Video of a dismissal railway with Mavic 2 Pro

[Franco64]

Hi,
I should make (for business) a video with my Mavic 2 Pro along the entire track of a disused railway line, which can not be traveled with a cart because the rails are not usable (weeds on the railway sleepers and other obstacles on the path).

The idea is to follow the railway path with my Mavic 2 Pro at 10 mt circa of height from the ground, to show the condition of tracks and the near terrain.

One problem that I see with Dji Go 4 with Video Caption and waypoints on is that I need that height of the drone should remain fixed 10 mt high compared to the underlying soil, regardless of unevenness of the terrain. As I know, this is not possible: you can only fix a path with height of the drone referred to the starting point.

Is there any app (Android) suitable for the purpose, which uses waypoints, follows a correct path also in height and allow me to record a video synchronized with the geographical data (latitude and longitude)?

 

[BD0G]

Lichti will do what you want to do. Both iOS version and Android versions available.
It has a Height Above Ground Tick box when creating a waypoint mission to fly.
Whats nice is you can construct and prefly the mission from your desktop using the Lichti Online Mission Hub and Google Earth to prefly using LVM (Lichti Virtual Mission). Lichti Virtual Mission is a tool developed by a member of the forums and can be found using those search terms within the forum search option.

You can browse the online mission hub at Mission Hub - Litchi

 

[Jackcutrone]

That is good information to know. How accurate are ground level heights above msl in google earth? What would be a minimum safe height agl to fly?

 

[BD0G]

Thats conditional and situational. If I were to plan a mission above water that was still still and calm I would fly at 10 feet or so if I wanted to be really low. If I was flying over the same water that was choppy I would fly at 15-30 feet above the surface.

Same idea with trees and other obstructions. One would have to survey the terrain , but not count on Google Earth to be perfect with its elevations of tree's and other structures as that could lead one to fly a mission that puts thier Mavic directly inline with a tree or outcropping.

I typically construct the mission within the online Lichti Hub to get it nearly perfect and then fly it virtually using Virtual Lichti Mission through Google Earth to make sure there are not some glaring mistakes with the Mission. Then fly the mission onsite with the camera pointed straight and forward. That way I can observe the Mavics position relative to any potential obstacle. If I get too close then I switch to Sport Mode which truncates the mission quickly and make simple tweaks to the Mission in the field to avoid those obstacles.

 

[m chaussettes]

That is good information to know. How accurate are ground level heights above msl in google earth? What would be a minimum safe height agl to fly?

You can check the VFR charts VFR Raster Charts

 

[Jackcutrone]

Thanks to you both

 

[BD0G]

Were here for ya! Be aware Lichti is a paid application and just because you purchase the iOS version it does not entitle one to the Android application. So choose carefully depending on the device type you will favor.

 

[Treeofliberty]

Do be careful flying a Litchi mission at that height. You can pre-fly the mission in 3D with Google Earth pro, but it won't save you from thin tree branches, power lines, or other low-hanging small obstructions. On the plus side, if you fly low and slow, even a crash will likely result in minimal damage.

I was flying a similar mission along a small river, at 30 meters high, and suffered power line poisoning of the aircraft. Luckily, the Rapid Unplanned Disassembly was followed by a spiral to the brush below, with minimal damage.

 

[kilomikebravo]

..power line poisoning

What a great term! Got a good laugh out of that one...very witty. And ONE of these days, I'm GONNA try a waypoint mission with Litchi, it's just too tempting NOT to. <grin>

 

[Ken K]

That is good information to know. How accurate are ground level heights above msl in google earth? What would be a minimum safe height agl to fly?

Your height agl settings will only be as good as the last Google Earth scans.
if a berm has been added or a hill levelled or a structure built since the last scan you could be in trouble.
Best to do a site visit in person before you fly.

 

[BD0G]

Or if a tree has grown many feet upwards and outwards or a new tree has been planted since the last GPS scan by Google.

 

[Franco64]

if a berm has been added or a hill levelled or a structure built since the last scan you could be in trouble.
Best to do a site visit in person before you fly.

The tracks are still on the ground, no human structures are built on the path and the difference in height is necessarily moderate - it is a railway line. Trees should not have grown over one meter in height.

However, it seems to me an excellent suggestion to do a reconnaissance flight before that necessary to make the final video footage.

 

[BD0G]

Yep, Just plan you mission with all surroundings in mind. Then visit site . Launch Lichti Mission and make sure camera is pointed forward. Track the real time video feed and look for anything in the way of the chosen waypoint Mission. As you get close to something that you did not expect. Either Click into Sport Mode and back real quick to stop the Mission or press the Pause button on the remote. Change the waypoint mission in the field. (You will need internet connectivity to save that Mission (so a hotspot on phone unless you are flying with a phone). Then you have made your subtle tweaks and can fly it in its entirety.

 

[53-63-6f-74-74]

Your height agl settings will only be as good as the last Google Earth scans.
if a berm has been added or a hill levelled or a structure built since the last scan you could be in trouble.
Best to do a site visit in person before you fly.

Also be aware that Google Earth photo geo-referencing is not the best on the XY axis, either. In my area of the world there is about 6-7 foot difference between GE coordinates and real-world locations.

 

[Treeofliberty]

What a great term! Got a good laugh out of that one...very witty. And ONE of these days, I'm GONNA try a waypoint mission with Litchi, it's just too tempting NOT to. <grin>

What I love about the Litchi missions is that you can pre-plan them, getting the angles and the shots just right, making the turns very smooth and fluid, and thus, the video is so much better. You an also manually adjust the gimbal during the flight.