Download latest release View on GitHub

This is the project page for the IOOS customized build of the 52┬░North Sensor Observation Service (SOS).

i52n-SOS extends the stock upstream 52┬░North (52n) SOS with IOOS specific encoding formats, test data, and more.

The IOOS custom encoding formats include:

  • Enhanced GetCapabilitiesResponse (extra metadata)
  • Enhanced SensorML (extra metadata and network/station/sensor hierarchies)
  • O&M and SWE (IOOS m1.0 SOS format)
  • netCDF (CF 1.6/ACDD 1.1/NODC 1.0/IOOS 1.0 conventions)
    • application/x-netcdf - single sensor/observed property
    • application/zip; subtype=x-netcdf - zipped, supports multiple sensors

NOTE: netCDF encoding formats require the installation of the netCDF4 C library on the server. For Debian/Ubuntu systems, this is the libnetcdf-dev package.

The IOOS test data:

  • Generates network, station, and sensor procedures
  • Uses IOOS SensorML formats and metadata
  • Uses CF standard names for observed properties
  • Uses udunits
  • Generates time series and time series profile data
  • Randomly generates global station locations
  • Includes test client example requests matching test data values

The project currently aims to conform to the IOOS SOS Milestone 1 Standard.

Release Notes

See Release notes document.

Mailing List

i52n-sos@googlegroups.com (Sign-up and archive)


i52n-sos can be run in Docker using prebuilt images available on the IOOS Docker Hub. See the i52n-sos Docker Hub page for more details.

Installation (non-Docker)

See installation instructions.


See upgrade instructions.

Test Data

To experiment with test data in your SOS, see test data instructions.


For tools to populate your SOS, see populating instructions.


For an overview of SOS concepts, see concepts.

Test instances

A test instance of the latest release of i52n-SOS is available:


A test instance of the current development version (bleeding edge/not yet released) of i52n-SOS is also available:


Testing the i52n-sos implementation

The i52n-sos implementation of the IOOS SOS specification can be tested using an (incomplete) collection of CTL tests. See the ioos-sos-compliance-tests project.

Issue Tracker

Report issues on the GitHub issue tracker.

Known Limitations

  • Quality flags not yet supported
  • Profile orientation/pitch/roll static data block not supported in GetObservation output
  • Station and sensor location in GetObservation are determined from observation locations
  • ResultTemplate operations are not supported

Other resources

Upstream 52North resources:

IOOS SOS resources:

Information on OGC SOS standards can be found here.