31444 - Topography T

Learning outcomes

Provide the basic elements of Geomatics disciplines with particular reference to the topography, the classical instrumentation and GPS. Provide basic elements concerning Cartography map projection theory and some applications.

Course contents

GEODESY
Shape of the Earth - Notes about the composition and motion of the earth - the geocentric coordinate system . Gravitational Field - Geoid - Heigths Definition - Coordinate System - Contourn Lines. The Reference Ellipsoid as reference surface - ellipsoidal coordinates (geographic coordinates) - Geoid Undulation- Geodetic Reference Systems (Geodetic Datum ) - Elementary Elements considered for a topographic survey: angles, distances, differences in height.
Geometry of the ellipsoid. Sections of the ellipsoid : normal , main - bending radii - Transformation between geographic and geocentric coordinates - local geodetic system .
Positioning of points. Geodetic lines - Difference considering Geodetic lines or Normal sections - Puiseux-Weingarten Series - Approximate reference surfaces: plane approx and spherical approx. The Italian geodetic network .

Introduction to experimental errors and their propagation.

Probability ( Bullets ) : definitions, simple and compound events .
Random Variables . (Recall ) continuous and discrete variables - Function and cumulative probability density function - Probability associated with a range of values : confidence interval - Parameters of a distribution ( centrality and dispersion ) - Variable standardized - Covariance and correlation coefficient. Sample (Recall ) . Estimation of the mean and sample variance - estimation Features - Criterion to reject data. Propagation of the mean and variance. Cases linear and non-linear , single and multi-dimensional . Compensation of the observations. Types of Errors - Constraints between observations - Redundancy - Criterion of Least Squares . Method of indirect observations . Functional model and statistical - Observed with linear constraints - Solution and calculation of the estimate of the unknowns - Non-linear models and iterations - Statistical properties of estimates - linearization of the equations azimuthal angle , direction and distance - the difference in height equations and some basic about GPS . Calculation of a network. Intrinsic Compensation - Analysis of residuals - Accuracy of a network. Inserting into an existing network : compensation bound and conformal transformation .

SURVEY Trigonometric networks . National networks elevations - planimetric - GPS . Procedure to perform correct practical Survey: from general to particular - Geodetic Networks grades-
Planimetric survey . Reduction measures to the reference surface - elementary diagrams of measurements: intersections (forward , side, back ), polar, branches of polygonal - Polygonal bound and closed - Survey of detail.
Heights differences surevey techniques. Types of heights and reference surfaces - trigonometric leveling chart and the necessary instrumentation , mutual , from one extreme - Refraction - accuracies achievable - Geometric Leveling, - Line of leveling : preparation, execution and control - accuracies achievable in geometric leveling precision .
Measure altitude using GPS ellipsoidal and ripple .
GPS survey . Preparation and planning - Sessions and independent bases - Compensation bases - Transformation in the national system

OPERATING INSTRUMENTS AND METHODS OF USE Measuring angles . Theodolites . Constituent parts : axes , collimator telescope , circles , reading devices , levels, commuters systems - Setting up - A method of reading azimuthal angles : rule of Bessel, layers - Reading zenith angles - Zenit instrumental .
Electronic theodolites . Automatic measurement and data storage
Measuring distances . Geodimetri . Operating principle - Fundamental equation - Accuracy instrumental , ambient effect .
Total stations . Flow measurements - calculations.
Measurement of height differences . Levels . Constituent parts - Precision level - Staffs invar - Leveling the middle - Accuracy of a joke and a line.
G.P.S. Principle of operation of the system - Segments space of contol , user - The GPS signal - Systematic errors - Observed pseudo- range and phase - Processing of the bases : phase differences , interruptions, ambiguity.

MAPS The cartographic representation. Deformation and modules - Laws of representation - Conformal mappings , general equation - Representation of Gauss - Using geodetic representation of Gauss. The mapping system Boaga Gauss - The mapping system UTM UPS - The cartography of the IGM - Cartography Regional - Numerical cartography (notes).

Readings/Bibliography

Reference documents concening the topics of the course are available on the web site virtuale.unibo.it.

Teaching methods

The course is organized with lessons in the classrooms and some practice for the knowledge of the classical topographical instrumentation

Assessment methods

The final exam is unique and verifies the acquisition of the expected knowledge and skills by carrying out a written and oral test, without the help of notes or books.

At the time of the test, students must have an identification document (Identity Card or Driving License or Passport) and a badge and show it to the examiners.

The written test consists of 10 multiple-choice questions about the topics of the course of Digital Mapping and GIS. Only one of the 5 answers is correct. Each correct answer is worth 3/30, wrong answers are worth 0. The test must be performed within the indicated time range. The test must be carried out within the indicated time range. From the moment of the beginning, it lasts 30 minutes. The oral discussion takes place immediately after the written test and aims at evaluating the critical and methodological skills acquired by the student during the entire course.

Following the national emergency state of 31 January 2020 and the issuing of D.L. February 23 2020 n. 6, containing urgent actions regarding the containment and management of the epidemiological emergency from COVID 19, and in order to give continuity to the verification processes, the exam can be taken, if necessary, at the students' homes in online mode, using the EOL platform to supply the written test and the ZOOM application for the supervision.

In the case of exam in online mode, it is necessary to have all the tools listed below:

• a stable internet network
• a desktop or notebook (hereafter PC) connected to the electricity network and to Internet
• a mobile device (smartphone or tablet) connected to the electricity network and to Internet, equipped with a video camera, which will be used as means of supervision by the examiners inside the Virtual Classroom
• the ZOOM app that allows video meeting and access to the virtual classroom must be installed on the mobile device
• the possibility of using a quiet environment in one's own home, free from other people and correctly lit, in which to set up a space with the elements listed above.

Teaching tools

Practice Laboratory (6 hours): basic functioning of topographical instruments

Office hours

See the website of Stefano Gandolfi