Drone LiDAR REVIEW | LiAirV | DJI LiVOX

[Music] international iter with a DG I live on are complete review [Music] well hey there guys well you really wanted me to do a complete review of that livebox lidar sensor so here it is today I'm here with the backpack and Indiana drones fashion and I'm going to do a complete review of that lighter sensor we're gonna go someplace really cool with a nice Canyon nice trees a beautiful place to see some light our data and fly a mission and show you exactly what the data looks like ok so here we got the M 210 drone with that ly air V installed we're gonna go ahead and just set it up right over here in this clearing and begin recording our static measurements on the GPS from the lidar and getting about five minutes of static measurements to continue doing the setup we have to set up the GNSS base station now the lie RV from Green Valley comes with its own base station and GNSS GPS antenna there's a nice little monument marker right here on this manhole I'm going to place our GPS directly on top of that and then we're going to set the base station which is now on it runs off this Mavic battery and this will last you on a full battery probably all day it's very low-power okay now we have the mission plan the drones been sitting for about five minutes recording static GPS measurements all the while we have the base station been recording the entire time and it will continue to record throughout the entire time we're out here now it's time to do a calibration flight with a drone [Music] beautiful takeoff alright we're in here now and it looks great it looks a little little notes have um takeoff but other than that the flight characteristics they're looking perfect let's go ahead and upload that mission plan and start flying the mission [Music] all righty then welcome back to the office wasn't that a good flight I had a great time did you I thought it was really good this this bird performed really well and it carried this lightweight sensor my go is nothing so the next thing we're going to do is process the data from the lidar and the base station to get the point cloud but before we do that let's take a second to talk about the tech specs of this lidar sensor so this is the liar V package from Green Valley and inside of it includes the live ox mid 40 lidar sensor the live ox itself just the laser sensor sends out a hundred thousand laser pulses a second and this can be configured in two different ways actually three different ways it can either do 100,000 pulses per second with one return meaning one pulse one measurement or it can do 200,000 points per second with two returns that means one pulse two measurements coming back and then also they can do three returns but you lose some points there because of the bandwidth-limited of the data connectivity of the lidar sensor itself now the accuracy of this it comes out of all the points come out of this window focused this direction so this is a little bit contrasting with other line our scanners on the market that will spin around on a full 360 degrees whereas this may be good if you're using an autonomous vehicle and you see all around the vehicle it's not necessarily the best thing for a drone on the drone you're gonna waste a lot of those points shooting straight up into the sky whereas the lie box it points all of those points directly out this window towards the ground now there is a 40 degree window where it goes 40 degrees in this x direction and y direction and spins an interesting cloverleaf pattern coming out so all those points may be hitting straight towards the ground live ox itself quotes that it gets two centimeters precision from the sensor itself now this is a little misleading because they measure that at 20 meters and we're almost never going to be flying at 20 meters and then the other things that you have to factor in precision is the fact that inside of this case to make it a mapping system you have to have a GPS as well as an inertial measurement unit so when you combine the accuracy of the GPS along with the accuracy of the inertial measurement and the accuracies of the laser sensor itself you actually get a compounded error that's going to result in something maybe closer to 5 to 10 centimeters but we're gonna find that out when we process the data oh one more important fact it has a 260 meter range to it so at 80% reflectivity it will see something as 260 meters away that's pretty darn far let's put this liner back onto the drone plug in the power and pull the data off and pull the data off the base station well awesome there we go that is the data this looks really good I am looking at the lighter data right now so right now we're looking at the 80 meter example the blue is really low and the red is high so it's the elevation and this is the canyon right here in the middle we took off and and landed somewhere over here on this side where you see a little bit more density this is a road that comes along up here and there's also a road here and this is all a big valley and let's go ahead and toggle the hundred meter example see it looks a little bit different on the road you can see the road marks there one of the important things to look at with this lidar data is seeing just how fuzzy the data is so you can actually pull up something called a cross section which is gonna cut right through the data and we're just gonna look right down that right down the plane of the data and we're gonna be able to see a single line and see just exactly how good the data looks so let's grab a big area but then I'm gonna shrink this down to really small it's your 0.1 ok so now we can zoom in on that so we get this should be a pretty flat area this is the road up here and so if we look mostly on the road and let's do one other thing we're gonna colorize the hundred meters let's colorize that as red and then let's grab the eighty meters turn that on and we will turn that into how would you guys say let's do yellow yeah then grab this will turn that point size up quite a bit wait we just colored the what's called the 80 meter yellow well this is interesting I did not expect that I didn't expect that at all so what I'm seeing here if you what do you guys think it looks like the yellow is thicker than the red but the red was flung higher than the yellow huh you think if you're closer the accuracy would be higher and if you're further away would be less what would be something else that good now maybe it's something to do with like I said it's like a statistical sampling so since we flew lower and the lines were spaced closer so there's more points per square meters so maybe it's just statistics like the law of large numbers but you think the distribution would be the same either way I don't really know that's a very interesting fine so maybe flying at 100 meters is the way to go this is a flat hard surface this is just a road so this should tell us pretty because the roads the road is flat other things when you're looking at the thickness of it maybe it's looking at grass blades or you know you're looking at some brush so it may not be so accurate but this is a hard flat surface so that's about 14 let's round it up say 15 centimeters so that 15 centimeters spread is only one part of the accuracy we also want to make sure that the entire data set is located in the correct location on the earth so to do that we're going to use ground control points using another GPS receiver to make some measurements of the earth and compare the lidar data set to those well we got our first ground control point and we're gonna use this data to actually check the accuracy from the lidar scan so this is a traditional surveying method and what we're doing are taking static measurements so basically we're taking a measurement from the GPS satellites every second and just keep recording that in effect what we're doing with this measurement is we're getting a very accurate single point on the ground and we're gonna get the accuracy down to about one centimeter with this all right we're back here in the office I just finished processing those ground control points using the opus resources online let's see how well they line up with our line our data set the red point here is what I measured using the external GPS device and then I use the post-processing technique available online called Opus here in the United States which basically allows you to do a network adjustment it takes into account a bunch of other gps's that are operating around the US and helps you correct your data so that way you can get millimeter precision so we know that our red dot is very accurate and we can see it's basically within the within the fuzz a little bit on the low side but just definitely slower than the fuzz of our data set now for comparison's sake I went ahead and flew the Nspire and made Northam was a ik and a 3d model using drone deploy software and dren deploys are really good at stitching together photos making 3d three-dimensional models and so this is the results from that flight so now we can see here is just a two-dimensional view and I'll click onto that 3d view you see all the blobby blobby owls if you will of the cars and trees I mean it's still really good and something that really amazes me is up here this is there's one of trees but trying to play manages stitch the trees away into the digital elevation model so very very cool stuff with their algorithms I cannot wait to see this improve a little bit more it's already pretty phenomenal but let's take a look at the model so this is the 3d model now you can see where the challenge would arise if you are trying to grab the ground off of this and see the actual contours of the the ground you know it's just these trees are just big blob yowls and that's normal I mean you had a camera in use that's all you see so I went ahead and published some of these datasets onto this viewer and so after you take the data so this is kind of a one-to-one comparison of the lidar data to the photogrammetry data what one thing we do is we classify those ground points so that is now if you only look at the ground points you get rid of all that vegetation so I mean this is really what you want to see with the lidar data so you want to be able to see underneath those trees in the ground okay so here's a big tree yeah and you can see right here underneath that tree you're not really getting good good penetration I mean it's seeing a little bit but there's a big missing spot Sophie remove that yeah we kind of see that's where the gaps in the data are we I mean that still extending again comparing this back and forth back and forth see it there and see that and then we do it here so this is ground classified lidar data from the light box lidar sensor on the ly RV greenvalley package well everyone that was the complete ly RV review I hope you enjoyed it we went out and flew the lidar we processed the data we got some notable findings including the accuracy of about 15 centimeters now it's not gonna replace totally the more expensive lidar systems like the Regal and we saw it with that vegetation penetration and those more expensive sensors will penetrate that foliage and get the ground much more covered so if you're in the rainforest or you know somewhere else like this very dense vegetation maybe that's probably gonna be the best sensor for you and also there is the accuracy so the Regal systems you're gonna get sub five centimeter all the time everywhere but that being said it still is a very affordable solution and provides a lot of really great data so I will be using this and it will be another tool in my arsenal but you know I'm excited to go out and keep flying live ox regal lidar photogrammetry thermal I got some cool videos coming up with some avalanches and some landslide stuff going on here so I hope you guys like the video and as always like subscribe comment below and I'll see you on the next one you

Channel: Indiana Drones

Views: 27,851

Keywords: drones, LiDAR, DJI, LiVOX, LiAirV, DroneDeploy, photogrammetry, terrain, map, mapping, land survey, land surveying, UAS, UAV, review, technology, IMU, drone data

Id: ksJ8RalOBTk

Length: 14min 47sec (887 seconds)

Published: Mon Apr 06 2020

Reddit Comments

[u/scottthemedic]

I didn't catch the cost...?

[u/sir-bro-dude-guy]

Great video!

[u/[deleted]]

Thx for sharing! Recommend that you check out or attend the Int'l Lidar Mapping Forum (www.lidarmap.org), which will be co-located with the ASPRS Annual Conference (www.asprs.org), as well as the SPAR 3D (www.spar3d.com/event) & AEC Next (www.aecnext.com) conferences. Lots of great technical presentations and amazing networking!!

[u/sethzora33]

I was told around $35k.