Atmospheric Radiation Measurement Climate Research Facility US Department of Energy


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sacradvqvp > SACR Advance Quasi-Vertical ProfileVAP Type(s) > Baseline • Evaluation

SACR-ADV-QVP provides a quasi-vertical representation of azimuthal averaged polarimetric variables such as differential reflectivity (ZDR), specific differential phase (KDP) and correlation coefficient (rho hv), and linear depolarization ratio (LDR) to reveal important signatures in ice and mixed-phase clouds. SACR-ADV-QVPs are produced using a sequence of plan-position-indicator (PPI) scans. The second generation SACR (SACR2) is a polarimetric radar capable of observing cloud/precipitation particle properties. The polarimetric variables from lower elevation angle observations (e.g. plan position indicator, PPI) are more informative. However, it is difficult to directly compare the polarimetric variables observed at lower elevation angles with other profiling measurements (e.g., KAZR, microwave radiometer, and ceilometer).

PPI scans are at constant elevation with changing azimuth scans. This scan strategy typically covers three different elevation angles and is repeated every 30 minutes.

The scientific basis of the algorithm is described in Ryzhkov et al. (2016). For the three elevation PPIs, observations at constant range are averaged over azimuth angles. The standard deviation over azimuth angles is used as an error estimate.

The input product of this VAP should include reflectivity, differential reflectivity, spectrum width, differential phase, linear depolarization ratio, and correlation coefficient, all of which are better off with free of noise, insects, and second trip echo and all of which are in native radar polar coordinates.

This VAP outputs a daily NetCDF file containing quasi-vertical profiles of all aforementioned polarimetric variables every time the PPI scan strategy is performed (this could cause an irregular time stamp). This product is produced at a 10 m height resolution at an elevation angle of 20 degrees.


Data were calculated in order to provide a quasi-vertical representation of azimuthal averaged polarimetric variables, and thereby reveal important signatures in ice and mixed-phase clouds.

Primary Derived Measurements


  • Fixed
  • AMF1
  • AMF2
  • AMF3

Data Details

Developed By Meng Wang | Scott Giangrande | Mariko Oue
Contact Meng Wang
Resource(s) Data Directory
Data format netcdf
Site OLI
Content time range 28 March 2016 - 30 June 2017
Attribute accuracy No formal attribute accuracy tests were conducted
Positional accuracy No formal positional accuracy tests were conducted
Data Consistency and Completeness Data set is considered complete for the information presented, as described in the abstract.Users are advised to read the rest of the metadata record carefully for additional details.
Access Restriction No access constraints are associated with this data.
Use Restriction No use constraints are associated with this data.
File naming convention KA band SACR radar, qvp data caluculated
Citations Ryzhkov A, P Zhang, H Reeves, M Kumjian, T Tschallener, S Tr??mel, and C Simmer. 2016."Quasi-Vertical Profiles - A New Way to Look at Polarimetric Radar Data." Journal of Atmospheric and Oceanic Technology, 33(3), doi:10.1175/JTECH-D-15-0020.1