Multiple Flight Mission's Footage Isn't Lining Up

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#1

Hi All,

Over the past few weeks I’ve completed multiple flight missions circling a construction jobsite so that I could create a progression video. However now that I’m reviewing my footage, none of the shots are lining up with one another in the way I think they would. The gimbal is at a slightly different angles in each video so the POV is altered with some of the jobsite being excluded, or in one shot there is a lot of camera movement to focus on the POI while another one is more seamless.

I haven’t altered my mission. I know I didn’t launch from the same exact point every time but the elevation variance in my launches couldn’t have been greater than 8’. I don’t think that would explain the whole problem.

I’m hoping there are some ideas about what I might have done wrong as well as some tips you might have for future progress flights. I’ve watched a few of Rich Charpentier videos for help but that’s it.

#2

GPS is only accurate to plus or minus a couple meters. As a result, when flying the same mission at different times, the resulting videos will not line up with each other exactly. This is not your fault nor the fault of Litchi. Instead, it is a limitation of consumer GPS and inaccuracies in the height of the drone as determined by barometric pressure.

I have done several videos where I flew the same mission multiple times with the goal of merging the resulting video clips together to show progression. What I had to do during post-processing was to scale up the video clips to about 110% and then move each clip up or down or left or right to match the previous footage. Then, I “key-framed” each clip so that the X or Y offset gradually reduced to zero by the end of the clip. I then used the same procedure with the following clip until I completed the video. Using these steps I was able to achieve a pleasing video hyper-lapse showing changes over time.

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#3

  1. Consumer GPS positioning is typically accurate to plus or minus a few meters.
    GPS.gov: GPS Accuracy

  2. VSC-drones seldom fly smoothly (path- heading- & gimbal pitch wise).
    VIRTUAL STICK COMMANDS (vsc)

  3. Wind speed influences the drone’s behaviour.

  4. Changes in air pressure during flight will influence the drone’s altitude.

In other words: It’s normal behaviour.

Here’s an example using the methods @wesbaris mentioned.
‘Seasonal changes’

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#4

I had encountered this as well. I had hoped to take identical photos of an area over time.

I can’t even re-create them during the same flight. I can fly the same mission several times in a row, and they’re all slightly different. The nature of the beast I guess. :frowning:

#5

Thank you for the suggestion! Sounds time consuming, but I guess it’s better than not being able to use the footage at all.

I do also have a Phantom 4 RTK drone for surveying which obviously has more accurate positioning. However, I have the remote with the built in-screen and I don’t believe there is anyway within that DJI app to create an automated mission like the ones in Litchi with Waypoints and POIs…are there?

#6

Thanks for the breakdown. As I told @wesbaris I do have a Phantom 4 RTK drone for surveying which obviously has more accurate positioning. However, I have the remote with the built in-screen and I don’t believe there is anyway within that DJI app to create an automated mission like the ones in Litchi with Waypoints and POIs…am I right in that or are there creative options?

#7

Result of a quick search for ‘RTK’ on this forum: