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1、Unit1 What is Geomatics ? Geomatics :Where does the word Geomatics come from? GEODESY +GEOINFORMATICS = GEOMATICS or GEO- for earth and -MATICS for mathematical or GEO- for Geoscience and -MATICS for informatics .Now the term includes the traditional surveying definition along with surveying steadil
2、y increased importance with the development of new technologies and the growing demand for a variety of spatially related types of information, particularly in measuring and monitoring our environment . Geomatics bridges wide arcs from the geosciences through various engineering sciences and compute
3、r sciences to spatial planning, land development and the environmental sciences .ISO: the International Standards Organization ( ISO) surveyor :The term “surveyor” is traditionally used to collectively describe those engaged in the above activities . Unit 2 Geodetic Surveying and Plane Surveying Geo
4、detic Surveying : The type of surveying that takes into account the true shape of the earth is called geodetic surveying . This type of survey is suited for large areas and long lines and is used to find the precise location of basic points needed for establishing control for other surveys . In geod
5、etic surveys, the stations are norm ally long distances apart, and more precise instruments and surveying methods are required for this type of surveying than for plane surveying . Geodetic control survey points: Widely spaced , permanent monuments serve as the basis for computing lengths and distan
6、ces between relative positions . These basic points with permanent monuments are called geodetic control survey points, which support the production of consistent and compatible data for surveying and mapping projects . Plane Surveying : The type of surveying in which the mean surface of the earth i
7、s considered a plane, or in which the curvature of the earth can be disregarded without significant error, generally is called plane surveying . The term is used to designate survey work in which the distances or areas involved are of limited extent . the curvature of the earth must be taken into co
8、nsideration only in precise surveys of large areas . Surveys for the location and construction of high ways, railroads, canals, and in general, the surveys necessary for the works of human beings are plane surveys, as are the surveys made to establish boundaries, except state and national . There is
9、 close cooperation between geodetic surveying and plane surveying . The geodetic survey adopts the parameters determined by measurements of the earth , and its own results are available to those who measure the earth . The plane surveys, in turn , are generally tied to the control points of the geod
10、etic surveys and serve particularly in the development of national map series and in the formation of real estate cadastres . Unit3 Distance Measurement Electronic Distance Measurement (EDM): EDM instruments refer to the distance measurement equipments using light and radio waves . Both light waves
11、and radio waves are electromagnetic .The advent of EDM instrument has completely revolutionized all surveying procedures, resulting in a change of emphasis and techniques . 优点：Distance can now be measured easily , quickly and with great accuracy , regardless of terrain conditions . 分类：The EDM instru
12、ments may be classified according to the type and wavelength of the electromagnetic energy generated or according to their operational range . EDM instruments use three different wavelength bands: ( 1) Microwave systems with range up to 150 km , wavelength 3 cm , not limited to line of sight and una
13、ffected by visibility; (2 ) Light wave systems with range up to 5 km (for small machines) , visible light, lasers and distance reduced by visibility; ( 3) Infrared systems with range up to 3 km , limited to line of sight and limited by rain , fog , other airborne particles . 两种方法：There are basically
14、 two methods of measurement employed which may divide the instruments into two classification as electro-optical (light waves) and microwaves ( radio waves) instruments . These two basic methods are namely the pulse method and more popular phase different method . They function by sending light wave
15、s or microwaves along the path to be measured and measuring the time differences between transmitted and received signals, or in measuring the phase differences between transmitted and received signals in returning the reflecting light wave to source . Unit 4 Angle and Direction Measurement A vertic
16、al line: A vertical line at any point on the earths surface is the line that follows the direction of gravity at that point . It is the direction that a string will assume if a weight is attached at that point and the string is suspended freely at the point . At a given point there is only one vertical line . A horizontal line: A horizontal line at a point is any line that is perpendicular to the vertical line at the point . At any point ther
