ISIS 3 Application Documentation
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Create a digital elevation model from one or more control network files.
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The cnet2dem applicaton produces an interpolated digital elevation model (DEM) from one or more control networks. There are fourteen different algorithms that may be selected that provide either absolute radius values or other information, such as radius and point distance statistics, computed at each output DEM pixel value. The range and type of the DEM generated from cnet2dem is a standard ISIS map definition or a projected ISIS cube file containing a map definition. You can select any number of algorithms in the ALGORITHM parameter. The output cube will contain the same number of bands in the same order algorithms are specified in the parameter. The BandBin group Name parameter will also contain the name of the algorithm that cooresponds to the data contained in each band.
Note that the control network is expected to be the output results of the bundle adjustment computed by jigsaw. Additionally, jigsaw must have been used to solve for radius. Otherwise, you will be using the apriori radius which is typically the PCK defininition (will will result in the ellipsoid).
The adjusted latitude/longitude coordinate is used to compute the location of all the control points. The adjusted coordinates are compute by jigsaw. If it doesn't exist, the apriori coordinate will be used but know that this coordinate is typically computed from each reference image in each control point (so it may not be consistent).
Also, in some cases, one or more of the algorithm radius bands in the output of cnet2dem may be sufficient for direct use as an ISIS shape model (after demprep is run!). However, this is generally not the case and some of the radius bands may require a series of filters to smooth out the results.
Name  Description 

CNET  Master control network file to match. 
CNETLIST  List of merger control network files. 
MAP  Specifies a file containing the output map specfications. 
Name  Description 

TO  Output DEM ISIS cube 
TRIM  Null all pixels outside lat/lon boundaries. 
Name  Description 

SEARCH  Optional tolerance for radial search range (meters). 
DISTANCE  Specifies the radial search distance to search. 
KDNODES  Specify the leaf size of the kdtree. 
NEIGHBORS  Specify the number of nearest NEIGHBOR points 
MINPOINTS  Specify the minimum number of search points per pixel. 
SIGMARADIUS  Specifies noise tolerance in radius. 
ALGORITHM  Type of data to provide a each output pixel location. 
A single control network file used to create the point cloud to produce the interpolated output DEM radius at each output pixel.
Type  filename 

File Mode  input 
Internal Default  None 
Filter  *.net 
A list of control network files that are combined into the point cloud to produce the interpolated output DEM radius at each output pixel.
Type  filename 

File Mode  input 
Internal Default  None 
Filter  *.lis 
A standard ISIS map definition file or a map projected ISIS cube file containing a mapping group. This file will be used to create the output DEM ISIS cube.
Type  filename 

File Mode  input 
Filter  *.map *.cub 
Specifies the name of an output ISIS cube file that is created to write the DEM. The output DEM may require demprep to be run on it before it can be used as an ISIS DEM shape model.
Type  cube 

File Mode  output 
Pixel Type  real 
Filter  *.cub 
If this option is selected, pixels outside the latitude/longtiude range will be trimmed (set to null). This is useful for certain projections whose lines of latitude and longitude are not parallel to image lines and sample columns.
Type  boolean 

Default  FALSE 
This parameter allows the user to specify the size of the radius search at each output map pixel. If not provided, the pixel resolution of the projection is used to specify the search diameter.
Type  string  

Default  RADIAL  
Option List: 

Radial distance in meters to search for control points measured from the center of the ouput map pixel.
Type  double 

Internal Default  None 
Number of leafs in the kdtree structure.
Type  integer 

Default  10 
Specify number of control points that will be selected in the nearest NEIGHBOR search query to produce the output DEM pixel values.
Type  integer 

Default  0 
Specify number of minimum number of points to accept from the RADIAL search query of the point cloud at each output DEM pixel. If the result set for each pixel does not have at least MINPOINTS, NULL values will be written to the output DEM pixel.
Type  integer 

Default  0 
If provided, a noise filter is applied to the radius of the point set at each output pixel. The SIGMARADIUS is the number of standard deviations from the median radius from all control points.
Type  double 

Internal Default  None 
This parameter provides numerous methods to compute the output radius value for a given latitude, longitude and map grid point. Any number of methods can be specified by enetering a commadelimited lisf of the method names.
Name  Parameters  Description 

AverageRadius  None  For all control points found in the RADIAL and/or NEARESTNEIGHBOR kdtree search, computes the average radius value (the average Euclidean distance of all points from the surface to the center of the body). 
MaximumRadius  None  Computes the maximum radius (in meters) of the control points. 
MinimumRadius  None  Computes the minimum radius (in meters) of all control points. 
MedianRadius  None  Computes the median radius (in meters) of all control points. 
StandardDeviationRadius  None  Computes the standard deviation (in meters) of the radii of the control points. 
MaximumDistance  None  Computes the maximum surface distance (in meters) of all control points with respect to the latitude, longitude coordinates of the central pixel. 
MinimumDistance  None  Computes the minimum surface distance (in meters) of all control points with respect to the latitude, longitude coordinates of the central pixel. 
MedianDistance  None  Computes the median surface distance (in meters) of all control points with respect to the latitude, longitude coordinates of the central pixel. 
AverageDistance  None  Computes the average surface distance (in meters) of all control points with respect to the latitude, longitude coordinates of the central pixel. 
StandardDeviationDistance  None  Computes the standard deviation (in meters) of the surface distance of all control points with respect to the latitude, longitude coordinates of the central pixel. 
FrankeNelsonRadius  None  Computes the radius of the control points (in meters) using the FrankeNelson method. 
ShepardsRadius  None  Computes the radius of the control points (in meters) using Shepard's weighted algorithm. 
NaturalNeighborRadius  None  Computes the radius of the control points (in meters) using the Nearest Neighbor interpolation algorithm. 
TypeCount  None  Returns the total number of pixels in the point collection. It additionally applies a signed (+/1) value to indicate if the FLANN (Fast Library for Approximate Nearest Neighbors) search type was nearest neighbor (1) or radius (+1). 
Type  string 

Kris Becker  20151113  Original Version 
Tyler Wilson  20160310  Minor documentation corrections. 