Using QCed Line-of-Sight data

Using QCed Line-of-Sight data

Files of quality-controlled (QCed) line-of-sight (LOS) data, also known as Mini Raw, contain LOS wind speed component measurements at 50 Hz resolution from around the lidar's scan.

This data format is intended for use by floating lidar OEMs to allow the effects of buoy motion to be removed from the reconstructed wind speed. While the effects of buoy motion on the mean wind speed across a 10-minute period are small, the standard deviation of the wind speeds within that period, and hence the measure of turbulence intensity derived from that standard deviation, can be artificially high.

QC is applied to the data using the lidar's built in algorithms for assessing "1-second" reconstructed horizontal wind speed data. If the 1-second data point fails quality control then all 50 LOS values are filtered out of the Mini Raw data file.

To be able to access the Mini Raw data, the user must:
  1. Contact ZX Lidars to ensure that the storage of Mini Raw data is available on your lidar;
  2. Enable the Mini Raw data storage option on your lidar using Waltz;
  3. Any Mini Raw data files stored on the lidar can be accessed through ftp. Append "-raw" to your normal username, with the same password as used for your ftp / Waltz login;
  4. Mini Raw data files can be converted from ZPH to CSV format using either the Waltz or ZPH2CSV utilities.