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Maps have traditionally been made using pen and paper, but the advent and spread of computers has revolutionized cartography. Cartography or mapmaking (in Greek chartis = map and graphein = write) is the study and practice of making maps or globes. Most commercial quality maps are now made with map making software that falls into one of three main types; CAD, GIS, and specialized map illustration software.

Maps function as visualization tools for spatial data. Spatial data is acquired from measurement and can be stored in a database, from which it can be extracted for a variety of purposes. Current trends in this field are moving away from analog methods of mapmaking and toward the creation of increasingly dynamic, interactive maps that can be manipulated digitally. The cartographic process rests on the premise that there is an objective reality and that we can make reliable representations of that reality by adding levels of abstraction.

Geomatics is the discipline of gathering, storing, processing, and delivering of geographic information.

The term geomatics is fairly young, apparently being coined by B. Dubuisson in 1969. It is commonly defined to include the tools & techniques used in land surveying, remote sensing , Geographic Information Systems (GIS), Global Positioning System (GPS), and related forms of earth mapping. The term geomatics has been adopted by the International Standards Organization and many other international authorities, although some have shown a preference for the term "geospatial technology."

What is a Geographic Information Systems (GIS)?

GIS is a system for creating and managing spatial data and associated attributes. In the strictest sense, it is a computer system capable of integrating, storing, editing, analyzing, and displaying geographically-referenced information.

In a more generic sense, GIS is a "smart map" tool that allows users to create interactive queries (user created searches), analyze the spatial information, and edit data.

Geographic information systems technology can be used for scientific investigations resource management asset management development planning , cartography and route planning. For example, a GIS might allow emergency planners to easily calculate emergency response times in the event of a natural disaster , or a GIS might be used to find wetlands that need protection from pollution. GIS data represents real world objects (roads, land use, elevation) with digital data.

Real world objects can be divided into two abstractions: discrete objects (a house) and continuous fields (rain fall amount or elevation). There are two broad methods used to store data in a GIS for both abstractions: Raster and Vector.

Raster Data

Rasterdata type consists of rows and columns of cells where in each cell is stored a single value. Most often, raster data are images ( raster images), but besides just color, the value recorded for each cell may be a discrete value, such as land use, a continuous value, such as rainfall, or a null value if no data is available. While a raster cell stores a single value, it can be extended by using raster bands to represent RGB (red, green, blue) colors, color maps (a mapping between a thematic code and RGB value), or an extended attribute table with one row for each unique cell value. The resolution of the raster dataset is its cell width in ground units. For example, one cell of a raster image represents one meter on the ground.

Vector Data

Vector Vector data type uses geometries such as points, lines, or polygons, also called areas (shapes bounded by lines), to represent objects. Examples include property boundaries for a housing subdivision represented as polygons and well locations represented as points. Vector features can be made to respect spatial integrity through the application of topology rules such as 'polygons must not overlap'. Vector data can also be used to represent continuously varying phenomena. Contour lines and triangulated irregular networks (TIN) are used to represent elevation or other continuously changing values. TINs record values at point locations, which are connected by lines to form an irregular mesh of triangles. The face of the triangles represent the terrain surface.

What is Global Positioning Systems (GPS)?

GPS Global Positioning System is a satellite navigation system used for determining one's precise location anywhere on Earth. The system is an intermediate circular orbit satellite constellation of 24 satellites. Many refer to the system as the NAVSTAR GPS - Navigation Signal Timing and Ranging Global Positioning System.

The more satellites used the higher the accuracy of location. The precision of the GPS signal itself is about 20 meters (65 ft). Using differential GPS and other error-correcting techniques, the precision can be improved to about 4 inches or less. If desired GPS surveys can provide sub-centimeter accuracy.

The GPS system was designed by and is controlled by the United States Department of Defense and can be used by anyone, free of charge. The GPS system is divided into three segments: space, control and user. The space segment comprises the GPS satellite constellation.

The control segment comprises ground stations around the world that are responsible for monitoring the flight paths of the GPS satellites, synchronizing the satellites' onboard atomic clocks, and uploading data for transmission by the satellites. A GPS receiver decodes time signal transmissions from multiple satellites and calculates its position by trilateration.

The cost of maintaining the system is approximately US$400 million per year, including the replacement of aging satellites. The first GPS satellite was launched in February 1978, and the most recent launch was in September 2005. The oldest GPS satellite still in operation was launched in February 1989.

What is Computer Aided Design (CAD)?

CAD Computer-aided design (CAD) is the use of a wide range of computer -based tools that assist engineers, architects and other design professionals in their design activities. It is the main geometry authoring tool within the Product Lifecycle Management process and involves both software and sometimes special-purpose hardware . Current packages range from 2D vector based drafting systems to 3D parametric surface and solid design modelers.

CAD is sometimes translated as "computer-assisted", "computer-aided drafting ", or a similar phrase. Related acronyms are CADD, which stands for "computer-aided design and drafting", CAID for Computer-aided Industrial Design and CAAD, for "computer-aided architectural design". All these terms are essentially synonymous, but there are some subtle differences in meaning and application

What is Remote Sensing (RS)?

Data Remote Sensing is the science and art of obtaining information about an object, area, or phenomenon through the analysis of data acquired by a device that is not in contact with the object.

It is the utilization at a distance (as from aircraft, spacecraft, or satellite) of any device for gathering information about the environment. Remote Sensing makes use of devices such as a camera, laser, light, or radar to gather data.

The basic unit used in remote sensing is the wavelength of reflectance which is measured in nanometers (nm). This kind of data collection normally makes use of the emitted or reflected electromagnetic radiation of the examined object in a certain frequency domain (infrared, visible light, microwaves). This is possible due to the fact that the examined objects (plants, houses, water surfaces, air masses ...) reflect or emit radiation in different wavelengths and in different intensity according to their current condition. These levels emitted by different objects are commonly known as their "spectral signature".

What is Vegetation Modeling?

Vegetation absorbs light as part of the photosynthesis process.

6H20 + 6C02 + light = C6H12O6 + 6O2

The reflectance pattern of green vegetation in the visible wavelengths is due to selective absorption by chlorophyll, the primary photosynthetic pigment in green plants. Plant reflectance in the range 700 to 1,300 nm results primarily from the internal structure of plant leaves. It is a well known fact that the spectral shape and reflectance of green vegetation is sensitive to damage.

Area The reflectance of healthy vegetation increases as we go from the visible to the near-infrared portion of the spectrum at about 700 nm. Various mathematical combinations of the near infrared (NIR) channel and the red channel have been found to be sensitive indicators of the presence and condition of green vegetation. These mathematical quantities are thus referred to as vegetation indices. Vegetation indices may be used as an indicator of relative biomass and greenness. Mapping relative biomass or greenness for harvesting the "cream of the crop."

What is LiDAR?

LiDAR LiDAR technology involves a scanning and ranging laser system that produces pinpoint accurate, high-resolution, topographic maps. The entire process of airborne laser mapping is highly automated from flight planning, to data acquisition, to the generation of digital terrain models. The basic components of a LiDAR system are a laser scanner and cooling system, a Global Positioning System (GPS), and an Inertial Navigation System (INS).

The laser scanner is mounted within a properly outfitted aircraft and emits infrared laser beams at a high frequency. The scanner records the difference in time between the emission of the laser pulses and the reception of the reflected signal. A mirror that is mounted in front of the laser rotates and causes the laser pulses to sweep at an angle, back and forth along a line. The position and orientation of the aircraft is determined using a phase differenced kinematic GPS. GPS systems are located in the aircraft and at several ground stations within the area to be mapped.

What is Surface Modeling?

Topography refers to the "lay of the land" in terms of elevation, slope, and orientation.

Terrain "is a similar concept, used more to describe the land itself than the study of it." Relief " is often used to refer to the third dimension of a map whether in actuality (as in a "raised relief" map, or drawn, as with contours, hachures or shading) or the territory it describes.

Garland Topography is similar to topology, popularly thought of as the mathematical study of surfaces. This may help explain its adoption in the world of geographers. Its actual original meaning, from Greek "topos" (place) and "graphein" (to draw), relates to the description of places rather than broad regions, in topographic surveys.

Most 18th and early 19th century national surveys did not record relief across the entire area of coverage, calculating only spot elevations at survey points. The United States Geological Survey (USGS) topographical survey maps included contour representation of relief, and so maps that show relief, especially with exact representation of elevation, came to be called topographic maps (or "topo" maps) in the United States , and the usage has spread internationally.

Aerials The understanding of topography is critical for a number of reasons. In terms of environmental quality, agriculture, and hydrology, understanding the topography of an area enables the understanding of watershed boundaries, drainage characteristics, water movement, and impacts on water quality.