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Go beyond maximum altitude of 500m setting?

paulatkin73

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We are not talking about the same thing. Yes - it's trivially available for mission planning - Litchi already does that. And you could certainly upload a local DEM to the aircraft in advance for use while flying. I'm referring to what would be needed to fly anywhere in the world (or even just North America, for example) without having to upload DEM data before each flight for the specific area that it is flying, which is the kind of solution that DJI is going to want to implement.
I do not think it has to be global as a map itself is also not global and is either pre-downloaded, or requested dynamically.
 

sar104

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I do not think it has to be global as a map itself is also not global and is either pre-downloaded, or requested dynamically.
Agreed, but many people fly without a network connection. I guess the firmware could limit either to 500 m AGL or above terrain if DEM data are available.
 

paulatkin73

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Agreed, but many people fly without a network connection. I guess the firmware could limit either to 500 m AGL or above terrain if DEM data are available.
Dunno. A partial solution is better than no solution at all. Only point i tried to comment on was that terrain tracking is nothing new and can ve done easily. Why it is not there is odd.
 

dbj702

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I live in Las Vegas Nevada. Here in the valley we are surrounded by mountains so it is very easy to find yourself above 500 meters. I recall a flying session at RedRock Canyon where i took off from Calico Tanks Trailhead and followed a gradual incline as I followed Turtlehead Peak. Before I knew it, my Mavic Platinum was telling me I was 400 meters up when i was actually just 50 feet from the ground.

I was a new pilot then and fearing what could happen should return home kick in 2 miles from where I took off I turned around and headed back. I think DJI should be able to GEO fence altitude restrictions within certain areas while leaving secluded areas open for free flight to higher altitudes. Maybe not, but it is very easy to find yourself higher than 500 meters in an area like Las Vegas.

On another flight later that day I flew back into IceBox canyon, a winding spectacle of rock. If anyone knows anything about flight around rocks that are hundreds of feet high, they know there is no penetration and your signal will be gone almost instantly should you turn a corner. This happened to me and RTH kicked in. The Mavic doesn’t return the path in which it came when RTH kicks in. It climbed to my specified RTH altitude of 40 meters and began flying the most direct rout to the takeoff area. I was in horror as I thought i lost my drone 1/2 mile into this huge canyon.

I lost everything in an instant and I could not even hear it. As I proceeded back into the canyon about a quarter mile, boom! My signal returned. I could not see or hear the drone from the ground nor could I recognize where i was from the drones camera. I stood still and listened as it headed home to the launch location. Eventually a could hear it pass over but it was too high to see. I began following the sound out of the canyon and eventually spotted it as it began to descend. I recovered it. I went home and watched the footage the drone continued to record. It was only then that I realized how close to loosing it I was.

When the drone instantly lost signal in the rock, RTH kicked in. The drone ascended as if was climbing steps until it cleared the top of the canyon and proceeded to the RTH spot. Each time the drone would come within a few feet of the canyon, stop and ascend on 3 different occasions. At its highest altitude it reached over 1000 feet before it cleared the canyon. I was in my first ten flights and I learned a lot that day but again had the canyon been higher than 500 meters I could have lost my drone. Thank goodness it wasn’t. It was that day that I learned the drone measures its altitude based on where it took off, not where its at.

Peace.
 
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sar104

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I live in Las Vegas Nevada. Here in the valley we are surrounded by mountains so it is very easy to find yourself above 500 meters. I recall a flying session at RedRock Canyon where i took off from Calico Tanks Trailhead and followed a gradual incline as I followed Turtlehead Peak. Before I knew it, my Mavic Platinum was telling me I was 400 meters up when i was actually just 50 feet from the ground.

I was a new pilot then and fearing what could happen should return home kick in 2 miles from where I took off I turned around and headed back. I think DJI should be able to GEO fence altitude restrictions within certain areas while leaving secluded areas open for free flight to higher altitudes. Maybe not, but it is very easy to find yourself higher than 500 meters in an area like Las Vegas.

On another flight later that day I flew back into IceBox canyon, a winding spectacle of rock. If anyone knows anything about flight around rocks that are hundreds of feet high, they know there is no penetration and your signal will be gone almost instantly should you turn a corner. This happened to me and RTH kicked in. The Mavic doesn’t return the path in which it came when RTH kicks in. It climbed to my specified RTH altitude of 40 meters and began flying the most direct rout to the takeoff area. I was in horror as I thought i lost my drone 1/2 mile into this huge canyon.

I lost everything in an instant and I could not even hear it. As I proceeded back into the canyon about a quarter mile, boom! My signal returned. I could not see or hear the drone from the ground nor could I recognize where i was from the drones camera. I stood still and listened as it headed home to the launch location. Eventually a could hear it pass over but it was too high to see. I began following the sound out of the canyon and eventually spotted it as it began to descend. I recovered it. I went home and watched the footage the drone continued to record. It was only then that I realized how close to loosing it I was.

When the drone instantly lost signal in the rock, RTH kicked in. The drone ascended as if was climbing steps until it cleared the top of the canyon and proceeded to the RTH spot. Each time the drone would come within a few feet of the canyon, stop and ascend on 3 different occasions. At its highest altitude it reached over 1000 feet before it cleared the canyon. I was in my first ten flights and I learned a lot that day but again had the canyon been higher than 500 meters I could have lost my drone. Thank goodness it wasn’t. It was that day that I learned the drone measures its altitude based on where it took off, not where its at.

Peace.
As you discovered, the real problem with flying higher, even when staying within 400 ft of the ground, is being beyond VLOS. And unlike the altitude issue, that's a requirement, even for recreational flight.
 

ruaidhri

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Just on the mountain flying issue, has anyone taken off at the side of a mountain and then land say at 100m, then take off again? Will this reset the home point altitude to 0 and give you an extra 500m? Or is the 500m limit from the controller location?
 

sar104

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Just on the mountain flying issue, has anyone taken off at the side of a mountain and then land say at 100m, then take off again? Will this reset the home point altitude to 0 and give you an extra 500m? Or is the 500m limit from the controller location?
The 500 m is from the power up location - that is where the altitude reading is initialized. So you would have to land, turn off the aircraft and then power it up again.
 
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ruaidhri

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Thanks for clearing that up. Just a thought I had didn't know if it would work.

The 500 m is from the power up location - that is where the altitude reading is initialized. So you would have to land, turn off the aircraft and then power it up again.
 

Spike151

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Just on the mountain flying issue, has anyone taken off at the side of a mountain and then land say at 100m, then take off again? Will this reset the home point altitude to 0 and give you an extra 500m? Or is the 500m limit from the controller location?
There is a video of a guy in Hong Kong who flies up the tall building used in the mission impossible film. He land near the top, as he’s at 500 agl, resets the RC then gets another 500m, so I think it’s set by the rc
 
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sar104

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There is a video of a guy in Hong Kong who flies up the tall building used in the mission impossible film. He land near the top, as he’s at 500 agl, resets the RC then gets another 500m, so I think it’s set by the rc
No - it's not set by the RC. The altitude reference is the aircraft's barometer.
 

tcope

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Just on the mountain flying issue, has anyone taken off at the side of a mountain and then land say at 100m, then take off again? Will this reset the home point altitude to 0 and give you an extra 500m? Or is the 500m limit from the controller location?
Not recommended as this would normally set the RTH point to that spot.
 

Spike151

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No - it's not set by the RC. The altitude reference is the aircraft's barometer.
So by your logic anyone trying to fly their drone that is above 500 m agl on take off cannot take off
 

sar104

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So by your logic anyone trying to fly their drone that is above 500 m agl on take off cannot take off
Assuming that you mean > 500 m MSL, it's because the aircraft zeros its barometric altimeter on power up and then measures how far it ascends above that point. How did you think it worked?
 

paulatkin73

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Assuming that you mean > 500 m MSL, it's because the aircraft zeros its barometric altimeter on power up and then measures how far it ascends above that point. How did you think it worked?
all they need to do is exactly what i wrote before - when it is getting a map of a local region - also need to get a terrain data, and then, during the flight, IF that terrain data was provided the flight controller needs to adjust the calculation of the max altitude to work relative to the following the current terrain level instead of a direct subtraction of the initial baro reading at home point from current baro reading at the altitude.
all that is pretty trivial and it is really frustrating and stupid that they consistently refuse to do it. again, nothing in this method is new. it is and was a standard for a very long time or most RC planes would be smacking into hills on their way.
 

sar104

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all they need to do is exactly what i wrote before - when it is getting a map of a local region - also need to get a terrain data, and then, during the flight, IF that terrain data was provided the flight controller needs to adjust the calculation of the max altitude to work relative to the following the current terrain level instead of a direct subtraction of the initial baro reading at home point from current baro reading at the altitude.
all that is pretty trivial and it is really frustrating and stupid that they consistently refuse to do it. again, nothing in this method is new. it is and was a standard for a very long time or most RC planes would be smacking into hills on their way.
Agreed - but I was replying to a specific question about landing to reset the altitude.
 

dewster

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I’d worry about not being able to recover my drone due to high winds. I can see a need if you are close to a mountain and are trying to ascend to a point on the mountain.
 

Spike151

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Assuming that you mean > 500 m MSL, it's because the aircraft zeros its barometric altimeter on power up and then measures how far it ascends above that point. How did you think it worked?
The evidence is there to see on the video it’s quite obvious what he’s doing, and I mean agl above ground level or take off point
 

sar104

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The evidence is there to see on the video it’s quite obvious what he’s doing, and I mean agl above ground level or take off point
I finally got around to checking whether it is a motor start or power up that resets the relative altitude. The following height and motor speed data show a takeoff followed by a landing at a higher elevation followed by a motor restart.

altitude_reset_motor_start.png

The data clearly show that the relative altitude is set and then reset on motor start and so your statement was correct - ascending, landing and then restarting the motors will reset the altitude and allow the aircraft to climb cumulatively to more than 500 m.
 

Torcan

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this one thread is worth its weight in gold. Great information. Thanks all !!!
I guess the lesson is to make sure that where you reset and take off from is a safe place for a RTH if need be.