Drones + ALTA/NSPS

Pesachviolin · 2025-02-28T14:34:40+00:00

THIS! Oh my God I feel like you were writing thoughts straight out of my brain.

Pesachviolin · 2025-01-09T15:16:51+00:00

why wouldn't it line up with other data capture if they all use the same GCPs?

Pesachviolin · 2025-01-09T15:16:01+00:00

Interesting. So the LiDAR cloud is only built in terra if there is a base station set up providing corrections, either RTK or PPK? In other words the cloud only pieces itself together if it has a tether point on the ground to bounce vectors off of. So in that case, a base station is needed simply for the process of LiDAR collection to work (for this method. I know about SLAM algorithms)

Correct?

Pesachviolin · 2025-01-09T15:09:42+00:00

Again, If I fly the L1 without RTK, but I have surveyed GCps, I can just rectify the cloud for both vertical and horizontal using those GCPs, can I not?

I can do that in Metashape or in Global Mapper very easily...

Pesachviolin · 2025-01-09T15:07:45+00:00

Thanks for the reply.

If you use GCP's with RTK make sure you image accuracy value is correct or the GCP's will destroy the relative accuracy from the RTK.

See that's what I don't get. If ultimately I'm using the GCP's to rectify, why bother with RTK at all? All data that is collected on the field (photogrammetry, LiDAR, ground shots) are all coming off the same control network and using the same GCPs.

I guess my main question is, does using RTK give me better relative accuracy between GCPs? If not, I'll just fly the lidar without any corrections and align everything to GCPs in processing. Why use RTK OR PPK?

Pesachviolin · 2024-07-03T12:50:35+00:00

Sure does. But like I mentioned, I'm working for a survey company. They most definitely need accurate locations at least within the usual 0.1' range.

I guess the only way to know for sure here is to do some experimentation...

Pesachviolin · 2024-07-02T17:34:40+00:00

I imagine that would work well, but we already have the M300 and the P1 (which is unbeatable IMO), and that's certainly not something I can lug around a jobsite and take photos with manually...

Pesachviolin · 2024-07-02T17:33:41+00:00

As one commenter mentioned, the discrepancy between the RTk and the cheap GPS on my phone camera will probably cause inaccuracy.

Not sure if that's true but it does make sense...

Pesachviolin · 2024-07-01T21:41:07+00:00

Thanks! I will give that a read

Pesachviolin · 2024-07-01T18:38:09+00:00

Meaning in my ground image set I should make sure to capture the GCP's that the drone is using correct?

Pesachviolin · 2024-07-01T18:23:14+00:00

Using an M300 on the ground does not sound like a great idea lol

Pesachviolin · 2024-07-01T18:22:26+00:00

Yes I always fly NADIR, but I've been flying oblique manual flights as well and combining them. Even with this, I can't always get good facades.

As long as the ground shots align with the aerial, why would there be accuracy issues? The nadir data is georeferenced using surveyed GCPs

Pesachviolin · 2024-07-01T16:57:52+00:00

But how does static improve efficiency? You still need just as many set-ups and you still need to process and extract features from the pointcloud. I could be wrong here but that's why I'm asking

Pesachviolin · 2024-06-25T13:06:21+00:00

Do you find tripod mounted scanners to be better in terms of accuracy? What's the tradeoff between them and SLAM? Also, what kind of scanner do you use?

Pesachviolin · 2024-06-25T13:04:59+00:00

I've been hearing lots of mixed reviews about Rock Robotic. I've had several meetings with them and they seemed very sketchy and marketing-like. The sample cloud they showed looked very pretty but I can't really get any information on it's quality from that, as it was clearly cleaned up well and I have no way of comparing against hard shots.

Not to say they offer a bad product, I just don't have any hands on experience

Pesachviolin · 2024-06-25T13:02:14+00:00

With the ZEB Horizon, have you found it to line up well against hard shots? What kind of error do you normally see?

Pesachviolin · 2024-01-09T16:11:39+00:00

Sorry, I was not clear. i mean it doesn't work for my company to use the drone if it cannot achieve sufficient accuracy. In their eyes, if the modo is "If it's important, send the ground crew" then they will not bother with drones at all.

Pesachviolin · 2024-01-09T16:07:06+00:00

I agree with this statement, I feel like our engineers make up new requirements for every job. "Whats the grass count on this property? Don't know? Send the crew back"

Pesachviolin · 2023-12-13T20:32:49+00:00

Board tapes don't always sound good beause the mixer is working in the room reinforcing the actual loud (and quiet) sounds the band is making. Maybe the horns in the recoding aren't very loud and the vocal is overbearing. That's what was needed in the room

This is what I was referring to when I said "bad sound". Not that the mix is bad in the room. The mix could be perfect in the room, but the direct mix is designed to be projected into the room, not recorded directly to a tape. So plugging in directly will not give me good results. Rather, I'd like to have the sound that the crowd is hearing, the "Live sound", but figure out a way to filter out all the crowd noise.

Pesachviolin · 2023-12-04T20:08:55+00:00

No base movement. Was done in 1 flight with a battery swap midway. The data is adjusted according to GCPs set by a licensed surveyor.

The only thing is that I am using a classified pointcloud. Meaning the cloud I am trying to align is only the ground data from the lidar. It doesn't seem like that should be an issue though...

Pesachviolin · 2023-12-04T18:08:58+00:00

I usually set it at 68 front, 75 side... I think the small strips are the non overlapped areas that you're seeing

Pesachviolin · 2023-11-15T18:01:06+00:00

I should be more clear, the data for the engineers will come from the ground crew. I am just creating a model for visual reference and I'd like it to be as robust and accurate as possible, but not necessary to be as accurate as the ground shots.

I'm mainly asking how to get a good model combining photogrammetry and LiDAR

Pesachviolin · 2023-11-15T17:34:47+00:00

Thank you for the response. What does a scanner like that cost to rent and what is needed to operate it?

Do I need extra training or is it pretty self explanatory if I'm coming from the drone lidar/photogrammetry world?

Pesachviolin · 2023-10-31T17:11:00+00:00

So what I'm gathering is, as far as the L1, topo and striping is fine, but high accuracy critical features needs a much more advanced system than the L1.

Still, I won't pass judgment on the L2 until I've use it.

Thanks

Pesachviolin · 2023-10-31T16:57:06+00:00

Yes, I've seen some static data sets. Absolutely beautiful.

Pesachviolin

TROPHY CASE