Radial data files contain radial components of sea surface parameters measured by HF ocean radars operated by Australian Coastal Ocean Radar Network (ACORN), a facility of Integrated Marine Observing System (IMOS).
Regardless of the radar system (WERA or SeaSonde), the primary product is the radial component of the sea surface current along a line between the radar station and a point on the sea surface. By combining radials measured at two stations surface current vectors can be constructed. These surface current vectors can then be used to study tides, wind-driven currents and perform lagrangian particle tracking.
Raw data collected at each radar site are re-processed by ACORN in order to assign quality control flags to data points. This is not possible in real-time because real-time data are produced by proprietary manufacturer software without quality control flags and it is not feasible to transfer the raw data to ACORN in real-time.
Each radial file contains a set of standard metadata fields, such as radar system type, operating frequency and bandwidth. Other metadata fields describe radar system type-specific parameters. Radial file metadata fields are described in a separate ACORN data document.
In addition, for WERA radar systems, ACORN provides quality controlled heights of left and right bragg peaks, from which the wind direction can be inferred.