Search results
Results From The WOW.Com Content Network
Traditional geodetic instruments such as theodolites rely on the gravity field for orienting their vertical axis along the local plumb line or local vertical direction with the aid of a spirit level. After that, vertical angles ( zenith angles or, alternatively, elevation angles) are obtained with respect to this local vertical, and horizontal ...
Instruments used in surveying include: Alidade; Alidade table; Cosmolabe; Dioptra; Dumpy level; Engineer's chain; Geodimeter; Graphometer; Groma (surveying) Laser scanning; Level; Level staff; Measuring tape; Plane table; Pole (surveying) Prism (surveying) (corner cube retroreflector) Prismatic compass (angle measurement) Ramsden surveying ...
A direct-readout theodolite, manufactured in the Soviet Union in 1958 and used for topographic surveying. A theodolite (/ θ i ˈ ɒ d ə ˌ l aɪ t /) [1] is a precision optical instrument for measuring angles between designated visible points in the horizontal and vertical planes.
Geodesy or geodetics [1] is the science of measuring and representing the geometry, gravity, and spatial orientation of the Earth in temporally varying 3D.It is called planetary geodesy when studying other astronomical bodies, such as planets or circumplanetary systems. [2]
A gyroscope is mounted in a sphere, lined with Mu-metal to reduce magnetic influence, connected by a spindle to the vertical axis of the theodolite. The battery-powered gyro wheel is rotated at 20,000 rpm or more, until it acts as a north-seeking gyroscope. [2]
Such instruments are capable of an accuracy of about 2 ppb or 0.002 mGal [1] and reference their measurement to atomic standards of length and time. Their primary use is for calibrating relative instruments, monitoring crustal deformation, and in geophysical studies requiring high accuracy and stability. However, absolute instruments are ...
A wooden tripod holding an optical level is set up firmly on the ground. Levelling or leveling (American English; see spelling differences) is a branch of surveying, the object of which is to establish or verify or measure the height of specified points relative to a datum.
Surveying instruments ... Pages in category "Geodesy" The following 166 pages are in this category, out of 166 total. ... Physical geodesy; Planetary coordinate system;