Terrain Awareness & Way-points

Hello all from Australia.

I use DD for volumetric capture in both urban and remote areas here in Australia and usually don’t have any issues.Recently I was capturing a site with very high terrain and used the terrain awareness feature however, during the flight the software displayed the planned flight route ended much earlier than the planned area. At the end of the route DD software advised me the aircraft was descending. At this point I RTH, replaced the battery and continued the mission until the same problem occurred.

  • Are missions limited to a maximum number of way-points? When using terrain awareness does the software limit the amount of way-points available as it uses some of them for altitude adjustment?

  • Is terrain awareness now available for offline / no cellular connectivity? In the past while operating in remote areas I was given a warning that terrain awareness is not available however, on my last capture I was given no warning and the aircraft varied altitude accordingly.

Any advice would be appreciated.

Regards,

Jad

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Hi Jad, Fellow Australian here.
I’ve also experienced this recently, though I was alerted to the issue prior to taking off… It appears DJI’s integration works by loading waypoints into DJI GO4, which appears to be limited to 240 waypoints.
The DD software seems to include altitude changes as individual waypoints, with currently no ability to increase or decrease the density of those waypoints.
Like you, I found this was restrictive in a highly variable work-site, where a single run from one side of the work site to the other can have 13 waypoints for altitude changes. I ended up having to create 6 different flight plans for what would have been a 2 flight plan job if I wasn’t using terrain follow.
It would be fantastic if DD had the ability to make altitude changes less granular, so you could go from 13 waypoints for altitude back to 2 or 3 in each run.
Perhaps a good consideration for future versions?

@Isotope_Media has got it down. This also occurs on large flights without TA now that precision point return has been released and the interface will only show the first batch of flight lines. There is no way to change the density of the points because they are generated from the surface characteristics, not by the planning algorithm. To combat this on TA enabled missions try running parallel with the slopes as much as possible. This is also a safer method of TA flight.

Perpendicular to Slopes

Parallel

Very interesting, thanks Michael.

I’ll try the flight direction trick next time on site.

It would still be interesting to see an adjustable smoothing model added to the terrain awareness, to remove the number of small adjustments made for minimal height differentials. Surely this couldn’t be beyond DD to implement?

Still better to have that not for the most part where a specific GSD is required. Perhaps a better outcome would be for future versions of DJI GO to allow more waypoints? (Up to 1000 would probably suffice?)

I do have quite a large cross-hatch mapping job coming up to 3D model a large Dam, so we’ll see how DD manages that with the Matrice 210.

Cheers!

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I agree a sampling rate has to be a possibility but TA has already been a fickle beast regardless of flight software so I would understand any hesitation of throwing additional variables at it. I think one of the most interesting possibilities that we have chatted about in the past is the ability to run a 300-400ft Live Map which in a very short period of time could generate a sparse surface for the TA. Then you are getting a true real-time DSM to base your altitudes from that is exponentially more accurate than any 25m SRTM.

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That is a pretty cool idea.
Remember every parallel line is 2 waypoints. So if you’re creating extra little lines around certain features, sometimes less complicated is better. Dont want to get halfway through a 5 battery mission and the app won’t take off because two point are all of a sudden now too close to eachother so the whole map plan needs to be changed and restarted. Failed to load plan bs.

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