Editing 2888: US Survey Foot
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The use of helicopters — which cannot fly 8,000 miles unaided — also suggests an imaginative situation in which NIST teams with access to helicopters are distributed around the globe, perhaps at US air bases and on US aircraft carriers. | The use of helicopters — which cannot fly 8,000 miles unaided — also suggests an imaginative situation in which NIST teams with access to helicopters are distributed around the globe, perhaps at US air bases and on US aircraft carriers. | ||
− | ===Real world | + | ===Real world example=== |
In the early 2000s, Survey Foot/International Foot conversion issues created difficulties in the civil engineering industry after a commonly used CADD design software package changed how it processed units. Prior versions of the software program Microstation were unit-agnostic, relying only on absolute coordinates assigned to elements from survey data. Starting with Microstation Version 8, internal software calculations were performed entirely in metric units and relied on a units definition file to seamlessly convert to the unit system being used for a project. The default options in the program being “Foot” (i.e., International Foot) or “Survey Foot”, many users were unaware of the difference and selected “Foot” even when a project’s field survey was performed in survey feet. In the US, most states have their own coordinate systems, referred to as State Plane Coordinates, to correct for the approximation of projecting the Earth’s spherical surface into a cartesian X,Y plane. Some states have coordinate zones which span their entire length, so a project’s coordinates can be millions of feet from the origin, a scale on which the minuscule difference between Survey and International feet conversion becomes whole feet. | In the early 2000s, Survey Foot/International Foot conversion issues created difficulties in the civil engineering industry after a commonly used CADD design software package changed how it processed units. Prior versions of the software program Microstation were unit-agnostic, relying only on absolute coordinates assigned to elements from survey data. Starting with Microstation Version 8, internal software calculations were performed entirely in metric units and relied on a units definition file to seamlessly convert to the unit system being used for a project. The default options in the program being “Foot” (i.e., International Foot) or “Survey Foot”, many users were unaware of the difference and selected “Foot” even when a project’s field survey was performed in survey feet. In the US, most states have their own coordinate systems, referred to as State Plane Coordinates, to correct for the approximation of projecting the Earth’s spherical surface into a cartesian X,Y plane. Some states have coordinate zones which span their entire length, so a project’s coordinates can be millions of feet from the origin, a scale on which the minuscule difference between Survey and International feet conversion becomes whole feet. | ||
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==Transcript== | ==Transcript== |