|
17 | 17 | config = json.load(f) |
18 | 18 |
|
19 | 19 |
|
| 20 | +def _bahamas_fix_time(ds): |
| 21 | + """Fix time coordinate of BAHAMAS datasets.""" |
| 22 | + return ds.rename({"tid": "time", "TIME": "time"}).set_index(time="time") |
| 23 | + |
| 24 | + |
| 25 | +def _radar_fix_time(ds): |
| 26 | + """Fix time coordinate of RADAR moments datasets.""" |
| 27 | + datetime = ( |
| 28 | + np.datetime64("1970-01-01", "ns") |
| 29 | + + ds.time.values * np.timedelta64(1, "s") |
| 30 | + + ds.microsec.values * np.timedelta64(1, "us") |
| 31 | + ) |
| 32 | + |
| 33 | + return ds.assign(time=datetime).drop_vars("microsec") |
| 34 | + |
| 35 | + |
| 36 | +def _radar_add_dBZ(ds): |
| 37 | + """Add reflectivity in dB.""" |
| 38 | + ds = ds.assign( |
| 39 | + dBZg=lambda dx: 10 * np.log10(dx.Zg), |
| 40 | + dBZe=lambda dx: 10 * np.log10(dx.Ze), |
| 41 | + ) |
| 42 | + ds.dBZg.attrs = { |
| 43 | + "units": "dBZg", |
| 44 | + "long_name": "Decadal logarithm of equivalent radar reflectivity of all targets (Zg)", |
| 45 | + } |
| 46 | + ds.dBZe.attrs = { |
| 47 | + "units": "dBZe", |
| 48 | + "long_name": "Decadal logarithm of equivalent radar reflectivity of hydrometeors (Ze)", |
| 49 | + } |
| 50 | + |
| 51 | + return ds |
| 52 | + |
| 53 | + |
| 54 | +def _fix_radiometer_time(ds): |
| 55 | + """Replace duplicates in time coordinate of radiometer datasets with correct time and ensure 4Hz frequency.""" |
| 56 | + |
| 57 | + # replace duplicate values |
| 58 | + time_broken = ds.time.values |
| 59 | + first_occurence = time_broken[0] |
| 60 | + n = 0 |
| 61 | + time_new = [] |
| 62 | + for i in range(len(time_broken)): |
| 63 | + if time_broken[i] == first_occurence: |
| 64 | + time_new.append(time_broken[i] + pd.Timedelta("0.25s") * n) |
| 65 | + n += 1 |
| 66 | + else: |
| 67 | + n = 1 |
| 68 | + first_occurence = time_broken[i] |
| 69 | + time_new.append(first_occurence) |
| 70 | + |
| 71 | + ds = ds.assign_coords(time=time_new).sortby("time").drop_duplicates("time") |
| 72 | + |
| 73 | + # ensure 4Hz frequency |
| 74 | + start_time = ds.time.min().values |
| 75 | + end_time = ds.time.max().values |
| 76 | + time_expected = pd.date_range(start=start_time, end=end_time, freq="0.25s") |
| 77 | + ds = ds.reindex(time=time_expected, fill_value=np.nan) |
| 78 | + |
| 79 | + return ds |
| 80 | + |
| 81 | + |
| 82 | +def add_georeference(ds, lat, lon, plane_pitch, plane_roll, plane_altitude, source): |
| 83 | + """Add georeference information to dataset.""" |
| 84 | + ds = ds.assign( |
| 85 | + plane_altitude=plane_altitude.sel(time=ds.time, method="nearest").assign_coords( |
| 86 | + time=ds.time |
| 87 | + ), |
| 88 | + lat=lat.sel(time=ds.time, method="nearest").assign_coords(time=ds.time), |
| 89 | + lon=lon.sel(time=ds.time, method="nearest").assign_coords(time=ds.time), |
| 90 | + plane_roll=plane_roll.sel(time=ds.time, method="nearest").assign_coords( |
| 91 | + time=ds.time |
| 92 | + ), |
| 93 | + plane_pitch=plane_pitch.sel(time=ds.time, method="nearest").assign_coords( |
| 94 | + time=ds.time |
| 95 | + ), |
| 96 | + ) |
| 97 | + ds.attrs["georeference source"] = source |
| 98 | + return ds |
| 99 | + |
| 100 | + |
| 101 | +def bahamas(ds): |
| 102 | + """Post-processing of BAHAMAS datasets.""" |
| 103 | + return ds.pipe( |
| 104 | + _bahamas_fix_time, |
| 105 | + ) |
| 106 | + |
| 107 | + |
| 108 | +def radiometer(ds): |
| 109 | + """Post-processing of radiometer datasets.""" |
| 110 | + return ( |
| 111 | + ds.rename(number_frequencies="frequency") |
| 112 | + .set_index(frequency="Freq") |
| 113 | + .pipe( |
| 114 | + _fix_radiometer_time, |
| 115 | + ) |
| 116 | + ) |
| 117 | + |
| 118 | + |
| 119 | +def iwv(ds): |
| 120 | + """Post-processing of IWV datasets.""" |
| 121 | + return ds.pipe(_fix_radiometer_time) |
| 122 | + |
| 123 | + |
| 124 | +def radar(ds): |
| 125 | + """Post-processing of Radar quick look datasets.""" |
| 126 | + return ds.pipe( |
| 127 | + _radar_fix_time, |
| 128 | + ).pipe( |
| 129 | + _radar_add_dBZ, |
| 130 | + ) |
| 131 | + |
| 132 | + |
20 | 133 | def _selective_where(ds, condition): |
21 | 134 | """ |
22 | 135 | Apply where to dataset but do not touch georeference data which should not be masked |
@@ -419,31 +532,6 @@ def add_masks_radar(ds, sea_land_mask): |
419 | 532 | ) |
420 | 533 |
|
421 | 534 |
|
422 | | -def filter_spikes(ds, threshold=5, window=1200): |
423 | | - """ |
424 | | - Filters out spikes in a time series by comparing the difference between each point |
425 | | - and the minimum of the surrounding 5 minutes. |
426 | | -
|
427 | | - Parameters |
428 | | - ---------- |
429 | | - ds : xr.DataArray |
430 | | - DataArray to filter. |
431 | | - threshold : float |
432 | | - Maximum allowed difference between the data and the minimum within the window. |
433 | | - window : int |
434 | | - Size of the window in seconds to compare the data, default is 5 minutes. |
435 | | -
|
436 | | - Returns |
437 | | - ------- |
438 | | - xr.DataArray |
439 | | - Filtered DataArray. |
440 | | - """ |
441 | | - diff = ds - ds.rolling(time=window, center=True, min_periods=1).min() |
442 | | - filtered = ds.where(abs(diff) < threshold) |
443 | | - interpolated = filtered.interpolate_na("time", method="linear") |
444 | | - return xr.where(abs(diff) < threshold, ds, interpolated) |
445 | | - |
446 | | - |
447 | 535 | def correct_radar_height(ds): |
448 | 536 | """Correct radar range gates with HALO flight altitude to height above WGS84 ellipsoid. |
449 | 537 |
|
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