Frequency Plan

It is important to carefully plan the setup of your sensors before adding them to the system. You can create a table with a list of frequencies and complete it when you add sensors.

Frequencies and intervals

The diagrams below show the bandwidth of the different types of Marport sensors and intervals you must respect when adding other sensors.

Figure 1. PRP sensors (e.g. Catch sensor, Trawl Speed, Spread sensor...)

Example: If the frequency of the sensor is 40kHz, there should be no sensors between 39.9 and 40.1kHz.

Figure 2. Marport Pro sensors (e.g. Trident, Door Explorer, Door Sensor Pro, all Navigator range except Catch)

Example: If the frequency of the sensor is 40kHz, there should be no sensors between 39.8 and 41.2kHz.

Figure 3. NBTE sensors (e.g. Speed Explorer, Trawl Explorer, Catch Explorer, Catch Navigator, Door Sounder)

Example: If the frequency of the sensor is 40kHz, there should be no sensors between 39.8kHz and 40.6kHz.

Example: If the frequency of the sensor is 40kHz, there should be no sensors between 39.8kHz and 41kHz.

Example: If the frequency of the sensor is 40kHz, there should be no sensors between 39.8kHz and 42.6kHz.


Frequency of the sensor	Bandwidth	Mandatory distance with other sensors	Recommended distance with other sensors

Examples of frequency allocations

We recommend to allocate frequencies between 34 and 56 kHz for wideband hydrophones and between 41 kHz and 44 kHz for narrowband hydrophones.
Echosounders are usually placed around 38 kHz, make sure to allow enough distance with them.


Example of a system with Spread, Catch, Trawl Speed sensors and Speed Explorer, Catch Explorer, HDTE and Door Sounder.


Example of a system with Spread sensors with positioning, Catch sensors, Trawl Explorer and Catch Explorer.


Example of a system for purse seining, with a Seine Explorer and depth Seine sensors.

Bandwidth Mandatory distance with other sensors Avoid allocating frequencies between 37 and 39 kHz because this range is generally used by echosounders.