Calculating Areas and Distances

Hi I am a farmer from England (UK). I am interested in using DD for Field Mapping and accurately calculating areas and Distances. How accurate is the area calculation tool when using the free version or Pro?
Many Thanks

In terms of area and laying, all of my checks have come back dead on. This is without the use of any ground control points. I think the ground control points and more detailed checks would be required if you start looking at volumes. With that being said my volume calculations without ground control points have been with a 98% of expected numbers. I have found that my numbers may be slightly off due to which pixel I click on as my starting in points which obviously would impact your measurements. For greater detail I have been using the auto cad files to make measurements.

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Peter - I have mapped a 385 acre diary farm in Leicestershire to calculate all the field sizes. The farmer employs the New Zealand grazing system so the farm is made up of 52 fields. I did some area calculations in DD and they were fine although I did all the final work in ArcGIS. Lots of flights!!

Good to hear you were successful Jeremy and DragonFlyer.

@peterthefarmer the accuracy will be best on pro, but probably fine on free.

Would it be accurate to 0.01 of a Ha.? This is a requirement for Agricultural area Measurements for the Purposes of Cross Compliance etc.

Hi @peterthefarmer,

I’d love to hear what the alternative ways to measure fields are that farmers are using for this purpose. Both curiosity, and also to understand how people avoid errors in their measurements. I’ve seen some people use GPS measurement apps, or expensive survey tools. For this purpose I’d assume the latter is prohibitively expensive.

I don’t think we can give you a broad legal assurance for that particular use case, but stitched aerial imagery from drones can give you the quality of results you are looking for. We have customers using us for precision down to a few centimeters, though construction sites are often easier to stitch together than fields (Try completing a puzzle with only grass/sky).

The most important thing for the accuracy of your measurements will be:

  1. the confidence accuracy of the map (look for less than 3m)
  2. the size of your field (the larger the field, the less (3) will affect you)
  3. the precision with which you place your area markers in our software.



So, some of this I heard and stole and part of it is my opinion:

Stolen Info:
It is important to understand that traditional, professional boots on the ground, surveyors should be providing the most accurate data at a given point at a given time. Where the drones and DD come into play is in the bulk points that we can collect data on. A surveyor will walk a grid, outline or path and collect data at a given interval. They may gather 100 points of data over a couple of acres, with each of those points being highly accurate. With the drone though, we can collect 1,000,000 points over the same area with an accuracy that is highly, but possibly just slightly less, accurate. Using the drone data we can better fill the gaps between the surveyors shots with actual collected data, opposed to interpolation.

I think every project demands different things. If I am building a nuclear missile site, I want boots on the ground. If I am doing a large cut/fill analysis for a subdivision, I want the drone. It is a value engineering question that needs to be evaluated on a case-by-case basis. Do you need a sledge hammer to hang up a poster in your game room???