Hi Mansi,
It seems you have the daily(assuming) chlorophyll-a data from the MODIS sensor on NASA's Aqua satellite ready with you in a csv file which consists of dates,coordinates and their respective chlorphyll-a data. Further you wish to query the chlorophyll data in MATLAB for any given coordinate on any given date.
Since you mentioned, you have already put a condition on the dates, Next you can retrieve the chlorophyll data corresponding to the query [latitude,longitude] by calculating the euclidean distance between the dataset [latitude, longitude] and your query coordinates, then selecting the data point with the smallest distance and finding the chlorophyll data from it.This will provide you with the closest available match within your dataset for the given [latitude, longitude] pair.
If this doesn't fit in your use-case, you may also explore resampling the data using interpolation techniques.
Hope this answers your query.
Regards,
Vinayak Luha
