Keywords: muses, thermal

Summary

This demo shows how setup DIRSIG to run the MuSES temperature prediction and infrared signature model developed by ThermoAnalytics, Inc. on-the-fly. The MuSES plugin for DIRSIG will make sure to sync the conditions between DIRSIG and MuSES (e.g., geographic location, date, time, weather, orientation), run MuSES and then read the temperature results and MuSES material properties in. The plugin supports having multiple MuSES targets and/or multiple instances of the same target(s) in a single DIRSIG simulation.

Important
 MuSES and the MuSES plugin described in this demo are only supported in Windows and Linux.

Related Materials

The following demos, manuals and tutorials can provide additional information about the topics at the focus of this demo:

  • Related Demos

    • The Muses1 demo is an example of a "level-0 integration" (which is to say, a simple import of a pre-run MuSES solution).

  • Related Manuals

  • Related Tutorials

    • None.

Details

Unlike the Muses1 demo that uses the simple GLIST data import mechanism, this example demonstrates how the MuSES plugin can be used to achieve a level-1 integration between DIRSIG and MuSES, where key modeling variables are automatically synchronized between the two models.

Important Files

This section highlights key files important to the simulation.

The Plugin Configuration

The key component of this simulation is the configuration of the MuSES plugin(s) in the demo.jsim file. The plugin has a series of variables that are described in the plugin manual.

Important
 For this demo to run as is the environment variable MUSES_EXE must be set to the path of the MuSES executable. Otherwise you can update the JSIM configuration to include the muses_exe_path variable (in each plugin instance) that is set to the path of the MuSES executable.

The MuSES plugin is requested with the plugin name Muses. The demo.jsim file for this demo has three instances of the plugin configured:

  1. An instance of the "truck" object with a heading of 135 degrees East of North.

  2. A second instance of the "truck" object with a heading of 225 degrees East of North.

  3. An instance of a second MuSES object (the North/South/East/West object).

The first instance of the truck TDF file is shown below. Note that the time resolution for the MuSES simulation is 300 seconds, or 5 minutes.

The first truck target plugin configuration.
    { 
      "name": "Muses",
      "inputs": {
        "tdf_filename": "geometry/truck_cold_to_idle_2020R1.tdf",
        "prefix": "geometry/truck_inst1_",
        "heading": 135,
        "location": [5,-7,0],
        "tdf_time_resolution": 300
      }
    },
    {

The second instance of the truck TDF file is shown below, which is identical to the first with the exception of the location and heading. This demonstrates how the same truck TDF can be placed at a separate location and orientation in the scene. The other difference with this plugin instance is that the MuSES time resolution was set to 1800 seconds, or 30 minutes.

The second truck target plugin configuration.
      "name": "Muses",
      "inputs": {
        "tdf_filename": "geometry/truck_cold_to_idle_2020R1.tdf",
        "prefix": "geometry/truck_inst2_",
        "heading": 225,
        "location": [-5,-7,0],
        "tdf_time_resolution": 1800
      }
    },
    {
      "name": "Muses",
Note
 If we change the setup for this simulation to collect images for period of time, we would see the MuSES predicted temperatures for the first truck change every 5 minutes but the temperatures for this second truck only change every 30 minutes.

The third MuSES plugin instance in the JSIM file configures a different MuSES target, which is composed of four 3-D letters that define the cardinal compass directions (North, South, East and West). This objects is captured in the geometry/NSEW.tdf file. The target is placed with a 0 degree heading and can be used to confirm the orientation of other object in the scene.

The NSEW target plugin configuration.
      "inputs": {
        "tdf_filename": "geometry/NSEW.tdf",
        "prefix": "geometry/NSEW_inst1_",
        "heading": 0,
        "location": [0,2,0],
        "tdf_time_resolution": 1800
      }
    }
  ]
}]

Simulations and Results

To run the simulation,

$ dirsig5 demo.jsim

Load the resulting demo.img radiance file and demo_truth.img truth image file into the DIRSIG image viewer and display the LWIR band using one of the high dynamic range scaling options (e.g., "two percent" scaling):

lwir 2 percent
Figure 1. The LWIR radiance image (2% scaling).

Due to the simple materials in the scene and the MuSES TDF files, the temperature truth image is visually very similar:

tempK 2 percent
Figure 2. The temperature truth image (2% scaling).

Due to the prefix used in the plugin instances, if you look in the geometry folder, you will find the temporary MuSES TDF files are located there. If you open the respective instance TDF files in the MuSES interface, you will visually see the differences in solar loading due to different orientations (headings) used inside DIRSIG. You will also see that the available result times reflect the respective 300 and 1800 time resolutions for each instance.

tdfs loaded back into muses
Figure 3. Comparing the two truck TDF files in MuSES reveals the different times computed for each.