The netCDF L1 data file contains level 1 (L1) data from the ceilometer.
NetCDF L1 filenames have the following format:
L1_<STATION_NUMBER>_YYYYMMDDHHMM_<FREE_FORMAT>.nc
| Name | Description |
|---|---|
| L1 | Identification of the data level |
| STATION_NUMBER | WMO station number, if defined in . |
| YYYYMMDDHHMM | UTC time |
| FREE FORMAT | File suffix, if defined in . |
Example filename: L1_06610_201906180358
The L1 files contain the following dimension, variable, and global attribute information.
| Dimension | Description |
|---|---|
| timeDim | Number of profiles |
| nameDim | − |
| range | Number of vertical bins |
| message_typeDim | − |
| versionDim | − |
| date_stampDim | − |
| periodDim | − |
| tilt_angleDim | − |
| cloud_statusDim | − |
| cloud_dataDim | − |
| status_bitsDim | − |
| profile_scaleDim | − |
| profile_resolutionDim | − |
| profile_lengthDim | − |
| Type | Variable | Attributes | Description |
|---|---|---|---|
| int | time |
Units = seconds since 1970-01-01 00:00:00.000 Type = double Dimension = time axis = T |
Unix time |
| string | name | Dimension = timeDim | Data identifier (ceilometer name) as defined in |
| int | range | Dimension = range | 7700 m (25 260 ft), values with 10 m (33 ft) resolution meaning 770 samples |
| int | message_type | Dimension = timeDim | Ceilometer data message type (11, 12, 13, 16, 21, 22, 23, or 26) |
| int | version | Dimension = timeDim | Ceilometer version number |
| string | date_stamp |
Units = seconds since 1970-01-01 00:00:00.000 Type = double Dimension = time axis = T |
Measurement timestamp in textual form (yyyy-MM-dd hh:mm:ss) |
| int | period | Dimension = timeDim |
Sending frequency of ceilometer data message in milliseconds. The boundary layer height algorithm is optimized for 16 second message interval |
| int | tilt_angle |
Units = degree Type = integer Dimension = time |
Ceilometer tilt angle (0 ... 90 degrees). |
| int | cloud_status | Dimension = timeDim |
0 = no significant backscatter/some obscuration but determined to be transparent 1 = one cloud layer 2 = two cloud layers or full obscuration (vertical visibility and highest signal detected) 3 = three cloud layers 4 = change cloud status to 2, reports vertical visibility and highest signal |
| int | cloud_data | Dimension = timeDim | Cloud bases or vertical visibility/highest signal detected (meters or feet) |
| string | status_bits | Dimension = timeDim | Ceilometer status bits (12 characters) |
| int | profile_scale | Dimension = timeDim | Scaling parameter of ceilometer signal backscatter profile (0 ... 9999, 100 = no scaling) |
| int | profile_resolution | Dimension = timeDim | Resolution of ceilometer signal backscatter profile (5, 10, or 20 m (16, 33, or 66 ft), depending on the message type) |
| int | profile_length | Dimension = timeDim | Number of samples in ceilometer signal backscatter profile (385, 770, or 1540), depending on the message type |
| int | rcs_910 | Dimension = timeDim, range |
Ceilometer signal backscatter profile Each sample is coded with a 20-bit HEX ASCII character set |
| Attribute |
|---|
| site_location |
| instrument_type |
| latitude |
| longitude |
| altitude |
| offset |