The Open Geospatial Consortium PUCK Standard: Building Sensor Networks with Self-Describing Instruments

Sensor technology is rapidly advancing, enabling smaller and cheaper instruments to monitor Earth's environment. It is expected that many more kinds and quantities of networked environmental sensors will be deployed in coming years. Knowledge of each instrument's command protocol is required to operate and acquire data from the network. Making sense of these data streams to create an integrated picture of environmental conditions requires that each instrument's data and metadata be accurately processed and that "suspect" data be flagged. Use of standards to operate an instrument and retrieve and describe its data generally simplifies instrument software development, integration, operation and data processing. The Open Geospatial Consortium (OGC) PUCK protocol enables instruments that describe themselves in a standard way. OGC PUCK defines a small "data sheet" that describes key instrument characteristics, and a standard protocol to retrieve the data sheet from the device itself. Data sheet fields include a universal serial number that is unique across all PUCK-compliant instruments. Other fields identify the instrument manufacturer and model. In addition to the data sheet, the instrument may also provide a "PUCK payload" which can contain additional descriptive information (e.g. a SensorML document or IEEE 1451 TEDS), as well as actual instrument "driver" code. Computers on the sensor network can use PUCK protocol to retrieve this information from installed instruments and utilize it appropriately, e.g. to automatically identify, configure and operate the instruments, and acquire and process their data. The protocol is defined for instruments with an RS232 or Ethernet interface. OGC members recently voted to adopt PUCK as a component of the OGC's Sensor Web Enablement (SWE) standards. The protocol is also supported by a consortium of hydrographic instrument manufacturers and has been implemented by several of them (https://sites.google.com/site/soscsite/). Thus far PUCK has been deployed on oceanographic observatories in North America and Europe, and is generally applicable to environmental sensor networks. As an example we describe how PUCK can be used with other established and emerging OGC SWE standards to simplify configuration and operation of environmental sensor networks, and to automate assessment and processing of the sensor data. The PUCK specification is free of charge and can be downloaded along with tools to implement and use the standard from http://www.opengeospatial.org/standards/puck.