map		Precision surveying instrument for measuring horizontal and vertical angles.
stadia		Establishing correct relationship in direction with reference to points of the compass; the state of being in correct relationship in direction with reference to the points of the compass.
relief		In astronomy, the angular distance of a celestial body above (north, plus) or below (south, minus) the celestial Equator. Magnetic declination is the angular difference between magnetic north and true (geographic) north at the point of observation; it is not constant but varies with time because of the "wandering" of the magnetic north pole.
trilateration		Technique of distance measurement wherein the observer reads the intercept subtended on a graduated rod between two marks on the reticle of the telescope.
landmark		Pertaining to the use of binocular vision for observation of a pair of overlapping photographs or other perspective views, giving impression of depth.
township		New material printed on a map or chart to show data of importance or special use, in addition to those data originally printed.
declination		Instrument for plotting a map by observation of stereomodels formed by pairs of photographs.
erosion		Science that deals with the measurement and description of the physical features of the oceans, seas, lakes, rivers, and their adjoining coastal areas, with particular reference to their use for navigation.
formlines		Precision surveying instrument; a theodolite in which the telescope can be reversed in direction by rotation about its horizontal axis.
latitude		Figure of the Earth visualized as a mean sea level surface extended continuously through the continents. It is a theoretically continuous surface that is perpendicular at every point to the direction of gravity (the plumbline).
scale		Science or art of obtaining reliable measurements or information from photographs or other sensing systems.
leveling		Line separating the body of a map from the map margin. On a standard quadrangle map, the ?????? are the meridians and parallels delimiting the quadrangle.
graticule		Artificial bank confining a stream channel or limiting adjacent areas subject to flooding; an embankment bordering a submarine canyon or channel, usually occurring along the outer edge of a curve.
meanderable		Unit of survey of the public lands of the United States, normally a quadrangle approximately 6 miles on a side with boundaries conforming to meridians and parallels within established limits, containing 36 sections. Also, in minor governmental subdivision.
dike		Science or art of determining terrain relief, by any method.
hypsometry		Vertical distance of a point above or below a reference surface or datum.
estuary		Instrument consisting essentially of a drawing board on a tripod and some type of sighting device (alidade) with attached straightedge, used for plotting the lines of survey directly from observation in the field.
hachure		Network of uniformly spaced parallel lines intersecting at right angles. When superimposed on a map, it usually carries the name of the projection used for the map- that is, Lambert grid, transverse Mercator grid, universal transverse Mercator grid.
traverse		Any portion of a map lying outside the nominal map border (neatline).
neatline		Group of natural processes including weathering, dissolution, abrasion, corrosion, and transportation that remove material from any part of the Earth's surface.
hydrology		Technical means, usually electronic, to extend man's natural senses by detecting emitted or reflected energy. The energy may be nuclear, electromagnetic (including the visible and invisible portions of the spectrum), chemical, biological, thermal, or mechanical
levee		Production of a map or chart manuscript from aerial photographs and geodetic control data by means of photogrammetric instruments.
stereocompilation		Monument of material mark or fixed object used to designate a land boundary on the ground: any prominent object on land that may be used to determine a location or a direction in navigation or surveying.
photogrammetry		Capable of being depicted by reference to a meander line.
geoid		That portion of a stream influenced by the tide of the body of water into which it flows; an arm of the sea at a river mouth.
datum		Method of extending horizontal position on the surface of the Earth by measuring the angles of triangles and the included sides of selected triangles.
transit		Great circle on the surface of the Earth passing through the geographical poles and any given point on the Earth's surface.
orthophotoscope		Line on a map or chart connecting points of equal depth below the datum.
planimetry		Plan details of a map - those having no indication of relief or contour.
section		Angular distance, in degrees, minutes, and seconds, of a point east or west of the Greenwich meridian.
triangulation		Elevations and depressions of the land or sea bottom.
shoreline		Intersection of the land with the water surface.
survey		Pertaining to the observation of a single photograph or other view.
planetable		Angular distance, in degrees, minutes, and seconds of a point north or south of the Equator.
meridian		Lines, resembling contour lines, drawn to present a conception of the shape of the terrain without regard to a true datum or regular spacing
longitude		Four-sided area, bounded by parallels of latitude and meridians of longitude used as an area unit in mapping (dimensions are not necessarily the same in both directions). Also, a geometric figure of significance in geodetic surveying.
quadrangle		Relationship existing between a distance on a map, chart, or photograph and the corresponding distance on the Earth.
hydrography		Comparatively flat zone of variable width that extends from the outer margin of the rather steeply sloping shoreface to the edge of the continental shelf.
topography		In surveying, a reference system for computing or correlating the results of surveys. There are tow principal types of datums: vertical and horizontal. A vertical datum is a level surface to which heights are referred. In the United States, the generally adopted vertical datum for leveling operations is the National Geodetic Vertical Datum of 1929. The horizontal datum is used as a reference for position. The North American Datum of 1927 is defined by the latitude and longitude of an initial point (Meade's Ranch in Kansas), the direction of a line between this point and a specified second point, and two dimensions that define the spheroid. The new North American Datum of 1983 is based on a newly defined spheroid (GRS80); it is an Earth-centered datum having no initial point or initial direction.
sensor		Sequence of lengths and directions of lines connecting a series of stations, obtained from field measurements, and used in determining positions of the stations.
upland		Highland; ground elevation above the lowlands along rivers or between hills.
overedge		Summation of all processes involved in printing copies from an original drawing. A printed copy of an original drawing made by the processes of reproduction
grid		Orderly process of determining data relating to any physical or chemical characteristics of the Earth. The associated data obtained in a survey. An organization engaged in making a survey.
orientation		Bank of earth or stone used to form a barrier, frequently and confusingly interchanged with levee.
overprint		Unit of subdivision of a township; normally a quadrangle 1 mile square with boundaries conforming to meridians and parallels within established limits, and containing 640 acres as nearly as practicable.
offshore		Photomechanical device used in conjunction with a double-projection stereoplotter for producing orthophotograph.
orthophotograph		Surveying operation in which heights of objects and points are determined relative to a specified datum.
hypsography		Configuration (relief) of the land surface; the graphic delineation or portrayal of that configuration in map form, as by contour lines; in oceanography the term is applied to a surface such as the sea bottom or surface of given characteristics within the water mass.
stereoscopic		Photograph having the properties of an orthographic projection. It is derived from a conventional perspective photograph by simple or differential rectification so that image displacements caused by camera tilt and terrain relief are removed.
plain		Topography referred to the national geodetic vertical datum of 1929. The science or art of describing heights of land surfaces with reference to this datum.
subsidence		Decrease in the elevation of land surface due to tectonic, seismic, or artificial forces, without removal of surface material.
reproduction		Graphic representation of the physical features (natural, artificial, or both) of a part or the whole of the Earth's surface, by means of signs and symbols or photographic imagery, at an established scale, on a specified projection, and with the means of orientation indicated.
elevation		Region of uniform general slope, comparatively level, of considerable extent, and not broken by marked elevations and depressions (it may be an extensive valley floor or a plateau summit); an extent of level or nearly level land; a flat, gently sloping, or nearly level region of the sea floor.
monoscopic		Scientific study of the waters of the Earth, especially with relation to the effects of precipitation and evaporation upon the occurrence and character of ground water.
depth curve		Network of parallels and meridians on a map or chart.
theodolite		Any series of lines used on a map to indicate the general direction and steepness of slopes. The lines are short, heavy, and close together for steep slopes; longer, lighter, and more widely spaced for gentle slopes.
monument		Permanent physical structure marking the location of a survey point. Common types of monuments are inscribed metal tablets set in concrete posts; and metal rods driven in the ground.
stereoplotter		Method of surveying wherein the lengths of the triangle sides are measured, usually by electronic methods, and the angles are computed from the measured lengths. Compare with triangulation.