PRECISION 1: "VERY HIGH-PRECISION POINT" [THIN-CROSS SYMBOL] ", i.e., a point location specified within a radius of 1 meter (3.3 feet). [This level of precision can be obtained using traditional surveying equipment, or using a high-quality differential GPS (DGPS) with post-processing of data to correct for signal degradation due to "selective availability". This level is needed when locating well-defined control points to determine the positional accuracy of a 1:24,000-scale map].
PRECISION 2: "HIGH-PRECISION POINT" [MALTESE-CROSS SYMBOL], i.e., a point location specified within a radius of 20 meters (66 feet, or 0.012 mile). [This level of precision (and SOMETIMES much better), can be obtained using a Real-time DGPS unit to navigate to the desired place (without post-processing of data). A Precise Lightweight GPS Receiver (known as a PLGR or "plugger") can also deliver this level of precision; however these units are generally available only to the U.S. military and to some federal agency personnel. We have intentionally set a broad limit for this level because we expect that collaborators will be using a variety of methods to determine position, and even high-quality GPS equipment may perform relatively poorly under some field conditions common in the islands. This level of precision is generally adequate for re-locating points in the field and for "ground-truthing" the thematic accuracy of map polygons, but not for verifying the positional accuracy of control point coordinates on maps of 1:24,000-scale].
PRECISION 3: "SPECIFIC SITE" [STAR SYMBOL], i.e., a point location specified within a radius of 100 meters (328 feet, or 0.06 mile. [This level of precision can be obtained using an inexpensive GPS unit which does NOT differentially correct for signal degradation due to "selective availability"; e.g., a hand-held "hikers GPS" unit].
PRECISION 4: "SPECIFIC LOCALITY" [CIRCLE SYMBOL], i.e., a point location specified within a radius of 536 meters (1,758 feet, or 0.33 mile).
PRECISION 5: "MEDIUM-PRECISION LOCALITY" [TRIANGLE SYMBOL], i.e., a point location specified within a radius of approximately 2,414 meters (1.5 miles).
PRECISION 6: "GENERAL LOCALITY" [SQUARE SYMBOL], i.e., a point location specified within a radius of approximately 8,046 meters (5 miles).
PRECISION 7: "AHUPUA'A LOCALITY", i.e., a location specified only by reference to a specific ahupua'a (a traditional Hawaiian land division); maps depicting the boundaries of some ahupua'a are available from state agencies. This precision designation would normally be used where the longest dimension of the ahupua'a is greater than 8,046 meters (5 miles); otherwise, one of the "point-and-radius" categories given in (1 - 6) above may be more appropriate.
PRECISION 8: "LANDSCAPE LOCALITY", i.e., a location specified only by reference to a land area which is a part of a larger landmass or island, contains more than a single ahupua'a, and has clearly defined (and mapped) political or physiographic boundaries (e.g., the East Maui Mountains above a certain contour line, as shown on USGS 7.5 minute Quad Map No. such and such). This precision designation would normally be used when the area's longest dimension is greater than 8,046 meters (5 miles); otherwise, one of the "point-and-radius" categories given in (1 - 6) above may be more appropriate.
PRECISION 9: "PLACE NAME LOCALITY", i.e., a location specified only by reference to a place name which is NOT tied to any mapped boundaries; i.e., the area included is thus very fuzzy and indeterminate; however, historical data sets sometimes have only this level of precision.
PRECISION 10: "WHOLE-ISLAND LOCALITY", i.e., a location specified only by reference to the entire area within the mapped coastlines of a given island. This precision designation would normally be used where the longest dimension of the island is greater than 8,046 meters (5 miles); otherwise, one of the "point-and-radius" categories given in (1 - 6) above may be more appropriate.
This page last updated 29 January 1997 by PT.