Institut national de l'information géographique et forestièreThe Institut national de l’information géographique et forestière (National Institute of Geographic and Forest Information), previously Institut géographique national (National Geographic Institute) or IGN is a French public state administrative establishment founded in 1940 to produce and maintain geographical information for France and its overseas departments and territories. The IGN depends on the French Ministry of Equipment, Transport, Town and Country Planning, Tourism and Sea. Its missions are fixed by decrees.
Contour lineA contour line (also isoline, isopleth, isoquant or isarithm) of a function of two variables is a curve along which the function has a constant value, so that the curve joins points of equal value. It is a plane section of the three-dimensional graph of the function parallel to the -plane. More generally, a contour line for a function of two variables is a curve connecting points where the function has the same particular value. In cartography, a contour line (often just called a "contour") joins points of equal elevation (height) above a given level, such as mean sea level.
OrthophotoAn orthophoto, orthophotograph, orthoimage or orthoimagery is an aerial photograph or geometrically corrected ("orthorectified") such that the scale is uniform: the photo or image follows a given map projection. Unlike an uncorrected aerial photograph, an orthophoto can be used to measure true distances, because it is an accurate representation of the Earth's surface, having been adjusted for topographic relief, lens distortion, and camera tilt. Orthophotographs are commonly used in geographic information systems (GIS) as a "map accurate" background image.
Geologic mapA geologic map or geological map is a special-purpose map made to show various geological features. Rock units or geologic strata are shown by color or symbols. Bedding planes and structural features such as faults, folds, are shown with strike and dip or trend and plunge symbols which give three-dimensional orientations features. Stratigraphic contour lines may be used to illustrate the surface of a selected stratum illustrating the subsurface topographic trends of the strata.
CartographyCartography (kɑːrˈtɒgrəfi; from χάρτης chartēs, "papyrus, sheet of paper, map"; and γράφειν graphein, "write") is the study and practice of making and using maps. Combining science, aesthetics and technique, cartography builds on the premise that reality (or an imagined reality) can be modeled in ways that communicate spatial information effectively. The fundamental objectives of traditional cartography are to: Set the map's agenda and select traits of the object to be mapped. This is the concern of map editing.
TheodoliteA theodolite (θiˈɒdəˌlaɪt) is a precision optical instrument for measuring angles between designated visible points in the horizontal and vertical planes. The traditional use has been for land surveying, but it is also used extensively for building and infrastructure construction, and some specialized applications such as meteorology and rocket launching. It consists of a moveable telescope mounted so it can rotate around horizontal and vertical axes and provide angular readouts.
Aerial photographyAerial photography (or airborne imagery) is the taking of photographs from an aircraft or other airborne platforms. When taking motion pictures, it is also known as aerial videography. Platforms for aerial photography include fixed-wing aircraft, helicopters, unmanned aerial vehicles (UAVs or "drones"), balloons, blimps and dirigibles, rockets, pigeons, kites, or using action cameras while skydiving or wingsuiting. Handheld cameras may be manually operated by the photographer, while mounted cameras are usually remotely operated or triggered automatically.
National Library of WalesThe National Library of Wales (Llyfrgell Genedlaethol Cymru), Aberystwyth, is the national legal deposit library of Wales and is one of the Welsh Government sponsored bodies. It is the biggest library in Wales, holding over 6.5 million books and periodicals, and the largest collections of archives, portraits, maps and photographic images in Wales. The Library is also home to the national collection of Welsh manuscripts, the National Screen and Sound Archive of Wales, and the most comprehensive collection of paintings and topographical prints in Wales.
AngleseyThe Isle of Anglesey (ˈæŋɡəlsiː; Ynys Môn ˈənɨs ˈmoːn) is a county off the north-west coast of Wales. It is named after the island of Anglesey, which makes up 94% of its area, but also includes Holy Island (Ynys Gybi) and some islets and skerries. The county borders Gwynedd across the Menai Strait to the southeast, and is otherwise surrounded by the Irish Sea. Holyhead is the largest town, and the administrative centre is Llangefni. The county is part of the preserved county of Gwynedd.
