SGP/MMCR/C1 - Precipitation Mode Reflectivity Incorrect
|DataStreams:||sgpmmcrspecmomC1.a0, sgpmmcrspeccmaskcopolC1.a0, sgpmmcrspeccmaskprC1.a0, sgpmmcrmomC1.b1,|
The MMCR's precipitation mode is achieved by switching in one of two rf switches thereby intending to add approximately 25 dB of attenuation. This prevents the receiver and computer ADC from saturating. It now appears that the amount of attenuation actually being applied varied, and is not accurately known. The precipitation mode reflectivities values may not be quantitatively accurate. Most of the time a bit more than the intended 25 dB of attenuation was actually being applied. Mode 4 reflectivities are consistently less than Mode 3 reflectivities (by anywhere from a few to 10 dBZ).
The reflectivity values should not be used in a quantitative manner.