I am trying to radio-metrically normalize (RRN) DMSP-OLS and VIIRS-DnB acquired data for understanding urban dynamics from 2000 to 2017.  A related paper by Shao et al. (2014) mentioned the MT 2009 model for RRN b/w VIIRS-DnB and DMSP-OLS. It was used in the study to find the consistency between VIIRS-DnB acquired radiance and the radiance derived from the MT model with varying lunar phases.

Thus, I want to know how to implement MT 2009 model and also the working principles of MT2009 model.

References:

Shao, X., Cao, C., Zhang, B., Qiu, S., Elvidge, C., & Von Hendy, M. (2014). Radiometric calibration of DMSP-OLS sensor using VIIRS day/night band. SPIE Asia Pacific Remote Sensing, 9264, 92640A.