I have a LAS LiDAR file with the following header information: FILE_SIG LASF RESERVED 0 VERSION_MAJOR 1 VERSION_MINOR 1 SYSTEM_IDENTIFIER GENERATING_SOFTWARE Global Mapper FLIGHT_DATE 1 YEAR 2012 HEADER_SIZE 227 OFFSET_TO_DATA 439 NUM_VAR_RECORDS 2 POINT_DATA_FORMAT 0 POINT_DATA_RECORD_LEN 20 NUM_POINT_RECORDS 239424 Points by Return [ 1] 239424 Points by Return [ 2] 0 Points by Return [ 3] 0 Points by Return [ 4] 0 Points by Return [ 5] 0 X_SCALE_FACTOR 0.010000000 Y_SCALE_FACTOR 0.010000000 Z_SCALE_FACTOR 0.010000000 X_OFFSET 271946.73 Y_OFFSET 219291.28 Z_OFFSET 0.00000000 MAX_X 272319.80 MIN_X 271946.73 MAX_Y 219521.47 MIN_Y 219291.28 MAX_Z 421.26099 MIN_Z 356.02399 ========================================== ===== Projection Information ====== ========================================== GTMODELTYPEGEOKEY 1 GTRASTERTYPEGEOKEY 0 GTCITATIONGEOKEY GEOGRAPHICTYPEGEOKEY 4277 GEOGCITATIONGEOKEY GEOGGEODETICDATUMGEOKEY 0 GEOGPRIMEMERIDIANGEOKEY 0 GEOGLINEARUNITSGEOKEY 0 GEOGLINEARUNITSIZEGEOKEY 0.00000000 GEOGANGULARUNITSGEOKEY 9102 GEOGANGULARUNITSIZEGEOKEY 0.00000000 GEOGELLIPSOIDGEOKEY 0 GEOGSEMIMAJORAXISGEOKEY 6377563.4 GEOGSEMIMINORAXISGEOKEY 6356256.9 GEOGINVFLATTENINGGEOKEY 299.32498 GEOGAZIMUTHUNITSGEOKEY 0 GEOGPRIMEMERIDIANLONGGEOKEY 0.00000000 PROJECTEDCSTYPEGEOKEY 27700 PCSCITATIONGEOKEY PROJECTIONGEOKEY 0 PROJCOORDTRANSGEOKEY 0 PROJLINEARUNITSGEOKEY 9001 PROJLINEARUNITSIZEGEOKEY 0.00000000 PROJSTDPARALLEL1GEOKEY 0.00000000 PROJSTDPARALLEL2GEOKEY 0.00000000 PROJNATORIGINLONGGEOKEY 0.00000000 PROJNATORIGINLATGEOKEY 0.00000000 PROJFALSEEASTINGGEOKEY 0.00000000 PROJFALSENORTHINGGEOKEY 0.00000000 PROJFALSEORIGINLONGGEOKEY 0.00000000 PROJFALSEORIGINLATGEOKEY 0.00000000 PROJFALSEORIGINEASTINGGEOKEY 0.00000000 PROJFALSEORIGINNORTHINGGEOKEY 0.00000000 PROJCENTERLONGGEOKEY 0.00000000 PROJCENTERLATGEOKEY 0.00000000 PROJCENTEREASTINGGEOKEY 0.00000000 PROJCENTERNORTHINGGEOKEY 0.00000000 PROJSCALEATNATORIGINGEOKEY 0.00000000 PROJSCALEATCENTERGEOKEY 0.00000000 PROJAZIMUTHANGLEGEOKEY 0.00000000 PROJSTRAIGHTVERTPOLELONGGEOKEY 0.00000000 VERTICALCSTYPEGEOKEY 0 VERTICALCITATIONGEOKEY VERTICALDATUMGEOKEY 0 VERTICALUNITSGEOKEY 9001 I'm trying to open it using the convert LAS data function. I get a file with the following map info: Proj: TM Pixel: 5m Datum: Ordnance Survey of Great Britain '36 UL Geo: 0º0'NaN''E, 0º0'NaN''N UL Map: 271946.733, 219526.277 All of this is fine except the UL Geo part. I've just been using the defaults that ENVI gives me as trying to convert to a different projection (UTM or geo lat/lon) was giving me an error about array sizes needing to be greater than zero. Any help on what I'm doing wrong or how to fix this would be great