Remote Sensing Lectures Notes

Geophysics and Remote Sensing is a 12-credit course.
It is delivered within the Environmental Engineering master’s degree program.
The course is taught by two lecturers: Prof. Alberto Godio (Geophysics) and Prof. Piero Boccardo (Remote Sensing).
Students are mainly from Environmental Engineering but also from other master's and Ph.D. programs.
Most students take the full course (12 credits), while some take only Geophysics or Remote Sensing.
Geophysics ranges from 6 to 8 credits depending on the master’s degree, while Remote Sensing is consistently 6 credits.
Remote Sensing labs are divided into three groups:
- Groups 1 and 2: Environmental Engineering and other programs (Climate change, Planning, Ph.D., etc.) on Thursdays at 11:30-13:00 and 13:00-14:30, respectively, in English.
- Group 3: Environmental Engineering (Italian path) and Geography students on Thursdays at 11:30-13:00, in Italian.
Remote Sensing lectures are entirely in English.

Teaching materials available on the student portal:
1. "Remote Sensing and Earth observation" - A comprehensive textbook.
2. Envi user guide - A complete user guide for the software used in labs.
3. Lecture presentations.
4. Software and license for personal use.
5. Satellite images (data).
6. Pre-recorded videos of all lectures and labs.
The content presented in lectures and labs is based on the teaching materials.
The teaching materials might include more information than is required to pass the examination.
During lectures and labs, the instructor will clarify which topics are not part of the teaching program.

Remote Sensing lectures and labs are typically in the same room to tightly integrate theory and practice.
Students are encouraged to bring laptops for lab sessions.
Lectures and labs will start on time.

A single mark is given for the entire Geophysics and Remote Sensing course, calculated as the mean of the two parts.
The Remote Sensing mark, if accepted, is valid for future examination sessions.
The Remote Sensing examination is split into two parts:
1. A practical report.
2. A theoretical examination based on questions.
The final mark is the mean of the practical and theoretical marks (expressed out of 30).
- Example: practice = 26/30, theory = 30/30, final mark = 28/30.
The practice part involves a final assignment (individual or groups of up to 3 students).
The assignment involves research using open-source satellite data (multispectral and multitemporal) in areas freely chosen by the students.
Research topics:
- Production of land cover maps.
- General environmental analysis.
The theoretical and practical parts can be taken in different examination sessions.
Examination dates are available on the Politecnico portal.
Registration occurs after all partial marks are obtained (theory + practice + applied geophysics).
Students must register for the examination sessions.
Successful examination results are registered electronically and published on the personal portal for approval.
The examination is definitively registered after a check and approval period.

The instructor will be available during and after lessons.
For further information or clarifications, contact the instructor during lectures or via email at piero.boccardo@polito.it.
Students are encouraged to ask questions during lessons.

The need to understand the territory and environment is vital.
Historically, information was limited to routes for food.
Today, satellite data provides physical measurements and scientific observations.
Platforms conveying information are essential for future challenges.
Observing the Earth from above became possible with aerospace technology.
Developments in photography, optics, and electronics extended acquisition capabilities beyond the visible spectrum.
Electromagnetic radiations are classified by frequency (cosmic rays, gamma, X-rays, ultraviolet, visible, infrared, microwave, radio, direct current).
Remote Sensing studies reality from spectral and radiometric perspectives.
It combines observations of dynamic phenomena and their physical properties with spatial positioning information.
Remote Sensing began with photography in 1838, which allowed for objective and permanent recording of observations.
The telescope (1609) and photography (1838) improved observation and enabled permanent and quantitative recording of visual information.
Remote sensing developed significantly after World War II with advancements in optics, electronics, and information technology.
New sensors and data processing techniques extended visual perception beyond natural limits across the electromagnetic spectrum.
The first Earth images from the TIROS-I meteorological satellite in 1960 demonstrated the potential of space platforms.

Studies the shape of the Earth (geoid).
Requires precise knowledge of the gravity field and its spatial distribution.
Linked to topography, photogrammetry, remote sensing, cartography, astronomy, geophysics, geology, and oceanography.
The concept of a spherical Earth was proposed by ancient Greek philosophers.
Modern Geodesy was formulated in the 18th century by French mathematicians.
It has improved through mathematical analysis and precise measurements.
The Earth is no longer considered a rigid body due to movements in the Earth's crust, terrestrial tides, and other phenomena.
GPS (Global Positioning System) techniques allow for centimetric measurement accuracies globally.

Deals with methods and tools for determining and representing points and elements on the Earth's surface.
An ancient discipline used for economic, strategic, and religious purposes.
Involves metric representation and clear description of the physical surface for activities linked to the territory.
The product is a metric map or a digital terrain model.
Aims to depict portions of the territory in a descriptive or synthetic manner.
Involves control of structures, design of reliefs for civil engineering works, measurement of areas and volumes, and surveying urban centers, archaeological sites, and monuments.

Aerial photogrammetry is a modern surveying method for producing metric maps.
Based on analytical and projective geometry, using perspective properties of photographs for terrain surveys.
Used for detailed surveys at various scales (1:50,000 to 1:200) and for surveying architectural complexes, monuments, and civil infrastructures.

The basic problem is representing a curved surface on a plane, requiring deformations to assimilate the Earth's shape.
Relies on mathematics, projective and descriptive geometry, and information technology.
Digital cartography and GIS (Geographic Information Systems) are increasingly important.
Representation can maintain angles, surfaces, or distances, but not all simultaneously, leading to different types of maps and projections.
Pursues metric and thematic objectives.
- Metric Cartography represents the territory accurately, maintaining dimensions after scale reduction; it is generally symbolic and based on geodetic and aerial photogrammetric surveys.
- Thematic cartography represents the territory by surfaces or