seedgrid

This program creates a control network for a latitude/longitude range on a specified target planet. The control network that is created is a grid of evenly-spaced control points. The control network generated will have no control measures, but will instead have a known latitude and longitude for each control point. The resulting control network can then have images added to it by using the cnetadd application.

Description

This is the planet on which the Lat/Lon range resides. The target can be specified in one of two ways: by typing the name of a planet for this parameter, or by including the TargetName in the MAP file. If the user specifies both, then the TARGET parameter will be used instead of the TargetName in the MAP file. If neither is specified, the program will throw an error.

Type	string
Internal Default	From MAP file

Description

A file containing the mapping parameters in PVL form. This file can be a simple PVL file or an existing cube label that contains a Mapping group. By default, the program will use a standard map template for a Sinusoidal projection. If the keyword TargetName is not in this mapping file, then the user must specify a value for the TARGET parameter. You can produce map files using the maptemplate program.

Type	filename
File Mode	input
Default Path	$ISISROOT/appdata/templates/maps
Default	$ISISROOT/appdata/templates/maps/sinusoidal.map
Filter	*.map *.cub

Description

This is the minimum latitude for the Lat/Lon range. Control points are added to the control network starting from this latitude.

Type	double

Description

This is the maximum latitude for the Lat/Lon range.

Type	double

Description

This is the minimum longitude for the Lat/Lon range. Control points are added to the control network starting from this longitude.

Type	double

Description

This is the maximum longitude for the Lat/Lon range.

Type	double

Description

This option allows the user to specify the type of spacing the program will use when generating the control points. Selecting METER spacing will use a projection to attempt to place control points every XSTEP meters within the longitude range, and every YSTEP meters within the latitude range. Conversely, LATLON spacing will simply place control points every LATSTEP and LONSTEP within the range.

Type	string
Default	METER
Option List:	Option Brief Description METER Space control points in the range by meter increments. This option will space control points in the range by a specified XSTEP and YSTEP given in meters on the planet's surface. If this option is selected, the user must also specify a MAP file, but not necessarily a value for TARGET if the projection contains the TargetName keyword. Exclusions LATSTEP LONSTEP Inclusions MAP XSTEP YSTEP LATLON Space control points in the range by latitude and longitude increments. This option will space control points in the range by a specified LATSTEP and LONSTEP, given in terms of the planet's degrees latitude and longitude, respectively. If this option is selected, the user must specify a TARGET name, but not a MAP file. The lat/lon coordinates are in universal format: the longitude domain is 0-360, the longitude direction is positive east, and the latitude coordinate system is planetocentric. Exclusions MAP XSTEP YSTEP Inclusions TARGET LATSTEP LONSTEP

Description

Points will be placed on the grid in the longitude range in the step described here in meters.

Type	double

Description

Points will be placed on the grid in the latitude range in the step described here in meters.

Type	double

Description

Points will be placed on the grid in the latitude range in the step described here in degrees latitude.

Type	double

Description

Points will be placed on the grid in the longitude range in the step described here in degrees longitude.

Type	double

Description

The ID or name of the control network that is created. This string should be unique.

Type	string
Internal Default	No Id

Description

A string with one and only one set of question marks ("?"). This string will be used to create unique IDs for each control point created by this program. The question marks will be replaced with a number beginning with zero. For example the pattern "User????" would create point IDs "User0001" through "User9999". Note: Make sure there are enough "?"s for all the control points that may be created during this run. If all question marks are exausted the program will throw an error.

Type	string

Description

A string describing the purpose of this control network. For example, a description might be "LROC NAC MareSmythii GRID NETWORK". This description indicates that the control network is for the LROC mission using the narrow angle camera instrument, and the feature of interest is Mare Smythii. The description string can be literally anything, but it is helpful to make it something that is descriptive of the control network.

Type	string
Internal Default	No Description

Description

This file will contain the control network that is created.

Type	filename
File Mode	output

This example illustrates how to generate a control network for the target planet Mars. The resulting control net is named 'out.net', and has control points seeded from -90 to +90 latitude, 0 to 360 longitude with a spacing of 20 degrees between each point.

seedgrid TARGET=mars LATSTEP=20 LONSTEP=20 MINLAT=-90 MAXLAT=90 MINLON=0 MAXLON=360 ONET=out.net SPACING=latlon POINTID='id????'

The resulting control network	This is the control network that is created by seedgrid.

Resulting distribution of points in the network

Point Distribution Visualization This image is a visualization of the point distribution within the control network. This is projected using a sinusoidal projection. Please note that this image is not an output of the seedgrid application. It is included as a visual aid only.