acoustic_signature

acoustic_signature <signature-name> … end_acoustic_signature

acoustic_signature <signature-name>
   data_reference_range <length-value>

   state <state-name> | default
      spectrum_data
         freq <frequency-value> noise_pressure <noise-pressure-value>
         freq <frequency-value> noise_pressure <noise-pressure-value>
         ...
      end_spectrum_data

   state ...
end_acoustic_signature

<signature-name>

Name to be given to the signature. This must be unique among all acoustic signatures. A particular signature may be redefined, with the last definition being used.

Overview

acoustic_signature defines an acoustic signature for a platform type. It is used when an acoustic sensor attempts to detect a platform. The acoustic signature consists of one or more tables where each table defines the signature that applies when the platform is in a particular ‘state’. A ‘state’ represents a condition such as ‘landing-gear-down’.

Commands

data_reference_range <length-value>

The reference range that the following acoustic data was calculated or measured at. This value is used to adjust the following acoustic data to a zero slant range value.

state [ <state-name> | default ]

Indicates that the following table definition will be used when the platform is in the signature state <state-name>. If default is specified then the subsequent table will be used if the platform is in a signature state that does not match any of the states defined in the signature.

If a state command is not specified then the signature has one signature table that applies to all signature states.

freq <frequency-value>

1/3 octave center frequency of signature value.

Note

These must occur in increasing order within a single state.

noise_pressure <noise-pressure-value>

Acoustic noise pressure (dB/20 uPa) at specified 1/3 octave center frequency.