I want to mask ImageCollection ("MODIS/061/MCD15A3H") let's call it modis using forest class from another ImageCollection ("MODIS/006/MCD12Q1") let's call this LULC. modis has images every 4 days while LULC has one image per year. I want to mask modis images by LULC that corresponds to the same year i.e. modis image 2003-01-01 to be masked by LULC 2003-01-01; modis image 2004-01-01 by LULC 2004-01-01. However, I don't know how to iterate this. The range of the analysis needs to be 2003-01-01 to 2021-01-01.
This is a GEE [link] (https://code.earthengine.google.com/d142f50cb851bd9fa6adc6f428303458) that needs update.
Thank you in advance.