image: elevation_map.pgm
resolution: 0.15
origin: [-11.0714, -78.9207, 0.0]
width: 792
height: 991
min_elevation: -1.98525
max_elevation: 2.99994
unknown_value: 0
# decoding: pixel==unknown_value -> unknown; otherwise
# z = min_elevation + (pixel - 1) / 254.0 * (max_elevation - min_elevation)