In case you aren’t on Twitter, Facebook, LinkedIn, Slack, YouTube, Instagram or Geonet (don’t laugh I hear there are users) I decided that I needed a new challenge and to get behind a winning team.
There are many areas of the geospatial world that interest me, I am a huge fan hydrography and positional accuracy, though there is one area which I feel is getting under-represented…..3D. As I have stated before, we see, live and interact within a 3D world, in fact this year is set to be the year of the VR (Virtual Reality Headset) with sales estimated to be over $1bn. Having seen some of their work and hearing some of their plans, there was only one choice – Garsdale Design Ltd.
Garsdale Design struck a chord with me, they were REALLY eager to point out that a visualisation wasn’t just a simple thing to look at any more. The conversations we always had were around the concept of 3D GIS, where the visualisation ends and the real analysis begins, more on this in another blog, but think to yourself….what defines GIS?
Although it is early days, one of my drivers for Garsdale Design is to not only put 3D GIS on the map (apologies for the pun) but to be able to provide it in both proprietary and open source formats, providing platforms for all users to build and develop, create tools and have a product which we all have wanted.
Let’s be honest, ArcScene came close, though was too quirky, QGIS2ThreeJs is good but misses options for modelling larger areas….I could go on, but the future is ESRI CityEngine, Cesium & QGIS, no I’m not mad and no, I haven’t sold out either. CityEngine is by far the best tool for 3DGIS at the moment but Cesium is gaining ground with an open platform which could be developed to serve measuring and analysis tools. Then we get to QGIS who are developing things which most GIS users could have only dreamed of 5yrs ago….and are now talking 3D, can you imagine the possibilities?
As with all things, a week into the job and there are many, many more plans which are super exciting which I am forced to keep silent about, I am really glad I made the move.
So, here we are, the dream team, I am the one with the Parka, note that the fells are covered in snow, I am not yet acclimatised and able to go sans jacket like these crazy northern UK people.
Parka or not, Garsdale Design now has a full suite of GIS services as well as 3D GIS services such as;
Geospatial Data Management & Processing Asset Management Cartographic Representation Web Mapping – Mapserver/Open Layers/PostGIS Constraints Mapping Site Selection through Multi-criteria Evaluation GIS Model Production/Training Spatial Analysis Least Cost Path Analysis Site Design & Layout Design Refinement/Micrositing Zone of Theoretical Visibility (ZTV) 3D Urban & Site Modelling Geospatial Data Standards and implimentation Metadata Standards and implimentation Geodatabase modelling Geoprocess modelling Ordnance Survey data structure and implimentation Data distribution and implimentation, providing map sharing solutions Interactive geospatial solutions Automatic Identification Systems (AIS)
Feel free to contact me if you need help or training on any of the above!
Be rest assured that my blogs will continue as they always have, though from time to time I may well discuss 3D GIS a little more, watch this space….
So far over 300 of you amazing geofolk have had a go at my fun Geotest…and I collated some interesting results, don’t worry, there will be no naming and shaming (though someone DID call themselves GEOGOD??!!), what is interesting though is the skill level(s) and knowledge of those taking the test. Read on…
All of the above
Measurement of the Earth
Representation of the Earth
Geodetics is the the study of what?
Who is the Father of GIS?
Allocating a data with a reference in physical space
Allocating a data within a sphere
Allocating a geographic barrier to the data
Gridding a dataset
What is “Georeferencing”
AutoCAD, QGIS, ArcGIS
AutoCAD, QGIS, ArcGIS, GRASS
QGIS, ArcGIS, GRASS
Name 3 GIS software (Pick 3 below)
What is the name for “data about data” which normally accompanies geospatial data?
Best practice when using text on maps is to use fonts with serifs
A line which gives indication of distance
A list of data & symbols for reference of the user
What is a “legend”
Does a maps scale change when the paper size is changed?
When dealing with datum, what is “z”?
Distance weighted analysis
Time based analysis
What is “temporal analysis”?
Statistics…we all love statistics
On average the test was taken twice, the first score being 7/10 and the second being 9/10
Over a FIFTH of people think Jack Dangermond is the Father of GIS
The most common name for people taking the test a second time was F*CK
Over 40% of people need to re-read their geodetic books
Over a quarter of people aren’t bothered about serifs
The average score over the current 300 users is 79.9%
I’ve really had fun answering your questions and seeing your scores. THERE WILL BE ANOTHER TEST!!
Definitions Provided By: Maps for America – Third Edition – Text obtained from World Atlas
Degree of conformity with a standard. Accuracy relates to the quality of a result and is distinguished from precision which relates to the quality of the operation by which the result is obtained.
Process designed to remove inconsistencies in measured or computed quantities by applying derived corrections to compensate for random or accidental errors.
adjustment, land- line
Positioning land lines on a map to indicate their true, theoretical, or approximate location relative to the adjacent terrain and culture, by reconciling the information shown on Bureau of Land Management plats and field records with the ground evidence of the location of the lines.
adjustment, standard accuracy
Adjustment of a survey resulting in values for positions and (or) elevations that comply with the National Map Accuracy Standards.
The process of developing a network of horizontal and or vertical positions from a group of known positions using direct or indirect measurements from aerial photographs and mathematical computations.
Instrument, or part of an instrument , for determining direction , either horizontal or vertical . In its simplest form, a peepsight or telescope mounted on a straightedge and used for plotting directions graphically. In such instruments as transits and theodolites, the alidade is the part containing the telescope and its attachments.
Instrument for measuring altitudes or elevations with respect to a reference level, usually mean sea level. The most common type is an aneroid barometer. A radar altimeter determines the height of an aircraft above the terrain by measuring the time required for an electromagnetic pulse to travel from aircraft to the ground and back.
Horizontal direction reckoned clockwise from the meridian plane.
Part of a beach that is usually dry and is reached only by the highest tides; by extension, a narrow strip of relatively flat coast bordering the sea.
See: map, base.
See: map, bathymetric
Science of measuring water depths (usually in the ocean) to determine bottom topography.
Zone of unconsolidated material that extends landward from the low water line to the place where there is marked change in material or physiographic form, or to the line of permanent vegetation (usually the effective lint of storm waves).
Relatively permanent material object, natural or artificial, bearing a marked point whose elevation above or below an adopted datum is known.
Material object placed on or near a boundary line to preserve and identify the location of the boundary line on the ground
Survey made to establish or to reestablish a boundary line on the ground, or to obtain data for constructing a map or plat showing a boundary line.
See: map, cadastral.
Survey relating to land boundaries, made to create units suitable for title transfer or to define the limitations of title. Derived from “cadastre” meaning a register of land quantities, values, and ownership used levying taxes, the term may properly be applied to surveys of a similar nature outside the public lands, such surveys are more commonly called “land surveys” or “property surveys.”
Science and art of making maps and charts. The term may be taken broadly as comprising all the steps needed to produce a map: planning, aerial photography, field surveys, photogrammetry, editing, color separation, and multicolor printing. Mapmakers, however, tend to limit use of the term to the map-finishing operations, in which the master manuscript is edited and color separation plates are prepared for lithographic printing.
Unit of length equal to 66 feet, used especially in the U.S. public land surveys. The original measuring instrument (Gunter’s chain) was literally a chain consisting of 100 iron links, each 7.92 inches long. Steel-ribbon tapes began to supersede chains around 1900, but surveying tapes are often still called “chains” and measuring with a tape is often called “chaining.” The chain is a convenient unit in cadastral surveys because 10 square chains equal 1 acre.
Special-purpose map designed for navigation or to present specific data or information. The term “chart” is applied chiefly to maps made primarily for nautical and aeronautical navigation, and to maps of the heavens, although the term is sometimes used to describe other special-purpose maps.
Charts designed to meet requirements of aerial navigating, produced in several series, each on a specified map projection and differing in scale, format, and content, for use as dictated by type of aircraft and whether flight is to be conducted under visual or instrument flight rules.
See: map, bathymetric
Representation of a portion of the navigable waters of the Earth and adjacent coastal areas on a specified map projection and designed specifically to meet requirements for marine navigation. Included on most nautical charts are depths of water, characteristics of the bottom, elevations of selected topographic features, general configurations and characteristics of the coast, the shoreline (usually the mean high water line), dangers, obstructions and aids to navigation limited tidal data, and information about magnetic variation in the charted area.
See: map, choropleth
See: map, slope
Process of preparing a separate drawing, engraving, or negative for each color required in the printing production of a map or chart.
Preparation of a new or revised map or chart, or portion thereof, from existing maps, aerial photographs, field surveys, and other sources.
Image not broken into dots by photographic screen; contains unbroken gradient tones from black to white, and may be either in negative or positive form. Aerial photographs are examples of continuous-tone prints. Contrasted with halftone (screened) and line copy.
Imaginary line on ground, all points of which are at the same elevation above or below a specific datum.
Difference in elevation between two adjacent contours.
Points of established position or elevation, or both, which are used to fix references in positioning and correlating map features. Fundamental control is provided by stations in the national networks of triangulation and traverse (horizontal control) and leveling (vertical control). Usually it is necessary to extend geodetic surveys, based on fundamental stations, over the area to be mapped, to provide a suitable density and distribution of control points. Supplemental control points are those needed to relate the aerial photographs used for mapping with the system of ground control. These points must be positively photoidentified; that is, the points must be positively correlated with their images on the photographs.
Point on the ground whose position (horizontal or vertical) is known and can be used as a base for additional survey work.
Linear and (or) angular quantities that designate the position of a point in relation to a given reference frame.
coordinates, origin of
Points in a system of coordinates which serves as a zero point in computing th
e system’s elements or in prescribing its use.
Features constructed by man that are under, on, or above the ground which are delineated on a map. These include roads, trails, buildings, canals, sewer systems, and boundary lines. In a broad sense, the term also applies to all names, other identification, and legends on a map.
datum (pl. datums)
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.
datum, national geodetic vertical See: national geodetic vertical datum of 1929
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.
Line on a map or chart connecting points of equal depth below the datum.
Rapid method for copying documents in which the image is developed by exposure to ammonia.
Bank of earth or stone used to form a barrier, frequently and confusingly interchanged with levee. A dike restrains water within an area that normally is flooded. See levee.
electronic distance measuring (EDM) device:
Instruments that measure the phase difference between transmitted and reflected or retransmitted electromagnetic waves of known frequency, or that measure the round-trip transit time of a pulsed signal, from which distance is computed.
Vertical distance of a point above or below a reference surface or datum.
See: map, engineering
Double-projection plotting instrument utilizing ellipsoidal reflectors for light projection.
Group of natural processes including weathering, dissolution, abrasion, corrosion, and transportation that remove material from any part of the Earth’s surface.
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.
Process of preparing a separate drawing, engraving, or negative for selected types of data in the preparation of a map or chart.
flood control map
See: map, flood control
Belt of low flat ground bordering a stream channel that is flooded when runoff exceeds the capacity of the stream channel.
See: map, forestry
Lines, resembling contour lines, drawn to present a conception of the shape of the terrain without regard to a true datum or regular spacing
Science concerned with the measurement and mathematical description of the size and shape of the earth and its gravitational fields. Geodesy also includes the large-scale, extended surveys for determining positions and elevations of points, in which the size and shape of the earth must be taken into account.
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).
See: map, geologic
Network of parallels and meridians on a map or chart.
System of coordinates of latitude and longitude used to define the position of a point on the surface of the Earth with respect to the reference spheroid.
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.
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.
A picture in which the gradations of light are obtained by the relative darkness and density of tiny dots produced by photographing the subject through a fine screen.
Maximum height reached by a rising tide. The height may be due solely to the periodic tidal forces or it may have superimposed upon it the effects of prevailing meteorological conditions. Use of the “high tide” is discouraged.
high water line
Intersection of the land with the water surface at an elevation of high water.
high water mark
Line or mark left upon tidal flats, beach, or along shore objects indicating the elevation or the intrusion of high water.
Survey of water area, with particular reference to submarine relief, and any adjacent land. See: oceanographic survey
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.
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.
See: map, hypsographic
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.
See: map, hypsometric
Science or art of determining terrain relief, by any method.
Visible representation of objects and (or) phenomena as sensed or detected by cameras, infrared and multispectral scanners, radar, and photometers. Recording may be on photographic emulsion (directly as in a camera or indirectly after being first recorded on magnetic tape as an electrical signal) or on magnetic tape for subsequent conversion and display on a cathode ray tube.
infrared scanner (thermal mapper)
Instrument that detects infrared radiation and converts the detected energy to an electrical signal for recording on photographic film or magnetic tape.
Chart showing isogonic lines properly labeled with their magnetic declination.
Line joining points on the Earth’s surface having equal magnetic declination as of a given date.
See: map, isopleth
Double-projection plotting instrument utilizing swinging lamps to transmit light through contact- size diapositives (positive transparencies).
land use classification system
Coding system of categories and subcategories designed for use
on a map to designate land or water use.
land use map
See: map, land use
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.
Angular distance, in degrees, minutes, and seconds of a point north or south of the Equator.
Line weighted with lead for making depth soundings in water.
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.
Surface which at every point is perpendicular to the plumbline or the direction in which gravity acts.
Surveying operation in which heights of objects and points are determined relative to a specified datum.
line copy (line drawing) Map copy suitable for reproduction without the use of a screen; a drawing composed of lines as distinguished from continuous- tone copy.
See: map, line
Angular distance, in degrees, minutes, and seconds, of a point east or west of the Greenwich meridian.
Minimum height reached by a falling tide. The height may be due solely to the periodic tidal forces or it may have superimposed upon it the effects of meteorological conditions.
low water line
Intersection of the land with the water surface at an elevation of low water. Not to be confused with mean low water line.
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.
Map on which information may be placed for purposes of comparison or geographical correlation. The term “base map” was at one time applied to a class of maps now known as outline maps. It may be applied to topographic maps, also termed “mother maps” that are used in the construction of other types of maps by the addition of particular data.
Maps delineating the form of the bottom of a body of water, or a portion thereof, by the use of depth contours (isobaths).
Map showing the boundaries of subdivisions of land, often with the bearings and lengths thereof and the areas of individual tracts, for purposes of describing and recording ownership. It may also show culture, drainage, and other features relating to land use and value. See:plat
Thematic map in which areas are colored, shaded, dotted, or hatched to create darker or lighter areas in proportion to the density of distribution of the theme subject.
Conversion of map data from graphic to digital form.
Map showing information that is essential for planning an engineering project or development and for estimating its cost. It usually is a large-scale map of a small area or of a route. It may be entirely the product of an engineering survey, or reliable information may be collected from various sources for the purpose, and assembled on a base map.
map, flood control
Map designed for studying and planning control projects in areas subject to flooding.
Map prepared principally to show the size, density, kind, and value of trees in a designated area.
Map showing the structure and composition of geologic features.
Map showing relief by any convention, such as contours, hachures, shading, or tinting.
Map consisting of lines connecting places of equal value of distribution for a given theme such as rainfall or temperature.
map, land use
Map showing by means of a coding system the various purposes for which parcels of land are being used by man.
Map composed of lines as distinguished from photographic imagery.
See: orthophotographic map
Map that presents only the horizontal positions for features represented. distinguished from a topographic map by the omission of relief in measurable form. The features usually shown on a planimetric map include rivers, lakes, and seas; mountains, valleys, and plains; forests, and prairies; cities, farms transportation routes, and public utility facilities; and political and private boundary lines. A planimetric map intended for special use may present only those features essential to the purpose to be served.
Orderly system of lines on a plane representing a corresponding system of imaginary lines on an adopted terrestrial or celestial datum surface. Also, the mathematical concept for such a system. For maps of the Earth, a projection consists of 1) a graticule of lines representing parallels of latitude and meridians of longitude or 2) a grid.
Family of maps conforming generally to the same specifications and designed to cover an area or a country in systematic pattern.
map, slope (clinometric map)
Map showing the degree of steepness of the Earth’s surface by the use of various colors or shading for critical ranges of slope.
Map that shows the constitution, structure, and texture of the soil and identifies ongoing erosion.
map, storm evacuation
Map designed to identify coastal areas subject to flooding, to indicate recommended areas of refuge, and to emphasize available evacuation routes.
Map designed to provide information on a single topic, such as geology, rainfall, population.
Map that present the horizontal and vertical positions of the features represented; distinguished from a planimetric map by the addition of relief in measurable form.
Area of salt-tolerant vegetation in brackish and (or) saline-water habitants subject to tidal inundation.
Tract of low wet ground, usually miry and covered with rank vegetation.
mean high water
Tidal datum that is the arithmetic mean of the high water heights observed over a specific 19-year Metonic cycle (National Tidal Datum Epoch). For stations with shorter series, simultaneous observations are made with a primary control tide station to derive the equivalent of a 19-year value. Use of “mean high tide” is discouraged.
mean high water line
Intersection of the land with the water surface at the elevation of high water. See: shoreline
mean low water
Tidal datum that is the arithmetic mean of the low water heights observed over a specific 19-year Metonic cycle (National Tidal Datum Epoch). For stations with shorter series, simultaneous observations are made with a primary control tide sta
tion to derive the equivalent of a 19-year value. Use of “mean low tide” is discouraged.
mean low water line
Intersection of the land with the water surface at the elevation of low water.
mean sea level
Tidal datum that is the arithmetic mean of the hourly water elevations observed over a specific 19-yearMetonic cycle (National Tidal Datum Epoch). Shorter series are specified in the name; that is, monthly mean sea level and yearly mean sea level. See: datum
Metes-and-bounds traverse approximately along the mean high water line of a permanent body of water. By following the sinuosities of the bank or shoreline, the meander line provides data for computing the area of land remaining after the water area has been segregated. A meander line differs from other metes and bounds surveys in that it does not ordinarily determine or fix boundaries.
Capable of being depicted by reference to a meander line.
Great circle on the surface of the Earth passing through the geographical poles and any given point on the Earth’s surface. All points on a given meridian have the same longitude.
metes and bounds
Method of describing land by measure of length (metes) of the boundary lines (bounds).
Period of 235 lunations or about 19 years. devised by Meton, an Athenian astronomer (5th century B.C.) for the purpose of obtaining a period at the end of which the phases of the moon recur in the same order and on the same days as in the preceding cycle.
Decimal system of weights and measures based on the meter as a unit length and the kilogram as a unit mass.
Pertaining to the observation of a single photograph or other view.
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.
Assembly of aerial photographs whose edges usually have been torn or cut selectively and matched to the imagery on adjoining photographs to form a continuous representation of a portion of the Earth’s surface.
Stereoplotter of the double-projection type characterized by its use of reduced- scale diapositives and stationary lamphouses with condensing lenses.
multispectral scanner (MSS)
Device for sensing radian energy in several channels of the electromagnetic spectrum.
national geodetic vertical datum of 1929
Reference surface established by the U.S. Coast and Geodetic Survey in 1929 as the datum to which relief features and elevation data are referenced in the conterminous United States; formerly called “mean sea level 1929.”
National Map Accuracy Standards
Specifications promulgated by the U.S. Office of Management and Budget to govern accuracy of topographic and other maps produced by Federal Agencies.
Water usable, with or without improvements, as routes for commerce in the customary means of travel on water.
Line separating the body of a map from the map margin. On a standard quadrangle map, the neatlines are the meridians and parallels delimiting the quadrangle.
Survey or examination of condition in the ocean or any part of it, with reference to animal or plant life, chemical elements present, temperature gradients, etc. See: hydrographic survey
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.
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.
origin of coordinates
Point in a system of coordinates that serves as a zero point in computing the system’s elements or in prescribing its use.
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.
Map produced by assembling orthophotographs at a specified uniform scale in a map format.
Orthophotographic map with contours and cartographic treatment, presented in a standard format, and related to standard reference systems.
Monocolor orthophotgraphic map presented in a standard quadrangle format and related to standard reference systems. It has no contours and little or cartographic treatment.
Photomechanical device used in conjunction with a double-projection stereoplotter for producing orthophotograph.
Any portion of a map lying outside the nominal map border (neatline).
Printing or drawing on a transparent or translucent medium intended to be placed in register on a map or other graphic and which shows details not appearing or requiring special emphasis on the base material.
New material printed on a map or chart to show data of importance or special use, in addition to those data originally printed.
parallel of latitude
A circle, or approximation of a circle, on the surface of the Earth, parallel tot he Equator, and connecting points of equal latitude; a circle of the celestial sphere parallel to the ecliptic, and connecting points of equal celestial latitude.
Science or art of obtaining reliable measurements or information from photographs or other sensing systems.
photomap (photographic map)
Map made by adding marginal information, descriptive data, and a reference system to a photograph or assembly of photographs.
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.
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.
See: map, planimetric
Plan details of a map – those having no indication of relief or contour.
Diagram drawn to scale showing all essential data pertaining to the boundaries and subdivisions of a tract of land, as determined by survey or protraction. As used by the Bureau of Land Management, the drawing which represents the particular area included in a survey, such as township, private land claim, or mineral claim, and the lines surveyed, established, or retraced, showing the direction and length of each such line; The relation to the adjoining official surveys; the boundaries, descriptions, and area of each parcel of land subdivided; and, as nearly as may be practicable, a representation of the relief and improvements within the limits of the survey.
Meridian of longitude 0 degrees, used as the origin for measurements of longitude. The meridian of Greenwich, England, is the internationally accepted prime meridian on most charts. However, local or nation
al prime meridians are occasionally used.
See: map, projection
public land system
Public lands are subdivided by a rectangular system of surveys established and regulated by the Bureau of Land Management. The standard format for subdivision is by townshipsmeasuring 6 miles (480 chains) on a side. Townships are further subdivided into 36 numbered sections of 1 square mile (640 acres) each.
Middle exposure of a phototriplet (three consecutive aerial photographs) take so that the middle photograph is exposed directly above the center of the quadrangle and the preceding and following photographs are exposed directly above the boundaries of the quadrangle. The flying height is set such that the quad-centered photograph covers the entire quadrangle.
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.
Determination of the location of points by the successive intersection and resection of direction lines radiating from the radial centers of overlapping aerial photographs.
The process of scanning and reprojecting a photograph onto a horizontal plane in differential elements to remove displacements caused by tilt and relief. The process may be accomplished by any one of a number of instruments developed specifically for the purpose.
Projection of an aerial photograph (mathematically, graphically, or photographically) from its plane onto a horizontal plane by translation, rotation, and (or) scale change to remove displacement due to tilt of the camera.
Elevations and depressions of the land or sea bottom.
Technique for making hypsography on a map appear three dimensional by the use of graded shadow effects. Generally, the features are shaded as though illuminated from the northwest.
Process of detecting and (or) monitoring chemical or physical properties of an area by measuring its reflected and emitted radiation.
Scale of a map or chart expressed as a fraction or ratio that relates unit distance on the map to distance measured in the same unit on the ground.
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
Relationship existing between a distance on a map, chart, or photograph and the corresponding distance on the Earth.
sea level (water level)
Height of the surface of the sea at any given time.
Unit of subdivision of a township; normally a quadrangle 1 mile square with boundaries conforming tomeridians and parallels within established limits, and containing 640 acres as nearly as practicable.
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
Intersection of the land with the water surface.
See: map, slope
See: map, soil
Mathematical figure closely approaching the geoid in form and size and used as a surface of reference for geodetic surveys. A reference spheroid or ellipsoid is a spheroid determined by revolving an ellipse about its shorter (polar) axis and used as a base for geodetic surveys of a large section of the Earth (such as the Clarke spheroid of 1866 which is used for geodetic surveys in the United States).
Point on a map or chart whose height above a specified datum is noted, usually by a dot or a small sawbuck and elevation value. Elevations are shown, on a selective basis, for road forks and intersections, grade crossings summit of hills, mountain
Technique of distance measurement wherein the observer reads the intercept subtended on a graduated rod between two marks on the reticle of the telescope.
See: adjustment, standard-accuracy
state plane coordinate system
Coordinate systems established by the U.S. Coast and Geodetic Survey (now the National Ocean Survey), usually one for each state, for use in defining positions of points in terms of plane rectangular (x,y) coordinates.
Production of a map or chart manuscript from aerial photographs and geodetic control data by means of photogrammetric instruments.
Instrument for plotting a map by observation of stereomodels formed by pairs of photographs.
Pertaining to the use of binocular vision for observation of a pair of overlapping photographs or other perspective views, giving impression of depth.
storm evacuation map
See: map, storm evacuation
Decrease in the elevation of land surface due to tectonic, seismic, or artificial forces, without removal of surface material.
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.
Surveying instrument designed for use in the rapid determination of distance, direction, and difference of elevation from a single observation, using a short base which may be an intergraph part of the instrument.
See: map, thematic
Precision surveying instrument for measuring horizontal and vertical angles.
Periodic rise and fall of the water resulting from gravitational interactions between the Sun, Moon, and Earth. The vertical component of the particulate motion of a tidal wave. Although the accompanying horizontal movement of the water is part of the same phenomenon, it is preferable to designate this motion as tidal current.
See: map, topographic
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.
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.
Precision surveying instrument; a theodolite in which the telescope can be reversed in direction by rotation about its horizontal axis.
Sequence of lengths and directions of lines connecting a series of stations, obtained from field measurements, and used in determining positions of the stations.
Method of extending horizontal position on the surface of the Earth by measuring the angles of triangles and the included sides of selected triangles.
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.
Universal Transverse Mercator (UTM) grid
Military grid system based on the transverse Mercator projection, applied to maps of the Earth’s surface extending from the Equator to 84 Degrees north and 80 degrees south latitudes
Highland; ground elevation above the lowlands along rivers or between hills.
Instrument for observing starts near the zenith (a point on the celestial sphere directly above the observer’s position). ground below the water table where all the pores in rock, sediment, and soil are filled with water
I swore I would never do this, giving opinions on an ever changing industry which is in its’ infancy still is a job for the companies wanting to make money out of the word. Yet here I sit, about to put a few thoughts out to you, peers, colleagues and those ready to cut me down and wear my skin (you know who you are :P).
Who said that?
Previously I have discussed what it is I do within my chosen career and the constant question of “what is GIS” and it would appear that even within the industry that there is still no agreement as to what it really is. Some saying it is computer software and others simply stating that it is a system for analysing geographic data. Here are just a few of the more prominent statements on “What is GIS?”
In the strictest sense, a GIS is a computer system capable of assembling, storing, manipulating, and displaying geographically referenced information, i.e. data identified according to their locations. Practitioners also regard the total GIS as including operating personnel and the data that go into the system.” USGS http://www.usgs.gov/
“A geographic information system (GIS) is a computer-based tool for mapping and analyzing things that exist and events that happen on earth. GIS technology integrates common database operations such as query and statistical analysis with the unique visualization and geographic analysis benefits offered by maps.” ESRI http://www.gis.com/whatisgis/index.cfm
“GIS is an integrated system of computer hardware, software, and trained personnel linking topographic, demographic, utility, facility, image and other resource data that is geographically referenced.” NASA http://gis-www.larc.nasa.gov/public/
“A Geographic Information System (GIS) can save, search, retrieve and analyze geographic data. GIS is currently being used academically and in many professional fields including environmental science and transportation. Everyday GIS use can be seen in the hand-held Global Positioning Systems (GPS) carried by hikers and fishermen and in navigation systems that many cars have today.” Dr Wansoo http://mappler.net/ilovegis/about/
“Put simply, a GIS is a geographical information system, and to make that system work, you need maps and some software. We are one of many organisations producing map data for use in GIS. There are many more companies who then produce GIS software. A GIS can be a simple desktop software package costing a few hundred pounds, running on a standalone PC or it could be a large network of workstations and servers with many different software components costing millions of pounds. Through using a GIS, a simple map can become a very sophisticated information source. A GIS can take in all of the information on a map about features, their uses, names and more and record it in electronic form” Ordnance Survey http://www.ordnancesurvey.co.uk/blog/2013/12/what-is-gis/
If us professionals are confused, then imagine how the learners feel!
So it is a software, a hardware, a method for presenting types of geographical data, a utility, a GPS….no wonder no one understands what we do! In fact, the more I speak with the professionals around me, the more confused I get about what GIS actually is.
A good question I get asked is, “What did people do before GIS?” and my answer is always “Exactly what they do know, only with computers”. That is not to say that GIS is solely computer based, it is more that the term was coined to make using a computer more inviting…..just look at “Word processing” (instead of writing) or “emailing” (instead of posting) or my personal favourite “CAD” (instead of technical drawing), all jargon designed to get people used to the new digital format.
The actual word GIS first appears around 1960 when the federal Department of Forestry and Rural Development. Developed by Dr. Roger Tomlinson, created a new computerised mapping system called the “Canada Geographic Information System” (CGIS) and was used to store, analyze, and manipulate data collected for the Canada Land Inventory – an effort to determine the land capability for rural Canada by mapping information about soils, agriculture, recreation, wildlife, waterfowl, forestry and land use at a scale of 1:50,000. A rating classification factor was also added to permit analysis. As a result of this, Tomlinson has become known as the “father of GIS”, particularly for his use of overlays in promoting the spatial analysis of convergent geographic data
Before 1960 there were computerised mapping software but it is the CGIS which is THE first recorded reference of the term, first written about 1967 in “An introduction to the geo-information system of Canada Land Inventory”
Now it is interesting to note that although the CGIS was a computer based system, the “Geographic Information System” referred to in the image above was a COMPUTER BASED geographic information system, contrary to the belief that a GIS is solely computer based.
What is interesting to know here, is that the work had been done for many years beforehand manually, a manual system was already in place, though it was so expensive to do, the computer based system HAD to be built. Here is a video from the ESRI website which shows Tomlinson in 1967 selling the need for the system: http://bit.ly/c9CmI5
So lets consider the facts and come to the wrong decision…
I propose this: A Geographical Information System is a system designed to (but not limited to) capture, store, manipulate, analyze, manage, and/or present all types of geographical data based on a geodetic system
Note the “based on a geodetic system”…I strongly believe that we are missing the essential criterium in our definition of a GIS, tools like QGIS, ArcGIS, GRASS, Google Earth all have a geodetic system at its base, you can still do the analysis/mapping/survey manually using the geodetics but without the geodetics it be merely mapping analysis….I’ll give you a minute to chew that one over but I have thought about this for a while and have sat back watching the industry move and the one thing getting missed in everything is the “Balls”
Let’s think about it:
Overlaying an 2 acetates with layers of the same geographic area NOT GIS
Overlaying 2 layers based on a datum (manually or computational)- GIS
Measuring a distance on a web map NOT GIS
Measuring a distance based on a geodetic system GIS
I could go on, though I assume you get the idea, in every example I can see for GIS, it is essential that geodesy is involved…..
So, after a lot of talk with @WildlifeGISgirl, @UUDreams, @Brian_Bancroft & the plethora of super geoninja on the #GISTribe forum (is it a forum, a meet, a symposium or even a tweeting?)…..I think I have the happenings of an outline for a challenge but feel free to comment and advise on how this can be made better. Here is my brain dump on how I think this could work;
The rules of running the challenge:
1. The challenge is monthly
2. The challenge is hosted by someone different
3. The challenge must be able to be done cross platform so that anyone (and I include my 7yr old daughter in this) can do it
4. The subject matter should be something that betters or helps the community (GIS or humanity)
5. All data/resources should be open source and in the public domain for ease of use (and legal!)
Does this sound fair? I am guessing that if we stick to these basic rules that we can add/remove more later if the game expands…One thing that I, personally, am keen on is introducing people to new data and new ways of working with it…so introducing people to the great open data from across the globe to solve interesting problems.
So here it is:
I was originally going to do a challenge based on cumulative impacts of offshore infrastructure and shipping within the United States and how it would affect other countries, though I thought that it would be a little mean for a first challenge. Luckily or rather I SHOULD say unfortunately, something else has dominated the news, Ebola….so this will be the challenge for this month.
Ebola is currently the word on everyones lips, in September, the World Health Organisation released information that the first human to human transmission of the disease had occured outside of Africa (Article here).
Objective: Using the resources provided, create a map which can be used to inform the public of the Ebola situation
The product can be of your choosing, you could provide a historic map of Ebola cases, you could provide a map of the increase in cases, you could even create a timeline map or a 3D flythrough of Africa with people waving and saying hello (as long as it relates to Ebola)….or, of course, you could produce something of your own which would help disseminate information about Ebola (using geo as a base)
All entries should be submitted on the #GISTribe site (or for PDF & other formats to email@example.com) by SUNDAY 9th NOVEMBER 2014.
This will give the judges time to review all entries prior to the result on #GISTribe the following Wednesday during the weekly hangout/meet/tweeting etc,,,
Of course, to do this challenge you will require the necessary Ebola data, this can be found below;
I’m back! Yes, I know, I said that a month ago but baby number 4 arrived as well as building a new intranet map system for the company I work for AND writing articles for a magazine set to take over the world – xyHt.
Building your own web mapping system has become a right of passage in the GIS world, it’s easy to buy something off the shelf like ESRI’s ArcServer but how does it really work and there is still a lot of learning to be done with cost being related to “number of cores”, “spatial database format” & my personal favourite, “server OS” (I mean, a server is a server right?!).
I went down the ESRI route and it is a phenomenal system, when it works, it is unstoppable and you have full support to answer all those crazy questions but at a huge cost, when I moved jobs to a smaller company and they wanted an internal mapping system & told them about ArcServer they laughed……in hindsight I can see why now, £100,000 for a web map system for 40 employees is a bit OTT.
As a sort of cleansing of the soul, I thought it might be useful for those of you entering into the world of building web maps to share my love/hate of web maps so far……
Mapserver or Geoserver….that is the question
Okay, lets clear this up right from the start, if you are building a web map system, you are going to be looking at open source. Sure, there are other methods like Mapbox, CartoDB, QGIS Cloud, LizMaps and others but they mostly promise a free system for web mapping but then give you (a rather meager) 50mb of space or don’t include the tools you need, this is better for the smaller business but at the end of the day you will feel cheated….for full control you really need to build it yourself from scratch.
When I first started out with this web mapping 6yrs ago, there were 2 options if you wanted to create a web map, Geoserver or Mapserver. Both work with Windows & Linux, both are well developed and both are open source, completely free and extremely develop-able with some great tools included out of the box, the problem I had was choosing one….
On paper, Geoserver and Mapserver are pretty identical, both publish geospatial data from almost any format and have huge communities who can provide help and advice. If you get really stuck, there is also commercial support for both systems. The primary difference is the choice of programming language, although both systems use a combination of languages for certain tools, Geoserver is Java based whereas Mapserver is C at its core with a lot of PHP.
Okay, so let’s roll back, already we are talking programming languages! To get on the web you need a way of getting the data into a format that can be read by the internet, to do this you need a server, for maps you need a geo/map server, something that takes the shapefiles or dxf files and gets it onto a html page which can be put on a webpage somewhere.
As you can see from the above diagram, the web server is the “converter” to get the data onto the internet, the data is “served” from the computer/server onto the internet. The format the data is most commonly used is Web Map Service (WMS) format.
Out of the box with both Mapserver and Geoserver you will get a server (Jetty/Tomcat/other), tools for conversion of data built in (GDAL, fTools), a LOT of projection systems (Proj4), OpenLayers (a web interface tool) and a demo map. Both systems initially install to your “LocalHost” which is a local network for your computer (it can’t be seen by anyone but you, though you will have a http address like http://localhost), to get the web server to be seen by the outside world you will need to adjust the settings in the systems server config to read the same as your outward going port connection (This may be worth checking out)
Mapserver or Geoserver….that is STILL the question….
So, going back to the Geoserver v Mapserver question, my first choice as a complete noob was Mapserver. Why? Because it sold me on its integration with QGIS, see my previous posts on how awesome QGIS is, essentially you can build your map in QGIS and then hit the “export to Mapserver” button and you have a webmap….if only….. Don’t get me wrong it is 100% better than building the map yourself but to a noob I assumed I could just use shapefiles and rasters and shunt it all to the internet with a shiny big button.
Once the Mapserver is installed and QGIS is up and running I stupidly expected to have a fully web mapping experience which would take over the world……not quite, QGIS provides you with a .map file which you then tweak and then you need to build a html page and the map tools (openlayers) around it. I may have spent my youth programming my Sinclair ZX80 & ZX81 but this was a huge step to start understanding how CSS & HTML worked and the OpenLayers (I’ll refer to it as OL from here) worked.
Tip 1: Firebug is your friend – you’ve probably seen a little picture of a bug in the top right of your screen when using Mozilla Firefox, this is a great tool for exploring the code which makes up webpages. Turn it on and waft your mouse around the page & you can see how bits of scripts work (or don’t work).
I am not afraid to say that my first map resembled something worse than a bad ZX Spectrum game, the tools didn’t work properly due to bad links, some of the layers didn’t draw up right and worse of all I felt completely out of my depth….I would post questions on the forums and it would appear that the questions I had were SO BASIC that they were mostly ignored…..
After 1 month of developing what I thought would be a new Google Earth, I put it on hold to think things over.
Don’t give up, it’s not as bad as you think
After a couple of months of chewing it over and feeling like a failure, I got back on the horse & read a couple of tutorials on the QGIS website written by the rather amazing Anita Graser. I’m not ashamed to say that I have a bit of a fan-crush on Anita, I contacted her on Twitter a few times when trying this system and she was so patient and really helped to make it easy to get going. Needless to say, after another couple of weeks of trial and error, I had a web map up and running.
Tip 2: Don’t be afraid to ask! Sites like GIS StackExchange are supported by some of the top people in the industry with some great advice. Even the dumbest questions get answered, we’ve all been there!!
Tip 3: Download and install PostGres & PostGIS – PostGIS is a spatial database system, much like the ESRI geodatabase, which is SQL based & is a more efficient and flexible way of storing spatial data. It is the most common way of storing data for web mapping & you will find it easier to work with this format in most systems.
A change is as good as a rest
Although I was having success with Mapserver, you always get that niggling thought that the grass is always greener on the other side, so decided to try Geoserver.
Much like Mapserver, Geoserver works straight out of the box on the localhost and has a nice interface for importing and managing the data.
To be honest, although the Mapserver had an easy system for making a map in QGIS, this interface made it easy to understand what was going on. I could load up layers, apply styles (in SLD format) and then use the layer preview to see what they would look like. The only downside? There is no map system integrated into it, so it can server WMS, WFS & others but you need to have a little HTML know-how to build it all into a map.
Tip 4: In Geoserver, layer groups are your friend, with these you can either create a basemap by grouping several layers together OR you can server a simple static map by using the wms direct in your browser
Tip 5: Static and Slippy…..There are 2 different types of web map, a static map which is nothing more than a picture or an interactive map which is known in the industry as a “slippy” map.
The great thing with Geoserver is that if you DON’T want to build a web map and just want to supply layers via wms to people, it is near perfect! The wms feed can be used within most GIS systems like QGIS, ArcGIS, uDIG, CadCorp and GRASS, to name a few. Again, the time and effort with this system is mostly spent designing the web map interface, calculating where tools need to sit, getting the legend to expand properly or getting the frame size just right with the company logo in the right place.
The one thing I have learned from all this? Don’t be afraid to dive in, everything I learned from playing and trying to build in Mapserver, although in a different language, was similar in structure within Geoserver. The components and way the core works is essentially the same, it’s just deciding what you prefer in a system.
Once you have started to build one of these systems you begin to respect and appreciate the complexities of software like ArcGIS & QGIS but at the same time you start to understand how it all fits together. Although a stressful and humbling experience, it is one I recommend to any GIS noob.
Why go through all the pain?
Okay, so here is where I unveil the ninja-tricks, why go through all the pain of the above? What if there was a system which had the awesome interface of Geoserver but also integrated with QGIS, automatically installed PostGIS AND provided a map interface with a plethora of useful tools….all open source with the safety net of support (at a fantastically cheap cost) if you need it?
It’s true, I kicked myself 2yrs ago when I found OPENGEO SUITE by Boundless, although it has its quirks, it takes all the pain out of everything. Sure, there is some configuration to do, some of the tools like the print and CSS styling don’t work out the box but that is what people like me are here for (contact me for installs of OpenGeo or help adding tools).
First off, this isn’t a sales pitch, although I install OpenGeo Suite systems, I do it because since I found it, I want the world to use it….you could spend hundreds of thousands of pounds on a web mapping system which has a GIS front end and a web map output. OpenGeo Suite really is as simple as creating your map in QGIS (or ArcGIS then using GeoCat bridge) and then exporting it to Geoserver, you then use their GeoExplorer to show the layers.
The point is?
Building your own web map system as a noob is scary and complex, lots of new terminology & methods. The developer & programmer types will bombard you with questions about your tile caching or getfeatureinfo whereas the average user will be asking whether they can upload their new NetCDF file.
Your experience will probably not be as bad as mine, things have developed FAST! Mapserver is now part of QGIS and there is a “QGIS Server” which is Mapserver based & Geoserver is now in version 2.5 – There are now so many users on Twitter & StackExchange that getting help is very easy.
My advice? Build a solution from scratch as a hobby, spend a little time every evening having a read and a play with either Geoserver or Mapserver….try and put your own map on a localhost system. When you can do that, install OpenGeo Suite and dazzle your employer!