Hello,

recently, I was flyling the Spark in a small canyon with no sufficient GPS-Signal.
So the aircraft switched into OPTI-mode, using its downward vision system.
Everything was working perfectly except of one important detail: the flight altitude was limited to only some meters (4 or 5 m).

In the Mavic-forum I found out that this limitation is due to the OPTI-mode and that it can be deactivated by switching off the downward vision system in the DJI GO 4 app. Doing so, the aircraft will switch to ATTI-mode and will have hight limitation of 30 m, which would be enough for me.

Unfortunately, I cannot find that option in the app for the Spark. The only thing I can find, is the activation/deactivation of the forward vision system.

So my question is, how can I turn off the downward vision system for the Spark so that I can reach higher altitudes when there is no GPS-signal?

Thanks a lot for your advice!

This option is not available for the Spark. But users have started a motion to get it in the future.

but,if i deactive sensor(obstacle sensor...) ..don't work?

You can de-activate the front obstacle sensor but not the VPS unter the Spark.

Lian82 Posted at 2017-9-23 01:53
but,if i deactive sensor(obstacle sensor...) ..don't work?

different sensors..  obstacle avoidance uses front firing sensors located above the camera.. the VPS/Opti sensors use the down firing camera on the belly of the drone..

so if DJi gave spark users the option to disable VPS it would not interfere with its avoidance systems, but it would be more "unfriendly"  since VPS is used when lighting is good and GPS is bad.. like indoors and under trees and stuff..  also used to palm launch and land and with vps disabled/forgotten.. probably be more of a panicky attack drone...

however i think dji should give users the option to disable it and every new flight session (like every time you relaunch the dji go app) it auto enables it again.. or soemthing

ya the mavic pro is targeted to prosumers and spark is targeted to entry market..this means DJi is pushing the spark to be more "friendly" which means a lot of little extras the spark will miss out on...since alot of these extras probably cause potential harm to the market dji is targeting with the spark...like panicky drones and attack drones.. like imagine doing a palm landing with spark then the spark moment it lands on ur hand goes full retard and attacks you or something..or youy forget dont have vps enabled and triy flyign it somewhere with no gps or limited gps and it spazzes out and crashes around..

as for disabling VPS in a canyon... not sure how much difference it would make... guessing very little, if u had not GPS and no VPS then you in full manual controll with altitude hold, this is called atti mode, and atti mode is agreesive and hard to handle with the smaller spark.. atti mode is the cause of alot of crashes since it drifts...ALOT!

places we mavic pro owners would typically disabling VPS/landing protection is like up in the clouds, or in the dense fog, or around water/under bridges...places that trigger false positives.. not sure i would disable VPS in a canyon but i may disable landing protection because a canyon may trigger ultrasonic false positives in tighter spaces..but the spark doesn't even have the hardware for landing protection...


however, i do want it to be on the spark in some way and form and manner..  however i cannot see dji giving spasrk uers such things anytime soon just based on way they market it..

HereForTheBeer Posted at 2017-9-23 02:17
ya the mavic pro is targeted to prosumers and spark is targeted to entry market..this means DJi is pushing the spark to be more "friendly" which means a lot of little extras the spark will miss out on...since alot of these extras probably cause potential harm to the market dji is targeting with the spark...like panicky drones and attack drones.. like imagine doing a palm landing with spark then the spark moment it lands on ur hand goes full retard and attacks you or something..or youy forget dont have vps enabled and triy flyign it somewhere with no gps or limited gps and it spazzes out and crashes around..

as for disabling VPS in a canyon... not sure how much difference it would make... guessing very little, if u had not GPS and no VPS then you in full manual controll with altitude hold, this is called atti mode, and atti mode is agreesive and hard to handle with the smaller spark.. atti mode is the cause of alot of crashes since it drifts...ALOT!

Yes, I fully share your analysis. But there is always hope...

Thanks for your replies!
So it's not possible to turn off the VPS. That's a pity.

I agree with you that this would make the control of the aircraft more difficult and the VPS is doing a great job.
But whenever you want to go higher than the 5 m limitation, it should be possible as the Spark has an ATTI mode.

However, my aim is not to turn off VPS. I just want to get over the 5 m limitation, for example in an indoor hall.

So I could imagine the following logic:
- VPS is automatically activated when the aircraft is turned on (that's what it actually does)
- When there is no GPS, the VPS will limit the hight to 5 m
- Whenever you want to go higher, you could for example validate a promt in the app of being aware of the consequences of flying in ATTI mode
- Then flying in ATTI mode up to 30 m altitude
- When you descend again under 5 m for example for landing, the VPS will automatically take control again and making the Spark safer to handle.

And for the absolute pros, VPS could be turned off manually in the app.
That would make sense and everybody would be happy or am I wrong?

Everyone has been very helpful in this point on the sensors. Safe to say, it helps to review what the various sensors do on the aircraft. You can find that information here on page 11 and forward from there: https://dl.djicdn.com/downloads/ ... ser+Manual+V1.4.pdf

Hi, Ive just joined this forum and the league of pilots flying a Spark. This is probably old news now but I had some observations about the vision system that I noticed while wrestling with the issue of RTH problems. I note that I'm not the only one who wondered why you cant select ATTI mode for casual flying. I also considered that in the situation where GPS and RC connection is lost, you should be able to specify that when RTH is triggered, the drone can ignore GPS and just use a "Land on the SPOT" protocol like a lesser drone might. This would be handy in bush situations etc. I sent my recommendations and a truth table to DJI hoping they might find some use in it. However this brought me to these forums on the topic. And of course the next issue is, for manual flight in true ATTI mode you would have to also disable the Vision system as it causes the Spark to make autonomous decisions which are sometimes wrong if the circumstances create bad feedback such as low light or when there is no pattern for reference.

So this might be known to everyone, but from my reading I think its worth sharing my observation.

So you fly indoors to block GPS in an attempt to force ATTI mode. It has been mention that you can turn off object avoidance. But what might not be understood for a newby like me is that the vision system (OPTI)  is completely separate to FORWARD object avoidance. While they are both employed for object avoidance only forward object avoidance can be turned off in the GO 4 menu. The vision system which points down cannot be turned off. The vision system has 2 parts. One is an optical camera which looks for shifts in patterns on the ground and the other is an infrared range finding system the measures the distance to the ground. The Spark uses this information to pinpoint its location far more accurately than GPS or the built in Barometer, GYRO and accelerometers at close ranges within a few metres of the ground.

So if you block the VISION system downward point camera and the laser range finder (with say, a lump of BLUE TAC, the SPARK must rely on the not so accurate Barometer for altitude information and the internal accelerometers to know whether its moving around. It cannot tell if it is drifting very easily (compared to an optical camera), hence, like a sport drone, you have to control it manually with stick inputs. And altitude must be maintained as a barometer will struggle to determine small changes compared to the highly accurate laser system. The laser is what allows Spark to accurately hover at 0.3m from the ground whilst waiting to land.

So the problem for the DJI programmers is not only adding a menu option to allow ATTI mode, but also finding a “fool proof” way to control the drone in the absence of the Vision system. You say why not just keep the Vision system in ATTI mode?  Thats fine but then its not truly Manual and is open to the flaws of the Vision system, such as short range capability, and it can make errors if the information coming in is bad causing erratic flight behaviour. The whole point of ATTI mode is that you fly by EYE and can make educated adjustments based on what you see without being judged by the drone! All the drone is supposed to do is accurately respond to sticks and return to level with no input.

An example of a problem to overcome is, how do you land a Spark that is designed to auto land with a controller that is designed to auto land and has no fine trim adjustments for correcting drift in manual flight? Without the Vision system the Spark is quite unstable on the ground and doesn’t know how to land. If you push the stick down it will hit the ground and bounce up and down and skid around as it doesn’t know to stop trying to hard!. You can’t use the auto land protocol because it doesn’t accurately know how close the ground is. With my BLUE TAC attached, I found I can lower the drone to the ground and then cut the engines and it works but its messy. If you are hovering in true ATTI, the Spark is not calibrated perfectly and drift around slightly. On a normal controller you would adjust the fine adjustment until it was sitting nicely. The RC has no such adjustment so that would need to be added for best performance. Another issue is the BAROMETER. A sport drone doesn’t use a Barometer as it can fluctuate with air pressure and change altitude without warning. Altitude is adjusted fully manually by EYE. DO we disable the Baro in ATTI mode? Then we could fly off cliffs without the drone freaking out. But what happens when you are at 50metres high and you can’t tell you’re dropping or ascending in the wind rapidly? What is the fall back behaviour if signal is lost? Land in the lake? Perhaps ViSION comes back on in a signal loss situation? Not straight forward.

Certainly not the kind of performance DJI would put their name to. There’s several other issues like that which are harder to work around in a system that is really designed to be autonomous.

So I expect it will take them some time if they are trying to find work-arounds for all the associated issues. By my reckoning its not as easy as just putting in a button that forces ATTI mode without also conceding that you are then flying a machine no more complicated than a $50 toy with a nice camera.

Hope you find these observations interesting. If you see a fault please comment.