accurate

Expeditionario

Hi there:
I want to know, when I´m measuring with polygons how accurate is the measure, I understand this is a math thing, so it should be 100 % but anyway I want to know for sure

Thanks

global_mapper

The perimeter measurements of the area should be extremely accurate as a sum of the great-circle lengths of the lines. Note however that these measurements are done at sea-level and don't take any terrain into account, so if your are measuring something that is actually very hilly or far from sea level then there may be some discrepancies.

For the calculation of enclosed area Global Mapper uses the common mathematical formula for calculating the enclosed area of a polygon if you are using a projected coordinate system. In this case, the accuracy of your measurement will depend on how much distortion there is in the projection system that you are using. If you are using an appropriate projected coordinate system for your location you should get extremely accurate results. If you are using a projection that is very distorted in the area of your mapping data, the quality of your results will diminish.

Let me know if I can be of further assistance.

Thanks,

Mike
Global Mapper Support
support@globalmapper.com

Expeditionario

Thans again Mike
I have another question. Once I make the polygon there are vertices like points of reference for the measurement, the question is ¿Can I have a list of all those points "vertices" using each point with their respective coordinates?
Thanks again...

Richard

global_mapper

Richard,

You can see a list of all of the vertices for a feature by selecting it with the Feature Info tool, then pressing the Vertices button on the dialog that appears.

Let me know if I can be of further assistance.

Thanks,

Mike
Global Mapper Support
support@globalmapper.com