An innovative and highly efficient acoustic solution
The seaCHIRP™ technology combines "Super Wideband" Chirp technology with Beamforming and Synthetic Aperture Sonar processing.
It was designed for the sole purpose of precise and efficient seabed assessment. To this end, two systems are currently in operation, seaCHIRP™ 2D and seaCHIRP™ 3D.
Data from both systems is processed using the proprietary seaLOGS software, the seaLOGS output then can be used as input into a number of geophysical workflows to produce a range of interpretation products.
In summary:
- The system provides 3D imaging of the backscattered arrivals either side of the survey line (seaCHIRP™ 3D)
- A very high-resolution seismogram along the line of survey is recorded.
- The hardware is rugged, compact and lightweight (90 to 120 kg depending on the version)
- The seaCHIRP™ surveys are customizable to optimize results according to client requirements / survey conditions
- The mobilization / demobilization is quick and easy
- The system allows for high survey speed (up to 5 knots) / high firing rate
- The processing is innovative, and the science is well understood
- The broadband nature of the seaCHIRP™ pulse allows the application of geophysical workflows to derive interpretation products.
The technology
- Super wideband Frequency Modulated pulse (« Chirp ») transmission (4.5 octaves)
- Synthetic Aperture Sonar (SAS) processing in the along-track direction
- Beamforming with transversal hydrophone array+
Super Wideband CHIRP technology
Chirp technology consists of emitting and recording Chirps; frequency modulated signals.
These wideband, long duration, high energy signals enable us to penetrate further into the seabed than other sub-bottom profilers which emit short pulses.
The depth of penetration, resolution performance and object detection capability are directly related to the Chirps' bandwidth. Our system, with its 4.5 octave frequency bandwidth is the best performing system on the market today. It allows high resolution (down to 7 cm) with a depth of imaging down to 15 m in sand, and can be used in water depths of up to 50 m.
seaWING and Beamforming
The seaWING is a streamlined transversal hydrophone array specially designed for the seaCHIRP™.
The beamforming takes advantage of the seaWING special geometry.
The signals collected by the hydrophone array are recorded and, in a second step, re-arranged to obtain beams corresponding to different steering angles. The large swath (±40°) and the narrow beams obtained (up to 10° for the central beam) allow complete coverage of the seabed with a reduced number of survey lines.
Synthetic Aperture Sonar (SAS) processing
As the SeaCHIRP traverses along a survey line, objects in the seabed are repeatedly illuminated by several Chirp signals. A coherent reorganization of the data then enables the generation of a long synthetic antenna, improving longitudinal resolution and S / N, or detection capacities. As the length of the antenna can be fine-tuned, the resolution becomes range independent.
This processing method requires accurate navigation data. Up to now, these requirements have limited the SAS method to very stable deep water carriers (ROV, AUV) and very high accuracy positioning systems.
Now, thanks to the low frequency content of our emitted Chirps and to the high-performance algorithms developed by SOACSY, SAS processing is available for shallow water and can be operated from any boat and by using standard positioning systems (10 cm accuracy in X,Y and 5 cm accuracy in Z).
After SAS processing, SeaCHIRP provides along-track resolution of 1.5 wavelengths (down to 30 cm) giving unparalleled images of the seabed (e.g landing sites) and embedded structures (pipelines, cables, etc.).
A modular system
SeaCHIRP’s modular structure allows for efficient transportation and operation.
All of our machines are ruggedized and designed to work at high humidity rates and extreme temperatures.
The amplifier is stored in a case made of polyethylene rotationally molded plastic with 2.5" wheels and an industrial pull handle. The acquisition box is transported in a Pelican Storm Case which is watertight and equipped with wheels and a telescopic handle. The Chirp emitter is protected by a robust stainless steel case.
The streamlined hydrophone array SeaWING is made of marine aluminum.
Each component weighs less than 40 kg for easy and low cost transportation and installation anywhere in the world.
