| Start Date | Start Time | End Date | End Time | Data Quality Metric |
|---|---|---|---|---|
| 11/05/2012 | 1700 | 06/19/2013 | 2359 | Suspect |
| Subject: | PVC/DL/M1 - Height-dependent ringing artifact in SNR and velocity field |
| DataStreams: | pvcdlppiM1.b1, pvcdlfptM1.b1, pvcdlcal2M1.b1, pvcdlcal1M1.b1, pvcdlrhiM1.b1 |
| Description: | The AMF1 Doppler lidar has exhibited a height-dependent ringing artifact in the intensity (SNR + 1) field since about 5 November 2012. This also affects the Doppler velocities. The problem results in a sinusoidal oscillation in the SNR (and velocity) with height. The period of the oscillation is roughly 3 km. The exact cause is not known at this time. However, it is similar to one described in the system user manual as being caused by an "unthermalized digitizer." The problem has been occuring intermittently since 5 November, 2012 (several days after hurricane Sandy). On average, it has occurred roughly once every 2 to 3 days, and typically persists for 1 to 3 hours at a time. |
| Suggestions: | Affected data show artificially elevated SNR values well above the boundary layer. The artifact is fairly easy to identify in time-height cross sections of SNR and/or velocity. Users should not use the affected data. |
| Measurements: | pvcdlcal2M1.b1: more
pvcdlppiM1.b1: more pvcdlfptM1.b1: more pvcdlcal1M1.b1: more pvcdlrhiM1.b1: more |