S-PolKa Users' Guide

S-PolKa REFRACTT06, Marshall Field Site, Colorado
May 2006 - Aug 2006

1. Introduction
   • Project Description: REFRACTT includes scientific research and operational application goals. Both have the goal of greatly enhancing the observed field of water vapor over the nation thus leading to improved precipitation forecasts. The scientific goal is to utilize multiple radars and GPS receivers to simultaneously obtain very high resolution measurements of water vapor variability and transport in the convective boundary layer and to assess potential improvements these enhanced water vapor measurements may have in numerical model forecasts of quantitative precipitation. The applications goal is to demonstrate the ability to collect radar refractivity data on the NEXRAD (WSR-88D) radars and to demonstrate the forecast value of this field to NWS forecasters. The ultimate goal is to implement radar refractivity measurements on the national network of operational radars.
   • The role of S-Pol-Ka was to provide real-time dual-frequency (S- and Ka- band), polarization diversity and refractivity data, as well as post-project fully quality controlled data sets.
   • Links to other project information

2. Siting
   • Location
   • Terrain, Ground Clutter
   • Site Photos

3. Dataset Description
   • Periods of Operation
     • Times listed as interactive plot: Click time period to launch data animation
   • List of Known Problems
   • Parameters Available
   • List of Data Tapes & Raw Data
   • Requesting Data
   • Post-processing corrections
     • S-band ZDR correction (based on vertical pointing and cross-correlation calibrations)
       • -0.14 dB before 14 July 2006
       • -0.21 dB thereafter
     • Range correction: S-band data moved one gate, or 150 m, further in range (verified by tower measurements)
     • Ka-band reflectivity calibration

4. Practical Notes on Using the Data
   • Quicklook image products
     • S-Pol DZ/VE scan image archive
   • Ka-band performance report
   • Data Availability

5. S-Pol Description
   • Physical layout
   • Receiver configuration
   • Parameter Calculations/Derivations
   • Internal computer network and data flow

6. Data Verification Issues
   • Ranging and Pointing
   • S/Ka beam alignment
     • Solar scans used to fine tune dish alignment. Example
   • Differential Reflectivity, Zdr
   • S-band Reflectivity
   • Ka-band noise power estimates and corrections
   • Ka-band Reflectivity
   • System sensitivity
   • Linear Depolarization Ratio, LDR
   • Radial Velocity
   • Miscellaneous

7. Corrections Made in Processing
   • (see summary document.)

Appendices

1. Operators' Log
2. S-Pol Calibration History