Marlene Jeffries (Observatory Data Specialist)
Graphical representation of the QA/QC data on a VENUS data plot
One of the problems facing a real-time oceanographic observatory is the ability to provide a fast and accurate assessment of data quality. VENUS is in the process of implementing measures of real time quality control on incoming scalar data that meet the guidelines of the Quality Assurance of Real Time Oceanographic Data (QARTOD) group. QARTOD is a US organization tasked with identifying issues involved with incoming real-time data from the U.S Integrated Ocean Observing System (IOOS). A large portion of their agenda is to create guidelines for how the quality of real-time data is to be determined and reported to the scientific community. VENUS is striving to adhere to these guidelines to provide trusted data to the scientific community.
In May 2011, VENUS launches the first step towards returning a quality controlled product to the VENUS user. Real time data quality testing at the VENUS includes tests designed to catch instrument failures and major spikes or data dropouts before the data are made available to the user. Tests include instrument manufacturer’s limits, climatological values and site ranges determined from the previous years of data. Due to the positioning of some VENUS instrument platforms in highly productive areas, we have also designed dual-sensor tests to catch conductivity cell plugs that cause a sudden drop in conductivity. All of the VENUS primary sensors are subject to the above tests with an overall quality control flag returned with the data requested by the user. Future forms of quality control that VENUS will implement include delayed-mode testing and manual quality control of archived primary sensor data. Manual quality control of archived data by a VENUS data expert will be available by June 2011 while delayed-mode testing is still in development.
