The OrthoImage plugin was created to allow users to quickly create orthogonal (non-perspective), spectral image cubes of a scene. These images can be used to analyze the spatial and spectral content of the scene or to make simple example images of the scene.


Rather than construct a carefully crafted platform file with a long focal length (to avoid persepctive effects), an appropriate platform motion, an appropriate task set and a simplified atmospheric configuration, the plugin dramatically simplifies the simulation configuration. The user needs to setup a streamlined configuration and use it with the desired scene file.

The input configuration file is a JSON formatted file. An example is shown below:

    "bandpass" : {
        "units"   : "microns",
        "minimum" : 0.500,
        "maximum" : 0.800,
        "delta"   : 0.010
    "gsd" : 0.05,
    "filename" : "tile1_ortho.img",
    "center" : {
        "x" : 655.0,
        "y" : 587.5
    "size" : {
        "x" : 1024,
        "y" : 1024

(required) The spectral bandpass for the output image to be created. At this time only microns units are supported.


(required) The ground sampling distance (GSD) for the output image to be created. The units are meters.


(required) The name of the output ENVI image file. Note that this plugin does honor the --output_folder and --output_prefix command line options.


(optional) The XY location (in the Scene ENU coordinates) for the center of the image.


(optional) The size of the output image file. The default is 1024 x 1024.


To use the OrthoImage plugin in DIRSIG5, the user must use the newer JSON formatted simulation input file (referred to a JSIM file with a .jsim file extension). At this time, these files are hand-crafted (no graphical editor is available). An example is shown below:

    "scene_list" : [
        { "inputs" : "./demo.scene" }
    "plugin_list" : [
            "name" : "BasicAtmosphere",
            "inputs" : {
                "atmosphere_filename" : "uniform.atm"
            "name" : "OrthoImage",
            "inputs" : {
                "input_filename" : "./input.json"