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On the table, the alidade with telescopic sight is seen. A plane table consists of a smooth table surface mounted on a sturdy base. The connection between the table top and the base permits one to level the table precisely, using bubble levels, in a horizontal plane. The base, a tripod, is designed to support the table over a specific point on ...
Alidade tables have also long been used in fire towers for sighting the bearing to a forest fire. A topographic map of the local area, with a suitable scale , is oriented, centered and permanently mounted on a leveled circular table surrounded by an arc calibrated to true north of the map and graduated in degrees (and fractions) of arc.
A rock peak 0.5 nautical miles (0.93 km; 0.58 mi) north of Mount Thundergut on the ridge extending to Plane Table. The name applied by NZ-APC presumably alludes to excellent views available from the summit.
Table of Surveying, 1728 Cyclopaedia. Abel Foullon described a plane table in 1551, but it is thought that the instrument was in use earlier as his description is of a developed instrument. Gunter's chain was introduced in 1620 by English mathematician Edmund Gunter. It enabled plots of land to be accurately surveyed and plotted for legal and ...
Flight levels [3] are described by a number, which is the nominal altitude, or pressure altitude, in hundreds of feet, and a multiple of 500 ft.Therefore, a pressure altitude of 32,000 ft (9,800 m) is referred to as "flight level 320".
A surface plate is a solid, flat plate used as the main horizontal reference plane for precision inspection, marking out (layout), and tooling setup. [1] The surface plate is often used as the baseline for all measurements to a workpiece, therefore one primary surface is finished extremely flat with tolerances below 11.5 μm or 0.0115 mm per ...
The alidade was often mounted on a plane table, which allowed for direct plotting of survey data. The theodolite, which emerged in the sixteenth century, eventually surpassed the dioptra in accuracy and ease of use due to technological advancements and refinements in optical and mechanical components.
The gyrotheodolite comprises a normal theodolite with an attachment that contains a gyrocompass, a device which senses the rotation of the Earth in order to find true north and thus, in conjunction with the direction of gravity, the plane of the meridian. The meridian is the plane that contains both the axis of the Earth's rotation and the ...