Let us ascend. Let us descend ascend. Let Us Drone. Have you ever wanted to fly your DJI drone up a hill without having to constantly adjust its height to keep from running into the ground? Well, if you have then Terrain Follow is for you.
Terrain Follow is an intelligent flight mode by DJI that allows you to fly in an area where there is an incline in the terrain. The drone will maintain a preset distance above the ground using its downward vision sensors as you control the speed, roll, yaw, and pitch of the drone.
What is the Terrain Follow intelligent flight mode?
As mentioned above, Terrain Follow in an intelligent flight mode that will allow the drone to keep a set distance from the ground while you are flying over terrain that is ascending.
I should mention that the drone will only maintain its distance above ground that has an incline, not a decline. In other words, the drone will not lower its altitude if you fly over terrain that is going down (descending).
Which drones have Terrain Follow ?
Not every DJI drone has the Terrain Follow intelligent flight mode. Here is a table with the ones that currently do. Keep in mind that future firmware updates may enable some other drones to use Terrain Follow as well.
| Drone | Terrain Follow |
|---|---|
| Mavic Pro | ✅ |
| Mavic Air | |
| Mavic 2 Pro/Zoom | |
| Spark | |
| Phantom 4 Series | ✅ |
| Inspire 1 | |
| Inspire 2 |
When to use Terrain Follow
Each intelligent flight mode is designed to make a particular aspect of flying easier or smoother. Some intelligent flight modes are immensely popular (i.e. ActiveTrack) because of their incredibly practical capabilities. Others, like Terrain Follow get little to no attention. This may be because their practicality or “coolness” factor isn't on the same level as their cousins.
Terrain Follow may not be all that popular because of it's limited capabilities and lack of real-world need.
Let me explain. As I mentioned, Terrain Follow only keeps the drone a set distance from the ground if the terrain is ascending. This is great if you want to fly up a mountainside or sloping grassland, but that is about where your scenarios run out.
Ok, maybe I'm being a bit critical, but how often are you going to fly over terrain that only ascends? If the drone was able to descend when the terrain took a dive, then that would be pretty awesome. Flying through rolling hills while getting cinematic shots of the sunset would be a lot easier if you didn't have to constantly adjust the height of the drone.
Not to mention that most action sports like mountain biking and snowboarding are a lot more exciting to watch when the athlete is going down the mountain, not up it.
So, when might you use Terrain Follow? If you want to fly over a terrain that is only ascending and not have to worry about adjusting the height of the drone, then Terrain Follow is your friend. This could allow you to focus on the gimbal tilt and camera settings to get the best possible shots.
How to enable Terrain Follow
The first thing you need to do is get airborne. You are not able to access Terrain Follow until the drone is up in the air at least 3 feet off of the ground.
Switch the drone into P-mode as you will not be able to access the intelligent flight modes in Sport or ATTI modes.
New to flying? Check out this post I wrote about P-mode,
Next, and this is very important; ensure that you are between 1 and 10 meters (or between 1 and 13 for the Mavic Pro) in height as this is the range where the drones downward vision sensors will work.
Once at your desired height, tap on the remote control icon to bring up the intelligent flight mode menu.
Scroll through until you locate Terrain Follow.
Once you've selected Terrain Follow, you will see a box pop up that gives you a description of the flight mode. Hit “ok” and you will see a menu on the righthand side of the screen.
Tap “apply” and Terrain Follow will be activated. You can proceed to fly forward, up the terrain. Tap “hide” to give you a full-screen view, and tap on the Terrain Follow icon in the bottom right-hand side to bring up the menu again where you can change the height at which you want the drone to fly above the ground.
Obstacle avoidance in Terrain Follow
Obstacle avoidance will be active while in Terrain Follow. As I always say, don't rely on the OA to keep you from crashing. While recording this YouTube video on Terrain Follow, the drone would have flown right into some branches that the forward obstacle sensors didn't pick up if I hadn't manually stopped.
Yes, the drone is using the downward vision sensors to maintain its set height above the ground, but be careful flying too low or where there
The drone will change its height automatically, but it needs some time to do so and flying at top speed could prove to be a bit reckless. My advice is to do a few flybys where you gradually increase the speed if you are unsure how fast you can go in a particular area where you'd like to get some video.
Also remember that most DJI drones don't have sensors on the top of the drone, which makes it easy to fly up into an object if you aren't careful. When you are controlling the height of the drone in normal mode, it's easy to remember not to ascend if there is a tree above you. In Terrain Follow, the drone will ascend right into that tree if you're not paying attention.
How to exit Terrain Follow
When you're done doing your “ascend only” flying, let's talk about how to exit Terrain Follow.
You have two options to exit this intelligent flight mode.
Option 1: Tap on the red “X” on the lefthand side of the screen. This will put you back into normal P-mode.
Option 2: You can also exit Terrain Follow by switching the drone out of P-mode into
Limitations and other options
As we've already discussed, Terrain Follow has its fair share of limitations. In addition to not being able to descend when there is a decline in the terrain, you also have to consider what type of terrain you're flying over and how steep it is.
The vision sensors do not work well in some environments, such as over water, where there is a glare, or in poorly lit areas.
Here is an excerpt from a DJI manual that mentions this:
It is important that you fly in conditions where the Vision Position System can function correctly; otherwise the Terrain Follow Mode will not work.
Mavic Pro Manual
You also have to consider the grade of the terrain that you're flying over. According to the manual, Terrain Follow is not to be used above inclines of over a 20-degree slope.
With that being said, I've used Terrain Follow on terrain with 60+ degrees of slope and the drone ascended just fine. I'd just advise you to go slower and slower as the terrain gets steeper and steeper.
If you are wanting the drone to follow you or a subject that is ascending a hill, I wouldn't use Terrain Follow to accomplish this.
This scenario would call for another one of DJI's intelligent flight modes like ActiveTrack or FollowMe that are designed to follow or track a specific subject.
Check out this post I wrote about ActiveTrack.
Check out this post I wrote about Follow Me.
Let's review
We've covered a lot, so let's review.
- Terrain Follow is an intelligent flight mode that uses the drones bottom vision sensors to keep the drone at a preset height above ground that has an incline.
- Terrain Follow is great for getting cinematic shots of the landscape because you are able to focus on the camera and gimbal tilt.
- You must be between 1 and 10 meters (3-33 ft) above the ground for the downward vision sensors to work.
- You must be in P-mode to use Terrain Follow.
- Terrain Follow will only allow the drone to automatically ascend. You will have to manually descend.
- Obstacle avoidance is active in Terrain Follow, but don't rely on it.
- To
exit Terrain Follow, you can tap on the red “x” on the screen or manually switch out of P-mode using the tactile button on the controller.
FAQ
By using its bottom vision sensors.
No. In Terrain Follow, the drone will automatically ascend but you have to manually descend.
No. Currently only the Phantom 4 series and the Mavic Pro have this flight mode. Check your user manual to see if yours does.
When you want to get good video/pics while ascending a hill without having to worry about the drone hitting the ground.
According to the user manual, the drone will ascend slopes up to 20 degrees.
The bottom sensors may have difficulty when you're flying over water, poorly lit areas, or spots with glare.
You will need to be between 1 and 10 meters (1 and 13 for the Mavic Pro) for Terrain Follow to work.
Trevor's Take
I have to admit that I hadn't used Terrain Follow all that often before writing this blog post and recording this YouTube video. I remember being thrilled the first time I used it only to be let down when I few over descending terrain and saw that the drone wasn't descending with the terrain.
I will say that I was quite impressed with how steep of an incline the drone could ascend with while in Terrain Follow. You'll see in the video I made that the drone is 100 feet below me as I stood at the top of an embankment. It was a very steep incline and my Phantom 4 Advanced ascended just fine.
Have you used Terrain Follow much? Have any ideas of creative ways we can use this shy intelligent flight mode? Comment below!
