Supported ENVISAT Products |

## Map Projection parameters

Fields of ENVISAT ASAR_Map_GADS Records

Index | Identifier | Field Type | Field Length | Description | Units
0 | `"map_descriptor"` | String | 1 | Map projection descriptor one of: UNIVERSAL_TRANSVERSE_MERCATOR, UNIVERSAL_POLAR_STEREOGRAPHIC, LAMBERT_CONFORMAL_CONIC, TRANSVERSE_MERCATOR, MERCATOR, POLAR_STEREOGRAPHIC | ascii
1 | `"samples"` | ULong | 1 | Number of samples per line | -
2 | `"lines"` | ULong | 1 | Number of lines | -
3 | `"sample_spacing"` | Float | 1 | Nominal inter-sample distance | m
4 | `"line_spacing"` | Float | 1 | Nominal inter-line distance | m
5 | `"orientation"` | Float | 1 | Output scene centre orientation | deg
6 | `"spare_1"` | Spare | 1 | Spare | -
7 | `"heading"` | Float | 1 | Platform heading, degrees | deg
8 | `"ellipsoid_name"` | String | 1 | Reference ellipsoid name | ascii
9 | `"semi_major"` | Float | 1 | Ellipsoid semi-major axis, metres | m
10 | `"semi_minor"` | Float | 1 | Ellipsoid semi-minor axis, metres | m
11 | `"shift_dx"` | Float | 1 | Datum shift parameter referenced to Greenwich: dx (metres) | m
12 | `"shift_dy"` | Float | 1 | Datum shift parameter perpendicular to Greenwich: dy (metres) | m
13 | `"shift_dz"` | Float | 1 | Datum shift parameter direction of the rotation axis: dz (metres) | m
14 | `"avg_height"` | Float | 1 | average scene height above ellipsoid used for geocoding | -
15 | `"spare_2"` | Spare | 1 | Spare | -
16 | `"projection_description"` | String | 1 | Map projection alphanumeric description | ascii
17 | `"utm_descriptor"` | String | 1 | UTM descriptorUNIVERSAL_TRANSVERSE_MERCATORØØØ | ascii
18 | `"utm_zone"` | String | 1 | UTM zone signature | ascii
19 | `"utm_origin_easting"` | Float | 1 | Map origin, false easting | m
20 | `"utm_origin_northing"` | Float | 1 | Map origin, false northing | m
21 | `"utm_center_long"` | SLong | 1 | Projection centre longitude, deg | (1e-6) degrees
22 | `"utm_center_lat"` | SLong | 1 | Projection centre latitude, deg | (1e-6) degrees
23 | `"utm_para1"` | Float | 1 | 1st standard parallel, deg | deg
24 | `"utm_para2"` | Float | 1 | 2nd standard parallel, deg | deg
25 | `"utm_scale"` | Float | 1 | Scale factor | -
26 | `"ups_descriptor"` | String | 1 | UPS descriptor | ascii
27 | `"ups_center_long"` | SLong | 1 | Projection centre longitude, deg | (1e-6) degrees
28 | `"ups_center_lat"` | SLong | 1 | Projection centre latitude, deg | (1e-6) degrees
29 | `"ups_scale"` | Float | 1 | Scale factor | -
30 | `"nsp_descriptor"` | String | 1 | NSP descriptor | ascii
31 | `"origin_easting"` | Float | 1 | Map origin, false easting | m
32 | `"origin_northing"` | Float | 1 | Map origin, false northing | m
33 | `"center_long"` | SLong | 1 | Projection centre longitude, deg | (1e-6) degrees
34 | `"center_lat"` | SLong | 1 | Projection centre latitude, deg | (1e-6) degrees
35 | `"standard_parallel_parameters.para1"` | Float | 1 | Standard parallel1, deg | deg
36 | `"standard_parallel_parameters.para2"` | Float | 1 | Standard parallel2, deg | deg
37 | `"standard_parallel_parameters.para3"` | Float | 1 | Standard parallel3, deg | deg
38 | `"standard_parallel_parameters.para4"` | Float | 1 | Standard parallel4, deg | deg
39 | `"central_meridian_parameters.central_m1"` | Float | 1 | Central meridian1, deg | deg
40 | `"central_meridian_parameters.central_m2"` | Float | 1 | Central meridian2, deg | deg
41 | `"central_meridian_parameters.central_m3"` | Float | 1 | Central meridian3, deg | deg
42 | `"projection_parameters.spare_3"` | Spare | 1 | Spare | -
43 | `"projection_parameters.spare_4"` | Spare | 1 | Spare | -
44 | `"projection_parameters.spare_5"` | Spare | 1 | Spare | -
45 | `"projection_parameters.spare_6"` | Spare | 1 | Spare | -
46 | `"position_northings_eastings.tl_northing"` | Float | 1 | Top left corner northing, meters; | m
47 | `"position_northings_eastings.tl_easting"` | Float | 1 | Top left corner easting, meters; | m
48 | `"position_northings_eastings.tr_northing"` | Float | 1 | Top right corner northing, meters; | m
49 | `"position_northings_eastings.tr_easting"` | Float | 1 | Top right corner easting, meters; | m
50 | `"position_northings_eastings.br_northing"` | Float | 1 | Bottom right corner northing, meters; | m
51 | `"position_northings_eastings.br_easting"` | Float | 1 | Bottom right corner easting, meters; | m
52 | `"position_northings_eastings.bl_northing"` | Float | 1 | Bottom left corner northing, meters; | m
53 | `"position_northings_eastings.bl_easting"` | Float | 1 | Bottom left corner easting, meters; | m
54 | `"position_lat_long.tl_lat"` | SLong | 1 | Top left corner latitude | (1e-6) degrees
55 | `"position_lat_long.tl_long"` | SLong | 1 | Top left corner longitude | (1e-6) degrees
56 | `"position_lat_long.tr_lat"` | SLong | 1 | Top right corner latitude | (1e-6) degrees
57 | `"position_lat_long.tr_long"` | SLong | 1 | Top right corner longitude | (1e-6) degrees
58 | `"position_lat_long.br_lat"` | SLong | 1 | Bottom right corner latitude | (1e-6) degrees
59 | `"position_lat_long.br_long"` | SLong | 1 | Bottom right corner longitude | (1e-6) degrees
60 | `"position_lat_long.bl_lat"` | SLong | 1 | Bottom left corner latitude | (1e-6) degrees
61 | `"position_lat_long.bl_long"` | SLong | 1 | Bottom left corner longitude | (1e-6) degrees
62 | `"spare_7"` | Spare | 1 | Spare | -
63 | `"image_to_map_coefs"` | Float | 8 | 8 coefficients to convert a line(L) and sample (S) position to the map projection frame of reference, say (E,N)E = A11 + A12*L + A13 *S + A14 *L*SN = A21 + A22*L + A23 *S + A24 *L*S | -
64 | `"map_to_image_coefs"` | Float | 8 | 8 coefficients to convert from the map projection (E,N) to line (L) and sample(S) position in the imageL = B11 + B12*E + B13 *N + B14 *E*NS = B21 + B22*E + B23 *N + B24 *E*N | -
65 | `"spare_8"` | Spare | 1 | Spare | -