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get_lonlatalt doesn't give correct results for Terra / Aqua #70

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@espg

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@espg
from datetime import datetime, timezone
from pyorbital import orbital
from pyhdf.SD import SD, SDC

t = datetime(2005, 6, 16, 1, 20, 0, 0, tzinfo=timezone.utc)
terra = orbital.Orbital("EOS-TERRA")

terra.get_lonlatalt(t)

Above code yields:

(166.84878227675836, 60.28586375275336, 718.455146236583)

Terra MODIS is a nadir looking instrument, so those coordinates (or relatively close to them) should be present in the data from the sensor... but...

pass1 = SD('MOD07_L2.A2005167.0115.061.2017291020316.hdf', SDC.READ)
pass2 = SD('MOD07_L2.A2005167.0120.061.2017291020310.hdf', SDC.READ)
lats1 = pass1.select('Latitude')
lons1 = pass1.select('Longitude')
lats2 = pass2.select('Latitude')
lons2 = pass2.select('Longitude')

print(np.max(lats1[:]),np.min(lats1[:]),np.max(lats2[:]),np.min(lats2[:]))

returns:

(-54.213318 -77.61293 -38.029873 -59.76777)

All the latitudes are in the southern hemisphere, while the pyorbital thinks that the satellite is close to the arctic circle in the northern hemisphere, so that's not great...

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