Calibration Verification for Reflectance Map

1. Description

This article explains how to verify if the reflectance calibration for a multispectral sensor is successful for photogrammetry processing.

When to check? Once the photogrammetry results are published in Alteia.

2. Workflow

2.1 Check

Step 1 - Open the survey and display the reflectance map in the “BASE LAYERS” section.

Step 2 - Click on the layer, and the right panel appears.

Step 3 - Select the blue band, set the "Absolute" mode, and look at the range.


The data set is not calibrated if the range goes to minimal values, for example, from 0 to 0.0009.


If the range is higher, for example from 0 up to 025 or 0.09, the data set is calibrated.

Step 4 - Check all the bands in the same way.


2.2 If the dataset is not calibrated

  • Check that there are no missing calibration target images in the dataset and that they are correctly captured with the drone.
  • Relaunch the photogrammetry with manual calibration, see Photogrammetry Process Launching‍.
  • If the problem persists, Contact Support.‍