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The Inverted Echo Sounder (IES) is an ocean bottom-moored instrument that measures the vertical acoustic travel time (VATT) round-trip from the sea floor to the sea surface and back. The VATT varies principally due to changes in the temperature profile of the water column, making the IES well-suited for monitoring changes in temperature structure and dynamic height (baroclinic signal). Currently, the Model 6.2, a combined IES, data-logger, and acoustic release, with optional measurements of bottom pressure, temperature and current speed and direction (with attached AanderaaTM Doppler current sensor) is produced at URI/GSO. Data are processed in situ and are available (optional) remotely by an acoustic telemetry link or expendable, satellite-link data shuttle. In addition to the IES-measured baroclinic signals, barotropic near-bottom pressure variations may be measured with the optional pressure sensor. A report was written in 1991 describing IES data processing (Fields et al., 1991). Since that report, significant improvements have been made to both IES hardware and software, warranting an update of the IES data processing. This report will document standard processing steps currently carried out for IES Models 6.1 and 6.2 at URI/GSO. A separate document, Inverted Echo Sounder User’s Manual, IES Model 6.2, describes the IES hardware and instrument configuration.

Addendum.pdf (25 kB)