The following is my Objective Analysis code for the analysis of scalar fields. There is both a FORTRAN version and a (rather crude) C version. I have included sample drivers for both and a sample input data set. The code is available shell packaged as a shell archive, objan.sh or as a tar archive, objan.tar
There is a Makefile for building these programs, you may need to change the compiler names and the paths depending upon your setup. (For testing I'd suggest changing the various directories to . -- the current directory).
I also have code for vector fields, and for multi-variate estimation. Contact me for details.
The FORTRAN version is heavily commented, and the C version follows the flow of the FORTRAN version so using the code should not be too difficult. The theory and the algorithm are documented in:
Carter, E.F. and A.R. Robinson, 1987; Analysis Methods for the Estimation of Oceanic Fields, J. Atomos. & Oceanic Technol. V. 4, No. 1, pp. 49 - 74