When I take off from my home position, which sits up on a hill, the Spark considers this my ground zero height. My question is if I fly the Spark down to the valley will the height go negative or will it read something else??
Height
- Thread starter DeadlyFrog
- Start date
Well that's what I keep reading but today I took off and the Spark rose to about 3.5 ft. as it should, I then maintain this height and flew it straight ahead on a descending hill and the height grew positive. It was actually showing me height versus the ground below???
By "down to the valley", I was assuming you meant descending into the valley.
If you fly straight across a valley, the current altitude will not change. The altitude only changes when you ascend or descend using the throttle stick on the remote controller.
If you fly straight across a valley, the current altitude will not change. The altitude only changes when you ascend or descend using the throttle stick on the remote controller.
Ok, a little more clear.
Yes I was descending as I went down the hill.
Ok, came home and gave it a test. Tookoff on top of a hill and Spark height reading went to 3-4 ft. I pushed the forward stick, not touching the descend/ascend stick, towards the descending hill and as the ground level decreased the height reading increased. I continued at the takeoff level till I hit a height reading of 20ft. Even though it is at the same level as when I tookoff. At 20ft. I lowered the descend stick and it slowly approached the lower hills ground as the height reading continued down. I descended until it was 4ft. This is not the same 4ft height reading I got when I tookoff. Does the spark actually have a sensor that reads the ground level??
Yes, the downward sensors will display the altitude above ground level if the Spark is close enough to the ground for those sensors to detect the ground. If the Spark is too high, you'll only be able to see the altitude estimated by the Spark's barometer (which is the altitude above the takeoff point).
You have been very helpful. Just so I understand, once your above the downward sensor capability, the barometer will take over and then I would read a negative height value if I was still below the RTH. Do you know how far the downward sensors can read to the actual ground?
The Spark manual does not document this well. It only mentions the "H" at the bottom of DJI GO is the height above the ground.
It appears DJI GO is showing the altitude from the downward sensors when the Spark is close to the ground and the altitude estimated by the barometer when the Spark is too far above the ground for the sensors to be used. If you upload one of your TXT flight logs here, you'll be able to see both the barometer altitude and VPS (downward sensors) altitude.
It appears DJI GO is showing the altitude from the downward sensors when the Spark is close to the ground and the altitude estimated by the barometer when the Spark is too far above the ground for the sensors to be used. If you upload one of your TXT flight logs here, you'll be able to see both the barometer altitude and VPS (downward sensors) altitude.
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I took your suggestion and opened a couple log files and there it was... exactly what I was looking for... IMU and VPS displaying as you said. Seems like the VPS drops out around 20ft. Thanks for the feedback and suggestions.
