How to convert the raw data into pixel-scale irradiance?

[zhuqingqi]

Hi I don't know whether I could obtain the pixel-scale irradiance of ground surfaces. I have tried "batch processing example", however, the results seem to be radiance instead of irradiance. Is it possible for me to multiply the pixel-scale raidance by math.pi for getting the irradiance of each pixel?

*Please notice that I focus on obtaining the irradiance of each pixel based on raw data of Rededge-MX. More details are explained in the Part 2.6 of this paper. DOI: 10.3390/s21144847

Moreover, the pixel of stacks generated from the "batch processing example" seems to be gray values (picture attached) instead of radiance. How do I convert these gray values into radiance?

Thanks for your reading

[fdarvas]

The Image.undistorted_radiance() method does return a floating point numpy array of the undistorted radiance. This can be multiplied by pi to get an estimate of the irradiance.

[zhuqingqi]

@fdarvas Thanks. However, the pixel of results generated from the "batch processing example" seems to be DN values or RGB (picture attached) instead of radiance. How do I convert these DN values/RGB into radiance? Thanks

Hope to hear from you. Thanks

[poynting]

To do this you'll need to know the reflectance of the surface, and assume it's lambertian. We did that here in one of the tutorials to estimate the irradiance of the panel knowing it's radiance and reflectance (albedo).