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These shots are mutually consistent. They cluster tightly around one another, but not around the bulls eye. We could say they are precise or have good precision.

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Theses shot evenly surround the bulls eye so we could say they are accurate or have good accuracy.

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Now these are precise and accurate. Both precision and accuracy are important for geodetic surveying. The aim is to get measurements that average as close as possible to the truth, and to do so in a way that's repeatable, so you can confidently compare them to any future measurements.

One way to verify your measurements is to compare them to a known position, such as one accessed through the national spatial reference system in the United States. The NSRS is established by the federal government using the most accurate surveying methods possible, in order to provide known starting points which act as truth for surveyors and map makers. In geodetic surveying, precision refers to how close the repeated measurements come to agreeing with each other.

Good surveying procedures contribute to precise measurements. However, just because something is repeatable does not make it accurate. Accuracy describes how well measurements of the same thing average to the truth. Consistently using an incorrect tripod height in a series of measurements may result in very precise but nonetheless inaccurate measurements. Verifying that your measurements yield final coordinates that agree with a known reference system such as the NSRS enables you to evaluate their accuracy. The NSRS is the most up to date version of positional truth available in the United States.

By tying into it you inherently gain the built-in accuracy of that system. And by carefully following proper surveying procedures you increase your chances of repeatable results... which promotes better precision.

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With both you'll be right on target!

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