diff --git a/aosstower/level_b1/nc.py b/aosstower/level_b1/nc.py
index fe5d6232ae7a2f17c9578dd4059e5d7cf68eb5af..ebf7a3d67b8fe76167f1f74c5e639b0d2fad20de 100644
--- a/aosstower/level_b1/nc.py
+++ b/aosstower/level_b1/nc.py
@@ -75,7 +75,7 @@ def write_dimensions(nc_file):
def create_variables(nc_file, first_stamp, database, chunk_sizes=None, zlib=False):
# base_time long name
- btln = 'base time as unix timestamp'
+ btln = 'Base time in Epoch'
# base time units
btu = 'seconds since 1970-01-01 00:00:00'
@@ -83,21 +83,25 @@ def create_variables(nc_file, first_stamp, database, chunk_sizes=None, zlib=Fals
# base time string
bts = first_stamp.strftime('%Y-%m-%d 00:00:00Z')
- # time long name
- tln = 'Time offset from base_time'
+ # time offset long name
+ to_ln = 'Time offset from base_time'
- # time units
- tu = 'seconds since ' + first_stamp.strftime('%Y-%m-%d 00:00:00Z')
+ # time offset units
+ to_u = 'seconds since ' + first_stamp.strftime('%Y-%m-%d 00:00:00Z')
+ # 'time' units
+ t_u = 'hours since ' + first_stamp.strftime('%Y-%m-%d 00:00:00Z')
coordinates = {
# fields: type, dimension, fill, valid_min, std_name, longname, units, valid_max, cf_role, axis
- 'time': [np.float64, ('time',), -999., None, None, "Time offset from epoch",
- "seconds since 1970-01-01 00:00:00Z", None, None, None],
+ 'time': [np.float64, ('time',), -999., None, None, "Hour offset from midnight",
+ t_u, None, None, None],
'lon': [np.float32, tuple(), -999., -180., 'longitude', None, 'degrees_east', 180., None],
'lat': [np.float32, tuple(), -999., -90., 'latitude', None, 'degrees_north', 90., None],
'alt': [np.float32, tuple(), -999., None, 'height', 'vertical distance', 'm', None, None],
+ # int64 for base_time would be best, but NetCDF4 Classic does not support it
+ # NetCDF4 Classic mode was chosen so users can use MFDatasets (multi-file datasets)
'base_time': [np.int32, tuple(), -999., None, 'time', btln, btu, None, None],
- 'time_offset': [np.float64, ('time',), -999., None, 'time', tln, tu, None, None],
+ 'time_offset': [np.float64, ('time',), -999., None, 'time', to_ln, to_u, None, None],
'station_name': ['c', ('max_len_station_name',), '\0', None, None, 'station name', None, None, 'timeseries_id'],
}
@@ -184,12 +188,8 @@ def calculate_wind_gust(wind_speed_5s, wind_speed_2m):
http://www.nws.noaa.gov/asos/pdfs/aum-toc.pdf
- Criteria Summary
- ----------------
-
- Wind Gust:
-
- 1. 2 minute average
+ Note: This operates on wind data in meters per second even though the
+ ASOS User's Guide operates on knots.
Arguments:
wind_speed_5s (Series): 5-second average of instantaneous wind speed magnitudes in m/s
@@ -289,15 +289,17 @@ def write_vars(nc_file, frame, database):
base_epoch = frame.index[0].replace(hour=0, minute=0, second=0, microsecond=0).value // 10**9
fileVar = nc_file.variables
+ # base_time is midnight of the current day
fileVar['base_time'].assignValue(base_epoch)
fileVar['time_offset'][:] = time_epoch - base_epoch
- fileVar['time'][:] = time_epoch
+ # hours since midnight
+ fileVar['time'][:] = (time_epoch - base_epoch) / (60 * 60)
# write coordinate var values to file
# alt might not be right, need to verify
fileVar['lon'].assignValue(station.LONGITUDE)
fileVar['lat'].assignValue(station.LATITUDE)
- fileVar['alt'].assignValue(328)
+ fileVar['alt'].assignValue(station.ELEVATION)
# write station name to file
fileVar['station_name'][:len(STATION_NAME)] = STATION_NAME
@@ -370,6 +372,8 @@ def create_giant_netcdf(input_files, output_fn, zlib, chunk_size,
chunk_sizes = [frame.shape[0]]
first_stamp = dt.strptime(str(frame.index[0]), '%Y-%m-%d %H:%M:%S')
+ # NETCDF4_CLASSIC was chosen so that MFDataset reading would work. See:
+ # http://unidata.github.io/netcdf4-python/#netCDF4.MFDataset
nc_file = Dataset(output_fn, 'w', format='NETCDF4_CLASSIC')
write_dimensions(nc_file)
create_variables(nc_file, first_stamp, database, chunk_sizes, zlib)
diff --git a/aosstower/station.py b/aosstower/station.py
index 681ca79fb5357977ffed52d781cee4c044420e77..88b301fe9926d94acea51680220c595ea4ecb1b2 100644
--- a/aosstower/station.py
+++ b/aosstower/station.py
@@ -5,8 +5,9 @@ from datetime import timedelta
# Time between data samples in seconds
DATA_INTERVAL = timedelta(seconds=5)
-# station elevation in meters above the surface in feet
-ELEVATION = 325
+# these heights are for the top of the penthouse roof
+ELEVATION = 329.522 # meters above mean sea level
+HEIGHT = 294.8338 # height in meters above ground level
# Id of station from v1 records
ID = 1