Station Set Up
** When setting up a station, it is imperative that they are tested with a live tag. Test tags and activators can be purchased from Tag Manufacturers (link), or Motus for about $500. **
The position and configuration of stations almost always depends on the specific objectives of individuals studies. To maximize long-distance detections of animals in flight, elevated locations with a clear lines of sight in the direction of the antenna are ideal. Aggregate sites and landfills can be especially useful. Rooftops of particularly high buildings will often give you clearance above surrounding canopies, urban or landscape features.
It is also very important to consider the potential power source (solar vs. AC outlet) and potential wireless or wired internet connection. AC power will always provide greater dependability than solar, and is much cheaper. Internet connection will allow for live monitoring and automatic download of data (SensorGnome receiver only). Cellular connectivity options are under development.
Stations affixed to buildings or other existing infrastructure (towers) tend to be the most stable and secure, and usually come with options for AC power and/or internet. A mast that can support antenna(s), can be mounted to just about any pre-existing structure (e.g. lighthouse or fire observation tower), or to a standard TV-antenna tower. Flat rooftops, or those with railings or similar existing structures are particularly well suited as are lighthouses, and existing radio-communication or internet towers. The vast majority of stations however, are guyed pop-up towers, which are well suited for locations where pre-existing infrastructure is unavailable.
A gallery of existing station types and instructions on installation of pop-up towers, is available on Sensorgnome.org. Many specifics within the instructions are applicable to all types of installation.
Powering your site
If AC outlets are available, this will be the most dependable source of power. If not available, you can use a battery and solar setup. Instructions for Solar arrays can be found here.
Station Configuration and Antenna Orientation
The orientation of antenna(s) at a given station depends largely on specific questions being asked, and importantly, the geography of the surrounding area as antennas should always be pointed away from any obstructions such as buildings, trees, or hills. Most often the goal is to cover as much ground as possible to detect movements from one space to another. This is usually done through the creation of turnstile, or fence arrays which consist of stations deployed in a line to “catch” migrants as they move in latitude or longitude, point-to-point arrays to capture migrants as they move between geographic locations (e.g., for species with well known breeding, wintering and stopover areas), and transient receivers on moving/floating platforms to capture movements of birds at sea. Local or regional grids of stations can be used to determine movements of animals in any direction throughout a given area, although the density of the array will depend on the level of research questions, level of precision desired, species, and landscape.
Data from specific automated stations does not provide very high spatial resolution, and researchers are often forced to use an implied location based on the location of the station and the direction of the antenna that the animal was detected on. The strength of the signal being emitted from tags, and the difference in the time between detections can be used as proxies for proximity to the station. At best, the level of resolution from automated data is currently a few hundred meters.
However, when supplemented with a manual tracking protocol, radio telemetry can provide the finest precision of any available technology, to <1m if desired.
It is important that stations generally be higher than the surrounding landscape giving antenna clear lines of sight in the direction they’re facing. Antenna can be affixed to just about anything. If you have any pictures that show different setups, please contact Motus.