DQR ID | Subject | Data Streams Affected |
---|---|---|
D050714.4 | SGP/MMCR/C1 - Poor cross polar isolation | sgpmmcrmomC1.b1 |
D100215.1 | SGP/VCEIL/C1/B4/B5/B6 - Reprocess: Incorrect serial_number and sum_backscatter fields | sgpvceil25kB4.b1, sgpvceil25kB5.b1, sgpvceil25kB6.b1, sgpvceil25kC1.b1 |
Start Date | Start Time | End Date | End Time |
---|---|---|---|
08/15/2004 | 0000 | 08/27/2010 | 2100 |
Subject: | SGP/MMCR/C1 - Poor cross polar isolation |
DataStreams: | sgpmmcrmomC1.b1 |
Description: | This last spring, Sergey Matrosov pointed out that the Circular Depolarization Ratio measurements on the SGP radar indicated the isolation between the co and cross channels was only about 15 dB. Typically isolation of 25-30 dB is expected for polarization measurements to be useful. We set about to see if we could identify the source of the poor isolation. Kevin Widener had purchased a custom built orthomode transducer and polarizer that hadn't gone through any previous testing and we decided to swap it out with an ETL unit that had shown good isolation in the past. Kevin performed the swap a couple of weeks back and this week the latest archive data was available to compare results between the OMTs. Results from two precipitating cloud conditions, where we looked below the melting layer, where we expect to find domination of spherical water droplets and therefore maximum values for cdr - the maximum isolation (CDR) appears to be about 17 dB. The results showed that the poor isolation is probably not due to the OMTs but rather to the antenna itself. |
Measurements: | sgpmmcrmomC1.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
04/01/2001 | 0000 | 10/31/2009 | 2359 |
Subject: | SGP/VCEIL/C1/B4/B5/B6 - Reprocess: Incorrect serial_number and sum_backscatter fields |
DataStreams: | sgpvceil25kB4.b1, sgpvceil25kB5.b1, sgpvceil25kB6.b1, sgpvceil25kC1.b1 |
Description: | Attribute serial_number: In most cases, this field is not representative of the actual serial number of the instrument because the value did not change when an instrument changed locations or was replaced with a spare. Variable sum_backscatter: An out-of-range condition for the "sum of detected and normalized backscatter" was reported as 0 instead of missing (-9999). The valid range is 0 - 0.0999 /srad. This DQR also applies to a1 level data collected prior to b1 level. |
Measurements: | sgpvceil25kC1.b1:
sgpvceil25kB4.b1:
sgpvceil25kB6.b1:
sgpvceil25kB5.b1:
|