DEM Export module

Description

The DEM Export module exports digital elevation models (DEM) and images to formats that can be viewed and edited in 3-D stereo editing software such as DAT-EM.

Parameters

Name	Caption
Input DEMs	Input DEM
Output Folder	Output folder
Output DEM Format	File format for output DEM
Overwrite Results	Overwrite existing results
Send Email	Email notification settings
Input Images	Input images
Export Input Images to GeoTIFF	Export input images to GeoTIFF format
Elevation Reference/Datum	Elevation model

Parameter descriptions

Input DEMs

The location of the input DEMs to export.

The value of this parameter can be a single DEM file or a folder of multiple DEM tiles.

Output Folder

The path and name of the folder to which to write the output files. This folder is created automatically during the export process.

Depending on the settings specified for this module, the output folder can also include an images subfolder of rpc text files and image files.

For example:

exported DEM files: outputFolder/*.las
image RPC files: outputFolder/images/*.rpc
exported image files: outputFolder/images/*.tif

For more information, see Module details.

Output DEM Format

The file format for the output DEM file.

Supported file formats are:

LASF: ASPRS LIDAR Data Exchange Format (.las)
GeoTIFF: TIFF file with embedded georeferencing information (.tif)

Overwrite Results

Select this check box to overwrite the existing output files, if any exist. If this check box is left clear, and an output file exists in the relevant folder, the status of the job displays a message informing you of the existence and name of the output file. The message is also written to the event log of the job.

Send Email

If necessary, you can set up CATALYST Enterprise to send an email notification on job start and job completion.

With this check box selected, an email message is sent to each address specified in the Email Addresses box after the job starts and on completion.

You can specify one or more addresses, and each must be separated by a comma or a semi-colon. The email address of the user currently logged in displays by default.

Input Images

The location of the input images from which to extract RPCs. These images are used to generate the RPC text files that describe the math model of the image.

This parameter can specify a single file or a folder of image files.

The input images must be those used to create the DEM; that is, the images used as input to the DEM Extraction module or DEM Extraction Airphoto module. Typically, the input images for this module are created by one of the following modules:

Data Ingest module or the Airphoto Ingest module
Data Ingest and GCP Collection module
Tie-Point Collection and Refinement module

This parameter is optional.

Export Input Images to GeoTIFF

Selected by default, this check box determines whether the module exports the input raw images to GeoTIFF format using the Tiled256 option.

When clear, the input images are not exported.

Elevation Reference/Datum

The vertical reference for the elevation values in the source digital elevation model (DEM), or for the constant value of the Elevation Offset and Elevation Scale parameters, when available, and specified.

Available values are as follows:

Mean Sea Level: Elevations are referenced to mean sea level (MSL). The EGM2008 geoid model is used to convert the elevations to ellipsoidal heights.
Ellipsoid: Elevations are referenced to the ellipsoid. The coordinate system of the DEM raster file is examined to determine which ellipsoid and datum to use. For example, if the DEM file is referenced to NAD83, the heights are assumed to be NAD83 ellipsoidal heights. If the DEM and math model are based on different coordinate systems, the heights are converted automatically to the math-model coordinate system before use.
Automatic: Select this option when you want the module to automatically determine the elevation reference based on your input data.

Details

General job details

Preprocessing requirements

Before running this module, the following requirements must be met to ensure the job processes successfully and produces accurate results:

Raw input images must be the following:
- output from the Data Ingest module or the Airphoto Ingest module
- output from the Data Ingest and GCP Collection module
- ouput from the Tie-Point Collection and Refinement module

Module details

The DEM Export module creates DEM and imagery files that can be viewed and edited in a 3-D editing program, such as DAT-EM. The module exports to LASF and GeoTIFF format, and generates an RPC text file for the math model associated with the images.

Job results

When the job processes successfully, the output folder will contain the exported DEMs. Depending on the settings specified for this module, the output folder may also include an images subfolder containing rpc text files and image files.

For example:

exported DEM files: exported DEMs are created in the format specified for the Output DEM Format parameter. The name of the output DEM file is the same as that of the input DEM, but with a .las or .tif extension; for example, Ottawa-dem.las.
image RPC files: a text file containing the math model of the image exported as Rational Poynomial Coefficients (RPCs). Image RPC files are written to an images subfolder. The name of the output text file is the same as that of the input image file, but with an .rpc extension; for example, Hi-RGB_02152_RAW_MS.rpc
exported image files: these images are created only if the Export Input Images to GeoTIFF check box is selected. The output format for exported images is always GeoTIFF. Exported images are written to an images subfolder. The name of the exported image is the same as that of the input image, but with a .tif extension; for example, Hi-RGB_02152_RAW_MS.tif.