20801979 - GEOMATICS

FORMATIVE AIMS TO PROVIDE BASIC KNOWLEDGE ON MAJOR THEORETICAL, METHODOLOGICAL AND OPERATIONAL ISSUES INVOLVED IN SURVEYING, SO THAT THE STUDENT CAN ACQUIRE THE NECESSARY SKILLS TO DESIGN AND PERFORM A SURVEY AND TO PROCESS THE DATA RELATED TO IT. WE DISCUSS THE BASIC PRINCIPLES OF GEODESY AND CARTOGRAPHY, THE PRINCIPLES OF SURVEYING AND THE QUANTITIES THAT CAN BE MEASURED WITH THE TOPOGRAPHICAL INSTRUMENTS, BOTH TERRESTRIAL AND SATELLITE, THE SURVEY METHODS AND THE TREATMENT OF OBSERVATIONS.
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Mutuazione: 20801979 GEOMATICA in Ingegneria civile L-7 N0 FIANI MARGHERITA

Programme

GEOMATICA course program – prof. Margherita Fiani


Introduction:
Principles of survey. Definitions. Measurement and their units. Precision and accuracy in surveying.
Geodesy:
Shape of the Earth. Earth gravity field. Equipotential surfaces. Geoid. Definition of height. Reference ellipsoid. Geoid undulations. Coordinate systems: natural, geocentric, ellipsoidal. Geometry of the ellipsoid of rotation. Normal sections. Principal curvatures. Geodesic. Reference surfaces used to approximate the ellipsoid. Geodetic networks and Datums. Horizontal and vertical Datum. Datums used in Italy. Geodetic, astronomical, cartesian geocentric, cartesian local coordinates. Coordinate transformations. Transformations between Datums. Practical geodetic problems.
Theory of errors and statistical treatment of observations:
Types of measurement errors: gross, systematic and random. Probability distributions. Normal (Gaussian) distribution. Estimation of characteristic parameters of a distribution. Confidence intervals. Standardized variables. Two-dimensional continuous random variables. Covariance and correlation coefficient. Propagation of variance-covariance. Applications to surveying problems. Method of least squares. Adjustment with the method of indirect observations.
Cartographic representations:
The problem of map projections. Deformation modules. Analytical approach to map projections. Classification of map projections. Conformal projections. The conformal Gauss map and its geodetic use. Contracted coordinates and modules expressions. The Italian official cartography. Coordinates measurement on the map of Italy at the scale of 1:25000. The UTM-UPS mapping system.
Surveying:
National geodetic networks: planimetric, leveling, IGM95 networks. Reference, thickening and local networks. Planimetric survey, reduction of distances to the reference surface. Main surveying schemes: triangulation, intersection and radiation methods, open and closed traverses, detailed survey. Vertical survey: orthometric and normal heights, reference surfaces. Trigonometric and geometric leveling: scheme, instrumentation, accuracy. Practical aspects of GPS surveying, sessions and independent baselines, baselines computation, transformation in the national reference system. Design, planning, materialization, surveying and adjustment of planimetric, leveling and GPS networks.
Instrumentation and operational methods:
Measure of angles. Theodolites. Main components: telescope, vertical and horizontal circles, circle reading and optical micrometer, optical plumb. Setting up. Reading method of azimuth angles. Bessel’s method. Zenith angles. Electronic theodolites. Measure of distances. Geodimeters: operating principle, fundamental equation, accuracy of a geodimeter. Total stations. Leveling. Levels, types of levels, main components: telescope, level plumbs, leveling screws. Bessel’s method. Invar stadia. GPS: basic concepts, GPS constellation and control segment. GPS signal structure. GPS biases and errors. GPS receivers. WGS84. Pseudo-range and carrier phase measurements. GPS modernization. Other GNSS systems.


Core Documentation

GEOMATICA course program – prof.ssa Margherita Fiani

Support material:
Lecture notes from the course teacher
Additional texts:
G. Inghilleri, L. Solaini. Topografia. Levrotto & Bella, 1997.
G. Folloni. Principi di Topografia – Patron, 1982
G. Bezoari, C. Monti, A. Selvini. Topografia Generale. UTET, Milano, 2002
B. Hofmann-Wellenhof, H. Lichtenegger, J. Collins. Global Positioning System: theory and practice. Springer-Verlag, 1997.


Type of evaluation

The exam at the end of the course aims to assess the achievement of learning objectives, in particular concerning the following aspects: - elements of Geodesy; - coordinate and reference systems; - theoretical and practical basis for the use of land surveying instruments for angles, distances and height differences measurements and for the use of global satellites positioning systems; - statistical treatment of simple survey networks; - introductory concepts of the theory of mapping representations, in order to know how to use cartographic layers at different scales. The exam consists of: a written exam (numerical exercise on a scheme survey), a practical test (computation of a geodetic arc length and azimuth, reading of the coordinates of a point on an IGM map element) and an oral interview on all topics covered during the course.