VR28 Tracking System

The VR28 Tracking System consists of a four channel ultrasonic receiver, connected to a four element hydrophone array. The quad hydrophone array provides 360 degrees of monitoring coverage so that the bearing to a transmitter can be determined without having to rotate a directional hydrophone. The VR28 Receiver is connected to a computer through an RS-232 serial port. The user supplied computer controls all VR28 Receiver functions, including frequency, gain and echo rejection blanking interval. All data received by the VR28 Receiver is saved to a disk file by the computer.

FEATURES:

• TRACK28 - Windows based software.
• 360 Degree display of transmitter bearing.
• Data displayed on screen and stored to disk.
• GPS data displayed, with NMEA 0183 information input to computer serial port.
• Tracks pingers or telemetry transmitters.
• VR28T version allows communication with transponders and CHAT tags.
• Hydrophone array can be mounted on a pole or a towed body.
• Towed body and haired fairing electromechanical cable options available.
• Headphone compatable for audio tracking (headphones shown in photo).

The VR28 Receiver contains four separate VR21 Receiver Modules (port, starboard, bow and aft), a microprocessor based Controller Module and a Stereo Audio Module, interconnected by a back plane. The quad hydrophone array is connected to the VR28 Receiver by a multi-pair cable through a Hydrophone Input Module. The back plane and the modules are housed in a 19 inch card cage. Each Receiver Module is connected to the Hydrophone Input Module by a 0.5 m BNC to BNC cable and can be removed from the card cage in its own shielded assembly. The Stereo Audio Module contains a headphone output jack that provides audible 2 kHz signals, converted from the received ultrasonic transmissions. The Stereo Audio Module has separate left and right controls that allow the user to monitor either a different channel in each ear or the same channel in both ears. The audio output feature allows the monitoring of signal and background noise levels during setup and aids the user, when tracking, to aurally determine the direction of transmitted signals before the receiver detects them electronically. The computer uses the RS-232 serial connection to monitor the signal strength on each of the receivers and uses this information to calculate the bearing to the transmitter. The bearing is shown graphically along with a bar graph of signal strength and background noise level on each hydrophone. TRACK28's main tracking screen is shown below.