ACOUSTIC MODEM
An acoustic modem is used to transmit and receive data underwater.
The communication network will comprise of one base station node and two deployment nodes. The acoustic modem is an underwater data communication equipment. The modem should be interfaceable to a Computer/Radio Modem through an Ethernet Interface. The system will have a Linux-based embedded computing platform at its heart, on which the various communication algorithms can be implemented.
The system should also house the required signal generation/acquisition/ amplification hardware for half-duplex communications. The acoustic modem submersible in water up to 20 Meters and can withstand 5 Bar external pressure. This system consists of Transmitter and Receiver Platforms
Transmitter Platform
The key components of the Transmitter Platform:
- FPGA / DSP Platform with USB / Ethernet / RS232 Interfaces
- Output Digital to Analog Converter – 16bit, 2MSPS
- Output Power Amplifier – Class D – 150W Output with Variable Gain
- Output Impedance Matching Circuit
- Output Neptune D-45 Transducer
- Mother board
- Power Supply and Power Conditioning Circuits
Receiver Platform
The key components of the receiver platform:
- Input Neptune D-45 Transducer
- Input Hydrophone Amplifier
- Input Analog to Digital Converter – 16bit, 2MSPS
- FPGA / DSP Platform with USB / Ethernet / RS232 Interfaces
- Motherboard
- Power Supply and Power Conditioning Circuits
The design of the Acoustic Modem Hardware is to test hydrophones, design and selection of parts for the hydrophone interface on the receiver and transmitter side – including hydrophone preamplifier, power amplifier, impedance matching circuit, analog to digital converter, digital to analog converter, motherboard and power conditioning circuits.
- System Specifications
| ADC Resolution and Type | 24-bit, 96ksps or better | |
| Processor | ARM Cortex-A7 or better 600MHz Clock Speed or Better Linux Operating System Support | |
| Memory | 512MB RAM 16GB or more of Storage Memory/SD Card | |
| Maximum Shock | 20g , 11ms half sine | |
| Ingres Protection | IP65 Rated or better | |
| Temperature | Operating: 0°C - +60°C Storage: -4°C - +60°C | |
| Maximum Shock | 20g, 11ms half sine | |
| Maximum Vibration | Frequency range 5 -150 Hz, 5 -25 Hz: ± 2 mm; 25 -50 Hz: 5g | |
| Battery Voltage | 14V | |
| Battery Capacity | 32AH | |
| Material | Stainless Steel, SS304 |
CUSTOMIZATION, DESIGN, DEVELOPMENT AND INTEGRATION SERVICES AND HAS EXECUTED PROJECTS SUCH AS
