Optical calibration - SPOT 1-5 - TOA reflectance to TOC reflectance

Hi
I’m new on this forum. I don’t speak very well english but i’ll try.
I’m studying geography in Nantes and currently i’m in internship in a regional natural park in the Pyrenees.

I have some Spot images from the Infrastructure of Spatial Data Theia (World Spot Heritage) which are distributed only in TOA reflectance. I would like to convert this image into TOC reflectance using “Optical calibration” from the OTB.

In this tool there is the choice between three options :

  • Image to TOA
  • TOA to image
  • Image to TOC

And I want to modify my image from TOA reflectance to TOC reflectance.

Which option should I use ?

(I have already read the cookbook and the user manuel)

Thank you
Thibaud
OTB 6.6.1 / QGIS 3.4 / Win 10

Have you tried TOA to image, then image to TOC?

Thank for the answer!
I didn’t try but i’m not sure to have all the metadata to do this.
For example I don’t have “solar illumination”…