Europa Control Network
This page has been created as part of a project to put planetary control networks on the web. This control network for Jupiter’s moon, Europa, 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). It has been converted into files that could be used with (successively) the RAND/USGS Planetary Geodesy (RUPG) Software, the USGS ISIS2 software (using the application, described by Edmundson et al. 2012),and the USGS ISIS3 software (using the jigsaw application). 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. Formatting of this control network data for Saturn’s moon, Europa, has been updated for compatibility with the USGS ISIS3 cartography software. This network consists of 1924 control points and incorporates 120 images from the Voyager I and II missions. The RAND control network available here is the 1995 version of work first described in (Davies et al., 1979); the USGS versions used this RAND network as a starting point. This release is comprised of data from original RAND control network solutions, the USGS ISIS2 qmatch-formatted control network, the new USGS ISIS3 control network (converted from ISIS2 using the program mat2cnet), Voyager I and II images (processed to both ISIS2 and ISIS3 formats), ISIS scripts to process PDS (.imq) images into both ISIS2 and ISIS3 formats, and file-format description files.
- USGS Astrogeology Science Center
- Added to Astropedia
- 21 July 2016
- 9 August 2019
Created as part of a project to put planetary geodesy control networks on the web. The Europa Voyager 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 Europa control network in the USGS ISIS3 (.net) format. The ZIP file also contains previous versions of this control network in the ISIS2 qmatch format (.mat) and in its original RAND solution format.
Because ISIS3 requires the input of all component images when opening a control network, ISIS3-formated images are also included in the ZIP file. Additionally, the ZIP file contains all necessary ISIS2 data to re-create the control network in ISIS3 format using mat2cnet. The procedure to generate the ISIS3 control network is outlined in ‘ISIS-PG-FMT101_ISIS3_net’. Scripts are provided to re-generate these images from PDS (.imq) format into either ISIS2 (.cub) or ISIS3 (.cub) formats, if necessary.
ISIS3 Control Network:
Europa_control_RAND.net – RAND solution measurements in ISIS3 format. Converted to ISIS3 by the routine mat2cnet.
Europa_control_images.zip – All Voyager I & II images in the Europa control network, formatted as ISIS3 (.cub) files. These are required to open the control network in ISIS3. ISIS2 (.cub) files are also included.
Control Network in previous formats:
Voyager data only (RAND):
zche.dat – RAND solution residual output file.
euxy0.dat – RAND solution image measurements (mm and pixels) input file.
euxy0.mat – RAND solution image measurements (mm and pixels) in ISIS2 qmatch match point format.
euxy0_adj.mat – Same as euxy0.mat, slightly reformatted to be read by the ISIS3 routine mat2cnet. In this version the line and sample columns have been transposed, and no data are altered.
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.
zout_adj.dat – RAND solution “poles, points, and positions” output file adjusted to be read by the ISIS3 routine mat2cnet. In this version, the exponential notation is expressed with E+/E- rather than D+/D-. Unused ‘junk’ spaces and hidden characters have also been removed; no data were altered.
zpar.dat – RAND solution program operation control input file.
Voyager and Galileo data combined (USGS):
wche.dat – residual output file.
winp.dat – “poles, points, and positions” a priori input file.
wmea.dat – image measurements (mm) input file.
wout.dat – “poles, points, and positions” output file.
wout_adj.dat – “poles, points, and positions” output file adjusted to be read by the ISIS3 routine mat2cnet. In this version, the exponential notation is expressed with E+/E- rather than D+/D-. Unused ‘junk’ spaces and hidden characters have also been removed; no data were altered.
Documentation and Information:
Europa_image_list.txt – Text file listing all Voyager I & II images in the Europa control network. These images are archived at pds.nasa.gov in PDS (.imq) format. Scripts to process these into ISIS2 (.cub) or ISIS3 (.cub) formats are included here.
euxy0_ISIS2_lev0_script – ISIS2 image processing script that converts PDS-formatted (.imq) images to the ISIS2 (.cub) format. Use of the ISIS3 routine mat2cnet to convert ISIS2 control networks (.mat) into the ISIS3 format (.net) requires input from all component images in both ISIS2 and ISIS3 formats.
euxy0_ISIS3_lev0_script – ISIS3 image processing script that converts PDS-formatted (.imq) images to the ISIS3 (.cub) format. Use of the ISIS3 routine mat2cnet to convert ISIS2 control networks (.mat) into the ISIS3 format (.net) requires input from all component images in both ISIS2 and ISIS3 formats.
ISIS-PG-FMT101_ISIS3_net – Description of format of file Europa_control_RAND.net (in PDF format).
ISIS-PG-FMT101_XXxy0_dat – Description of format of file euxy0.dat (in PDF format).
ISIS-PG-FMT101_XXxy0_mat – Description of format of file euxy0.mat (in PDF format).
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-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).
- Source Originator
- Source Title
- Control Networks of the Galilean Satellites: November 1979
- Source Online Linkage
- Type of Source Media
- Feature Name
- Quad Name
- Horizontal Coordinate System Units