I'm actually really interested in the technical details of the tracking devices. They had to have batteries that lasted months and they had to be designed to work with the cellular networks in basically any country on Earth. (I'm assuming they weren't satellite based, maybe they were.)
Does anybody have any details on the devices themselves?
If you have a look at the first link in the text, it will take you to the full "e-Trash Transparency" report (http://www.ban.org/trash-transparency). When you download the 'Report', on page 105 it describes, in detail, the methodology used.
Extracts from the report:
"In order to determine and procure the best equipment for the e-Trash Transparency Project, BAN tested several different subscription-based tracking systems. Based on the findings, it was determined that BAN’s case scenario was better served by a customized solution, but one that made use of “off-the-shelf” GSM/GPRS tracking hardware."
Source: https://s3.amazonaws.com/ban-reports/Trash+Transparency/Disc...
"The combined cost of a single tracker, external battery, the SIM card, the M2M service rates package was approximately $175 (including shipping and taxes). The project, funded in large part by a grant from the Body Shop Foundation, included the purchase of over 200 trackers."
"Free and open source software called OpenGTS was used to collect and display data in a user-friendly manner...software included integration with Google Maps"
"The trackers that were used usually had at least a 9-month battery life, with some trackers still communicating after 12 months. The battery life varies depending on many factors including signal strength, temperature and sleep mode settings. Prolonged battery life is primarily attributed to the tracker possessing a sleep mode function, which allows the device to hibernate in a power-saving mode for a preset time. Typically, each tracker was set to “wake up” every 24 hours, calculate its position based on the satellite signals it received, send the data to BAN’s server via local GSM networks and then reenter sleep mode function."
> Prolonged battery life is primarily attributed to the tracker possessing a sleep mode function, which allows the device to hibernate in a power-saving mode for a preset time.
It would be cool if the time between wakeups could increase dramatically towards the end of the life of the battery. Or only wake up when temperature conditions are favourable toward having enough power to go through a cycle.
"Pawtrack needs to be able to be working in a compatible country, and in addition needs to have GPRS (2g) connectivity to allow live updates. The cat tracking collar will work in 171 countries, including USA/ Canada, the EU, UK as well as Australia and New Zealand. In addition, the cat GPS collar will transmit via home Wifi."
"The Pawtrack cat GPS collar takes about 4 hours to be fully recharged, and once charged will last up to 3 days once the Wifi modules and Intelligent Power Control settings are switched on."
I learned about this through a classmate doing a presentation on his work for this project (at MIT).
Iirc, they used modified android devices with larger batteries. The devices mostly slept and occasionally woke up to check in so they lasted awhile. I don't remember the specifics of how they communicated unfortunately. I'm somewhat surprised this article is out. When I heard about it (~1 year ago), I thought they weren't going to release the data because it technically acquired illegally with the tracking devices.
What laws did they violate? Just to disambiguate my tone, I don't doubt they could have violated laws, I'm just not very knowledgable in this area of the law and would like to learn more.
My understanding it was some sort of law related to the tracking feature, and possibly some sort of espionage related laws. This was a speaking class (6.UAT), so I don't know much about the details. Hopefully someone from the project shows up and can answer better.
Devices can either use cellular networks or satellite networks. The amount of data sent is extremely small, so bandwidth isn't an issue. The device can wake up, get a fix, store it, and then sleep again for a set duration of time. They're off the shelf, or you can build a custom device using an Ardunio board (or any microcontroller really).
Your endurance is limited only by the size of the battery you use (and if you use solar somehow, infinite).
I don't know what they used for this project, but I have built similar things with the recently-released Particle Electron that I got on Kickstarter, though now I believe it's released widely. Works really great, I was using the Spark Core before, same company and concept but with wifi instead of cellular.
Does anybody have any details on the devices themselves?