How to process Thermal Datasets in Pix4Dmapper

With all thermal dataset, we recommend a high overlap (90%) because of the sensor's low resolution.

Nadir dataset with accurate image geolocation
Oblique dataset with accurate image geolocation or nadir dataset without image geolocation
Dataset with both thermal and RGB imagery

 

Nadir dataset with accurate image geolocation

  1. Create a new project: 202557369.
  2. Import the images: 202557319.
  3. In the Image Properties window, in the Selected Camera Model section click Edit… In the Camera Model Parameters section, make sure that the Pixel Size is correct (17μm for supported cameras: 210140783), and that the Focal Length corresponds to the camera model (9mm, 13mm,...): 202560169 and click Next.
  4. (optional) In the Select Output Coordinate System window, select output/GCP coordinate system: 202560029 and click Next.
  5. In the Processing Options Template window, select the template Thermal Camera and click Finish.
  6. In the Processing bar, click Start to start the processing. After step 1. Initial Processing, step 2. Point Cloud and Mesh and step 3. DSM, Orthomosaic and Index are processed, a Thermal Index Map is generated.
  7. Click View > Index Calculator, to open the Index Calculator.
  8. In the Index Map section of the sidebar, select the band containing the thermal data.
 
Information: For Thermomap projects, the Temperature index should be used to obtain absolute temperatures. For Flir Vue Pro R and Zenmuse XT R projects, one can use the index 0.04*thermal_ir - 273.15 to obtain absolute temperatures.
  1. In the Color Map and Prescription section of the sidebar, increase the number of classes to 32 and choose Equal Spacing from the drop down list: 204631495.
  2. (optional) If the 3D Textured Mesh output is desired, in the Menu bar click Process > Generate 3D Textured Mesh202557899.
  3. (optional) Click View > rayCloud, to open the rayCloud and load the 3D Textured Mesh by ticking the Triangle Mesh box in the Layers section of the left sidebar: 202558079.
  4. (optional) In the Triangle Meshes Layer of the left sidebar, select Display Properties and change the Shader to Thermal.

 

Oblique dataset with accurate image geolocation or nadir dataset without image geolocation

  1. Follow step 1-4 above.
  2. In the Processing Options Template window, select the template 3D Models and click Finish.
  3. In the Processing bar, click Start to start the processing.
  4. (optional) Click View > rayCloud, to open the rayCloud and load the 3D Textured Mesh by ticking the Triangle Mesh box in the Layers section of the left sidebar: 202558079.
  5. (optional) In the Triangle Meshes Layer of the left sidebar, select Display Properties and change the Shader to Thermal.

 

Dataset with both thermal and RGB imagery

  1. Process step 1. Initial Processing for the thermal dataset following the instructions of nadir or oblique above.
  2. Process step 1. Initial Processing for the RGB dataset in another project. 
  3. Identify at least 3 points of interest that are visible and recognizable both in the RGB and thermal dataset. Create at least 3 MTP with identical names in both datasets. Reoptimize both datasets: 202560349.
  4. Merge the RGB and the thermal projects: 202558529.
  5. Click Process > Processing Options. In 2. Point Cloud and Mesh, under the tab Advanced, make sure that Thermal IR is unchecked and group1 is checked for the Point Cloud and for Mesh Geometry. Ensure that Thermal IR is checked and group1 is unchecked for Mesh Texture204644369.
 
Information: The Point Cloud will be generated from the RGB images, the Mesh Geometry will be created from this RGB point cloud, the texturing will be done using the thermal imagery.
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