Antennas

Biomark offers pass-by and pass-through PIT-tag antenna designs. Pass-by antennas detect PIT-tagged animals as they pass over the antenna; whereas, pass-through antennas detect tags as they pass-through the antenna opening. Antennas are constructed of durable, weather resistant thermoplastic. The antennas are connected to the FS1001M reader by a control or exciter cable; one cable per antenna. To maximize performance, the exciter cable is typically 100 ft or less in length. Each antenna is thoroughly tested as part of the fabrication process.

Pass-by Antennas


Pass-by antennas are designed to facilitate installation without requiring attachment to an existing structure. The antennas are secured within a shallow trench in the river substrate, resulting in the antenna surface being level with the river bottom. This approach minimizes the potential for antennas to be dislodged by high flow, debris, and/or ice. Biomark currently offers pass-by antennas in 20, 10, and 6 ft lengths. Nominal detection distances, vertically above the antenna, are 15, 20, and 24 in, respectively.

 

Pass Through Antennas


Pass-through antennas are designed to detect PIT-tagged animals as they move through a defined area such as a fishway or den entrance. Pass-through antennas are secured in an upright orientation and can be placed in existing guide slots, mounted to the entrance/exit of an opening, or be free-standing in the case of small stream applications. Common opening sizes for Biomark pass-through antennas are 10' x 4' and  5 ' x 5'. Custom sized antennas can be designed for specific applications. PIT-tagged animals can be detected on either side of the antennas as well as throughout the antenna opening.  For example, the nominal detection range of the 5 ft x 5 ft antenna can extend up to 24 in from each side of the antenna.

 

Floating Antennas

Biomark developed the floating antenna to be used in single or multiple antenna arrays or as a mobile detection system for floating down rivers and streams.  The antennas are designed to float on the surface of the water and detect PIT-tagged fish as they swim underneath.  Inflatable antennas can be deflated and rolled up for easy transport to remote sites.  Each floating antenna is 10 feet wide, constructed with durable UV resistant material, and capable of detecting 12mm, FDX-B PIT-tags up to 30 inches.