Solution for Outdoor Geolocation

Question

I am new to the Internet of Things space and would like to inquire if a solution exists / could be created for real-time geolocation of an intermittently mobile object (not an automobile)? The GeoLocation would have to work mostly outdoors and would need to transmit location every few minutes to some cloud-based system. The device will also need to have the ability to be switched on and off by a human being and/or programmatically when the object does not need to be tracked.

I am looking for a few questions to be answered:

1. Is there any product available which can achieve outdoor geolocation with <100 meter accuracy which costs less than $40 ?

2. If no such product exists, how complicated would it be for me (an IoT novice) to build a system that achieves outdoor geolocation using a raspberry pi (maybe for about $30 - $50)?

Any guidance or additional resources that would help me gain clarity is greatly appreciated.

Here are the answers to some questions in the comments:

1. How long does the device need to report location? A. I am assuming the device will be reporting location once every 5 minutes. The device will need to report location through out the day, maybe from 7 AM - 11 PM every day, so for about 16 hours a day (although this isn't a hard constraint i.e it could report for less time).

2. How large is the object? A. The object can be thought of as not being too large. It will be about 1.5 - 2 meters in height and about half a meter wide.

3. Does the mechanism need to be covert? A. No there is no special requirement for being covert w.r.t the geolocation process. However, the data once collected needs to be secure and the actual geolocation device should allow me to add layers of security into it to prevent malicious entities from manipulating the geolocation process and / or unauthorized entities collecting the geolocation data. However, an important feature that the device will need to have is the ability to be able to be switched on and off by a human.

4. What power source is available? A. For now, I am assuming that a power source will be intermittently available (i.e 1 - 2 hours a day), i.e the device will be charged once a day using a regular charging port. Or, if it would be possible for such a device to have rechargeable batteries, then some solution could be possible achieved with a set of 2 - 3 rechargeable batteries cycled through out the day, however I fear this will go over the $40 budget that I have set for such a device.

5. It needs to report location so often because the location of the object will govern certain processes in the backend. Think of it akin to a ride matching part of a ride-sharing service like Uber (only w.r.t the reason for frequent location reporting) wherein the location of a driver is collected at some frequency to match them with a trip.

What research was done previously:

1. One approach that I have thought about is to use cheap smart phones with GPS capabilities and deploy them instead of sensors on the objects. However, the cheapest smartphones that I was able to find were about $70, not to mention the phone plan requirements etc, as the geolocation will have to happen in the abscence of wifi.

2. Another device that I have looked at (although I must admit I didn't understand the explanation enough to evaluate if this would work for my application) is Apple's iBeacon devices. However, I do not have the answers to most of the aforementioned questions in the context of iBeacon devices.

Answer 1

Regarding question 1:

There is a vast amount of GPS trackers (accuracy of a few meters) that are commercially available and that come with their own tracking server accessible via app or web-interface.
Normally, they either come with a built-in SIM-card or you have to put in a SIM-card yourself. The location is communicated either via SMS or via mobile data to the tracking server. Needless to say that you will have monthly running costs due to the SIM card.

Typically, they are used for tracking pets (e.g. cats) or vehicles, amongst others. Their price range is quite wide, depending on where you order and what features they incorporate (e.g. microphone and/or speakers, additional WiFi). Nevertheless, you should be able to find one that is in your price range, if you search for "GPS tracker" on the standard platforms for electronic equipment.

Regarding question 2:

If you are worried about privacy, you can host your own tracking server on a Raspberry Pi. A popular solution is the traccar server, which is open source and free of charge.
You can use with compatible devices (listed on their homepage) or a Traccar client app on your mobile phone. For running the server you simply need a Raspberry Pi connected to the internet (no additional hardware required), with an exposed port for the traccar server.

Answer 2

I would recommend the TTGO T-Beam, or a similar device, using LoRaWAN.