Station Structures
There are countless ways to install a Motus station and it’s not always clear which is best. For the most part, your station will depend on the structure you have to install the antennas on. Here are a number of different installation methods used across the Motus network to help you decide which setup suits your location best. For any inquiries, please Contact Motus for additional support.
Overview
Motus stations have been built on just about anything – lighthouses, towers, trees, cars, drones, planes, ships, buoys, bamboo masts, and just about every type of building you can dream of.
The actual structure doesn’t necessarily matter as long as it’s strong and elevated enough to provide a clear line-of-sight, and the antennas are not mounted close to sheet metal or other antennas (see Antenna Interference above). The easiest and often the cheapest method is to use a pre-existing building or structure upon which masts or antenna can be affixed to existing railings, or on the side of buildings where a DMX-style structure can be mounted. Installation can be tricky, and every situation is different, but once it’s set up there shouldn’t be much maintenance or worry.
In remote locations where there aren’t any buildings to attach towers, one can use a tripod and mast like those manufactured by Wade Antenna, or a DMX-style tower that is either guyed or unguyed. Pop-up towers must be guyed (3 lines per 10-foot section) and anchored (1 anchor per guy or just 3 strong anchors). Pop-up towers are more sensitive to wind and ice than the DMX-style structures so regular maintenance will be necessary.
We can’t stress enough the importance of excess supports in any setup situation. Use more and stronger guy wires than you think you need, more waterproofing, more wall mounts, bigger batteries, bigger solar panels, and strong gauge, galvanized or stainless steel materials (especially in marine environments). It will cost you more in the end per setup, but shortcuts will often cost you more in the long-term.
Sourcing equipment outside of North America and Europe
The list below includes a list of structure types that are commercially available, but these products are typically not sold outside of North America and Europe by this supplier. In these cases, a local solution will need to be found which we provide examples of in the list. Please contact us if you would like to contribute to this list of suppliers.
Looking for local solutions can be difficult. If you plan to install large antennas (i.e.; 9-element Yagis) in a location that may experience high winds, it's especially important to look for robust solutions that won't fail after the first storm. If at all possible, it's best to avoid installing your own free standing structure and instead use a pre-exisiting tower or attach a mast to a building. It's usually easiest to find piping for a mast (aluminum or zinc-plated/galvenized steel) and a bracket that will hold to an exterior wall.
Structure types
Lattice tower
It is highly recommended for collaborators to install a tower that is intended for longer-term use which typically involves a lattice tower. These types of towers have several names, including: Rohn tower, DMX, Golden nugget, Delhi tower. It is common to see this type of tower for weather stations, rural internet and TV, or HAM radio, which is a testament to their utility.
While installing this type of tower can be a significant increase in cost from the pop-tower, it will reduce your overall long-term expense. These structures have fewer individual parts and are stronger than the pop-up masts so require less maintenance and do not always need to be guyed giving it a smaller footprint. Certain models of lattice towers can be attached to a building, cutting costs significantly.
Common setup locations
Buildings
Parks
Interpretive Centres
Forests
In Canada, Wade Antenna sells DMX towers in 8′ sections or Golden Nugget towers in 10' sections, making them fairly transportable like pop-towers. In the United States, Rohn sells their lattice towers in 7' sections (shipped by UPS) or 10' sections. In some countries, it may be most practical to commission the construction of lattice towers by contacting local metal fabricators.
There are two main types of lattice towers: self-supported and bracketed. Self-supported towers are either guyed or unguyed (require a concrete base) and will most often require professionals for proper installation since it must be climbed using appropriate equipment and training. Bracketed towers are attached to buildings and do not require a concrete base. Lattice towers come in modular sections allowing them to be anywhere from 10- to 100-feet tall, which is often necessary to reach above the forest canopy.
On a building
There is an unlimited number of ways antennas can be mounted, it all depends on location. Co-locating a station can save on costs and is often necessary for some locations.
Common setup locations
Houses
Out buildings
Public schools, universities, museums
Guard Rails
Wall-mounted mast
This is essentially a metal pipe bolted onto the wall of a building using some sort of bracket. The bracket you use will depend on two things:
What's the expected maximum load on the mast?
How deep are the eves?
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Guard Rails
Many buildings and other structures will have guard rails at their highest point which can serve as a great place to anchor your mast. Also see lighthouses and fire towers for similar examples.
Co-locating3.jpgBolt-on roof mount
If it's possible to bolt into the roof, this can be the best solution to get the clearance required a low-profile structure.
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Laboratorio Costero Calfuco11_Lucas Berrigan.jpgNon-penetrating Roof mount
There are many cases where you need to install a station on a flat roof and it's not possible to bolt into the roof. A non-penetrating roof mount is essentially a platform that is weighted down with aa mast at the center.
On a pre-existing tower
Fire Tower
The Northeast Motus Collaborative has had a lot of success getting permission to install antennas on fire towers across the state of Pennsylvania. This is an ideal situation for any collaborator since it significantly reduces costs, maintenance, and risk of vandalism or theft and also provides an excellent vantage point and sometimes a reliable power supply. This is an example of a creative approach that has been very beneficial for the whole network. Not every strucutre is in a perfect location nor is every structure clear of vegetation and safe to climb so everything must still be assessed on a case-by-case basis. While you may not have the same success with fire towers in your region, it’s still worth thinking outside the box to help reduce the costs and time investment.
Commercial Tower
Some researchers have had success with installing antennas on commercial telecommunications towers. These are often in great locations and are usually powered, but they require a professional climber (+$1000 in fees) and sometimes rental fees.
Commercial2.jpgWeather Station
Weather stations are a great place to host a Motus station if you're able to convince the owner to co-locate your antennas on their tower. They can also be easily located by using maps of weather stations like WunderMap.
Lighthouse
These days, most lighthouses have been decommissioned and offer a great opportunity for hosting a robust Motus station. One of the very first Motus stations was installed on Sable Island off of Nova Scotia and operated without a hitch for over 5 years. Getting permission to host a station on a lighthouse can be tricky depending on the jurisdiction, but in many cases local communities are in charge of keeping the lights and getting permission is not difficult.
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Pictou2_Lucas Berrigan.jpgFree-standing
Pop-tower
These are very common setups since they can be deployed almost anywhere, but the weight of the materials can be prohibitive. This type of tower is most-often limited by its height with anything taller than 50′ require a more robust and professional-grade installation.
This type of structure is more vulnerable to wind/ice damage and corrosion so it’s typical to require a mast replacement within 5 years, especially when exposed to salt spray or fog.
Common setup locations
Hilltops
Clearcuts
Sea/Lakeshore
General open spaces
Pop-tower stations are typically built using a tripod and 30-40′ popup mast from Wade Antenna. In some instances antennas can be installed on a mast alone, like on a sand dune (see picture below). Lots of other equipment is required for these installations, including: guy lines (3/32 recommended), guy line anchors (~4′ rebar), quick links or carabiners (to attach guy lines to mast), aluminum angle-iron for solar panel mount, and lightening protection (if deemed necessary).
A comprehensive list of equipment and installation guide is currently in development. Stations can also be installed on rooftops using a non-penetrating roof mount and masting.
Mast only
Using just the mast is a smallest practical version of a free-standing Motus station. Usually these only host omni antennas due to the weight restrictions, but more robust version can hold Yagi antennas as well. This has become a widely used setup for temporary installations due to its low cost and ease of use, but generally limits the number and size of antennas that can be deployed and they are less reliable in high winds.
Weighted platform
These are a bit heavier to transport, but can be the only solution for locations where there is no soil layer to anchor guy wires.
Utility Pole
Utility poles are a good long-term solution for a Motus station as they can last decades without requiring any maintenance; however, the initial installation costs can be prohibitive due to the heavy machinery and skilled worked required.
On a vehicle
Mounting antennas to a vehicle can require a fair bit of improvisation depending on the antenna and vehicle types. Below are just a few examples of what has been done in the past. Most of the time it only makes sense to use an omni antenna which has a low profile, but also a limited range.
Car
All examples of car-mounted antennas with Motus have used omni antennas with varied success due to the limited range of omnis (0.5-1 km).
Photos to come
Boat
If planned well, boats can be a great place to host a Motus station due to the fact they have their own power source and their weight capacity allows for multiple of any antenna type to be attached. For instance, a ferry with two 9-element Yagi pointing down its bow and stern could detect animals as they move down a strait. In another case, fishing boats have been fitted with omni antennas to detect Phalaropes while they are at sea.
Photos to come
Plane
Aerial surveys have been conducted in the past where an omni antenna was placed on the bottom of the aircraft, but ultimately it's usually up to the pilot to decide what they are comfortable with.
Photos to come
Drone
Only an omni antenna can be used with drones. All examples have used flexible whip antennas which hang from the base of the aircraft.
Photos to come
Antenna Spacing
Yagi antennas should be vertically spaced according to their direction and frequency. Make sure you have ample spacing between your antennas and any sheet metal, such as roofing. The typical figure for minimum spacing and metal roofing is 1 full wavelength. Yagi antennas that point in the opposite direction (parallel) will interfere with each other if spaced too close together, essentially eliminating the directionality and severely impacting the detection range. Antennas that are parallel (180 degrees) should be at least ½, but best at a whole wavelength apart. Antennas that are perpendicular (90 degrees) should be at least ¼ wavelength apart.
Antenna Type
Tags
Frequency
Wavelength
9-element Yagi
Lotek
166.380 MHz
1.80 meters
9-element Yagi
Lotek
151.500 MHz
1.98 meters
9-element Yagi
Lotek
150.100 MHz
2.00 meters
9-element Yagi
CTT
434 MHz
0.69 meters
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