Receivers
Sonotronics manufactures receivers that remotely detect ultrasonic transmitters and decode transmitter IDs and sensor data. These receivers fall into two categories: active tracking receivers and passive tracking receivers.
Active Tracking Receivers
Active tracking receivers work much like traditional radio receivers: they heterodyne an incoming signal with a local oscillator to create an audible signal that can be heard through headphones or a speaker. Built-in displays show the detection frequency, transmitter ID, and any sensor data encoded in the transmitter emission. These receivers also include local memory, allowing detections to be recorded for later analysis. Like radio receivers, active receivers require an external sensor—in this case, a hydrophone. For proper operation, the hydrophone must be submerged to detect transmitters more than a few meters away.
Passive Tracking Receivers
Passive tracking receivers are used primarily in long-term fisheries studies to record the movements of tagged animals over months. These self-contained receivers include a hydrophone and electronics for decoding and logging data from passing transmitters. They are typically submerged deep enough to avoid boat traffic and must be retrieved to download the collected detection data. In some applications, a passive underwater receiver can be paired with a surface unit to provide near real-time detection information. For a successful study, passive receivers must support the protocols used by all deployed transmitters, as well as any transmitters already within detection range. They are often arranged in lines or arrays to maximize detections as tagged animals pass through an area. In some cases, a passive receiver may be configured with low gain to confirm the presence of a tagged animal within a very small area.
SUR - Submersible Ultrasonic Receiver
Receiver Kits
The MANTRAK kit was designed to bring together the most common tools our customers have found to be valuable for manual tracking. The kit has become the most frequent package used by first time researchers.
The UDR-kit contains all of the basic tools necessary for locating transmitters from a surface vessel and while diving. This includes the UDR receiver, external hydrophone adapter, directional hydrophone and useful accessories, housed in a rugged Pelican case.
