Shooting 360 Panorama at dusk, problems with drone holding still, WHY?

[brian dentz]

I'm trying to understand why the drone was not able to hold still while shooting 360 Panoramas at dusk. The Inspire 2 was shooting panos during the day in the same position, with success. This is with using Litchi App. The location is on top of a 5 story high black tar roof. The drone needed to hover at 6 meters and again at 3 meters for the panos. The mission was to shoot the same panorama in different natural light situations(times of day.) The last shot needed to be dusk. The drone was not able to hold the correct heights at dusk, it floated up and down, and the height reading seemed incorrect on the controller. There was some wind, but not more than during daylight. The roof was very dark. GPS seemed good. I'm not sure how the light would effect the altimeter. Any ideas gentlemen? Gentlewomen? Thanks much for your wisdom, advice and thoughts.

 

[The Editor]

Moved to Inspire 2 Help section.

Insufficient light for the downward position sensors. (which work up to 10m as per the user manual).
Nothing to do with the barometer.

 

[brian dentz]

When I do the flight again, if I lite up the very dark black tar roof and the landing pad (I use a landing pad) do you think that would help hold the position stable for the 360 panorama shots? Even at 6 meters high? Thanks much for your help.

 

[PhilZ]

I was shooting a pano with Litchi yesterday about 30’ over a dark flat roof on a large home. It wasn’t dusk, but it was quite cloudy. It was stable until it went to capture the two final nadirs. Then as it spun around to shoot the two nadirs, it moved two to three feet. It was still a useable shot.
In Litchi, you can tell it to spin the bird, or spin the camera. In your instance, I would have it spin the camera, and allow the bird to maintain a singular position. There are a few shots at horizon level you will need to duplicate manually by spinning the aircraft in order to avoid using the shots with the landing gear legs. Good luck.

 

[brian dentz]

I was shooting a pano with Litchi yesterday about 30’ over a dark flat roof on a large home. It wasn’t dusk, but it was quite cloudy. It was stable until it went to capture the two final nadirs. Then as it spun around to shoot the two nadirs, it moved two to three feet. It was still a useable shot.
In Litchi, you can tell it to spin the bird, or spin the camera. In your instance, I would have it spin the camera, and allow the bird to maintain a singular position. There are a few shots at horizon level you will need to duplicate manually by spinning the aircraft in order to avoid using the shots with the landing gear legs. Good luck.

Thanks PhilZ, I have not been able to find this setting to spin the bird or just the camera for panos. Where is this option? I'm flying an Inspire2. Cheers.

 

[PhilZ]

Thanks PhilZ, I have not been able to find this setting to spin the bird or just the camera for panos. Where is this option? I'm flying an Inspire2. Cheers.

Remove the props, connect to the I 2 with Litchi, Go to the main settings screen (upper right hand corner), go to Gimbal Settings, set Gimbal Mode to “Free”.
Then go to Pano mode, enter the Pano Settings on the left, slide down to Mode under Capture Strategy and select Gimbal Rotation.
You will not see “Mode” if 1. You are not connected to the I 2, 2. You do not have the gimbal mode set to Free. That is when you will see Mode in the Pano settings.

Let us all know if that works better. I have not used a free gimbal pano mode since I quit flying my I 1. It had no chance of doing a pano by spinning itself. It would move 30’ over the course of the pano. What an improvement the I 2 is!!

 

[The Editor]

When I do the flight again, if I lite up the very dark black tar roof and the landing pad (I use a landing pad) do you think that would help hold the position stable for the 360 panorama shots? Even at 6 meters high? Thanks much for your help.

The downward vision systems needs ‘something‘ to lock onto to hold position. A dark roof when the light is failing won’t cut it.
Illuminating an area/landing pad that has a relative decent contrast pattern/writing/logo on will probably work.

 

[Donnie Frank]

I'm trying to understand why the drone was not able to hold still while shooting 360 Panoramas at dusk. The Inspire 2 was shooting panos during the day in the same position, with success. This is with using Litchi App. The location is on top of a 5 story high black tar roof. The drone needed to hover at 6 meters and again at 3 meters for the panos. The mission was to shoot the same panorama in different natural light situations(times of day.) The last shot needed to be dusk. The drone was not able to hold the correct heights at dusk, it floated up and down, and the height reading seemed incorrect on the controller. There was some wind, but not more than during daylight. The roof was very dark. GPS seemed good. I'm not sure how the light would effect the altimeter. Any ideas gentlemen? Gentlewomen? Thanks much for your wisdom, advice and thoughts.

The mod nailed it. Light up that landing pad so the sensors can do their job. I'll add....

Without the positioning sensors online, the bird relies on the barometer. As you may or may not be aware, a barometer measures barometric pressure. This pressure data is applied to an algorithm which is used to INTERPRET height. Check this screen shot.



The above flight was 130 feet AGL (if memory serves). My waypoint app tells the bird, "Fly @ 130' AGL." The IMU does some math that basically says "Okay, Bar 46.7 = 130 feet AGL. So we will do our best to maintain Bar 46.7." So if the barometric pressure changes - because the IMU wants to remain constant @ Bar 46.7 - it will tell the bird to ascend or descend to FIND Bar 46.7. As long as the pressure remains constant, the bird's altitude will remain fairly stable.

So we have to ask 2 questions:

1) What happens if pressure changes?
2) What environment variables effect barometric pressure?

Answers:

1) If pressure changes, the bird's altitude changes.
2) Wind blowing across the barometer will change pressure.

Conclusion: Without vision positioning, your drone defaults to barometer data, which is only consistent if there is no wind. Even a light wind can effect the barometer.

D

 

[brian dentz]

Thanks Donnie for the well explained answer. That all makes sense now. Tomorrow at dusk I will try again with a light on the landing pad.
PhilZ, you are correct, now I see the option for gimbal rotation. Have you had better results with gimbal rotation or drone rotation for 360 Panoramas?
My Height is set at 70 degrees and I'm using a 15mm lens, Not sure if the landing arms will show up in the shot? I'll check pictures before I leave location.
I much appreciate the wise advice from you both.

 

[PhilZ]

I always shoot my panos at 90 degrees to the horizon, so I always get the legs in the photo with an X4s camera. So, I always shoot with the gimbal locked to the I 2. Haven’t tried a free gimbal since my I 1.

 

[brian dentz]

Hi Donnie and PhilZ,
Just wanted to report that with lights aimed at the landing pad, the drone did indeed perform as expected and hover in place. Even with snow cover on the ground, which I read is not ideal for the down pointing sonar sensor. There was almost no wind as well which helped. The I2 shot the 360 panoramas with the gimbal spinning, not the drone. This seems like a better option. Thanks for all your advice. - Brian

 

[PhilZ]

So glad we could help. That is what the forum is for. Keep on creating.

 

[Donnie Frank]

Hi Donnie and PhilZ,
Just wanted to report that with lights aimed at the landing pad, the drone did indeed perform as expected and hover in place. Even with snow cover on the ground, which I read is not ideal for the down pointing sonar sensor. There was almost no wind as well which helped. The I2 shot the 360 panoramas with the gimbal spinning, not the drone. This seems like a better option. Thanks for all your advice. - Brian

Nice! Glad it worked!

D