HY/T 0448-2024 in English
VALIDOcean Acoustic Survey Requirements
- Issued on:2024-09-13
- Implemented on:2024-12-01
- File Format:PDF
- Delivery:Via email within 6 business days
$756.00
| Standard No: | HY/T 0448-2024 |
| Document status: | VALID |
| Title in English: | Ocean Acoustic Survey Requirements |
| Title in Chinese: | 海洋声学调查要求 |
| Language: | English |
| File Format: | Electronic (PDF) |
| Delivery: | Via email within 6 business days |
| Issued on: | 2024-09-13 |
| Implemented on: | 2024-12-01 |
| ICS Classification: | 07.060-Geology. Meteorology. Hydrology |
| Chinese Classification: | A45-Oceanology |
| Professional Classification: | HY-Marine |
| Related Keywords: | ocean acoustic survey requirements introduction standard overview
ocean acoustic surveys ocean acoustic technology marine acoustic survey technology system future ocean acoustic surveys |
Introduction
Standard Overview and Technical Background
HY/T 0448-2024, "Requirements for Marine Acoustic Surveys," is a marine industry standard jointly developed by authoritative institutions such as the Third Institute of Oceanography under the Ministry of Natural Resources and the Institute of Acoustics of the Chinese Academy of Sciences. Released in 2024, this standard is a key technical specification for marine acoustic surveys in my country, marking the further improvement of the country's marine acoustic survey technology system.
This standard, developed based on the GB/T 1.1-2020 Guidelines for Standardization, integrates four core areas of marine acoustic surveys: marine ambient noise surveys, marine underwater sound propagation surveys, marine reverberation surveys, and seabed acoustic characteristics surveys. The technical evolution of this standard reflects the trend from single-parameter measurement to simultaneous multi-parameter surveys, and from qualitative description to quantitative analysis.
Core technology system architecture
This standard constructs a complete ocean acoustic survey technology system. Each technical module is relatively independent but also interrelated, forming a systematic survey solution.
| Survey Type | Core Parameters | Key Technical Requirements | Application Scenarios |
|---|---|---|---|
| Marine Environmental Noise Survey | Noise Spectrum Level, Spatial-Temporal Correlation Characteristics, Directivity | Hydrophone Sensitivity ≥-185dB, Frequency Response Non-uniformity ±2dB | Marine Environmental Monitoring, Sonar Performance Evaluation |
| Underwater Acoustic Propagation Survey | Propagation Loss, Fluctuation Characteristics, Spatial-Temporal Correlation | Ranging Error <5%, Time Measurement Accuracy 0.1s | Sound Field Forecast, Underwater Communication |
| Ocean reverberation survey | Reverberation level, reverberation distance, scattering intensity | Number of transmissions ≥10 times, 1-2 minutes interval | Target detection, sonar design |
| Survey of seabed acoustic characteristics | Sound velocity, attenuation coefficient, acoustic impedance | Sound velocity measurement error ±0.75m/s | Seabed geological exploration, acoustic field modeling |
Analysis of technical requirements for instruments and equipment
Core technical indicators of acoustic receiving subsystem
The standard puts forward strict performance requirements for the hydrophone system:
| Parameter type | Acoustic Hydrophone (20Hz-20kHz) | High Frequency Hydrophone (15kHz-40kHz) | Test Conditions |
|---|---|---|---|
| Sensitivity | ≥-185dB | ≥-175dB | With Preamplifier |
| Frequency Response Unevenness | ±2dB | ±2dB | Full Frequency Band |
| Horizontal Directivity Deviation | ±1.5dB | ±2dB | Compared with Ideal Omnidirectional |
| Vertical directivity beamwidth | >60°(-3dB) | >30°(-3dB) | Array element consistency requirements |
The signal conditioning subsystem requires that the frequency response fluctuation within the filter passband be within ±0.1dB, the attenuation outside the passband be greater than 60dB, and the phase fluctuation of each channel be within ±1°, reflecting the extremely high requirements for signal fidelity.
Survey Implementation Technical Requirements
Marine Environmental Noise Survey Specifications
The standard specifies detailed technical requirements for field surveys: The hydrophone array should be no less than 1 km from shore, with the shallowest hydrophone located below 5 m below the sea surface, avoiding interference areas such as navigation channels and platforms. The survey vessel should be at least 20 km away from the self-sustaining acoustic receiving subsystem. Each station should be surveyed for at least 25 hours, with at least one survey every hour, and each survey lasting no less than 3 minutes.
Special Requirements for Underwater Acoustic Propagation Surveys
When conducting acoustic fluctuation surveys, multiple sets of identical signals should be transmitted at the same station, and the number of signal samples should meet the requirements for statistical averaging. The acoustic signal transmission time should be no less than two full diurnal tidal cycles, providing technical support for studying the timescale characteristics of ocean processes.
Data processing and analysis methods
Statistical analysis of marine environmental noise
Appendix A of the standard provides a complete noise statistical analysis algorithm, including:
- Noise spectrum level probability density calculation: based on histogram statistical method
- Spectral percentile value calculation: provides a complete percentile sequence of 1%-100%
- Frequency band sound pressure level calculation: supports 1/3 octave analysis and broadband summation methods
- Time-space correlation characteristic analysis: time domain and frequency domain processing methods
Quantitative model verification technology for underwater acoustic propagation
Appendix B proposes two underwater acoustic propagation model verification methods:
| Verification method | Calculation principle | Applicable scenarios |
|---|
| Measurement Method | Measurement Depth |
|---|
| Measurement Method | Measurement Depth | Technical Features | Applicable Conditions | Data Quality |
|---|---|---|---|---|
| Reflection and Refraction Method | Tens of meters | Measures the average sound velocity of each layer, high technical requirements | Requires a hydrophone array and multi-station measurement | Clear layered structure |
| In-situ Method | Limited Depth | Accurate and intuitive, maintaining the original state of measurement | Requires special seabed equipment | High data accuracy |
| Laboratory Method | Sample Length | Simple sampling and easy operation | Requires cylindrical samples | The data is highly discrete. |
Recommendations for the implementation of the standard and technical prospects
Implementation recommendations
Based on the technical requirements of the standard, the following implementation recommendations are proposed:
- Instrument selection and configuration: The appropriate hydrophone type should be selected according to the survey frequency band and accuracy requirements. For the acoustic frequency band, a hydrophone with a sensitivity of ≥-185dB should be selected, and for the high frequency band, a hydrophone with a sensitivity of ≥-175dB should be selected.
- On-site deployment optimization: Fully consider the marine environmental factors, reasonably arrange the survey stations, and ensure the synchronous acquisition of acoustic-related auxiliary parameters.
- Quality control system: Establish a complete instrument calibration, system integration, and data processing quality control process.
- Data standardization: Strictly process data in accordance with the appendix algorithm to ensure data comparability and repeatability.
Technology development trends
With the development of ocean acoustic technology, future ocean acoustic surveys will show the following trends:
- Multi-platform collaborative observation: Integrated observation by multiple platforms such as shipborne, buoyed, submerged, and shore-based platforms
- Real-time data processing: Real-time acoustic signal processing and recognition based on artificial intelligence
- High-resolution survey: Acoustic parameter acquisition technology with higher temporal and spatial resolution
- Standardization and expansion: Formulation and improvement of standards for ocean acoustic surveys in ice areas
The implementation of HY/T 0448-2024 will significantly enhance the technical level of my country's ocean acoustic surveys and provide reliable technical support for marine scientific research, resource exploration, national defense construction, and other fields.
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