Berkeley Sensor Database, an Implementation of CUAHSI's ODM for the Keck HydroWatch Wireless Sensor Network

The Keck HydroWatch Project is a multidisciplinary project devoted to understanding how water interacts with atmosphere, vegetation, soil, and fractured bedrock. It is experimenting with novel techniques to monitor and trace water pathways through these mediums, including developing an intensive wireless sensor network, in the Angelo Coast Range and Sagehen Reserves in California. The sensor time-series data is being supplemented with periodic campaigns experimenting with sampling and tracing techniques, including water chemistry, stable isotope analysis, electrical resistivity tomography (ERT), and neutron probes. Mechanistic and statistical modeling is being performed with these datasets. One goal of the HydroWatch project is to prototype technologies for intensive sampling that can be upscaled to the watershed scale. The Berkeley Sensor Database was designed to manage the large volumes of heterogeneous data coming from this sensor network. This system is based on the Observations Data Model (ODM) developed by the Consortium of Universities for the Advancement of Hydrologic Science, Inc. (CUAHSI). Due to need for the use of open-source software, UC Berkeley ported the ODM to a LAMP system (Linux, Apache, MySQL, Perl). As of August 2010, the Berkeley Sensor Database contains 33 million measurements from 1200 devices, with several thousand new measurements being added each hour. Data for this research is being collected from a wide variety of equipment. Some of this equipment is experimental and subject to constant modification, others are industry standards. Well pressure transducers, sap flow sensors, experimental microclimate motes, standard weather stations, and multiple rock and soil moisture sensors are some examples. While the Hydrologic Information System (HIS) and the ODM are optimized for data interoperability, they are not focused on facility management and data quality control which occur at a complex research site. In this presentation, we describe our implementation of the ODM, the modifications we made to the ODM schema to include incident reports, concepts of 'stations', reuse and moving of equipment, and NASA data quality levels. The HydroWatch researchers' data use vary radically, so we implemented a number of different accessors to the data, from real-time graphing during storms to direct SQL queries for automated analysis to full data dumps for heavy statistical modeling.