Nortek data formats (*.ad2cp, *.nmea, *.anpp)

Echosounder data recorded by Nortek Signature profilers combine a current profiler with an optional scientific echosounder that can transmit selected single frequencies or a chirp.

Echoview reads *.ad2cp files and creates raw variables derived from recorded environmental, echosounder, heading, pitch and roll data. For continuous wave (single) frequencies, Echoview calculates Sv and TS with Nortek equations.

The echosounder records processed pulse compressed data under sub-bands of the chirp bandwidth. The processed data benefits from wideband noise reduction and increased resolution, however the frequency response information is absent. Nortek processed pulse compression is proprietary and as a result, Echoview derives unspecified dB variables for the data from each sub-band. Such raw variables include the term 'pulse compressed' in their name as a reminder of the data's processed pulse-compressed nature. The nominal center frequency of the sub-band is assigned to the variable. Calibration values are based on those read from the first ping.

Echoview derives heading and position variables from reading associated *0.nmea, *1.nmea (see NMEA) and *.anpp files stored in the same folder as *.ad2cp files.

Nortek files can be verified by Echocheck.

See also

Raw variables derived from Nortek data files
Calibration settings for Nortek data
Nortek Power to Sv and TS
Nortek details