Software allows conversion of segy file trace header coordinates from one datum to another datum and/or from one UTM zone to another one. Over 200 datums and seven different projections supported. Datum conversion for coordinates in ascii files. module enabling writing of coordinates to trace headers in 2D and 3D segy files. It accepts as input ascii navigation files with geodetic (rectangular) coordinates, performs necessary interpolation and extrapolation and writes resulting coordinates to segy trace headers. Software also provide segy header viewer and editor. Text,binary and trace headers can be viewed and edited. Reports of selected trace header values can be generated and saved to ascii file. Concatenation and spliting of segy files, zeroing of noisy samples and traces, padding missing traces in 3D segy files. Reformating of header values. Addition of numbers and multiplication by specified factor of existing headers. Graphical display of header values. Software can provide very valuable help in segy data loading and editing.