I am attempting to work with worldview-2 imagery that I have downloaded and I am trying to radiometrically calibrate the raw imagery following the methodology outlined here. Since these are my first attempts, I wanted to make sure that I am doing it correctly.

In the first equation of page 9, one multiplies the image pixel value by the absolute radiometric calibration factor (Kband) and divides the result by the effective bandwidth (deltaK for each band). These values are contained in the .IMD file that comes with the downloaded imagery.

As an example, if a blue band pixel value is 4, and the .IMD data is

    absCalFactor = 1.783568e-02;
    effectiveBandwidth = 5.430000e-02;
    TDILevel = 10;

Then the resulting value would be (4 * 1.783568e-02) / 5.430000e-02 = 1.31

Is this the correct interpretation of the data and the correct method of calibration?


Yes. Your understanding of the formula is correct.

TOA_radiance = DN * absCalFactor / effectiveBandwidth

This is the formula that you need.
However, as you likely already know, your example value of 4 is a rather unrealistic value. Values around 200 to 400 are more normal.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.