I have some experience to share and see if anyone could shed me a light on how the bird actually works/behave before I hit the slope. In fact, I would like to test it one by one but don't have enough space and/or suitable environment. I am using 4.1.10 app and 1.00.0701 fw

1. I start with profile mode. Set the bird 4m high and 5m away from me. I start to run down a slope (1:8), the bird follow but fly horizontally instead descent with me as I expect.
2. Also Profile mode but this time I set the bird at 2 high and same 5m away from me, ie. shallower angle, this time, it fly and descent with me.
3. I rhen try trace mode, same thing happen. The bird fly horizontally when using a steeper track angle and descent when using shallower track angle.

I don't have the space to try flying the same height (4m) and farther away say 8m to test whether the height or the tracking angle actually matter.

Anyone know how actually the bird decide how to behave, fly level or descent, when tracking? using the gimbal pitch angle or other mechanism? How can I know if the bird will fly horizontally or descent with me before I move?

Further, the 1.00.0701 release note mentioned that when in gesture or active tracking mode engaged (with dynamic home point), it will not trigger the RTH even the battery is low. What will it do then? Just land as it is?

Another scenario, I understand that the bird will hover when it lost the tracking subject and I suppose it will land as it is when the battery ran out according to the release note (No RTH). But, how about when it lost the tracking subject (Hover) and at the sametime (or may be a bit later) lost signal/disconnection with the RC/mobile? What will happen? Stay there until the battery ran out and land or fly to some place else?

If you set it at 5 metre altitude it will stay at that horizontal I.E. so if you set off and descend 5 metre then spark will be 10 metre above you. If you set dynamic homepoint it will reset every 15 metre so if it looses you it will hover until low or critical battery and RTH where it’s last dynamic point was set.

hallmark007 Posted at 2017-11-4 05:37
If you set it at 5 metre altitude it will stay at that horizontal I.E. so if you set off and descend 5 metre then spark will be 10 metre above you. If you set dynamic homepoint it will reset every 15 metre so if it looses you it will hover until low or critical battery and RTH where it’s last dynamic point was set.

Yes, if I put it to 5m alti (From the ground), it fly horizontal. However, if I out it 2m alti (From the ground), it descent with me. as I ran down to the end, it show some -6m on the alti. Is there any chance it works with downward vision system? If I put it too high, the downward vision system won't work?

Edd_88 Posted at 2017-11-4 06:36
Yes, if I put it to 5m alti (From the ground), it fly horizontal. However, if I out it 2m alti (From the ground), it descent with me. as I ran down to the end, it show some -6m on the alti. Is there any chance it works with downward vision system? If I put it too high, the downward vision system won't work?

As far as I know it doesn’t or shouldn’t descend while tracking , I have never tried it but from what I know it should maintain its horizontal in the sky and yes it will show minus figure as you descend.

hallmark007 Posted at 2017-11-4 06:53
As far as I know it doesn’t or shouldn’t descend while tracking , I have never tried it but from what I know it should maintain its horizontal in the sky and yes it will show minus figure as you descend.

For Mavic, yes, it won't descend. For Spark, however, it descend with the subject at least in some occasion. You can check on youtub. As I mentioned above, it descend with me sometimes. Just want to make sure ahead in what occasion it will descend.

Edd_88 Posted at 2017-11-4 15:50
For Mavic, yes, it won't descend. For Spark, however, it descend with the subject at least in some occasion. You can check on youtub. As I mentioned above, it descend with me sometimes. Just want to make sure ahead in what occasion it will descend.

Hi Edd-88 there is no mention of spark descending in spark manual while in active track, if you have a video of this happening then upload it here or please put up link.

Edd_88 Posted at 2017-11-4 15:50
For Mavic, yes, it won't descend. For Spark, however, it descend with the subject at least in some occasion. You can check on youtub. As I mentioned above, it descend with me sometimes. Just want to make sure ahead in what occasion it will descend.

You may be talking about trace or profile mode but there is no mention in the manual that aircraft will ascend or descend in these modes.

If you want a drone to follow you as your elevation increases or decreases this is what DJI calls the "terrain follow" mode and it is available in the Mavic but not the Spark.

Spark can follow you but it cannot adjust its altitude to match your change in elevation.

Edd_88 Posted at 2017-11-4 18:54
Sorry that I don't have video ( Forgot to active video recodring. Anyway, I just a old bald head guy. Not much to see). However, you can view the flight record below to see how the bird behave in difference condition. The photo shows the testing site.

1. From 00:37 to 01:37 (Flight time not video time, same below)), profile mode, 3m from the ground (height) and approx 4-5m away from me, you will notice that it track me but keep the height (3-4m).

Hi Edd , you certainly have given food for thought with your test it seems you may be on to something, I would need to do some testing myself, but weather is pretty bad where I am for a few days.

I think to see this working consistently it needs to be tested at higher speeds like on a bicycle or on a ski slope, if you can test at higher speeds I would be interested.
It’s just another one of those things that dji fails to explain in proper detail and users are left to their own devices to figure out.
Thank you for the test look forward to hearing anymore you have to offer us.

Edd_88 Posted at 2017-11-5 05:23
Thanks hallmark007. I did a few more test today but this time I choose a steep hillside. The main purpose of this test is to find out which part of the setting, tracking angle (elevation) or the relative height (height from the ground where the drone is flying instead of the alti show on the screen), play the major role of the tracking behavior (Fly horizontal or descent/rise).

The following sketch roughly shows the 2different test arrangement. The results are A - descent/rise with me and B - fly horizontally.

Hey Edd, good work there is definitely something there in your methods, I will continue to follow, be careful when charging down the hill.
And yes it would be nice if someone from dji were able to throw some light on this subject, if you can work it I’m sure you will get some really good footage going down the slopes.
No way of deleting posts.

Edd_88 Posted at 2017-11-5 05:25
Sorry for double post as I got a Kong error. Is there any method to delete a post?

Yes, there is a way. Go to that post and click on "Edit" in the lower right corner. When in Edit mode go to the lower left corner and click on "Additional options". A menu will pop up and there you'll find the button to delete the entire post.

Wachtberger Posted at 2017-11-5 08:30
Yes, there is a way. Go to that post and click on "Edit" in the lower right corner. When in Edit mode go to the lower left corner and click on "Additional options". A menu will pop up and there you'll find the button to delete the entire post.

Done. Thanks Wachtberger.

Very interesting, I had a similar situation yesterday but with the subject going uphill on bike ( I assume going uphill is similar to going downhill):
https://forum.dji.com/thread-118682-1-1.html