Programmatic MERIS, SeaWIFS, MODIS-A, VIIRS granule search by location and date for verifying cor

[aiglipeyret]

Hello,

I am building an ocean color matchup database for satellite validation in the Mediterranean Sea (approximately 34–41°N, 17–27°E). I have a large set of in-situ chlorophyll measurements with dates and coordinates spanning from the late 1990s to present, and I need to programmatically find and download the correct L1A granules from SEAWIFS, MODIS-Aqua, VIIRS SNPP and L2 granules for MERIS that cover each measurement point for ocean colour.
However, for many date/location combinations the API returns no results, even for dates and sensors I know were operational but i don't know for sure if the locations that i want for these dates are covered by the swath and if so, at what time. In some other cases, It downloaded the files on the correct daate but eventually the swath didn't cover my location.
My questions are:

Is file_search the correct tool for spatial+temporal granule discovery for all of these sensors? Or should I use the CMR API (cmr.earthdata.nasa.gov) for some or all of them?

What are the correct sensor parameter values for each of these in file_search? I have been trying MERIS, SeaWiFS, MODIS, VIIRSN, are these correct?

For MERIS, is the full FRS L2 archive available on NASA OceanColor, or are some granules only accessible through ESA? My files are named like this as an example : ENVISAT_MERIS_FRS.20030611T092432.L2.OC.nc

Is there a recommended unified approach for searching and downloading L1A and L2 granules across all these sensors given a CSV of dates and coordinates? I am aware of getOC but are unsure if it handles all five sensors reliably.

Is there a minimum bounding box size or any known spatial filter limitation in file_search that could cause valid granules to be missed?

Thank you in advance,
Aigli Peyret

[OB.DAAC - amscott]

All of the tools are useful, but please be aware that Level-2 data are regional and don't cover the whole globe so its possible the areas you are searching for are not covered by each mission on the same days. You can also use Worldview to see data coverage day by day.