Atmospheric Radiation Measurement Climate Research Facility US Department of Energy

csapr > C-Band Scanning ARM Precipitation RadarInstrument Type(s) > Baseline • Guest

The C-Band Scanning ARM Precipitation Radar is a dual-polarization Doppler weather radar that operates in a simultaneous transmit and receive (STAR) mode, splitting the transmit signal so that power is transmitted on both horizontal and vertical polarizations at the same time. The CSAPR can also transmit on a single polarization (horizontal or vertical) and measure linear depolarization ratio (LDR).

In addition to the first three Doppler moments (reflectivity, radial velocity, and spectra width), the CSAPR also provides differential reflectivity, correlation coefficient, and specific differential phase. The dual-polarization variables enable the provision of rainfall rate estimates and identification of precipitation types.

For the 2018–2019 Cloud, Aerosol, and Complex Terrain Interactions (CACTI) field campaign in Argentina, ARM deployed a second-generation CSAPR, known as CSAPR2. CACTI data from the CSAPR2 are now available as b1-level products. Building on the original CACTI operational data, the b1-level products feature improved data quality resulting from extensive analyses and corrections. The data are cross-calibrated to a common point, datastreams are corrected for operational issues that occurred during the campaign, and several data quality masks and basic derived products are incorporated. For more information, read the CACTI radar b1-level processing report.


  • Fixed
  • AMF1
  • AMF2
  • AMF3


Collis SM, JJ Helmus, ZS Sherman, and RC Jackson. 2022. Corrected Moments in Antenna Coordinates (CMAC) X-SAPR Technical Report. Ed. by Robert Stafford, ARM user facility. DOE/SC-ARM-TR-283. 10.2172/1898601.

Lombardo K and M Kumjian. 2022. "Observations of the Discrete Propagation of a Mesoscale Convective System during RELAMPAGO–CACTI." Monthly Weather Review, 150(8), 10.1175/MWR-D-21-0265.1.

Oue M, S Saleeby, P Marinescu, P Kollias, and S van den Heever. 2022. "Optimizing radar scan strategies for tracking isolated deep convection using observing system simulation experiments." Atmospheric Measurement Techniques, 15(16), 10.5194/amt-15-4931-2022.
Research Highlight

Borque P, A Varble, and J Hardin. 2022. "Peak Rain Rate Sensitivity to Observed Cloud Condensation Nuclei and Turbulence in Continental Warm Shallow Clouds During CACTI." Journal of Geophysical Research: Atmospheres, , e2022JD036864, 10.1029/2022JD036864. ACCEPTED.

Feng Z, A Varble, J Hardin, J Marquis, A Hunzinger, Z Zhang, and M Thieman. 2022. "Deep Convection Initiation, Growth, and Environments in the Complex Terrain of Central Argentina during CACTI." Monthly Weather Review, 150(5), 10.1175/MWR-D-21-0237.1.
Research Highlight

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