This guide is intended to outline a standard image processing workflow for use with Pix4Dmapper. Pix4D is compatible with the RedEdge-P and RedEdge-MX Dual Camera systems.
- Start a New Project.
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Importing the Data
Imagery taken with MicaSense sensors will be automatically recognized since the camera is in the Pix4Dmapper camera database.
Add your images from the RedEdge-P (Red) and RedEdge-P Blue directories from your Dual Camera flight so that all 11 bands are included. Select Next.
- Verify that all desired bands are present and correct. Select Next.
- Select the appropriate Output Coordinate System. Auto Detected should work fine for most cases. Select Next.
- You will now be prompted to select a Processing Template. Always select Ag Multispectral when using a Dual Camera system. Ensure that Start Processing Now is disabled and select Finish.
- If you go into Processing Options > Index Calculator you will now see options to calibrate each band.
Under Radiometric Processing and Calibration, you can choose the following options, some of which may not be available for MicaSense Sensor data.
- No correction: no radiometric correction will be done
- Camera only: corrections will be applied for the parameters that are written in the EXIF metadata and relate to the camera (vignetting, dark current, ISO, etc...). This will still use the calibration panel images.
- Camera and Sun Irradiance: corrections will be applied for the camera parameters from the point above as well as for the sun irradiance information written in the XMP.Camera.Irradiance EXIF tag. Use this option to include data from your DLS.
- Camera, Sun Irradiance and Sun angle: corrections will be applied to take into account the sun position, as well as the camera information and the irradiance data. This option should only be chosen for flights that were done in variable sky conditions.
See this article for more details: Using Panels and/or DLS in Post-Processing
Important: Since the thermal imager in Altum is already radiometrically calibrated, you should choose the correction type "No Correction" for the LWIR band.
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Using the Calibration Panel
The Calibrate button allows users to take into account the information from a picture with radiometric calibration target if such a target was used during the project.
Obtaining your panel's reflectance values
If you have a MicaSense Reflectance Panel, you can get the reflectance values for your panel by contacting MicaSense Support.
This procedure will need to be done for each of the five bands, with the corresponding "albedo" value provided for each band. Please note the band order (Blue, Green, Red, NIR, Red Edge) and ensure you are entering the appropriate value for each band.
After clicking Calibrate for a camera model, the Radiometric Calibration pop-up appears.
If a radiometric calibration target is used, make sure that the radiometric target data is taken into account by ensuring the symbol in the Processing Options is a green check mark.
In File Name, the Browse button, opens the Select a radiometric calibration image pop-up. This pop-up allows the user to select the image in which the radiometric calibration target appears.
When an image is browsed, the user can draw a region on the image that will define the radiometric calibration. The Reset button, resets the area drawn by the user.
Use the left mouse button to draw the first three points, then draw the final point with the right mouse button.
Important: The albedo values range between 0.0 and 1.0. - From here, you can contrinue processing as usual. Please contact MicaSense Support if you need any assistance.