FUNCTION unwrap_phase_2d, data
;; first correct a reference column
result = data
refcol = transpose(result[0,*])
result[0,*]=unwrap_phase(refcol)
;; now correct all rows
FOR count = 0,(size(result))[2]-1 DO BEGIN
    refrow = result[*,count]
    result[*,count]=unwrap_phase(refrow)
ENDFOR
;; then correct all columns again to be sure
FOR count = 0,(size(result))[1]-1 DO BEGIN
    refrow = transpose(result[count,*])
    result[count,*]=unwrap_phase(refrow)
ENDFOR
return, result

END