- List
- Wassenaar Arrangement – List of Dual-Use Goods and Technologies – WA-LIST (25) 1
- Corresponding EU entry
- 6A001
a. Marine acoustic systems, equipment and specially designed components therefor, as follows:
1. Active (transmitting or transmitting-and-receiving) systems, equipment and specially designed components therefor, as follows:
Note 6.A.1.a.1. does not apply to equipment as follows:
a. Depth sounders operating vertically below the apparatus, not including a scanning function exceeding ± 20°, and limited to measuring the depth of water, the distance of submerged or buried objects or fish finding;
b. Acoustic beacons, as follows:
1. Acoustic emergency beacons;
2. Pingers specially designed for relocating or returning to an underwater position.
a. 1. a. Acoustic seabed survey equipment as follows:
Technical Note
For the purposes of 6.A.1.a.1.a., 'enhancement' includes the ability to compensate by external means.
1. Surface vessel survey equipment designed for seabed topographic mapping and having all of the following:
a. Designed to take measurements at an angle exceeding 20° from the vertical;
b. Designed to measure seabed topography at seabed depths exceeding 600 m;
c. 'Sounding resolution' less than 2; and
d. 'Enhancement' of the depth "accuracy" through compensation for all the following:
1. Motion of the acoustic sensor;
2. In-water propagation from sensor to the seabed and back; and
3. Sound speed at the sensor;
Technical Note
For the purposes of 6.A.1.a.1.a.1.c., 'sounding resolution' is the swath width (degrees) divided by the maximum number of soundings per swath.
a. 1. a. 2. Underwater survey equipment designed for seabed topographic mapping and having any of the following:
Technical Note
For the purposes of 6.A.1.a.1.a.2., the acoustic sensor pressure rating determines the depth rating.
a. 1. a. 2. a. Having all of the following:
1. Designed or modified to operate at depths exceeding 300 m; and
2. 'Sounding rate' greater than 3,800 m/s; or
Technical Note
For the purposes of 6.A.1.a.1.a.2.a.2., 'sounding rate' is the product of the maximum speed (m/s) at which the sensor can operate and the maximum number of soundings per swath assuming 100% coverage. For systems that produce soundings in two directions (3D sonars), the maximum of the 'sounding rate' in either direction should be used.
a. 1. a. 2. b. Survey equipment, not specified in 6.A.1.a.1.a.2.a., having all of the following:
1. Designed or modified to operate at depths exceeding 100 m;
2. Designed to take measurements at an angle exceeding 20° from the vertical;
3. Having any of the following:
a. Operating frequency below 350 kHz; or
b. Designed to measure seabed topography at a range exceeding 200 m from the acoustic sensor; and
4. 'Enhancement' of the depth "accuracy" through compensation of all of the following:
a. Motion of the acoustic sensor;
b. In-water propagation from sensor to the seabed and back; and
c. Sound speed at the sensor;
a. 1. a. 3. Side Scan Sonar (SSS) or Synthetic Aperture Sonar (SAS), designed for seabed imaging and having all of the following, and specially designed transmitting and receiving acoustic arrays therefor:
a. Designed or modified to operate at depths exceeding 500 m;
b. An 'area coverage rate' of greater than 570 m²/s while operating at the maximum range that it can operate with an 'along track resolution' of less than 15 cm; and
c. An 'across track resolution' of less than 15 cm;
Technical Notes
For the purposes of 6.A.1.a.1.a.3.:
1. 'Area coverage rate' (m²/s) is twice the product of the sonar range (m) and the maximum speed (m/s) at which the sensor can operate at that range.
2. 'Along track resolution' (cm), for SSS only, is the product of azimuth (horizontal) beamwidth (degrees) and sonar range (m) and 0.873.
3. 'Across track resolution' (cm) is 75 divided by the signal bandwidth (kHz).
a. 1. b. Systems or transmitting and receiving arrays, designed for object detection or location, having any of the following:
N.B. For acoustic seabed survey equipment, see 6.A.1.a.1.a.
1. A transmitting frequency below 10 kHz;
2. Sound pressure level exceeding 224 dB (reference 1 µPa at 1 m) for equipment with an operating frequency in the band from 10 kHz to 24 kHz inclusive;
3. Sound pressure level exceeding 235 dB (reference 1 µPa at 1 m) for equipment with an operating frequency in the band between 24 kHz and 30 kHz;
4. Forming beams of less than 1° on any axis and having an operating frequency of less than 100 kHz;
5. Designed to operate with an unambiguous display range exceeding 5,120 m; or
6. Designed to withstand pressure during normal operation at depths exceeding 1,000 m and having transducers with any of the following:
a. Dynamic compensation for pressure; or
b. Incorporating other than lead zirconate titanate as the transduction element;
a. 1. c. Acoustic projectors (including transducers), incorporating piezoelectric, magnetostrictive, electrostrictive, electrodynamic or hydraulic elements operating individually or in a designed combination, and having any of the following:
Note 1 The status of acoustic projectors, including transducers, specially designed for other equipment not specified in 6.A.1. is determined by the status of the other equipment.
Note 2 6.A.1.a.1.c. does not apply to electronic sources which direct the sound vertically only, or mechanical (e.g., air gun or vapour-shock gun) or chemical (e.g., explosive) sources.
Note 3 Piezoelectric elements specified in 6.A.1.a.1.c. include those made from lead-magnesium-niobate/lead-titanate (Pb(Mg_(1/3)Nb_(2/3))O₃-PbTiO_(3,) or PMN-PT) single crystals grown from solid solution or lead-indium-niobate/lead-magnesium niobate/lead-titanate (Pb(In_(1/2)Nb_(1/2))O₃–Pb(Mg_(1/3)Nb_(2/3))O₃–PbTiO_(3,) or PIN-PMN-PT) single crystals grown from solid solution.
a. 1. c. 1. Operating at frequencies below 10 kHz and having any of the following:
a. Not designed for continuous operation at 100% duty cycle and having a radiated 'free-field Source Level (SL_(RMS))' exceeding (10log(f) + 169.77)dB (reference 1 µPa at 1 m) where f is the frequency in Hertz of maximum Transmitting Voltage Response (TVR) below 10 kHz; or
b. Designed for continuous operation at 100% duty cycle and having a continuously radiated 'free-field Source Level (SL_(RMS))' at 100% duty cycle exceeding (10log(f) + 159.77)dB (reference 1 µPa at 1 m) where f is the frequency in Hertz of maximum Transmitting Voltage Response (TVR) below 10 kHz; or
Technical Note
For the purposes of 6.A.1.a.1.c.1., the 'free-field Source Level (SL_(RMS))' is defined along the maximum response axis and in the far field of the acoustic projector. It can be obtained from the Transmitting Voltage Response using the following equation: SL_(RMS) = (TVR + 20log V_(RMS)) dB (ref 1µPa at 1 m), where SL_(RMS) is the source level, TVR is the Transmitting Voltage Response and V_(RMS) is the Driving Voltage of the Projector.
a. 1. c. 2. Not used since 2014
N.B. For items previously specified in 6.A.1.a.1.c.2., see 6.A.1.a.1.c.1.
3. Side-lobe suppression exceeding 22 dB;
a. 1. d. Acoustic systems and equipment, designed to determine the position of surface vessels or submersible vehicles and having all of the following, and specially designed components therefor:
1. Detection range exceeding 1,000 m; and
2. Determined position error of less than 10 m rms (root mean square) when measured at a range of 1,000 m;
Note 6.A.1.a.1.d. includes:
a. Equipment using coherent "signal processing" between two or more beacons and the hydrophone unit carried by the surface vessel or submersible vehicle;
b. Equipment capable of automatically correcting speed-of-sound propagation errors for calculation of a point.
a. 1. e. Active individual sonars, specially designed or modified to detect, locate and automatically classify swimmers or divers, having all of the following, and specially designed transmitting and receiving acoustic arrays therefor:
1. Detection range exceeding 530 m;
2. Determined position error of less than 15 m rms (root mean square) when measured at a range of 530 m; and
3. Transmitted pulse signal bandwidth exceeding 3 kHz;
N.B. For diver detection systems specially designed or modified for military use, see the Munitions List.
Note For 6.A.1.a.1.e., where multiple detection ranges are specified for various environments, the greatest detection range is used.
a. 2. Passive systems, equipment and specially designed components therefor, as follows:
Note 6.A.1.a.2. also applies to receiving equipment, whether or not related in normal application to separate active equipment, and specially designed components therefor.
a. 2. a. Hydrophones having any of the following:
Note The status of hydrophones specially designed for other equipment is determined by the status of the other equipment.
Technical Notes
For the purposes of 6.A.1.a.2.a.:
1. Hydrophones consist of one or more sensing elements producing a single acoustic output channel. Those that contain multiple elements can be referred to as a hydrophone group.
2. Underwater acoustic transducers designed to operate as passive receivers are hydrophones.
a. 2. a. 1. Incorporating continuous flexible sensing elements;
2. Incorporating flexible assemblies of discrete sensing elements with either a diameter or length less than 20 mm and with a separation between elements of less than 20 mm;
3. Having any of the following sensing elements:
a. Optical fibres;
b. 'Piezoelectric polymer films' other than polyvinylidene-fluoride (PVDF) and its co-polymers {P(VDF-TrFE) and P(VDF-TFE)};
c. 'Flexible piezoelectric composites';
d. Lead-magnesium-niobate/lead-titanate (i.e., Pb(Mg_(1/3)Nb_(2/3))O₃-PbTiO_(3,) or PMN-PT) piezoelectric single crystals grown from solid solution; or
e. Lead-indium-niobate/lead-magnesium niobate/lead-titanate (i.e., Pb(In_(1/2)Nb_(1/2))O₃–Pb(Mg_(1/3)Nb_(2/3))O₃–PbTiO₃, or PIN-PMN-PT) piezoelectric single crystals grown from solid solution;
4. A 'hydrophone sensitivity' greater (better) than -180 dB at any depth with no acceleration compensation;
5. Designed to operate at depths exceeding 35 m with acceleration compensation; or
6. Designed for operation at depths exceeding 1,000 m and having a 'hydrophone sensitivity' greater (better) than -230 dB below 4 kHz;
Technical Notes
1. For the purposes of 6.A.1.a.2.a.3.b., 'piezoelectric polymer film' sensing elements consist of polarized polymer film that is stretched over and attached to a supporting frame or spool (mandrel).
2. For the purposes of 6.A.1.a.2.a.3.c., 'flexible piezoelectric composite' sensing elements consist of piezoelectric ceramic particles or fibres combined with an electrically insulating, acoustically transparent rubber, polymer or epoxy compound, where the compound is an integral part of the sensing elements.
Technical Notes cont.
3. For the purposes of 6.A.1.a.2.a., 'hydrophone sensitivity' is defined as twenty times the logarithm to the base 10 of the ratio of rms output voltage to a 1 V rms reference, when the hydrophone sensor, without a pre-amplifier, is placed in a plane wave acoustic field with an rms pressure of 1 µPa. For example, a hydrophone of -160 dB (reference 1 V per µPa) would yield an output voltage of 10⁻⁸ V in such a field, while one of -180 dB sensitivity would yield only 10⁻⁹ V output. Thus, -160 dB is better than -180 dB.
a. 2. b. Towed acoustic hydrophone arrays having any of the following:
Technical Note
For the purposes of 6.A.1.a.2.b., hydrophone arrays consist of a number of hydrophones providing multiple acoustic output channels.
1. Hydrophone group spacing of less than 12.5 m or 'able to be modified' to have hydrophone group spacing of less than 12.5 m;
2. Designed or 'able to be modified' to operate at depths exceeding 35 m;
3. Heading sensors specified in 6.A.1.a.2.d.;
4. Longitudinally reinforced array hoses;
5. An assembled array of less than 40 mm in diameter;
6. Not used since 2007
7. Hydrophone characteristics specified in 6.A.1.a.2.a.; or
8. Accelerometer-based hydro-acoustic sensors specified in 6.A.1.a.2.g.;
Technical Note
For the purposes of 6.A.1.a.2.b., 'able to be modified' means having provisions to allow a change of the wiring or interconnections to alter hydrophone group spacing or operating depth limits. These provisions are: spare wiring exceeding 10% of the number of wires, hydrophone group spacing adjustment blocks or internal depth limiting devices that are adjustable or that control more than one hydrophone group.
a. 2. c. Processing equipment, specially designed for towed acoustic hydrophone arrays, having "user-accessible programmability" and time or frequency domain processing and correlation, including spectral analysis, digital filtering and beamforming using Fast Fourier or other transforms or processes;
a. 2. d. Heading sensors having all of the following:
1. An "accuracy" of less (better) than 0.5°; and
2. Designed to operate at depths exceeding 35 m or having an adjustable or removable depth sensing device in order to operate at depths exceeding 35 m;
N.B. For inertial heading systems, see 7.A.3.c.
a. 2. e. Bottom or bay-cable hydrophone arrays having any of the following:
1. Incorporating hydrophones specified in 6.A.1.a.2.a.;
2. Incorporating multiplexed hydrophone group signal modules having all of the following characteristics:
a. Designed to operate at depths exceeding 35 m or having an adjustable or removable depth sensing device in order to operate at depths exceeding 35 m; and
b. Capable of being operationally interchanged with towed acoustic hydrophone array modules; or
3. Incorporating accelerometer-based hydro-acoustic sensors specified in 6.A.1.a.2.g.;
a. 2. f. Processing equipment, specially designed for bottom or bay cable systems, having "user-accessible programmability" and time or frequency domain processing and correlation, including spectral analysis, digital filtering and beamforming using Fast Fourier or other transforms or processes;
a. 2. g. Accelerometer-based hydro-acoustic sensors having all of the following:
1. Composed of three accelerometers arranged along three distinct axes;
2. Having an overall 'acceleration sensitivity' greater (better) than 48 dB (reference 1,000 mV rms per 1g);
3. Designed to operate at depths greater than 35 meters; and
4. Operating frequency below 20 kHz.
Note 6.A.1.a.2.g. does not apply to particle velocity sensors or geophones.
Technical Notes
1. For the purposes of 6.A.1.a.2.g., accelerometer-based hydro-acoustic sensors are also known as vector sensors.
2. For the purposes of 6.A.1.a.2.g.2., 'acceleration sensitivity' is defined as twenty times the logarithm to the base 10 of the ratio of rms output voltage to a 1 V rms reference, when the hydro-acoustic sensor, without a preamplifier, is placed in a plane wave acoustic field with an rms acceleration of 1 g (i.e., 9.81 m/s²).
b. Correlation-velocity and Doppler-velocity sonar log equipment, designed to measure the horizontal speed of the equipment carrier relative to the seabed, as follows:
1. Correlation-velocity sonar log equipment having any of the following characteristics:
a. Designed to operate at distances between the carrier and the seabed exceeding 500 m; or
b. Having speed "accuracy" less (better) than 1% of speed;
2. Doppler-velocity sonar log equipment having speed "accuracy" less (better) than 1% of speed.
Note 1 6.A.1.b. does not apply to depth sounders limited to any of the following:
a. Measuring the depth of water;
b. Measuring the distance of submerged or buried objects; or
c. Fish finding.
Note 2 6.A.1.b. does not apply to equipment specially designed for installation on surface vessels.
c. Not used since 2010
N.B. For diver deterrent acoustic systems, see 8.A.2.r.
OPTICAL SENSORS
1. Active (transmitting or transmitting-and-receiving) systems, equipment and specially designed components therefor, as follows:
Note 6.A.1.a.1. does not apply to equipment as follows:
a. Depth sounders operating vertically below the apparatus, not including a scanning function exceeding ± 20°, and limited to measuring the depth of water, the distance of submerged or buried objects or fish finding;
b. Acoustic beacons, as follows:
1. Acoustic emergency beacons;
2. Pingers specially designed for relocating or returning to an underwater position.
a. 1. a. Acoustic seabed survey equipment as follows:
Technical Note
For the purposes of 6.A.1.a.1.a., 'enhancement' includes the ability to compensate by external means.
1. Surface vessel survey equipment designed for seabed topographic mapping and having all of the following:
a. Designed to take measurements at an angle exceeding 20° from the vertical;
b. Designed to measure seabed topography at seabed depths exceeding 600 m;
c. 'Sounding resolution' less than 2; and
d. 'Enhancement' of the depth "accuracy" through compensation for all the following:
1. Motion of the acoustic sensor;
2. In-water propagation from sensor to the seabed and back; and
3. Sound speed at the sensor;
Technical Note
For the purposes of 6.A.1.a.1.a.1.c., 'sounding resolution' is the swath width (degrees) divided by the maximum number of soundings per swath.
a. 1. a. 2. Underwater survey equipment designed for seabed topographic mapping and having any of the following:
Technical Note
For the purposes of 6.A.1.a.1.a.2., the acoustic sensor pressure rating determines the depth rating.
a. 1. a. 2. a. Having all of the following:
1. Designed or modified to operate at depths exceeding 300 m; and
2. 'Sounding rate' greater than 3,800 m/s; or
Technical Note
For the purposes of 6.A.1.a.1.a.2.a.2., 'sounding rate' is the product of the maximum speed (m/s) at which the sensor can operate and the maximum number of soundings per swath assuming 100% coverage. For systems that produce soundings in two directions (3D sonars), the maximum of the 'sounding rate' in either direction should be used.
a. 1. a. 2. b. Survey equipment, not specified in 6.A.1.a.1.a.2.a., having all of the following:
1. Designed or modified to operate at depths exceeding 100 m;
2. Designed to take measurements at an angle exceeding 20° from the vertical;
3. Having any of the following:
a. Operating frequency below 350 kHz; or
b. Designed to measure seabed topography at a range exceeding 200 m from the acoustic sensor; and
4. 'Enhancement' of the depth "accuracy" through compensation of all of the following:
a. Motion of the acoustic sensor;
b. In-water propagation from sensor to the seabed and back; and
c. Sound speed at the sensor;
a. 1. a. 3. Side Scan Sonar (SSS) or Synthetic Aperture Sonar (SAS), designed for seabed imaging and having all of the following, and specially designed transmitting and receiving acoustic arrays therefor:
a. Designed or modified to operate at depths exceeding 500 m;
b. An 'area coverage rate' of greater than 570 m²/s while operating at the maximum range that it can operate with an 'along track resolution' of less than 15 cm; and
c. An 'across track resolution' of less than 15 cm;
Technical Notes
For the purposes of 6.A.1.a.1.a.3.:
1. 'Area coverage rate' (m²/s) is twice the product of the sonar range (m) and the maximum speed (m/s) at which the sensor can operate at that range.
2. 'Along track resolution' (cm), for SSS only, is the product of azimuth (horizontal) beamwidth (degrees) and sonar range (m) and 0.873.
3. 'Across track resolution' (cm) is 75 divided by the signal bandwidth (kHz).
a. 1. b. Systems or transmitting and receiving arrays, designed for object detection or location, having any of the following:
N.B. For acoustic seabed survey equipment, see 6.A.1.a.1.a.
1. A transmitting frequency below 10 kHz;
2. Sound pressure level exceeding 224 dB (reference 1 µPa at 1 m) for equipment with an operating frequency in the band from 10 kHz to 24 kHz inclusive;
3. Sound pressure level exceeding 235 dB (reference 1 µPa at 1 m) for equipment with an operating frequency in the band between 24 kHz and 30 kHz;
4. Forming beams of less than 1° on any axis and having an operating frequency of less than 100 kHz;
5. Designed to operate with an unambiguous display range exceeding 5,120 m; or
6. Designed to withstand pressure during normal operation at depths exceeding 1,000 m and having transducers with any of the following:
a. Dynamic compensation for pressure; or
b. Incorporating other than lead zirconate titanate as the transduction element;
a. 1. c. Acoustic projectors (including transducers), incorporating piezoelectric, magnetostrictive, electrostrictive, electrodynamic or hydraulic elements operating individually or in a designed combination, and having any of the following:
Note 1 The status of acoustic projectors, including transducers, specially designed for other equipment not specified in 6.A.1. is determined by the status of the other equipment.
Note 2 6.A.1.a.1.c. does not apply to electronic sources which direct the sound vertically only, or mechanical (e.g., air gun or vapour-shock gun) or chemical (e.g., explosive) sources.
Note 3 Piezoelectric elements specified in 6.A.1.a.1.c. include those made from lead-magnesium-niobate/lead-titanate (Pb(Mg_(1/3)Nb_(2/3))O₃-PbTiO_(3,) or PMN-PT) single crystals grown from solid solution or lead-indium-niobate/lead-magnesium niobate/lead-titanate (Pb(In_(1/2)Nb_(1/2))O₃–Pb(Mg_(1/3)Nb_(2/3))O₃–PbTiO_(3,) or PIN-PMN-PT) single crystals grown from solid solution.
a. 1. c. 1. Operating at frequencies below 10 kHz and having any of the following:
a. Not designed for continuous operation at 100% duty cycle and having a radiated 'free-field Source Level (SL_(RMS))' exceeding (10log(f) + 169.77)dB (reference 1 µPa at 1 m) where f is the frequency in Hertz of maximum Transmitting Voltage Response (TVR) below 10 kHz; or
b. Designed for continuous operation at 100% duty cycle and having a continuously radiated 'free-field Source Level (SL_(RMS))' at 100% duty cycle exceeding (10log(f) + 159.77)dB (reference 1 µPa at 1 m) where f is the frequency in Hertz of maximum Transmitting Voltage Response (TVR) below 10 kHz; or
Technical Note
For the purposes of 6.A.1.a.1.c.1., the 'free-field Source Level (SL_(RMS))' is defined along the maximum response axis and in the far field of the acoustic projector. It can be obtained from the Transmitting Voltage Response using the following equation: SL_(RMS) = (TVR + 20log V_(RMS)) dB (ref 1µPa at 1 m), where SL_(RMS) is the source level, TVR is the Transmitting Voltage Response and V_(RMS) is the Driving Voltage of the Projector.
a. 1. c. 2. Not used since 2014
N.B. For items previously specified in 6.A.1.a.1.c.2., see 6.A.1.a.1.c.1.
3. Side-lobe suppression exceeding 22 dB;
a. 1. d. Acoustic systems and equipment, designed to determine the position of surface vessels or submersible vehicles and having all of the following, and specially designed components therefor:
1. Detection range exceeding 1,000 m; and
2. Determined position error of less than 10 m rms (root mean square) when measured at a range of 1,000 m;
Note 6.A.1.a.1.d. includes:
a. Equipment using coherent "signal processing" between two or more beacons and the hydrophone unit carried by the surface vessel or submersible vehicle;
b. Equipment capable of automatically correcting speed-of-sound propagation errors for calculation of a point.
a. 1. e. Active individual sonars, specially designed or modified to detect, locate and automatically classify swimmers or divers, having all of the following, and specially designed transmitting and receiving acoustic arrays therefor:
1. Detection range exceeding 530 m;
2. Determined position error of less than 15 m rms (root mean square) when measured at a range of 530 m; and
3. Transmitted pulse signal bandwidth exceeding 3 kHz;
N.B. For diver detection systems specially designed or modified for military use, see the Munitions List.
Note For 6.A.1.a.1.e., where multiple detection ranges are specified for various environments, the greatest detection range is used.
a. 2. Passive systems, equipment and specially designed components therefor, as follows:
Note 6.A.1.a.2. also applies to receiving equipment, whether or not related in normal application to separate active equipment, and specially designed components therefor.
a. 2. a. Hydrophones having any of the following:
Note The status of hydrophones specially designed for other equipment is determined by the status of the other equipment.
Technical Notes
For the purposes of 6.A.1.a.2.a.:
1. Hydrophones consist of one or more sensing elements producing a single acoustic output channel. Those that contain multiple elements can be referred to as a hydrophone group.
2. Underwater acoustic transducers designed to operate as passive receivers are hydrophones.
a. 2. a. 1. Incorporating continuous flexible sensing elements;
2. Incorporating flexible assemblies of discrete sensing elements with either a diameter or length less than 20 mm and with a separation between elements of less than 20 mm;
3. Having any of the following sensing elements:
a. Optical fibres;
b. 'Piezoelectric polymer films' other than polyvinylidene-fluoride (PVDF) and its co-polymers {P(VDF-TrFE) and P(VDF-TFE)};
c. 'Flexible piezoelectric composites';
d. Lead-magnesium-niobate/lead-titanate (i.e., Pb(Mg_(1/3)Nb_(2/3))O₃-PbTiO_(3,) or PMN-PT) piezoelectric single crystals grown from solid solution; or
e. Lead-indium-niobate/lead-magnesium niobate/lead-titanate (i.e., Pb(In_(1/2)Nb_(1/2))O₃–Pb(Mg_(1/3)Nb_(2/3))O₃–PbTiO₃, or PIN-PMN-PT) piezoelectric single crystals grown from solid solution;
4. A 'hydrophone sensitivity' greater (better) than -180 dB at any depth with no acceleration compensation;
5. Designed to operate at depths exceeding 35 m with acceleration compensation; or
6. Designed for operation at depths exceeding 1,000 m and having a 'hydrophone sensitivity' greater (better) than -230 dB below 4 kHz;
Technical Notes
1. For the purposes of 6.A.1.a.2.a.3.b., 'piezoelectric polymer film' sensing elements consist of polarized polymer film that is stretched over and attached to a supporting frame or spool (mandrel).
2. For the purposes of 6.A.1.a.2.a.3.c., 'flexible piezoelectric composite' sensing elements consist of piezoelectric ceramic particles or fibres combined with an electrically insulating, acoustically transparent rubber, polymer or epoxy compound, where the compound is an integral part of the sensing elements.
Technical Notes cont.
3. For the purposes of 6.A.1.a.2.a., 'hydrophone sensitivity' is defined as twenty times the logarithm to the base 10 of the ratio of rms output voltage to a 1 V rms reference, when the hydrophone sensor, without a pre-amplifier, is placed in a plane wave acoustic field with an rms pressure of 1 µPa. For example, a hydrophone of -160 dB (reference 1 V per µPa) would yield an output voltage of 10⁻⁸ V in such a field, while one of -180 dB sensitivity would yield only 10⁻⁹ V output. Thus, -160 dB is better than -180 dB.
a. 2. b. Towed acoustic hydrophone arrays having any of the following:
Technical Note
For the purposes of 6.A.1.a.2.b., hydrophone arrays consist of a number of hydrophones providing multiple acoustic output channels.
1. Hydrophone group spacing of less than 12.5 m or 'able to be modified' to have hydrophone group spacing of less than 12.5 m;
2. Designed or 'able to be modified' to operate at depths exceeding 35 m;
3. Heading sensors specified in 6.A.1.a.2.d.;
4. Longitudinally reinforced array hoses;
5. An assembled array of less than 40 mm in diameter;
6. Not used since 2007
7. Hydrophone characteristics specified in 6.A.1.a.2.a.; or
8. Accelerometer-based hydro-acoustic sensors specified in 6.A.1.a.2.g.;
Technical Note
For the purposes of 6.A.1.a.2.b., 'able to be modified' means having provisions to allow a change of the wiring or interconnections to alter hydrophone group spacing or operating depth limits. These provisions are: spare wiring exceeding 10% of the number of wires, hydrophone group spacing adjustment blocks or internal depth limiting devices that are adjustable or that control more than one hydrophone group.
a. 2. c. Processing equipment, specially designed for towed acoustic hydrophone arrays, having "user-accessible programmability" and time or frequency domain processing and correlation, including spectral analysis, digital filtering and beamforming using Fast Fourier or other transforms or processes;
a. 2. d. Heading sensors having all of the following:
1. An "accuracy" of less (better) than 0.5°; and
2. Designed to operate at depths exceeding 35 m or having an adjustable or removable depth sensing device in order to operate at depths exceeding 35 m;
N.B. For inertial heading systems, see 7.A.3.c.
a. 2. e. Bottom or bay-cable hydrophone arrays having any of the following:
1. Incorporating hydrophones specified in 6.A.1.a.2.a.;
2. Incorporating multiplexed hydrophone group signal modules having all of the following characteristics:
a. Designed to operate at depths exceeding 35 m or having an adjustable or removable depth sensing device in order to operate at depths exceeding 35 m; and
b. Capable of being operationally interchanged with towed acoustic hydrophone array modules; or
3. Incorporating accelerometer-based hydro-acoustic sensors specified in 6.A.1.a.2.g.;
a. 2. f. Processing equipment, specially designed for bottom or bay cable systems, having "user-accessible programmability" and time or frequency domain processing and correlation, including spectral analysis, digital filtering and beamforming using Fast Fourier or other transforms or processes;
a. 2. g. Accelerometer-based hydro-acoustic sensors having all of the following:
1. Composed of three accelerometers arranged along three distinct axes;
2. Having an overall 'acceleration sensitivity' greater (better) than 48 dB (reference 1,000 mV rms per 1g);
3. Designed to operate at depths greater than 35 meters; and
4. Operating frequency below 20 kHz.
Note 6.A.1.a.2.g. does not apply to particle velocity sensors or geophones.
Technical Notes
1. For the purposes of 6.A.1.a.2.g., accelerometer-based hydro-acoustic sensors are also known as vector sensors.
2. For the purposes of 6.A.1.a.2.g.2., 'acceleration sensitivity' is defined as twenty times the logarithm to the base 10 of the ratio of rms output voltage to a 1 V rms reference, when the hydro-acoustic sensor, without a preamplifier, is placed in a plane wave acoustic field with an rms acceleration of 1 g (i.e., 9.81 m/s²).
b. Correlation-velocity and Doppler-velocity sonar log equipment, designed to measure the horizontal speed of the equipment carrier relative to the seabed, as follows:
1. Correlation-velocity sonar log equipment having any of the following characteristics:
a. Designed to operate at distances between the carrier and the seabed exceeding 500 m; or
b. Having speed "accuracy" less (better) than 1% of speed;
2. Doppler-velocity sonar log equipment having speed "accuracy" less (better) than 1% of speed.
Note 1 6.A.1.b. does not apply to depth sounders limited to any of the following:
a. Measuring the depth of water;
b. Measuring the distance of submerged or buried objects; or
c. Fish finding.
Note 2 6.A.1.b. does not apply to equipment specially designed for installation on surface vessels.
c. Not used since 2010
N.B. For diver deterrent acoustic systems, see 8.A.2.r.
OPTICAL SENSORS