top of page

RFS Scientific

SensorGnomes for your Motus receiving needs

What is a SensorGnome?

Jan 1 2024 UPDATE: We have currently ceased assembling SensorGnomes. We apologize for any inconvenience, but you still have options for your Motus receiver. SensorGnomes remain available from CompuData and SensorStations are available from Cellular Tracking Technologies. At present, we continue to supply FUNcubes for use in either system as availability allows, although turnaround times can vary with FUNcube availability from suppliers.

SensorGnomes are an open source telemetry system used to detect animals carrying VHF or UHF transmitters compatible with the Motus Wildlife Telemetry System. Specifically, equipped with compatible receivers, a SensorGnome can detect pulses from Lotek coded transmitters or Cellular Tracking Technology (CTT) coded transmitters.

A SensorGnome can be assembled from "off-the-shelf" components, but sourcing those components from multiple vendors can be challenging and time consuming. That's where RFS Scientific comes in. We take care of that challenge for you, and then assemble and test your SensorGnome to ensure it's ready to join and contribute to the Motus network.

Key Features of the SensorGnome for Automated VHF Telemetry:


  • Simultaneous scanning of multiple (up to 4) receivers (e.g., FUNcube Pro+, CTT Motus adapter)

  • Dual power source: 120V AC standard or, optionally, 9-36 V DC (e.g., solar)

  • Precise timekeeping (<1 microsecond accuracy via GPS sync)

  • Effectively unlimited storage, but 32GB standard

  • Stores a complete record of all 'detections' for later processing

  • Stores information on 'noise' and signal strength

  • Allows for multiple/alternate tag-detection algorithms

  • Uploads data directly to the Motus Wildlife Telemetry web-server if an internet connection is present

SensorGnome options

The SensorGnome is open source, and assembled from "off the shelf" components. Open source means reduced costs and flexibility in the choice of components. It means you can customize those components to fit your needs. It also means that you have some decisions to make regarding the components to use, and those decisions will affect the cost and performance of your SensorGnome. Here we discuss the components you're most likely to customize depending on your particular Motus station installation.

How many receivers?

Each antenna that you need for your Motus station requires its own dedicated receiver. How many antennas your Motus station needs depends on your objectives. A single omni-directional antenna may suffice to record presence/absence of, say, colonial roosting shorebirds. A "detection fence" arrangement of two pairs of opposing long-range Yagi antennas (one pair at each Motus frequency: 166 MHz and 434 MHz) may be adequate to detect animals passing by during migration. A more complicated arrangement of antennas may be required depending on your Motus objectives.

Standard SensorGnome assemblies easily accommodate up to 4 receivers (and thus antennas). Beyond 4 receivers and antennas, you may wish to look at other Motus-compatible receiver options.

AC or DC power source?

If you're confident you'll be installing your SensorGnome within a few feet of an AC power source (think of a standard wall outlet in your home), you can save on costs by omitting DC power source components. But if you're expecting to power your SensorGnome with solar or another DC supply (e.g., a 12V LED power supply), you will need to add the DC components. By the way, using a 12V power supply can be an attractive and cheaper alternative to solar when you have AC power nearby (within 500' or so) but not close enough to use the standard AC/DC power adapter. Ask us how!

What type of coaxial connector for your receivers?

Depending on your antenna source, you're likely going to be using coaxial cables with either PL-259/UHF-male connectors (e.g., Laird PLC-1669 9-element Yagi) or BNC-male connectors. We can also source and install N-type connectors, just let us know when you order the assembly.

Order turnaround time

We source, assemble, and test your SensorGnomes to order. As a one-employee operation, we aim for a shipping date 10 - 14 days after we receive your order. The turnaround time may be longer depending on order size. However, we will do our best to accommodate shorter turnaround times as necessary.

Contact Us

Have a question or need a quote or support? Let us help you find the SensorGnomes that meet your Motus receiving needs.

Thanks for contacting RFS Scientific. We'll be in touch as soon as possible!

bottom of page