400 Acre site guidelines

1

Hi Harrison, great news… My first paid lidar project is a 400 Acre site!

Can you give me some guidelines on how to handle that large of a project?

Thanks a bunch! Jim

2

Are you able to share me a KML? Then I can give you a little more insight into flight planning.

3

Hey guys, I have a similiar sized site and figured I’d jump in and share a kml. One thing I have noticed is that I capture a ton of area outside my KML on my m300 using the R2A specs. Wondering if we can eliminate some of that.

https://moorebass-my.sharepoint.com/:u:/p/dwindham/EdWUsKFxO2lDuFMwUK31Lq0BKOPF79aJOK3YOtSzg0afRQ?e=LWifC4

4

Yes you can! If you go into the PCMaster application when you are post processing there is a cloud filter button. What you are going to manipulate is the angular rotation values (default is 0 and 360). As we know the Avia LiDAR sensor covers a 70 degree area.

The center point of that 70° is 270°
Start point is 235°
End point is 305°

You can shave whatever you like off of that by taking it equally from both sides. I.E. (240° and 300°) would make that 70° 60°

Hope that helps, please share your results.

5

20210315_171053526_iOS
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Oh that is helpful! I was actually meaning in DJI pilot app for flight planning but I will definitely use that too in PCMaster. Attached is a flight plan I just did from a KML upload on the smart controller. The shaded area is actually where I need topo but the lines go quite a bit past that - I am used to having some overlap in my photogrammetry missions but didn’t know if this much was necessary for the R2A. It does the same thing if you rotate the flight lines, etc. This is based on the custom camera settings I made from another post on here that y’all responded to me on.

6

Could you let me know which camera settings you are using. I would like to double check that they are correct. Also what was your flight height in this survey, and did you use terrain follow?

7

These settings

My flight height was 250 and no I didn’t - should I use that with the RTK? I don’t know that I have a login for RTK through our survey provider available but I can try. Speed was 15 mph.

8

Terrain follow is a feature of DJI Pilot for the M300. It was recently updated so that it’s fully functional. However it is not thoroughly tested as of yet, so you still want to be mindful of your height when using it.

You shouldn’t have to use RTK in order to utilize terrain follow as the DTMs are built into the world map. More info on that at a later date. Happy flying!

9

Thanks. Do you think my camera settings are correct? Appreciate if!

10

Wanted to drop in and offer this: I just flew a 400+ acre site on some really low parameters- the goal was not survey grade topo but I’ll probably still get that level of accuracy after the processing finishes from the looks of it.

I flew at 400 feet. No terrain following
20 mph
30% overlap

So far the data seems perfect for our deliverable which is “GIS Level” topo. I noticed on one side of the project a control point was .2 ft off - no big deal at all.

1 Like
11

This is fantastic, nicely done sir! If you ever have any jobs like this that you’d be willing to share on the community please don’t hesitate to share a link.

12

Is this still true with updated firmware on remote and m300 rtk? I have a project that will need terrain follow.

IMG_4274
IMG_42743024×3024 1.8 MB

13

So I still seem to need a DSM file on my SD card or on internal memory for Terrain Follow to work.
To get that

  1. I went here: https://apps.nationalmap.gov/downloader/#/
    image
    image756×732 89.2 KB
  2. select the 1/3 arc sec DEM (just right density for M300), click search products and download it (geotiff).
  3. use your preferred GIS to clip it down to ~4sq miles (to fit within the M300’s max dsm file size).
  4. upload the geotiff to your controller and select that file.

it will calc it out and give you a color spectrum on each flight line.
NOTE: I have only planned with this so far… first Terrain Following flight is early next week… :wink: That said this is the DSM I have been using on our phantom drones (via Map Pilot).

EDIT: make sure you get an area a good bit larger than your flight area… I’d hate to think of what would happen should your drone ‘fall off’ the edge of the DSM surface… :slight_smile:

1 Like
14

Nice write up @anthonyhermanklj

What do you personally use to clip your .geoTIFF file?

Don’t suppose you’d like to do a similar walkthrough for that as well?

15

Thanks.
Engineering firm so we use ArcGIS Pro (ESRI). Their instructions are better than what I could write (link below), the only difference being drag a kml polygon into my project and can directly reference that in CLIP or EXTRACT rather than having to draw or convert something into a .shp file. I do the same for the created Point Clouds from PC master…

I know there are free ways to do this (the raster part), but ESRI is where I first learned and have since stayed.

or I hear QGIS is free and can do this…

16

do I interpret this as all we have to do is select “Terrain Follow” feature in the Pilot/Mapping app…and we don’t have to import any DEM file?

If I’m incorrect, please supply specific steps then.

THANKS!!!

17

See @anthonyhermanklj post above. It gives a pretty solid explanation of how to do this.

1 Like
18
  1. Obtain DEM…
  2. Load DEM.tiff onto the remote’s memory (I just made a permanent folder on the SD card we use in it).
  3. In the pilot app, select “terrain follow”. That should open an area below it to select or upload the DEM
    image
  4. From the app, browse to the folder you placed your DEM.tiff and select it.

It should show a screen like this:
image

Should be good from there… but sorry that’s all I can recall from memory (don’t have the drone at the moment).

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19

Thanks! I got it all working.

1 Like
20

So it says in remote to enable rtk before performing terrain follow. Necessary?