In order to connect directly to your SensorStation, you’ll need 2
USB->Ethernet Adapters (we recommend: https://tinyurl.com/yc6llze4), and an Ethernet Cable. If
you have a V2 station, you’ll need a
Raspberry Pi compatible USB WiFi adapter like this one https://store.celltracktech.com/products/wifi-usb-adapter-add-on-for-sensorstation-v2
if you want to connect via WiFi. If you have a V3 station or later, the
WiFi is pre-installed on the board. Make sure to have these
on-hand prior to receiving your SensorStation so there is no delay in
setup.
celltracktech2025.Problem: In addition to the above, because of a new USB Bus on the V3x stations, running 3 or more FunCube Dongles (FCDs) while also running both the Cellular Modem and Wifi module (or having a permanent Ethernet -> USB connection for a wired internet connection) may (heavy emphasis on “may” as this issue is not consistent across installs) cause excessive heat and power drops that may result in rebooting or “kicking off” of FunCube Dongles.
Solution #1: If you must run 3 or more FCDs, be sure to DISABLE whatever you are not using. If the station is using the cellular modem, disable the Wifi. If it’s using the Wifi, disable the cellular modem. If it’s using hard-wired Ethernet, disable BOTH the cellular modem and wifi. This will keep the power draw on the USB bus to a minimum, so that the FCDs will not experience lower power (they are very power hungry AND they are not all built the same, so there is considerable variation in power usage).
Solution #2: Use up to 2 FCD. We have demonstrated normal performance with 2 or fewer FCDs even with both cell and wifi running. That said, disabling whatever you’re not using just makes sense so please do that too.
V3.3 Owners (shipping now): The newest board run includes all elements of the PowerFilter, as well as heat dissipation mechanisms and a new USB Bus that avoids the aforementioned issues. Therefore, any new V3.3 boards that ship will have the latest disk image and not require any of the additional fixes noted above. The only recommendation for any new station is: Check the SensorStation User Guide and connect the station to the internet and run the over the air updater so that you have the latest patch fixes before deploying your station.
SensorStation updates are posted to the Motus forum (community.motus.org) and the CTT Support Slack group.
As of June 2022 we have released the 3rd version of the SensorStation. V3 SensorStations differ from V2 stations in a few important ways.
This User Guide has been redesigned around the new (ca.2020) Version 2 SensorStation (V2) which includes an LCD display. Otherwise, Version 1 stations (ca.2019) are nearly identical to V2 stations. In cases where they differ, we have made note in the manual. If you are setting up a V1 station you may want to begin at the QuickStart Guide in Appendix II. If you find inconsistencies in this manual please email us at support@celltracktech.com as we will be updating the manual regularly.
We now have a Slack workspace dedicated to CTT users.
Topics range from station logistics to study design, and from data
management to current development of novel analytic tool. Come be a part
of the discussion and engage with other users as we push the boundaries
of remotely sensed telemetry data! Click
here to request access to our free and vibrant Slack workspace.
If you are reading this document, then you most likely have purchased one of our Internet of Wildlife (IoW) components. Whether you’re doing localized detailed studies of small mammals or songbirds, or you’re setting up SensorStations as part of the global Motus Wildlife Tracking System (motus.org), or you’re doing something in-between, we’ve got you covered, and this document is meant to help you get started quickly and painlessly. If for some reason you get stuck along the way, please don’t hesitate to reach out to us directly either via email (support@celltracktech.com) or through our online Help Desk here: https://celltracktech.com/support/.
If you are setting up your SensorStation to participate in the Motus Wildlife Tracking System (motus.org), your station can still be used with CTT Nodes. In general, we recommend Motus stations to include 4 Yagi 10-element antennas pointing in the 4 cardinal directions. A fifth Omni antenna can be installed and dedicated to detecting nodes, or one of the Yagi antennas can be used for nodes while the other three are positioned at 120 degrees for full coverage. You may also add any number of 166MHz antennas by using a Software Defined Radio (SDR), such as a FunCube or RTL-SDR, via any of the USB ports on the SensorStation (SDRs are sold separately via third-party companies). A clear view of the horizon is preferred to get maximum range, so a height as high as possible is also advised. For more information on Motus, see Appendix I.
Treat your SensorStation board like you would any other motherboard, Arduino or Raspberry Pi. All electronics, no matter how robust, can be static sensitive. Take care no metal objects touch the board while it is operating, such as antenna connectors or cellular antennas, as this could cause electrical shorts that will damage the board. It is advised to wear an anti-static bracelet when handling SensorStation.
CTT’s Internet of Wildlife System (IoW) is a complete radio telemetry system that consists of transmitters (radio tags), and receivers. Currently CTT produces radio transmitters that communicate on two frequencies:
The CTT SensorStation collect data directly from
tags and can collect data from a series of Nodes to more
precisely locate tags within a study site. The
SensorStation stores data and, with an optional cellular
data plan, can also send those data directly to the CTT and Motus
servers.
CTT Nodes are essentially mini-base stations: devices with integrated solar panels, a lithium battery, and an antenna to collect data from 434MHz tags (V2 Nodes) or either 434MHz or 2.4GHz tags (V3 Nodes), and send those data to the SensorStation. These data can then be post-processed to localize tags within a grid of nodes over user-defined time steps.
The detection distance from Node to Tag varies for various reasons, including terrain, vegetation, and the behavior of the tagged animals. For instance, a bird flying overhead may be picked up over a kilometer away by a node, but one foraging in dense vegetation may only be detected from a few hundred meters. When using nodes for localization it’s important to note that the accuracy of locations of animals wearing tags can be as little as 30m, but can range widely depending on the density of Nodes. For localizing tag positions, the spacing and placement of nodes must allow for tags to be detected simultaneously by three or more nodes.
The detection distance from SensorStation to Node is
also affected by terrain and vegetation, but also antenna height and
type (omni-directional vs. directional). Therefore, while there
is no hard and fast rule, a good starting point is to keep your farthest
node within 1km of the SensorStation. The number of
SensorStations needed for each system depends on the size of the study
area. For instance, in a 2 KM2 plot, a SensorStation placed
at the center of the plot could detect nodes across the entire study
area, in most cases with only an omni-directional antenna. Because
Nodes are dependent on the SensorStation to receive their
data and aggregate it for analysis, it is critical to ensure each node
is within the detection radius of at least one
SensorStation at all times.
The detection distance from SensorStation to Tag is affected by the same factors as SensorStation to Node, but because many tags are on birds, bats and insects, the relationship between the two objects can change drastically over very short time steps. With line-of-sight, a tag on a bird has been shown to be detectable for dozens of kilometers by a SensorStation. On the other hand, birds foraging in dense vegetation may only be detectable by a station within a few kilometers. Therefore, careful consideration of station position with relation to the biological questions being asked is critical for a successful deployment.
For both the SensorStation and Nodes we recommend attaching to EMT conduit. We recommend this because it is rigid and easy to set up. This is not what’s commonly referred to as Black Pipe used for water and gas lines, but the galvanized steel pipe used for running electrical wiring inside.
We don’t recommend PVC because it moves in the wind, becomes brittle, and will snap over time. EMT can be painted if you would like them camouflaged.
The conduit can be attached to a tripod, mounted directly into the ground, or onto a building or other structure. The Nodes and SensorStations are then attached to the conduit. The diameter of the conduit is typically 1” for the top mast section of the SensorStation (the section to which the antennas are attached; light green in the picture below).
For every 7 feet of height the base section will increase in diameter by ¼”. For example, in the picture above, a 15 foot mast will have a 1” section (light green) inserted into a 1 ¼” (orange) and then into a 1 ½” (blue). If the conduit is inserted into the ground, the 1 ½” conduit should be inserted into a 4’ section of 2” pipe (dark green). The pipe in the ground is cut in half, the bottom flattened slightly with sledge hammer to keep soil from entering when it is driven into the ground. A block of wood can be used to pound the pipe into the ground to prevent bending the pipe. If the antenna mast is shorter, the next size up gets driven into the ground (1/ ¼”). Note that standard EMT conduit does eventually rust, however it will remain very strong for 6-10 years.
If desired, stainless conduit can be purchased, however it is much more expensive, but recommended if you are in an area that receives high winds. It is crucial to overlap each section of pipe by at least 2 feet. Self tapping screws are used to hold pipes together, but should not be used within 3-4” of the end of the pipes and/or seams. The chart below should help with what is needed for your setup per SensorStation.
| Total Approx Mast Ht. | EMT Needed for mast (10’) | Ground Section Needed (4’) | Coax Length Per Antenna |
|---|---|---|---|
| 7’ | 1” | 1 1/4” | min 10ft |
| 15’ | 1”,1 ¼” | 1 ½” | min 20’ |
| 23’ | 1”, 1 ¼”, 1 ½” | 2” | min 25’ |
| 28’ | 1”, 1 ¼”, 1 ½” | 2”- Use full 10’ | min 30’ |
Masts higher than 28’ not recommended with standard free-standing EMT conduit. Guy wires and/or scaffold or tripod masts are other options for higher towers.
Nodes are typically attached to the top of a ¾” piece of EMT. The clamps shown below come standard with the nodes and accept ¾ or 1” conduit.
A 7/16” socket is used to tighten the clamp bolts. The EMT is typically driven into the ground approximately 2 feet. The height of the nodes can be changed depending on the project, but for best results should be consistent within a study site. We recommend 8’ for most setups, see below for pictures of the node setup in the field. If you choose an alternate mounting method, care should be taken that they are secure. If they are mounted on anything that sways greatly with the wind, the readings won’t be consistent.
Note: Nodes purchased in 2020 and beyond have a built-in GPS. Prior to 2020 you must take accurate GPS readings and record that data with the Node ID in order to run post-hoc localization analyses.
Setting up the CTT Nodes is typically done in a grid in your study site. It is not imperative that they are exactly in a grid, but the closer you can set them up in a grid, the more accurate positioning you will get from the tags. In sites where this is not practical, you can simply set them up where you can, 50-200m apart, and record GPS of the Node locations. Even in a grid setup, it is best practice to take GPS coordinates whether or not they differ from the layout. Nodes should be placed above surrounding vegetation (to ensure solar recharging of the internal battery) or at least 2.5 meters above the ground.
If you are using Nodes, your SensorStation may be placed anywhere within range of the farthest node, which is typically 1km. See the next section on SensorStation Configuration and Antenna Detail for more details on this. It is recommended to place the SensorStation antennas at least 10 meters above the ground level. The higher the antennas, the better range you will get.
The standard configuration for the CTT SensorStation allows for receiving data on five 434MHz radio ports simultaneously. These can be configured to either record signals from LifeTags/PowerTags/HybridTags and ES-200 GPS loggers (hereafter “tags”), or to collect data from CTT Nodes. Tags and Nodes cannot be picked up on the same channel simultaneously, and how you configure your station depends on your study goals. The number of channels necessary on a SensorStation depends on the number of Nodes, whether you want to detect tags/transmitters and/or Nodes directly with the SensorStation, and the distance the Nodes are from the SensorStation. There is no hard limit to the number of nodes that can be detected by a single SensorStation, but it’s best to keep that number around 50 or less. Distance to the SensorStation will usually be the limiting factor for the number of nodes detectable by a single SensorStation.
Two types of antennas are commonly used with the SensorStation: Omnidirectional and Yagi. Omnidirectional antennas efficiently receive energy in a horizontal plane 360 degrees around the SensorStation. Omnidirectional antennas typically do not have as great a range as Yagis, but a benefit is the 360 degree detection, and great detection of tags and nodes that are near the station.
Note: Whereas in the past we have recommended specific polarization for omnidirectional antennas picking up Nodes vs. Tags, in our testing we have found the difference negligible and find vertical omni antennas to be much simpler and less expensive for a greater value over horizontally polarized omnis.
Yagis are directional antennas used to detect tags and nodes in a specific direction from the SensorStation. They typically have a 30-60 degree detection range that extends away from the SensorStation. For that reason typically 2-4 antennas are used, one pointed in each cardinal direction, or two pointed in opposite directions and used to make a “fence”. Yagis can also be used to pick up Nodes that are farther away from the SensorStation.
While there are many antennas to choose from, these are a few that we can recommend from experience:
Whatever you choose, make sure you get the proper coaxial end to connect your antenna to your SensorStation!
To connect antennas to your SensorStation you will need coaxial cable (we recommend LMR-400 or better) with the proper ends to connect to the antenna (manufacturer specific) and your SensorStation. If connecting directly to the board, each 434MHz radio has a SMA Female port, so your coaxial will require an SMA Male connector.
If connecting to our NEMA case, your coaxial will need a Type N Male connector.
If connecting an antenna for a different frequency, such as 166MHz, you will need to attach your Software Defined Radio (SDR) to one of the USB ports and your coaxial cable to the SMA connector on the SDR. Note that any 166MHz radios will only show up in the SensorGnome section of the Web Interface (see Sensor Station Web Interface).
Antennas are attached to the EMT conduit with the clamps that come with the antennas. If you have a setup that uses 4 yagis, than you will attach the yagis to a 4 or 5-way mounting “hat” you can purchase via online retailers. Once the antennas are on EMT, attach the coax and wrap the connection with coax tape. Run down the poles to where it will attach to the SensorStation. You can use zip ties to secure the coax to poles where needed.
Make sure you have enough coax to form a drip loop for each connection.
If you are using our on-board LTE modem for sending data to the cloud and to Motus, and you are finding you have a weak signal at your station site, you can add an optional cellular antenna to increase the range of your station transmission to the cell network. CTT does not sell cell booster antennas, but many are available on Amazon.com. Here is one example, but note that we have not tested this specific device; it’s simply to provide some idea of what might work: https://www.amazon.com/Directional-Universal-Cellphone-Amplifier-Signalbooster/dp/B089VXJV14/ref=sr_1_3?crid=L0H9JNP4DRQF&dib=eyJ2IjoiMSJ9.DwK2pym6t2RcsY6MY5SFAx_HO7CFELHCiEedhErb9Ib08Fv5Z512JpCcNzW5TUtQoA8dZItS8yOJAajf3bikFw.te4gjK0B-7qty7WuY-_NLxslPGjxqqpMRtLonWDJQOI&dib_tag=se&keywords=LTE+yagi+booster&qid=1704994609&sprefix=lte+yagi+boos%2Caps%2C133&sr=8-3
Typically, these cell booster antennas have an SMA male connector
that needs to somehow attach to the SensorStation board to communicate
with the modem. We have provided a SMA port on the board near the LTE
modem, labeled J7. That port is not activated without first
jumping the U.FL port on the modem labeled main,
to the U.FL port labeled J6 on the SensorStation board. In
doing so, you will activate the J7 SMA port on the board
which will allow you to attach the SMA connector on the cell booster
antenna to said port (see fig below).
Alternatively, you could attach a U.FL to SMA adapter
(see fig below) directly to the Main port on the
modem, and connect the SMA connector on the booster cable directly to
the adapter, bypassing the need to jump to the board and not using the
SMA port on the board itself. This option might be preferred if you use
a U.FL to SMA bulkhead, which you can mount to the side or bottom of
your case, allowing you to create a weatherproof access point to connect
an external antenna to the outside of your SensorStation case.
main port on the modem.Pink circle: Main U.FL port
on LTE modem (currently occupied)Blue rectangle: J6 U.FL port
on boardRed square: J7 SMA port on
boardmain port on the LTE
modem to the U.FL port at J6 on the SensorStation board,
first remove the antenna that comes with the SensorStationmain on the modem to J6 on the SensorStation
board, therefore activating the SMA port at J7. Now the
Cell Booster antenna can be attached to the SMA port at
J7J6 or J7 on the
boardThe SensorStation can be placed inside a building, or fastened to the pole or building, etc. It should either be close to the ground for easy access, or have an ethernet cable run down to an accessible location.
If placing your station inside a building be aware that this may affect GPS and/or cellular reception, possibly requiring an external antenna wired to the outside of the building. There are many possible external antennas, and searching Amazon for “external GPS antenna with SMA connector” will yield a number of options.
Your SensorStation ships with the onboard GPS chip-antenna activated. There is a small jumper near the GPS that must be moved into the disabled position to deactivate the chip antenna and activate the SMA port on the board. After moving the jumper, you can attach your external antenna to the SMA port and it will work. Be sure to confirm operation by witnessing a good GPS fix on the LCD, or via the web interface, before leaving your SensorStation.
Iridium satellite stations will require an external antenna. Typically, our customers will make use of a Taoglas IMA.01.105111. We can recommend Mouser.com, as they offer a good price with reasonable shipping costs.
You will also need coaxial cable to connect the antenna to the SensorStation. Both are SMA female connectors, so an SMA to SMA male coax cable is required.
The iridium antenna itself uses a marine antenna mount thread. You will need a Marine Antenna Base, which looks like this.
We at CTT have used the one above for testing. There is a slot on the antenna that the coax comes out, which allows you to screw it down to the base securely. Please look for one that suits your antenna mast needs.
The antenna itself does not need to be up high. It just needs a reasonably clear view of the sky and to be outdoors. If the SensorStation GPS works, Iridium will likely also work. It is quite resilient even in less than ideal conditions.
Lastly, the coax will need to be connected to the SensorStation. There is a SMA connector next to the SensorStation’s Iridium modem, and any stations shipped Iridium-ready will already include the jumper from the modem to the board to activate the SMA port.
CTT’s new power filter dramatically improves radio tag detection by eliminating electrical noise interference. With thousands of Sensor Stations deployed across diverse environments, we’ve observed that some sites suffer from significantly more electrical noise than others. This noise can come from power lines, solar panels, or other electronic equipment, and it interferes with your station’s ability to detect radio tags.
The Problem: Long power cables (especially from solar panels) act like antennas, picking up electrical noise and feeding it directly into your sensor station. This noise drowns out the weak signals from radio tags, reducing detection range and reliability.
The Solution: Our power filter combines an RF choke and EMI filter to block this unwanted noise while allowing clean power to reach your station. Think of it as a noise barrier that stops interference at the source.
What You’ll Experience:
Detect weaker tags that were previously lost in the noise
More consistent performance regardless of your site’s electrical environment
Better range and reliability in both noisy and clean locations
Instant improvement - benefits are immediate upon installation
Easy Installation: Simply plug the filter between your power source (solar, battery, or AC adapter) and your sensor station. No special tools required, no configuration needed - just plug in and experience cleaner reception immediately.
Whether your site currently has noise issues or not, every station benefits from improved signal-to-noise ratios that lead to better tag detection performance.
To receive your CTT Power Filter, fill out the form here: https://airtable.com/app20NXPv7qjXDfBN/pagrBcK1muqejz5os/form The form is password protected to keep out spammers. The password is celltracktech2025.
The power filter is attached in-line between the power source and SensorStation power block.
Disconnect your power from the station board.
Plug in the power filter wires into the appropriate polarity on the station board (red to positive, black to negative).
Plug your power source wires into the power filter terminal, again ensuring that you’re matching the polarity (brown with positive, blue with negative).