Ground Control Tips: 6 Ways of Using Your AeroPoints

ground control points for drone surveying

AeroPoints have been designed to be used in six different ways. Below is a summary of each of the ground control methods so you can select what suits you the best.

Please note that option one (using within Propeller Corrections Network coverage) is encouraged wherever possible. Also, for each method there are differing logging and placement requirements that should be adhered to.

 

1. Fully Automated Processing in Corrections Network Coverage Areas

Propeller has an extensive corrections network in many countries—and this is expanding all the time as more drone teams around the globe start using smart ground control points.

Automated processing is definitely the best way to use the AeroPoints. It ensures you have shorter turnaround time and enjoy all the efficiency benefits AeroPoints can provide. (Let us know if you’re not on the map today—we’re expanding our coverage network every week.)

We strongly recommend collecting the AeroPoints in reverse order for this method and any other to get the best possible result.

Here Richard is explaining the best way of collecting your AeroPoints:

For this method:

  • Global accuracy: the best available, 20mm/20mm/50mm
  • Consistency: the best available, 20mm/20mm/50mm
  • Internal accuracy: 10mm or less—precise internal reconstruction

 

2. Using Your Own Corrections

Provide us with RINEX formatted GNSS observations for the period of your survey and we can use that as the reference point.

Note that the RINEX file must contain an accurate location for the base, measurement method, the antenna type and height in the header as this is the information that will be used to calibrate your AeroPoints.

For this method:

  • Global accuracy: the best available,20mm/20mm/50mm
  • Consistency: the best available, 20mm/20mm/50mm
  • Internal accuracy: 10mm or less—precise internal reconstruction

Drone surveying explained: From GCP to PPK

 

3. Using an AeroPoint as a Base Station on a Known Mark

You can place one of the AeroPoints at a known survey mark or benchmark location. It needs to be activated for the duration of the survey. We can then use this AeroPoint, combined with the known coordinates of that mark, as the reference point for the other AeroPoints used in the survey.

Please note that the first AeroPoint unit that you place must be on the known mark.

setting up ground control points using Propeller AeroPoints
Placing an AeroPoint over a known survey mark.

For this method:

  • Global accuracy: If you place the AeroPoint accurately, the best available, 20mm/20mm/50mm (plus the accuracy of the mark itself)
  • Consistency: If you use the same known mark each time, the best available, 20mm/20mm/50mm
  • Internal accuracy: 10mm or less—precise internal reconstruction

 

4. Using an AeroPoint as a Makeshift Base Station

If there are no known marks, the accuracy of your data globally will be reduced. However, you can still use AeroPoints to get results that line up with each other over time.

Find somewhere recognizable that won’t move and establish your own “mark.” The first time we’ll calculate an estimated point, accurate within 50cm, and after that treat that coordinate as a “known mark.” You’ll need to place the AeroPoint on this exact mark each time.

To calculate an estimated point, the unit to be used as a “known mark” should be placed first and have at least two hours of logging time.

For this method:

  • Global accuracy: 500mm/500mm/500mm
  • Consistency: If you use the same known mark each time, the best available, 20mm/20mm/50mm
  • Internal accuracy: 10mm or less—precise internal reconstruction.

 

5. “Just Lay Them Out”

If none of the abovementioned is an option, unfortunately, there will be reduced accuracy globally, and there will be less alignment between sequential surveys. But, you’ll still get accurate internal reconstruction with AeroPoints—measurements and distances will be precise.

This can be very useful if you are only capturing a site once, like a damage assessment or traffic accident capture, and don’t need precise measurement of changes over time.

For this method:

  • Global accuracy: 500mm/500mm/500mm
  • Consistency: 500mm/500mm/500mm
  • Internal accuracy: 10mm or less—precise internal reconstruction.

 

6. Provide local grid calibration

If you work on a site with its own local grid you can set up your site in Propeller using your site calibration data. Then, processing your AeroPoints with the Local Site Survey Benchmark correction method will yield coordinates in your site’s local system.

For this method:

  • Global accuracy: Depends on the global accuracy of your site
  • Local accuracy: the best available, 20mm/20mm/50mm
  • Consistency: the best available, 20mm/20mm/50mm
  • Internal accuracy: 10mm or less—precise internal reconstruction.

 

Below is a table comparing accuracy and time requirements for these different methods:

 

 

Visit AeroPoints page to learn more about smart ground control technology.

 

Drone surveying explained: From GCP to PPK

 

You might also like:
Using AeroPoints to Produce Highly Accurate Elevation Maps
Better, Faster Topographic Surveys with Drones and AeroPoints
How Accurate is the new DJI Phantom 4 RTK?

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