Ceilometer Zarr¶

Path:

/data/aurora/products/cl61/gamb2le_depolarisation_lidar_ceilometer_aurora.zarr

Dataset shape¶

dimensions: time, range, layer
deployed shape when checked on 2026-05-21:
time=131442
range=3276
layer=5
time coverage when checked: 2026-05-06 14:34:37 to 2026-05-21 20:06:50
sorted unique time coordinate

Coordinates¶

time - profile timestamps
range - range gate center in meters
layer - cloud-layer index
latitude, longitude - site coordinates

Useful root attributes¶

title = "CL61D CL61 with Depolarization"
source = "gamb2le_depolarisation_lidar_ceilometer"
conventions = "CF-1.8"
profile_interval_in_seconds = 10
file_temporal_span_in_minutes = 5.0
schema_version = "1.3"
instrument_serial_number = "X1627532"
overlap_function_provided = 1
overlap_is_corrected = 1

Variable layout¶

Main `time x range` profile fields¶

beta_att
linear_depol_ratio
p_pol
x_pol

`time x layer` cloud diagnostics¶

cloud_base_heights
cloud_penetration_depth
cloud_thickness
sky_condition_cloud_layer_covers
sky_condition_cloud_layer_heights

`time`-only diagnostics¶

beta_att_noise_level
beta_att_sum
fog_detection
precipitation_detection
receiver_gain
sky_condition_total_cloud_cover
tilt_angle
tilt_correction
vertical_visibility

Scalar metadata¶

range_resolution
elevation
azimuth_angle
airplane_filter_max_range
cloud_calibration_factor
cloud_calibration_factor_user

Chunking¶

time x range fields such as beta_att are chunked (30, full-range)
time x layer diagnostics are chunked (30, 5)
time-only diagnostics are chunked (30,)

Append and repair notes¶

The CL61 appender filters incoming files down to genuinely new timestamps, loads that already-filtered block, and then appends it. This avoids partial chunk writes that can leave raw-valid range profiles as all-NaN stripes in the Zarr. The recent visible CL61 window was repaired from the raw mirror after this policy was added, and recent plotted fields have been checked against the source files.