I attended the SAEON Summit 2010 (South African Environmental Observation Network) where most of the papers dealt with long term environmental observation data streams of one form or another. These are observations and measurements that are crying out to be Sensor Web Enabled to aid in their discovery and accessibility and ultimately more widespread use. Here’s a sample of datasets and sensor systems covered at the Summit that in my opinion would benefit a large audience by being made available through OGC Sensor Observation Services:

Marine and Coastal:

  • Historical marine survey data and catch returns: 1898-1948–50 years of historical fish stock data discovered in musty old archives.
  • Comparison of gridded sea surface temperature (SST) products with in situ temperature time series at coastal sites in South Africa–a perfect example of the use of in situ observations for calibration and validation (Cal-Val) of remotely-sensed gridded products.
  • Long-term changes in demersal fish assemblages.
  • Algoa Bay long-term monitoring sentinel site–multiple instrument, multiple parameter observations offshore, along beaches and in estuaries. Sensor web enablement would allow these all to be visualised and analysed together.
  • Thirty years of the Durban beach monitoring programme–beach profiles, sand erosion and accretion.

Water

  • Thirty-five years of local and national hydrological monitoring–in a water-scarce country like South Africa, publicly available current and accurate observations of water quantity and quality are essential. Sensor Web Enablement means taking this great resource a step further.

Terrestrial

  • The South African Bird Atlas Project: 4 years and counting of 5′ grid, 5 day period bird species observations.
  • Long-term dynamics of vegetation structure and composition
  • Twenty years of human-environment research in communal lands–multiple social and environmental observations relating to natural resources.

Climate

  • Establishing a state-of-the-art long-term inland station for monitoring integrated climate change parameters–a terrestrial equivalent of the Cape Point GAW (Global Atmospheric Watch) station.

Sensor Web Enablement (SWE) is an emerging field. Two fundamental components of SWE are Sensor Observation Services (SOS) and Sensor Model Language (SensorML). A SOS is a web service endpoint for accessing sensor descriptions and data. SensorML describes the sensor platform and sensors. When data are requested from the SOS, they are served in the OGC ‘Observations and Measurements’ (O&M) encoding. Any observations that comply with these specifications can be interrogated or downloaded in the same standard way, ensuring that maximum value is derived from the investment in making those observations and that they provide maximum benefit to the widest audience.

Various implementations of SWE server components are available including 52° North, Deegree, MapServer and istSOS.  Emerging client applications include 52° North, OpenLayers and the Time Series Toolbox. Because we are dealing with a standard, open ‘API’ here, users have complete freedom to develop custom clients so expect this list to expand rapidly.

SAEON is the ideal body to facilitate Sensor Web Enablement in South Africa, whereby these SOS instances would be catalogued in the SAEON portal and South African GEOSS portal.