Mapping land input using Litchi

[xJaybirdx]

Hello,

Monday I will be mapping my first land parcel for a client, I am going to use the Litchi app to set waypoints and points of interest. I was wondering if anyone had any input that may help me out, I am welcome to all commentary. One thing I am wondering is what degree to angle my camera to get a good downward view of the land, not straight down though. I have seen some who use a 65 degree angle. I will have most of the waypoints focused on the point of interest I choose, is this a good idea?

Thank you,
Jaybird

 

[Meta4]

Monday I will be mapping my first land parcel for a client, I am going to use the Litchi app to set waypoints and points of interest. I was wondering if anyone had any input that may help me out, I am welcome to all commentary. One thing I am wondering is what degree to angle my camera to get a good downward view of the land, not straight down though. I have seen some who use a 65 degree angle. I will have most of the waypoints focused on the point of interest I choose, is this a good idea?

Have you done this before?
It's probably not a good idea to be flying a mapping mission for a client if you aren't already experienced with the technique you'll be using.

My suggestion would be to forget Litchi as it's not a mapping app at all.
It's not going to give you the proper overlaps that you need for mapping.
I'd suggest getting DroneDeploy which is a mapping app and will help you plan the mission, calculating overlaps, fly the mission and capture the images.
For mapping missions, you would want the camera pointing straight down.

It looks like much of the site is forest canopy.
That's always a problem for stitching and if it is, you can sometimes get results by flying higher and with bigger overlaps (something like 80%).

 

[Meta4]

Also ... what height above the tree tops are you planning to fly?
Looking at the numbers on that Litchi plan, it looks like you'll be too close which would cause differences between adjacent images to be too great for stitching properly.

 

[xJaybirdx]

Also ... what height above the tree tops are you planning to fly?
Looking at the numbers on that Litchi plan, it looks like you'll be too close which would cause differences between adjacent images to be too great for stitching properly.

I guess I should have been more specific, he only wants raw data of the land. I am not actually creating a map for him. I have used DroneDeploy befroe and it is nice, but I am not ready to pay a monthly fee for their software. I only want to use Litchi for the waypoints.

 

[Meta4]

I guess I should have been more specific, he only wants raw data of the land. I am not actually creating a map for him. I have used DroneDeploy befroe and it is nice, but I am not ready to pay a monthly fee for their software. I only want to use Litchi for the waypoints.

You don't have to pay to use DroneDeploy to fly the mission.
You only pay if you use their processing of the images you capture.

 

[xJaybirdx]

You don't have to pay to use DroneDeploy to fly the mission.
You only pay if you use their processing of the images you capture.

Ok I will check it out, thanks for the advice. I do already have an account so it will be worth looking into.

 

[Dirt Pilot]

I use the DJI app GSP to get pictures for maps. The free version works well for map making. I then process the pictures through WebODM, a freeware program (I donated $50 and bought the instruction book).

With GSP I fly 3 different patterns over the map location. For example, the first pattern is at 200' AGL, a heading of 90, with the camera at -90 degree angle with standard 70% overlap front and side. The second pattern , 170' AGL, heading of 90, camera set at -55 degree angle. The third pattern, 230' AGL, heading of 180, camera set at -55 degree angle. The -55 degree gimbal camera setting gets the vertical and sloped surfaces into your map without picturing the horizon.

On a 5 acre site, these settings will make under 300 good pictures to process into an orthophoto, a 3D model, and a usable point cloud file with WebODM. Here is my latest orthophoto:

 

[ArnoldLeVine]

When I went to WebODM, it has a $57 charge to dl the software. There is a Free option but way too complex for me to understand. Is this the $50 donation you refer to? Not a bad price, of course, if it does the job.
Too bad the DJI app GSP only works on Apple, especially since both the Crystal Sky and the SMart controller are both Android systems.
Does the WebODM software also include a mission planning module?
How long did your desktop (or whatever) take to process the above ortho using the 300 images. What size images are they, 12 or 20 megapixels?

 

[Dirt Pilot]

Check out the WebODM requirements of the specs for your computer system(see attached WebODM install manual). You will need a relatively new computer with at least 16 GB of RAM and the ability to run a separate virtual system. Then you will be able to process 300 pictures in under 3 hours. The $57 charge will get you a installer program which is worth it. The picture above is a composite of 300 Phantom 4 Pro V2.0 pictures at full resolution 20MP, but to post it I had to reduce it down to 1.85MB jpg file. The original orthophoto file is a TIF and 133MB, you can zoom in for incredible detail, and the perspective of every point is from straight above. WebODM is great, it outputs a .laz file (point cloud (N,E,elevation/point)) that I use to build 3D models for volume calculation and construction grading takeoff on AGTEK Gradework 4D software. Attached, find the drone topographic (2D print of my 3D model) I produced with the .laz file and Agtek, related to the above picture. WebODM is very accurate, if you fly the 3 patterns I described above. WebODM also has the option of using GCP's to make your data survey accurate, but you will need expensive survey equipment to locate the ground control points. I highly recommend WebODM for processing maps but it will not work on all computers.

 

[xJaybirdx]

Check out the WebODM requirements of the specs for your computer system(see attached WebODM install manual). You will need a relatively new computer with at least 16 GB of RAM and the ability to run a separate virtual system. Then you will be able to process 300 pictures in under 3 hours. The $57 charge will get you a installer program which is worth it. The picture above is a composite of 300 Phantom 4 Pro V2.0 pictures at full resolution 20MP, but to post it I had to reduce it down to 1.85MB jpg file. The original orthophoto file is a TIF and 133MB, you can zoom in for incredible detail, and the perspective of every point is from straight above. WebODM is great, it outputs a .laz file (point cloud (N,E,elevation/point)) that I use to build 3D models for volume calculation and construction grading takeoff on AGTEK Gradework 4D software. Attached, find the drone topographic (2D print of my 3D model) I produced with the .laz file and Agtek, related to the above picture. WebODM is very accurate, if you fly the 3 patterns I described above. WebODM also has the option of using GCP's to make your data survey accurate, but you will need expensive survey equipment to locate the ground control points. I highly recommend WebODM for processing maps but it will not work on all computers.

This may sound crazy, but I would love to zoom and screen share sometime to pick your brain and learn a thing or two from you.

 

[Dirt Pilot]

This may sound crazy, but I would love to zoom and screen share sometime to pick your brain and learn a thing or two from you.

Cool, send a ZOOM contact request to [email protected]

 

[Dirt Pilot]

Here is a WebODM processed orthophoto of a concrete waste stockpile in Sunol CA. I used the GSP app to control the P4PV2.

 

[Martin Healy]

In addition to all the good advice that other forum members have posted I would suggest that you also checkout Hivemapper. This is a new approach that uses video to process into 3D maps. Hivemapper supplies free templates for planning Litchi missions that collect the video. Processing of the video into 3D maps is free of charge but it can take several days/weeks for the maps to be produced.
All the best, Martin

 

[xJaybirdx]

In addition to all the good advice that other forum members have posted I would suggest that you also checkout Hivemapper. This is a new approach that uses video to process into 3D maps. Hivemapper supplies free templates for planning Litchi missions that collect the video. Processing of the video into 3D maps is free of charge but it can take several days/weeks for the maps to be produced.
All the best, Martin

Martin,
Apparently I cannot use the GSP app on my phone, it says I need an Ipad. I have an iPhone and and Android, however no iPad. I have a few days off this week so hopefully we can connect and have a zoom meeting.

 

[TxArch DroneGuy]

Maps Made Easy. Is great mapping app. It’s free to map and you can either pay mapsmadeeasy(low cost) or free depending on the number of photos or upload to pix4d, drone deploy, etc.

 

[Martin Healy]

Martin,
Apparently I cannot use the GSP app on my phone, it says I need an Ipad. I have an iPhone and and Android, however no iPad. I have a few days off this week so hopefully we can connect and have a zoom meeting.

Hi, I'd be happy to chat but I am in the UK on GMT+1 time so that may make it more difficult.
I think that you will find that Hivemapper is very easy to use and you can get up and running very quickly.
First step - read all the guidance on their website - Hivemapper - Collect video, upload to Hivemapper, and see your map.
Then watch the 'how to' videos that Hivemappaer have made to demo the product.
Setup an account at Hivemapper.
Download the 'lawnmower' flight plan template from Hivemapper. You can then drag and drop this template onto the Google map to overlay the area that you wish to map for your client. (I also adapted this template so that the drone fly back and forth along the 'lawnmower stripes' but then continues and turns 90 degrees and repeats the lawnmower pattern to cover the entire area in a grid of passes so that the camera get to view every feature such as a building from 4 directions. This will improve the 3D effect.

Plan your first mapping flight. I would suggest using the other smaller 'lawnmower' template from Hivemapper and then shrink it down to cover a smaller area (it can be a little unnerving to hand over control to the bird for autonomous flights so you may want to wear brown cords for your first go at it!).
Very important - make sure that you turn on 'camera captions' in DJI GO4. This creates an extra small file file with the same number as the video file but it holds all the telemetry data gps position, barometer et. Make a very short video recording and transfer both files to your PC. Play the video file and you will see that all the telemetry data is superimposed over the video at the bottom of the screen. When you don't need the data the video file still plays as normal if the 'captions' file isn't in the same folder. You could give copies of the video to your client for them to enjoy a birds eye view over their property.

After your mapping flight upload both files to Hivemapper and chill while you wait for their super computer to crunch the video into a 3D map - free of charge.

All the best, Martin

 

[xJaybirdx]

So I made my first map, some of the video is still uploading to Hivemapper. I only saw one file so I assume the video captions are included in that file, I did turn on the video captions beforehand. The map I see so far looks pretty cool, now I just need to learn what I am looking at.

 

[Martin Healy]

So I made my first map, some of the video is still uploading to Hivemapper. I only saw one file so I assume the video captions are included in that file, I did turn on the video captions beforehand. The map I see so far looks pretty cool, now I just need to learn what I am looking at.

A P4 definitely produces a second file with the same number as the video file but with the suffix .srt

When I first tried HiveMapper I turned on captions but didn't test it before flying the mapping flight. I don't know why but it didn't produce the .set file so HiveMapper couldn't process it. I ended up going over the turn on captions several times before it stuck and started producing the .srt files.
I have vague memory of reading that some aircraft do produce a video file with the data embedded.

Anyway

 

[xJaybirdx]

A P4 definitely produces a second file with the same number as the video file but with the suffix .srt

When I first tried HiveMapper I turned on captions but didn't test it before flying the mapping flight. I don't know why but it didn't produce the .set file so HiveMapper couldn't process it. I ended up going over the turn on captions several times before it stuck and started producing the .srt files.
I have vague memory of reading that some aircraft do produce a video file with the data embedded.

Anyway

I was able to produce a map through Hivemapper, I just do not remember seeing those files.