A method for representing surface deformation measurements, including providing InSAR data, wherein the InSAR data is line of sight InSAR data; providing Global Positioning System (GPS) data; filtering the InSAR data; assembling the GPS data over a time span; resolving the GPS data into a line of sight direction; determining a correction; generating a corrected line of sight image; generating a plurality of XY motion maps, wherein generating includes: correlating a plurality of XY motions from a plurality of GPS sites with a gradient of the corrected line of site image; determining a correlation coefficient; and building a plane of XY motion using at least one of the plurality of XY motions; using the correlation coefficient to produce a linear combination of the plurality of XY motion maps; and using the linear combination to convert the InSAR data to vertical motion.