djiuser_Kf4iPA3
 First Officer
Flight distance : 510968 ft
Israel
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TexasAerials Posted at 2017-10-26 09:34
Where your comment about dropping GPS data that "could save your craft" goes wrong is that you assume that the GPS data is accurate all the time. I have seen many GPS tracks from handheld GPS units that track within a foot up until they get near a cell tower or microwave antenna, and the location accuracy goes from tens of inches to tens of feet. I've seen GPS interference to a lesser extent from just tree cover, cause the spark to wander 6ft to the left or right. If the GPS data is suspect, the spark is right to ignore it, or it could cause crashes rather than prevent them.
Now, I don't think that is a good enough reason for the Go4 app to stop updating the crafts position on the screen, because that information along with the video feed would be very helpful in determining the location of the aircraft and getting it back home.
i get what you said, but think of it this way: these days there's GPS even in low-end smartphones, and they have to work in much tougher conditions than a drone does, typically. They work in cities, at ground level, surrounded by buildings, power lines, metal structures, transmitting antennas of all sorts. They see a smaller portion of the sky (hence, fewer satellites) than a drone in mid-air, which typically flies in an open environment, does. And yet they are able to acquire and maintain GPS, or re-acquire it quickly when the lose it, with excellent credibility and accuracy.
If Spark's GPS is so much more susceptible than a low-end smartphone's GPS, despite operating in typically better environmental conditions, then there are other questions that DJI need to be asked about the design of the GPS. That's another matter, though.
But I highly doubt that's the case. GPS in general is much more robust to magnetic interference than a compass, especially with the redundancy of satellites (if its firmware is smart enough).
But let's suppose for the sake of argument that what you say is right, and Spark's GPS is super susceptible to anything near it.
With our procedures, which I don't know whether you got to read in full, the drone first rises to its RTH altitude, which is enough to clear most obstacles (that's what RTH altitude is there for). And once up, Spark is always on the move, in order to find its bearing based on GPS alone. If something causes the super susceptible GPS to err, Spark will eventually move and the error will dissipate. Even with drift, it will be able to converge, after some zigzaging, to the right direction.
I disagree that it would cause more crashes or lost drones than ATTI mode. Most Spark users, seems to me, are not experienced pilots and rely on the technology to aid them as much as they can, especially if a system fails.
And like you said yourself, not everyone is lucky enough to have it happen to them right after takeoff. If it happens on the edge of your line of sight or the edge of your controller range, you are in trouble. A little wind drift away from you, pushing it out of range, and even the most proficient pilot would lose the drone. |
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