Snow sensor data quality indexing

California's automatic snow sensing network produces volumes of snow water equivalent (SWEQ) data. Even when the data is reduced to daily values, the sensor network produces over ten-thousand SWEQ values per snow season. With such a large and rapidly growing record, identifying which sensors and periods have good quality data and which do not is a problem. One solution is to index the quality of the snow sensor data. This paper describes a snow data quality index (SDQI) system that has been devised for California's snow sensor network. Using a unique feature of the California Data Exchange Center (CDEC) data base, SDQI scores, indicating the relative quality of the data, can be calculated for each sensor by water year. An SDQI score of zero indcates no usable data. An SDQI score of one-hundred indicates perfect data---should we ever achieve such a thing. These SDQI scores can be computer generated, using a program we wrote for this purpose. The SDQI scores can be displayed in a table.