Geomatics: An Introduction to Units, Significant Figures and Subdisciplines, Study notes of Earth Sciences

Download Geomatics: An Introduction to Units, Significant Figures and Subdisciplines and more Study notes Earth Sciences in PDF only on Docsity! Lec 1: Intro to Geomatics. Units. Significant figures. Outline: A. Geomatics is an “umbrella” term for a cluster of activities and technologies dealing with the locations and identities of earth features. “Geo” represents “geography” – the art and science of developing and interpreting graphical representations of the earth. The suffix “matics” is drawn from either “mathematics” or “information”, indicating that geomatics employs a methodical and technical approach to developing information about earth features. Geomatics has many subdisciplines: 1. Surveying is a traditional name applied to measuring features directly in the field with tools such as transits, theodolites, tapes, electronic distance meters, levels, and level rods. The word “surveying” is of French origin with the prefix “sur” meaning “from above” and “vey” meaning “to see”. The term applies to the process of taking measurements on the ground surface that can be reduced to a map that depicts the ground as if “seen from above”. A common use of surveying today is to map sites in advance of a design for a facility to be constructed. Other applications are for locating land boundaries, and setting stakes to guide construction. 2. Photogrammetry is the science of measuring from photos as opposed to direct field measurements. Most photogrammetry is done with aerial photos taken from an airplane with a precise mapping camera. Most topographic maps are made by photogrammetry today. 3. Remote Sensing is a general term about gathering information about an object from a far-removed sensor. In common usage, the term remote sensing applies to the acquisition and analysis of satellite imagery. Mapping satellites orbit the earth and sense the surface with a scanner, sending the sensed images to earth for use and analysis. 4. Geodesy is the term applied to the study of the earth’s size and shape. It is a highly mathematical and scientific study of the earth’s gravity field along with methods of positioning the latitude and longitude of features. 5. A Geographic Information System (GIS) is a collection of computer hardware and software used to house and analyze digital maps of the terrain along with information about the mapped objects. Most government units have built a GIS within the past several years. This is a very large current public expenditure that requires a significant amount of Geomatics expertise. A GIS has two sides: (1) the spatial side is in the form of layered digital maps, one map for each theme of information, and the (2) data side is in the form of a data base system containing the “attributes” of mapped features. 6. Cartography is the art and science of displaying and communicating information through a chart or map. Geography faculties have traditionally taught cartography. 7. The Global Positioning System (GPS) is a navigational system that uses a constellation of satellites that were designed and launched by the defense department. Civilian uses of GPS are for hunting, fishing, and vehicle navigation. Also precise surveying is done by GPS. B. Prominent Geomatics web sites The American Congress on Surveying and Mapping (surveying, cartography, geodetic surveying): www.survmap.com The U.S. Geological Survey (USGS): www.usgs.gov (mapping) The American Society for Photogrammetry and Remote Sensing: www.asprs.org The Urban and Regional Information Systems Association (URISA): www.urisa.org The National Geodetic Survey (NGS): www.ngs.noaa.gov The Land Boundary Information System (LABINS) of the Florida Department of Environmental Protection: www.labins.org C Who uses Geomatics? 1. Geomatics professionals offer Geomatics work to others as a service. These professionals are commonly called surveyors, mappers, land surveyors, photogrammetrists, GIS specialists, remote sensors, and geodesists. A distinct degree program in Geomatics is available at UF and on many other campuses. 2. Government Agencies need Geomatics expertise: Feds: U. S. Geological Survey (USGS) for making the “quad sheet” maps National Imagery and Mapping Agency (NIMA ) for defense mapping U. S. Department of Transportation for the federal road program Bureau of Land Management (BLM) for managing federal lands and GIS’s State: Departments of Transportation (DOT)’s for building roads and developing GIS’s Departments of Environmental Protection (DEP’s) for natural resources GIS’s Departments of State Lands for surveying state land purchases. Local: GIS Departments for building and maintaining county/city GIS’s Public Works for building roads and local facilities Property Appraisers for mapping parcels for base map purposes 3. Civil Engineering consultants use Geomatics on a regular basis. Information on the site for a future facility must first be captured through surveying and mapping methods. 4. Natural Resource consultants such as forestry, environmental science, and botany must map natural features for inventory and analysis purposes.