download as a pdf - Southern California Coastal Ocean Observing ...

Part I. OverviewPrimary Data Assembly and Quality Control (PDA&QC) processes lie at the interface betweenthe IOOS Observing Subsystem and the DMAC Subsystem. In general, some form of PDA&QC isrequired before IOOS data can be used. The character of this activity varies greatly by data type.It includes such processes as hand entry of numbers from log sheets, conversion from raw instrumentvoltages to physical units, calibrations, and the quality assessment of measured values againstneighboring measurements or climatological norms. It is in this activity that myriad individualmeasurements are assembled into “data sets” (named collections of data) that may be referencedand queried as a whole. The activity may be conducted as a part of a data management strategy fora particular measurement type, where examples include NOAA/NDBC management of mooringdata and NASA/PODAAC management of ocean satellite data. Alternatively, it may be managedby an IOOS Regional Association, for example assembling regional ecosystem measurements; orit may be found in conjunction with operational forecast modeling and state estimation, where aprime example is the U.S. GODAE Server (which operates in close association with the Navy’s FleetNumerical Meteorological and Oceanography Center).Because of its location at the boundary between two subsystems, the responsibilities for PDA&QCare shared between the Observing Subsystem and the DMAC Subsystem. As a general rule theDMAC Subsystem’s responsibility for procedures and standards of scientific quality control (QC)are limited to providing mechanisms to ensure that QC flags are reliably associated with the correspondingmeasurements. The standards and procedures for quality control will be developed bythe relevant marine science communities. The DMAC Plan (this document), however, also includesa management responsibility to ensure that all IOOS data steams undergo primary data assemblyand quality-control processing to make them available using DMAC standards and protocols at aspecified DMAC Data Entry Point. In some cases this responsibility may involve support for specificfacilities, such as the U.S. GODAE Server. In the future we may see the growth of “intelligent”instruments that can perform data assembly and quality control functions at the instrument subsystemlevel 5 .The telemetry systems that convey data from sensors to primary data centers/sites and the standardsand procedures for data assembly and quality control lie outside the scope of this DMACPlan. It is recognized, however, that these areas require careful planning within IOOS, and thesetopics will be addressed in future IOOS plans. The intent of the current DMAC Plan is to provide afoundation for these community building and planning activities.5Delin, K.A., 2002, The Sensor Web: A Macro-Instrument for Coordinated Sensing, Sensors, 2, 270-285)23