Navio+ and Reach for ground based robot

Hello all!
I am a complete noob when it comes to these things, so please bear with me.
I have, recently, been having back issues, along with many other people at my school. (Yeah, I’m quite young, yet I want to build a robot. Kind? Yes. Crazy? Very.) Anyway, I was going to use the Navio+ along with the Reach (For ultra accurate navigation), but I have a few issues. First being a fairly simple one, which 4G or 3G Modem is good for sending information to this? (Obviously I’ll need a SIM card. I think) The second question is, do I need one or two Reach’s for high accuracy navigation? Lastly, I was curious if a LIDAR system (Like the one here) would be a good add on for other uses.

If you want me to emphasize on a question or something else, please ask!
Thanks in advance!

Regarding the LIDAR you know that only points in one direction? Those “binocular” type units are typically used for accurate height in drones (as a better alternative to sonar which only works up to 7 meters away).

For a ground based robot the cheapest LIDAR I’ve seen so far which gives 360 coverage is this one:

As you probably know already the classic cheap solution is 4 or more sonar sensors pointing in each major horizontal direction NESW (a classic ground based robot). But the 360 LIDAR is going to be like the difference between a blind man walking across the street with a white stick (sonar) or more (e.g. 4 white sticks NESW), or a bat capable of understanding ultrasound in 3D. Depends on your budget though and what you want to do with it.

This 360 LIDAR appears to be in the horizontal plane only. If you wanted to sense the third dimension to move up and down ramps or not run off the edge of things, then unfortunately the price jumps to 1000s as you need one which takes a vertical slice rather than one point rotated.

p.s. Reach is currently sold in a kit of 2 last time I looked in the shop. As Navio running APM is not compatible with RTKLib in parallel (somebody stated in this forum recently) I think you’ll need both those units. But I have not personally tested that setup so hopefully somebody else can comment on the combined Reach/APM/Navio configuration.

Oh, ok, that makes sense.

Thank you for sending me this! It may be expensive, but it will do the job quite nicely!

Yeah, or somehow manage to put eight together, or something crazy like that. But I would rather be getting the 360 LIDAR for accuracy purposes.

The fact that it’s horizontal only is ok, that will help. It’s better than relying on GPS only. I don’t have the experience (yet) to actually get any decent use out of a 3D LIDAR

I think you can get Reach on its own though. So, APM can use two Reach’s at the same time? (Sorry, new to this, I really don’t know much, sorry)