Motus on moving ships

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Gabe Reyes

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Feb 9, 2024, 10:48:48 AMFeb 9
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Hi everyone! (I tried to post this question yesterday but nothing has show up, so I apologize if it gets posted multiple times...).

I may have an opportunity to place a motus receiver on a research ship, so I was curious to hear about how this would be handled by the Motus website, any issues with data and whatnot. And if people have experience doing this type of deployment? I saw a vague mention of it in the Motus guide pages, but nothing beyond that. 
I was thinking I would just do 1 directional yagi on each frequency, rather than omni antenna, to maximize coverage range. But it might be possible to do an omni and a directional yagi. For the 166 frequency, I would just do a 3 or 5 element antenna. Also, if the ship is travelling around the pacific ocean, would it be worth it to include the European lotek frequency? 

Any advice or feedback is much appreciated! 
Thanks!
-Gabe

Thorsten von Eicken

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Feb 9, 2024, 2:08:17 PMFeb 9
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Gabe, that sounds like a cool project! I hope you can run the Sensorgnome V2 software and have it internet connected for real-time updates!
The Sensorgnome V2 software gets a GPS fix every 60 seconds, the old software every 5 minutes. Either should be fine on a ship.

WRT antenna choice, remember that what you're changing is the shape of the antenna gain. The overall power received by the antenna is the same regardless of yagi, omni, etc. (I find it easier to think about TX power but RX is symmetrical.)
A directional antenna favors one direction and reduces others. A Yagi is kind'a like a cone pointed in one direction (with a small cone in the opposite direction) and "silencers" for the rest. A high-gain omni favors all directions perpendicular to the omni at the expense of vertical up&down. But both antennas will basically cover the same geographic area. It seems to me that an omni is easier to maintain on a ship and makes more sense from a coverage point of view. The thing to think about is whether it's worth to make an effort to capture high altitude birds. You could add a small (i.e. broad) yagi pointed straight up for that. Or, there are omnis that have an "electrical down tilt" typ of 7-10 degrees (think mountaintop trying to cover valleys around) and you could mount one of those upside-down (or find one with up-tilt?) in order to capture more high-altitude. Dunno whether that's really worth it, though.

I hope others can chime in with some real-world experience!

Cheers!
Thorsten

René Janssen

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Feb 11, 2024, 9:35:33 AMFeb 11
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Hi Gabe,

A plus for a Yagi is that you can mount it in a way you pick up the less noise as possible from the ship itself. A Omni can take all the noise in easily. I would go for two yagis that looks to both sides. 

The GPS will tell where the location was; on the MOTUS site you can use the option ship as installing location.


René


René

Op vr 9 feb 2024 om 20:08 schreef 'Thorsten von Eicken' via Motus Wildlife Tracking System <motu...@googlegroups.com>:
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The Motus Wildlife Tracking System (Motus) is an international collaborative research network that uses coordinated automated radio telemetry to facilitate research and education on the ecology and conservation of migratory animals. Motus is a program of Birds Canada in partnership with collaborating researchers and organizations. Learn more at https://motus.org
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Rebecca Holberton

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Feb 11, 2024, 9:35:38 AMFeb 11
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just to chime in re placing an antenna on a ship - You may want to mount the antenna pole on a gimbal or platform stabilizer so that it does not rotate or swing with the movement of the ship's roll, but can retain a fairly vertical placement, and keeping the antennas on a fairly constant horizontal plane.  Having worked at sea, it is hard to keep things stable and in a particular plane without a stabilizer or gimbal.  Just something to consider. Otherwise, your detection field will be all over the place at an array of angles, missing a lot of detections.   Have fun at sea!


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The Motus Wildlife Tracking System (Motus) is an international collaborative research network that uses coordinated automated radio telemetry to facilitate research and education on the ecology and conservation of migratory animals. Motus is a program of Birds Canada in partnership with collaborating researchers and organizations. Learn more at https://motus.org
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Former Director, NE Regional Migration Monitoring Network
Laboratory of Avian Biology
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Shirley, MA 01464

Corey Wotring

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Feb 11, 2024, 9:35:43 AMFeb 11
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Gabe,

For a shipboard situation I would think an omnidirectional antenna would be your best bet. A single Yagi, being highly directional will limit you to, well... one direction. You will have no control of where the Yagi is pointed and therefore could miss quite a lot in terms of detection probability.  For example the starboard facing antenna could miss the Pacific Island off the Port side of the ship. In a situation where a moving antenna will cover potentially hundreds of miles a day, you're better off sacrificing distance for total volume.

With regard to the up/down detection I think you're still going to have most success with an omnidirectional antenna. There is a "dead spot" directly above the antenna but most birds won't fly any higher than your lateral detection range is and ideally you would have captured the detection before it got above the antenna anyway. Omnidirectional antennas are used in aviation and at altitudes much higher with great results. 

All that to say that I believe an omnidirectional is the simplest and least expensive with the best probability of detection. 

Sounds like a great project and learning experience. Good luck

Corey Wotring
SW Michigan Motus

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Josh Sayers

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Feb 11, 2024, 9:51:03 AMFeb 11
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When it comes to your deployment metadata, there are a few "mobile" options, including for ship. You'll have the opportunity to select these when you add a receiver deployment to your station. It's at that point you can select a "mobile" option. I've attached a screenshot from a random Ontario station deployment as an example.

Josh

2024-02-11_094809.png

David La Puma

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Feb 11, 2024, 10:18:24 AMFeb 11
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Hi Gabe-

I’ll second the Omni directional recommendation. On a ship (especially if you’re having to convince someone to put a station on their ship) you’re likely gonna want to keep it as simple as possible. I would look into the offshore motus recommendations put out by Pam Loring from the USFWS and colleagues. These offshore installs, whether on buoys or turbines, have all of the challenges of a ship including wind loading, rocking wildly at sea (buoys), cramped and often restrictive mounting locations, etc. any station can be hacked to collect GPS more or less frequently if that is warranted by a moving ship. Noise will have to be something you test for and overcome through mounting or filtering. 

Cheers

David 

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On Feb 9, 2024, at 10:48 AM, Gabe Reyes <gabe.r...@gmail.com> wrote:

Hi everyone! (I tried to post this question yesterday but nothing has show up, so I apologize if it gets posted multiple times...).
--
The Motus Wildlife Tracking System (Motus) is an international collaborative research network that uses coordinated automated radio telemetry to facilitate research and education on the ecology and conservation of migratory animals. Motus is a program of Birds Canada in partnership with collaborating researchers and organizations. Learn more at https://motus.org
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