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 email@example.com as we will be updating the manual regularly.
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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 (firstname.lastname@example.org) or through our online Help Desk here: https://celltracktech.atlassian.net/servicedesk/customer/portals.
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 GSM 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 four radio transmitters: the LifeTagTM, PowerTagTM, ES-200 and ES-150.
The CTT LifeTag is 100% solar powered, and therefore has no battery. This allows the tag to persist for many years, beeping out its unique digital ID whenever it has sunlight. For species active during the day, and for small animals for which multi-season or multi-year data are required, LifeTags are the obvious choice.
The CTT PowerTag is battery powered which means it can beep out its digitally coded ID 24-hours a day. The life span of a PowerTag is defined by the beep rate (# of beeps per minute) and battery size. For species where nighttime data is important, PowerTags are the perfect fit.
The ES-200 and ES-150 are GPS logger tags that can also send data over the 434MHz frequency, and therefore can send archived telemetry data to the SensorStation. Since they communicate on the same frequency as LifeTags and PowerTags, no special radio configuration is needed. The difference between the two is that the ES-150 also has an Argos radio to send data via the Argos satellite network.
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 GSM data plan, can also send those data directly to the CTT Servers.
CTT Nodes are essentially mini-base stations: devices with integrated solar panels, a lithium battery, and an antenna to collect data from PowerTags and LifeTags 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 less than 5m, 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 1-1.5km 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.