Converting DMSP to VIIR

[shinunagaertner]

Hello,
I am an economic researcher and am using NTLI as an indicator for urbanisation in my research. I have hosuehold data from a panel survey spanning the last 20 odd years and have combined it with both the DMSP data and VIIR data on NTLI, depending on the year. I would now like to find a way to use one NTLI measure throughout the panel waves, so as not to lose continuity "simply" because of a sensor switch.
Is there a conversion factor, that would allow me to do so?

Thanks in advance. As this is not my field of expertise, I am not sure if there isn't perhaps a painfully obvious answer.