Hovering (Position Hold) question for the RTK drone experts

Flight - Discussion and Q&A
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New here and new to drones, but not so much to the RTK survey world, so don’t beat me up too badly please. :crazy_face:

Obviously this question would depend on the brand and model of the drone and it’s particular RTK setup. Any particular models recommended after going through the criteria?

From PROFESSIONAL EXPERIENCE, is it possible, via RTK and a multi-band BASE to HOVER the drone as steady as possible without too much drift or deviation in both the horizontal and vertical directions within cm (sub inch) accuracy?

Example being ideal non-windy or very minimal breeze conditions. Approximately 1 foot or 2 feet max above smooth surface clear of dirt and debris… may even need to hover lower 6 inches or so.

At a normal speed, without too much abrupt acceleration or abrupt braking, is it possible to fly to multiple waypoints and hover almost exactly to each of them as accurate as possible? Holding in place for a few seconds, like Stop & Go static action and also a smooth non-stop path action passing over waypoints start to end.

What is the general deviation of error in the horizontal components… and also the vertical component? I.e. at the best accuracy of the Rover/Base receivers via RTK LoRa (or other) such as 7mm horz 14mm vert? Or is error much more than that. I.e. 1 to 2 inches or more of deviation while it tries to keep steady hover over point?

Can it return exactly to start point with cm accuracy or is there a large amount of error? I.e. within a few hundred feet area in both directions. Since GNSS, assume it can return within cm accuracy of the start/end point, but keeping steady may be the issue?

Thank you!!!

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Hey Tim, good question and glad to see you here. Just think of the drone as a rover and expect the same accuracies. Modern drones are very good at holding position and making fine adjustments even without full on RTK so when that gets added to the mix you can hold 2-3cm and return to 2-3cm. That’s a part I think a lot of people don’t quite understand in that it’s not just the ability of the system to tag via the RTK value but the drone is holding true to what you told it to do because of RTK-aided navigation. You tell it 500ft MSL and it will hold that within a couple of centimeters. Then the whole attitude of the drone is better and is more stable in the air. We’re becoming confident enough in it now that we can let it do facade captures 20ft from the face of the structure and trust that it will hold that alignment.

Pretty crazy to where we were just 6-7 years ago, before the Phantom RTK. It still drives me up a wall that DJI would make a drone like the M30/T which has RTK navigation but not time-sync and thus RTK geotagging.

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Thank you @MichaelL for the help. Much appreciated as usual. Thank you for the DroneDeploy suggestion!

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