search

deeplycloudy / lmatools

Python code for working with VHF Lightning Mapping Array data
BSD 2-Clause "Simplified" License
22 stars 23 forks source link

Southern hemisphere coordinate transforms #6

Open deeplycloudy opened 8 years ago

deeplycloudy commented 8 years ago

Via @tjlang, "You had a bug in the attached script, which caused the projections to fail in the southern hemisphere (everything was erroneously rotated 180 degrees around the projection center). The specific issue was the definition of localy in the TangentPlaneCartesianSystem class. I fixed it with a simple if-then statement (see lines 277-280) and now the projections essentially match what Basemap does."

    localy = dot(P, northCenterECEF[:,newaxis] )
    if ctrLat >= 0:
        localy = -localy / norm(localy)  # negation gets x and y pointing in the right direction
    else:
        localy = localy / norm(localy)  # No negation in southern hemisphere