Alas I have no recommendations for you, but I want to say kudos for pursuing a no-trace approach.  Granted the impact of a handful of tracking tags being discarded is way down the list of global pollution sources by impact, but it's good (in our field) to lead by example.

Hi Gabriel,

Our TagRanger Tags can be used for tracking turtles,  we already have a tracking project commencing soon in South America for ~40 turtles...

https://www.tagranger.com/  

The Tags use LoRaWAN allowing you to communicate with your Tags in real time.  As well as requesting current GPS locations from long distances away  (20km Line of Sight) you can also use the integrated ranging tools which give you distance to your Tag in metres when you get closer.  

Key features:

LoRaWAN (tested > 20km line of sight). Use a 'Finder' which is a handheld gateway or you can also use your own LoRaWAN network.

UWB ranging gives distance (in metres) to the Tag up to 150m away

Hybrid Ranging combines the equivalent of a VHF pinger from a few km away (line of sight) with the UWB ranging when you get closer

Log Download remotely using UWB radio

The Tag can last for very long lifetimes depending on how you configure it

Please drop me a line if you are interested in hearing more about this and how we could configure it best for your application.

Craig

Hi Andrea,

The OpenLog Artemis might be an option. I haven't used one of these yet, but its what I immediately thought of. Built in real time clock and IMU that records to microSD. It has four 14-bit ADCs and I2C connectors for the 'Qwiic' or 'grove' sensor boards. I'm not sure if it has programmable on/off cycles with the clock but you may find an existing project that does this. 

Hi Maggie!

This sounds like a really interesting - and challenging project!

UHF is used for tranfer of acceleration data (along with other stuff like magnetometry and GNSS locations) by systems developed by companies like Milsar and TechnoSmart. 

Ceres Wild uses satellite transfer over the GlobalStar but no raw acceleration data is transmitted.

I would fear the bandwidth would be too restrictive if you insist in using satellite based transfer of accelerometry.

Cheers,

Lars

This sounds like a lot of fun!

The lowest cost satellite comm I know of is https://swarm.space/.  It's pretty cool tech, but the data rates are quite low.

Do you have any idea how much data you need to move per day on average?

Perhaps LoRa would be an option?  Here is an example of a LoRa device https://www.adafruit.com/product/4284

LoRa is not satellite, but it has quite a long range which may suffice?  It is also pretty low data rate, but it is a good deal better than Swarm.  The best thing about LoRa is that the end-point can be very low power, so battery life can be quite good.

If you know somewhere the crocs frequent, you might also be able to work something out with Bluetooth LE?  Both LoRa and Bluetooth would require the installation of at least one base station.  Lora's base station could be substantially further way.

I have a few suggestions Maggie. Hopefully one or more will be useful. 

Preprocessing - Compressing the data before transmission will reduce file size and reduce transmission time.

Reduce data volume - I guess the animals are only active for some periods and a lot of the time are just "cruising along". So a useful strategy could be to only start recording when a certain threshold of acceleration occurs. And if you also buffer the data for say 10 seconds, you will get info about what's leading up to the activity. And adding a GPS module you will get some info on where the activity occurred plus movements prior. This will of course increase the data volume but only recording the most recent location will probably suffice as the location of the previous activity will tell you how far the animal moved.

Use LoRa instead of satellite - LoRa is well suited to this type of application. I saw in 

that the home range of crocodiles is relatively small so although a forested area will limit LoRa performance, the range should be sufficient. You could also use multiple base stations if needed. 

Of course eventually the data that has been recorded at the LoRa base station(s) will need to be collected. You could add a long range radio to the base station, or just collect the data 'manually'.

Hope this helps

Hi Krasi! Greetings from Brazil!



That's a cool journey you've started! Congratulations. And I felt like theSearchLife resonates with the work I'm involved round here. In a nutshell, I live at the heart of the largest remaining of Atlantic forest in the planet - one of the most biodiverse biomes that exist. The subregion where I live is named after and bathed by the "Rio Sagrado" (Sacred River), a magnificent water body with a very rich cultural significance to the region (it has served as a safe zone for fleeing slaves). Well, the river and the entire bioregion is currently under the threat of a truly devastating railroad project which, to say the least is planned to cut through over 100 water springs! 



In face of that the local community (myself included) has been mobilizing to raise awareness of the issue and hopefully stop this madness (fueled by strong international forces). One of the ways we've been fighting this is through the seeking of the recognition of the sacred river as an entity of legal rights, who can manifest itself in court, against such threats. And to illustrate what this would look like, I've been developing this AI (LLM) powered avatar for the river, which could maybe serve as its human-relatable voice. An existing prototype of such avatar is available here. It has been fine-tuned with over 20 scientific papers on the Sacred River watershed.



And right now myself and other are mobilizing to manifest the conditions/resources to develop a next version of the avatar, which would include remote sensing capacities so the avatar is directly connected to the river and can possibly write full scientific reports on its physical properties (i.e. water quality) and the surrounding biodiversity. In fact, myself and 3 other members of the WildLabs community have just applied to the WildLabs Grant program in order to accomplish that. Hopefully the results are positive.



Finally, it's worth mentioning that our mobilization around providing an expression medium for the river has been multimodal, including the creation of a shortfilm based on theatrical mobilizations we did during a fest dedicated to the river and its surrounding more-than-human communities. You can check that out here:



 

Let's chat if any of that catches your interest!

Cheers!