fixed datetime conversions

Author: jpswinski

sliderule/gedi.py

@@ -75,9 +75,7 @@ def __todataframe(columns, time_key="time", lon_key="longitude", lat_key="latitu
         return sliderule.emptyframe(**kwargs)
 
     # Generate Time Column
-    timestamp = (columns[time_key]*1e9).astype('timedelta64[ns]')
-    gps_epoch = numpy.datetime64(sliderule.gps_epoch)
-    columns['time'] = geopandas.pd.to_datetime(gps_epoch + timestamp)
+    columns['time'] = columns[time_key].astype('datetime64[ns]')
 
     # Generate Geometry Column
     geometry = geopandas.points_from_xy(columns[lon_key], columns[lat_key])

sliderule/icesat2.py

@@ -153,9 +153,7 @@ def __todataframe(columns, time_key="time", lon_key="lon", lat_key="lat", **kwar
         return sliderule.emptyframe(**kwargs)
 
     # Generate Time Column
-    timestamp = (columns[time_key]*1e9).astype('timedelta64[ns]')
-    gps_epoch = numpy.datetime64(sliderule.gps_epoch)
-    columns['time'] = geopandas.pd.to_datetime(gps_epoch + timestamp)
+    columns['time'] = columns[time_key].astype('datetime64[ns]')
 
     # Generate Geometry Column
     geometry = geopandas.points_from_xy(columns[lon_key], columns[lat_key])

sliderule/sliderule.py

@@ -119,7 +119,7 @@
     "BITFIELD": { "fmt": 'x', "size": 0, "nptype": numpy.byte   },  # unsupported
     "FLOAT":    { "fmt": 'f', "size": 4, "nptype": numpy.single },
     "DOUBLE":   { "fmt": 'd', "size": 8, "nptype": numpy.double },
-    "TIME8":    { "fmt": 'Q', "size": 8, "nptype": numpy.datetime64 },
+    "TIME8":    { "fmt": 'q', "size": 8, "nptype": numpy.int64  }, # numpy.datetime64
     "STRING":   { "fmt": 's', "size": 1, "nptype": numpy.byte   }
 }