a conversion and archiving effort by the NASA Planetary Geology and Geophysics Program and the NASA Cartography Program.
- Geospatial Data Presentation Form
- Control Network
Contact and Distribution
- Access Instructions
Contained in the ZIP file are the necessary data to open the RAND solution of the Gaspra control network in its original RAND solution format.
The ZIP file contains all necessary data to re-create the control network including the raw Galileo images.
Gaspra_control_images.zip – All Galileo Gaspra control-network images in PDS3-format (.img files with detached .lbl labels).
Control Network in RAND format:
zche.dat – RAND solution residual output file.
zinp.dat – RAND solution “poles, points, and positions” a priori input file.
zmea.dat – RAND solution image measurements (mm) input file.
zout.dat – RAND solution “poles, points, and positions” output file.
zpar.dat – RAND solution program operation control input file.
Documentation and Information:
Gaspra_image_list.txt – Text file listing all Galileo images in the Gaspra control network. These images are
archived at pds.nasa.gov in PDS format (.img + .lbl).
ISIS-PG-FMT501_zpar_dat – Description of format of file zpar.dat (in PDF format).
ISIS-PG-FMT502_zout_dat – Description of format of file zout.dat (in PDF format).
ISIS-PG-FMT502_zinp_dat – Description of format of file zinp.dat (in PDF format).
ISIS-PG-FMT503_zmea_dat – Description of format of file zmea.dat (in PDF format).
ISIS-PG-FMT511_zche_dat – Description of format of file zche.dat (in PDF format).