Geomatics Program

deals primarily with computer techniques and software to produce maps from images. This is the modern equivalent of the earlier, analog approach of producing maps from images and is closely associated with Photogrammetry. In a broader sense, digital imaging and digital mapping can be considered separately. For example, a digital image can be subjected to various computer processing operations in order to identify features, without a resultant map product. On the other hand, we might look at how other forms of spatial data can be processed to produce a digital map.

By its nature, the study of digital imaging and mapping inevitably involves the use of a computer and associated software, and there are many examples and applications. One might use image processing software in order to detect the spread of disease in a forest. Data from digital sensors can be processed in order to produce a planimetrically correct image “map” called an orthophoto. Flood prone areas can be identified by computer processing of a large number of X,Y,Z data points on the surface of the terrain (collected by a system commonly known as LIDAR). This is just a small sample of the many applications in digital imaging and mapping.

is the branch of Earth sciences that deals with the division of the Earth. It deals with the geometric and the physical Earth in order to determine its size and shape and its gravity field. Geodesy is closely linked to surveying and mapping. Surveying and mapping professionals use planimetric flat Earth models for planimetric projects which comprise small areas. When the project area gets larger (usually larger than 20 km by 20 km), geodetic implications of a spherical/ellipsoidal Earth model becomes more relevant. The land ordinance of 1785 is a good example of how geodesy affects the surveying and mapping practice. The ordinance reads “… divide territory into townships of 6 miles square by lines running due north-south lines, and others cross at right angles.” The USPLSS was designed to be rectangular. However, due to the complexity of the Earth’s shape as in the convergence of meridians, a rectangular system was un-realizable on the ground. Corrections, using geodesy, were applied to account for the differences.

Angles and distances are measured by survey/geodetic equipment to determine locations of points on the surface of the Earth. Geodesy has two main branches, geometric and physical. Geometric geodesy handles positioning problems on the surface of the Earth using a spherical/ellipsoidal model. Satellite geodesy and geodetic astronomy, where either Earth orbiting satellites or celestial bodies are used to locate points on the Earth’s surface, are considered two sub-branches of geometric geodesy. Physical geodesy, on the other hand, studies the Earth’s gravity field to determine the Geoid and other equipotential surfaces. Physical geodesy models tie the mathematical model of the Earth to survey measurements. The Geoid, considered a best fit to the mean sea level, is also the datum for leveling heights. Both geometric geodesy and physical geodesy handle time-dependent variations of the coordinate systems caused by the Earth rotation, polar motion, and other perturbations. Geodesy as an Earth science is a corner stone in other Earth sciences like geography, geology, geophysics, oceanography, and glaciology. Geodesy as an applied science and technology lends itself to engineering, informatics, and professional surveying and mapping.

is the science involved in developing Geographic Information System technology, applications and algorithms. The scientific contribution to the development of current GIS can easily be recognized starting from basic theories and algorithms developed to handle spatial data problems up to recent utilization of the wireless technology and protocols in mobile GIS applications. Many scientific disciplines contribute to today’s GIS achievements. Scientists in the fields of mathematics, computer science, and cartography contributed significantly into core GIS development. Map projection is an example of a traditional scientific concept implemented in all GIS systems to provide the planimetric representation of features located on the curved earth surface.

is an information system that can be used to manage, analyze and present geographically-referenced data. GIS is used in many applications such as natural resources management, urban planning, real estate and land records management, emergency planning, and environmental modeling. Geomatics, by definition, is a major stakeholder in GIS data acquisition and error modeling. Three dimensional point coordinates resulting, for example, from LIDAR data can be used in a GIS to delineate stream and river basins and study surface water flow. Data extracted from Remote Sensing sources was traditionally used in GIS to model large phenomena such as forest fires, global warming and drought conditions. GIS also has a major role in modeling transportation networks, handling emergencies, and managing surveying and mapping resources.

Recently, GIS applications have shifted towards web-based services. A web client application can display, query, and analyze GIS data through the internet. Web-based applications such as Google Earth have become very popular and have introduced GIS concepts to the public. Many wireless GIS applications are also being developed for the navigation and vehicle-tracking market.

is a world-wide satellite-based radio navigation system developed and operated by the US Department of Defense (DOD) NAVSTAR (NAVigation System with Timing And Ranging) program; GPS first satellite launch was in 1978 but the system became fully operational in 1994. GPS was originally conceived as a military system to provide its ground, sea, and air users with all-weather all-time navigation and positioning capabilities. Today, civilian users surpassed military users in numbers and applications to the point that GPS is now an inevitable tool for them. Surveying, mapping, and navigation professionals rely on GPS to provide basic positioning information with the ease of pressing a button. Positioning with GPS is accomplished through trilateration by measuring at least four ranges between the satellites and the receiver on the surface of the Earth. Applications of GPS are enormous including surveying and mapping. One can use GPS in any project requiring positioning, timing, and navigation. Cars, boats, airplanes, tractors, etc are currently equipped with GPS receiving and processing units.

The GPS system itself consists of three main segments, space, control, and user segments. The space segment consists of a constellation of at least 24 satellites orbiting the Earth’s in nearly circular orbital plane at an approximate altitude of about 22,000 km above the Earth’s surface. Each satellite orbits the Earth twice every day. The expected life span for modern satellites is around 10 years after which the satellite has to be replaced. Each satellite is equipped with a precise atomic clock accurate to one billionth of a second. The satellites transmit radio signals which when received on the Earth’s surface by a GPS receiver enables the observer to locate itself with respect to an Earth-Fixed-Earth-Centered Coordinate system with high accuracy. The user segment is in effect the receiver and the antenna used to receive and decode the satellite signal. The control segment consists of five ground monitoring stations in Hawaii, Ascension Island, Diego Garcia, Kwajalein, and Colorado Springs. The station in Colorado Springs also serves as a master station that transmits corrections to the satellites for satellite ephemeris parameters and clock coefficients.

is the science of obtaining reliable measurements from photographs (images) in order to determine characteristics such as: size, shape, and position of photographed objects. The objective of photogrammetry is to invert the process of photography to reconstruct object space features such as buildings, roads, and shore lines. The output of photogrammetry is typically a map, drawing or a 3D model of some real-world object or scene. Many of the maps we use today are created with photogrammetry and photographs taken from aircraft.

Photogrammetry can be classified in a number of ways. One standard method is to divide photogrammetry based on camera location during photography. On this basis we have Aerial Photogrammetry, and Close-Range Photogrammetry.

• In Aerial Photogrammetry the camera is mounted in an aircraft and is usually pointed vertically towards the ground. Multiple overlapping photos of the ground are taken as the aircraft flies along a flight path. These photos are processed to generate several products such as topographic maps, contour plans, and 3D surfaces
• In Close-range Photogrammetry the camera is close to the object and is typically hand held or on a tripod. Usually this type of photogrammetry is used in non-topographic applications. Consumers-grade cameras are used to model buildings, engineering structures, vehicles, forensic and accident scenes, film sets, etc.

Land tenure systems define how a community (indigenous group), society or country assigns rights to its land and natural resources. These rules may be defined through formal law or through unwritten custom. Cadastral studies focuses on the cadastral and land registration systems that are used to document and secure land tenure rights. It includes processes such as cadastral (boundary) surveying, principles for resolving boundary ambiguities, and linking these spatial data to legal data describing the nature of the bundle of rights associated with an individual parcel of land. Our research has a significant focus on land tenure and cadastral issues in developing countries, where many landholders do not have formal documentation of their rights and where land administration systems are often overly centralized and bureaucratic.

Since land tenure is relevant to a number of disciplines, we work with faculty and students from several other units on campus. Through this collaboration we are carrying out research on the resilience of social-ecological systems in the SW Amazon and elsewhere. We have also begun to examine the role of land tenure in the governance of valuable natural resources, such as wildlife in Southern Africa.

is the technology that uses laser pulses to map the surfaces of the earth. In particular, a LIDAR system combines a single narrow-beam laser with a receiver system. The laser produces an optical pulse that is transmitted, reflected off an object, and returned to the receiver. The receiver accurately measures the travel time of the pulse from its start to its return. LIDAR mapping can occur day or night, as long as clear flying conditions are present. On a functional level, LIDAR is typically defined as the fusion of three technologies into a single system capable of acquiring data to produce accurate digital elevation models (DEMs). These technologies are; Lasers, the Global Positioning System (GPS), and Inertial Navigation Systems (INS). Combined, they allow the measuring of the footprint of a laser beam as it hits an object, to a high degree of accuracy. Lasers themselves are very accurate in their ranging capabilities, and can provide distances accurate to a few centimeters. The accuracy limitations of LIDAR systems are due primarily to the GPS and INS. As advancements in commercially available GPS and INS occur, it is becoming possible to obtain a high degree of accuracy using LIDAR from moving platforms such as aircraft.

covers a broad range of areas. People often consider land boundary applications to be the sole realm of a professional surveyor and mapper, but the subject encompasses much more. Most – if not all – of the areas in Geomatics fall under the general heading of surveying and mapping, and it is up to a professional to assure that the associated work is done to high standards of quality. Individual states regulate professional practice through statutes and codes, and the exact definitions of surveying and mapping vary from state to state. Nevertheless, the concept of a licensed professional is fundamental. A professional is one who has acquired specialized education and knowledge in order to perform expert services for members of the public. The professional is held in a position of trust by the public and therefore must adhere to a code of ethics and accept liability for his or her work.

A large percentage of the Geomatics graduates from the University of Florida go on into careers leading to professional licensure. After obtaining a baccalaureate degree, rigorous examinations must be passed and appropriate experience and moral character documented in order to acquire a license to be a professional surveyor and mapper.

is the science and art of obtaining information about Earth phenomenon without physical contact. This may be done through the photographic process, electro-optical sensors or other instruments. Platforms for these sensors may be on the ground, in the air or in space. In Geomatics, remote sensing is used a support tool for gathering data about a place. It may be used to collect primary data or for updates. There are many things that can only be detected through remote sensing while in other cases, remote sensing is simply a more efficient way of collecting data than doing it from the ground.Sensors used include film-based cameras, digital cameras, multi-spectral scanners, thermal infrared radiometers, radar, sonar, LiDAR and IfSAR.

Applications of remote sensing include: land use/land cover mapping, forest inventories, wildlife habitat mapping, soils mapping, wetland mapping, topographic mapping, deformation analysis, deforestation analysis, urban planning and geological mapping, to name a few examples.