¶ High Spectral Resolution Lidar (HSRL)
¶ Instrument Description
The High Spectral Resolution Lidar (HSRL) provides calibrated measurements of aerosol optical depth, volume backscatter coefficient, cross section, and depolarization.
- For more information see the HSRL Instrument web page and the documents attached at the bottom of this page.
¶ Expected Operations
Measurements are computed from ratios of the particulate scattering to the measured molecular scattering. This provides absolute calibration and makes the calibration insensitive to dirt or precipitation on the output window. A very narrow, angular field-of-view reduces multiple scattering contributions. The small field-of-view, coupled with a narrow optical bandwidth, nearly eliminates noise due to scattered sunlight.
¶ Metrics
¶ Plots
Particulate Backscatter
Circular Depolarization Ratio
¶ Attenuated Molecular Return
HSRL Diagnostics
- Instrument information including number of seeded shots, transmitted energy, and laser seeding quality.
¶ Site-Specific Information
The HSRL is currently located at NSA and AMF2. All locations operate similarly.
¶ Known Issues
¶ Known Behaviors
There are currently no known issues for this instrument. Document some here.
¶ Past Problems
List of past problems for this instrument that DO need to be mentioned in your DQA's:
Lost Lock Point
Double Pulsing of Laser
Occasionally, a double pulsing of the laser occurs and should warrant a DQPR. This can be diagnosed with the following criteria:
- A line of increased backscatter returns with depol ratios near zero
- Double cloud deck spaced roughly the same distance apart as the constant line of returns from the ground.
In this example, the constant returns are about 1 km in height.
