SGP/DL/C1 - Instrument failure

In July the SGP DL experienced a failure. The instrument was subsequently sent back to the 
vendor for repair and upgrade. That work was successfully completed in October. The 
instrument was then shipped back to SGP and reinstalled in November.

• North latitude(lat)
• azimuth
• time_offset
• Altitude above mean sea level(alt)
• Radial velocity(radial_velocity)
• range
• intensity
• Attenuated backscatter(attenuated_backscatter)
• East longitude(lon)
• base_time
• elevation
• time

SGP/DL/C1 - Instrument

The instrument failed to restart following a site-wide power outage due to a glitch in the 
automated start up procedure. The problem has since been fixed.

• North latitude(lat)
• azimuth
• time_offset
• Altitude above mean sea level(alt)
• Radial velocity(radial_velocity)
• range
• intensity
• Attenuated backscatter(attenuated_backscatter)
• East longitude(lon)
• base_time
• elevation
• time

SGP Site Power Outage Due to Winter Storm

On Saturday and Sunday, December 26 and 27th a powerful winter storm (Goliath) brought 
sleet and freezing rain to much of Oklahoma with wind gusts of 45 MPH at times. The result 
was very very slick roads and mass power outages.
 
The SGP central facility lost power at 8:55 PM CDT on Sunday, December 27th.  
The power was restored on 7:56 PM CDT on Wednesday, December 30th
 
Site Emergency procedures were activated and Technicians drained water out of instrument 
reservoirs and other measures as needed, early Monday morning.
 
On Wednesdays as roads and power started was restored to much of the areas east of I-35 , 
Site Technicians performed maintenance on several Extended Facilities.

During this period, data are potentially missing, incorrect, or suspect.  Carefully 
inspect the data before use.

• North latitude(lat)
• time_offset
• azimuth
• range
• Altitude above mean sea level(alt)
• Radial velocity(radial_velocity)
• intensity
• Attenuated backscatter(attenuated_backscatter)
• East longitude(lon)
• base_time
• time
• elevation

SGP/DL/DLPROF/C1 - Data collected at vendor facility

Data collected during this period were recorded at the vendor facility in England (not 
SGP) for test purposes only.

• time_offset
• Altitude above mean sea level(alt)
• Attenuated backscatter(attenuated_backscatter)
• qc_time
• base_time
• North latitude(lat)
• qc_radial_velocity
• azimuth
• range
• Radial velocity(radial_velocity)
• intensity
• East longitude(lon)
• time
• elevation

SGP/DL/DLPROF/C1 - Instrumental artifact in vertical velocity variance profiles

Long-term averages of vertical velocity variance profiles developed from vertical staring 
data show a height-dependent sinusoidal modulation superimposed on the atmospheric 
variance profile. This modulation causes a wiggle in the variance profile. The period of the 
wiggle is about 350 m, and the effect is most obvious during hot afternoon periods in the 
summer months. The exact cause of this problem is not known, but we suspect that it may be 
caused by temperature sensitivity in beam alignment.

• Radial velocity(radial_velocity)

SGP/DL/DLPROF/C1 - Reprocess: Incorrect serial number

The instrument serial number that appears in the netcdf files global attributes is 
incorrect. The correct serial number is 0116-107.

• base_time

SGP/DL/C1 - Power supply issue

The supply voltage from the external power supply was running low due to overheating. As a 
result, the instrument was intentionally shutdown for the long Memorial Day weekend.

• time_offset
• Altitude above mean sea level(alt)
• Attenuated backscatter(attenuated_backscatter)
• qc_time
• base_time
• North latitude(lat)
• qc_radial_velocity
• azimuth
• range
• Radial velocity(radial_velocity)
• intensity
• East longitude(lon)
• time
• elevation

SGP/DL/C1 - Returned to vendor for repair

No data was recorded during the period in question because the lidar was shipped to the 
vendor for repair to fix the problem with the high internal relative humidity.

• time_offset
• Altitude above mean sea level(alt)
• Attenuated backscatter(attenuated_backscatter)
• qc_time
• base_time
• North latitude(lat)
• qc_radial_velocity
• azimuth
• range
• Radial velocity(radial_velocity)
• intensity
• East longitude(lon)
• time
• elevation

SGP/DL/C1 - Instrument

The instrument was returned to service on 23 February following repair by the vendor. Once 
it was brought into service the lidar defaulted to a scan schedule that the vendor was 
using. This was a slant path stare at an elevation angle of 12 degrees. On 27 February the 
mentor reset the scan schedule to the "normal" schedule.

• time_offset
• Altitude above mean sea level(alt)
• Attenuated backscatter(attenuated_backscatter)
• qc_time
• base_time
• North latitude(lat)
• qc_radial_velocity
• azimuth
• range
• Radial velocity(radial_velocity)
• intensity
• East longitude(lon)
• time
• elevation

SGP/Central Facility - Power Outage

Automated scripts show that these instruments were affected by a power outage at the 
central facility resulting in missing data.  Most of the instruments came back online on March 
6th but some took longer.

• time_offset
• Altitude above mean sea level(alt)
• Attenuated backscatter(attenuated_backscatter)
• qc_time
• base_time
• North latitude(lat)
• qc_radial_velocity
• azimuth
• Radial velocity(radial_velocity)
• range
• intensity
• East longitude(lon)
• elevation
• time