0 degree isotherm height from Coordinates of the grid points Latitude/Longitudes

I would like assistance. I have 3 text files 121x241 double from the ITU Recommendation P.839-4 (09/2013) the zip file can be downloaded at https://www.itu.int/rec/R-REC-P.839-4-201309-I/en. The files contain data on the Earth’s 0-degree isotherm as a function of latitudes and longitudes. I have imported the data files into three Excel.CVs and I can-do manual searches. I would like to enter a specific LAT/LON and find the corresponding isotherm. The problem is, not all LAT/LON angles are in the database. Example, if I want to find the isotherm for LAT 35.77N, LON 54.45E the search results in a null-set. Therefore, I need to find the nearest LAT/LON pairs corresponding to the desired location. It's probably best to find two adjacent points and determine the average isotherm. Any help I will appreciate more than I can express. Thanks, all the best, Lino

Answer 1

[Raghav Singhal]

You can try data interpolation instead of averaging out the adjacent data points as it would give you a more accurate estimate.

Please refer to the following link here from MATLAB documentation for more information