DJI Inspire 1 Mapping Results

PIX4Dcapture PIX4Dcapture Questions/Troubleshooting
1

Can anyone give me positive and negative feedback on mapping results using the DJI Inspire 1? Any idea on when the capture app will be available?

2

I find I get some serious Camera Calibrations errors 1000% difference ??? I’ve also noticed that the height geo-tagged position from the Inspire 1 is actually only the flying height of the drone and not the above ellipsoid height, so when I have GCPs in my countries co-ordinate system I’m getting the initial processing 100’s of metres below my actual datum. I’m trying to fool the software by modifying the “Z” … we’ll see. Maybe I shouldnt be experimenting with a 300 image project :slight_smile:

3

I’m using the Inspire 1.
Very predictable, consistant results. There is no app nor now (may 2015) but no big deal. By now Im pretty comfortable collecting data manualy. No big deal. With no app you actually have to think - what detail you want to capture. I often fly nadir plus 1 or 2 circles shooting at 45 degrees at different heights. Pix4d crunches it with no problem. The only difficulties I get is when I shoot from ground up (walking the drone around the scene). That can confuse pi4d.
Otherwise Inspire 1 and Pix 4d are a match made in heaven '))

4

Thank you for the feedback. Thinking of using the Inspire 1 as a learning tool before buying a proper mapping Multi-copter. Dennis, are you happy with the camera and resolution? What size projects are you flying and typically at what height? Sounds like the Inspire 1 is perfect for smaller 3D models. Multi-copter obviously the better choice, with 24M camera, mission planner, etc. but at least twice the price.

5

I did various sites with the I1. Smallest perhaps was the several hundred years old volcanic hut in rural china. the Point Cloud Densification Area 10 x 15 meters. The largest is an urban site 1200m by 1200m.
The height depends on the precision required. When I need to see every stone - I make several spiral loops 15m to 5m around the subject. Although 20 m still gives very decent results.
On sites over 10 Ha, where no one cases to see every single stone - 50m is quite adequate. Once there were high-rises on the site over 140m tall, so I flew a mission at 160m and still got all the major features. the 1200x12000m site took me 2 batteries.
The only problem that I have with Inspire, and I hope it will be considered in the pix4d app is the speed. I1 is really fast, especially downwind. That could be a problem. Several times I flew a bit too fast and the photos got smeared. That becomes a serious concern on lower altitudes where objects move across the lenz much faster. So the 12mp camera or 24mp camera doesn’t matter if a photo is not sharp. Just don’t fly at full speed below 80m. If it is cloudy (low light -slower shutter speeds) and the altitude is 20m - I completely stop the drone in the air before taking a picture.
I HOPE THAT PIX4D APP FOR I1 WILL COORDINATE THE SHUTTER SPEED OF THE CAMERA WITH THE SPEED OF THE DRONE.
I think that I1 is quite adequate platform for pix4d.
Let say you have 24mp. That will allow you to fly at higher altitudes to capture the same detail and take less photos. That might not be worth the extra money. For now I’m fine snapping twice the number of pix.
That doesn’t mean that when DJI comes out with 24mp camera I’m not going to order it the same day when it comes out ))
What industry are you in. Paul how you plan to use pix4d?

6

Dennis, thank you for the detailed response. I am a professional land surveyor. 60% to 70% of my work is around property rights, new developments, subdivisions, etc. but with each new development I am often involved in the contours, maps, as built, setting out, etc.

7

Anthony,
I/m an architect. I dont really have a clue how to make a more or less professional topo map out of pix4d. I know there is export option. However, what comes out is not exactly a product one can sell.
How difficult is it to learn to make one with what pix4d gives? or it is quite complicated and I’m better of paying someone to do it?

8

Dennis, creating an orthomosaic/map is fairly simple and mostly automated, however you need to ensure you have consistent forward and side overlap, generally at least 80% and 70%, flying nadir, and therefore flight planning essential. Furthermore to produce something useful and properly geo-referenced you need to have ground control on site, with accuracies of around 2cm (yxz). I recommend lots of ground control to validate the results. You can find lot’s of info in the seminars. It can get complicated depending on the terrain, in particular buildings, and you will not get good contours if there is a lot of vegetation.

9

Hi All,

The flight plan design will depends on if you want to produce a 3D model or produce a DSM / Orthomosaic.

  • For the DJI Phantom 3 Pro and Inspire 1 soon we have ready our capture app.
  • For the DJI Phantom 3 Advanced, it will comes after.

Please note that as soon as we have them ready, it will be announced in:

At the same time, when the iOS version supports Free Flight and/or Responsive Flight Grid, it will be announced in:

Using the application:

  • If you want a 2D aerial model, you need to use the grid flight plan.
  • If you want a 3D model, you need to use the free flight mode.

For more information: https://support.pix4d.com/hc/en-us/articles/hc/en-us/sections/200733429

If flying manually:
*If you want a 2D aerial model:

  1. Use aerial nadir images, with an overlap of minimum 80% frontal and side.
  2. Fly a larger area than the desired area to map, since the borders of a project have less images to be used and the results are less accurate.
  3. Ensure that the images are not blurry and that the images have the same brightness and lightening conditions, the ideal is fly when there are very few clouds since then, the light in the terrain and objects is homogeneous.
  4. If flying more than once, ensure that there is a good overlap between flights.
  5. Design the flight plan following: https://support.pix4d.com/hc/en-us/articles/202557409
  6. It is recommended the use of GCPs: https://support.pix4d.com/hc/en-us/articles/202557489

Process following: https://support.pix4d.com/hc/en-us/articles/204911905

*If you want a 3D model:

  1. Take aerial and oblique images:
    1.1. Aerial with at least 80% frontal and side overlap.
    1.2. Aerial oblique (with angle between 45º and 80º) and/or exterior terrestrial images and/or interior terrestrial images, any 2, 3 or 4 out of the 4 mentioned types: Each set of images should have enough overlap themselves (take images constantly and make smooth changes in angles, do not change the angle of the camera very much between consecutive images) and enough overlap between sets.
  2. For such cases it is strongly recommended to use GCPs or Manual Tie Points to properly adjust the different sets of images.
  3. Ensure that the images are not blurry and that the images have the same brightness and lightening conditions, the ideal is fly when there are very few clouds since then, the light in the terrain and objects is homogeneous.
  4. Design the flight plan following: https://support.pix4d.com/hc/en-us/articles/202557409
  5. It is recommended the use of GCPs: https://support.pix4d.com/hc/en-us/articles/202557489

Process following: https://support.pix4d.com/hc/en-us/articles/204911905

Regards,