Duration
Introduction to satellite oceanography : 15h Th, 15h Pr
Advanced satellite oceanography : 15h Th, 15h Pr
Number of credits
| Master in oceanography (120 ECTS) (MER - Erasmus mundus) | 6 crédits |
Lecturer
Introduction to satellite oceanography : Yves Cornet
Advanced satellite oceanography : Yves Cornet
Coordinator
Language(s) of instruction
English language
Organisation and examination
Teaching in the first semester, review in January
Schedule
Units courses prerequisite and corequisite
Prerequisite or corequisite units are presented within each program
Learning unit contents
See educational commitments of the two component courses:
OCEA0059-Aa: Introduction to satellite oceanography, 15h Th, 15h Pr
OCEA0059-Ba: Advanced satellite oceanography, 15h Th, 15h Pr
Introduction to satellite oceanography
As this course is geared towards students with very different technical and scientific backgrounds, its goal is to provide a common theoretical ground of general concepts used in the processing of digital images recorded by satellite sensors. We have decided to concentrate our formation program on these aspects because satellite oceanography is a very broad field of study, dealing with the observation of water bodies using sensors that detect visible light, reflective infrared, thermal infrared, and microwaves (hyperfrequencies - RADAR imagers). These sensors can be atmospheric sounder, radar altimeter; imaging instrument...
The atmospheric sounders are often used to modelize weather conditions and radiative transfer through the atmosphere. Processing data from such atmospheric sensors requires advanced knowledge in atmospheric and aerosol physics. Another field of satellite oceanography aims at determining a geoid model and measuring the sea surface height above/below this reference, while filtering disruptive effects (waves, tides ...). This is achieved by applying advanced concepts of geodesy, analyzing the satellites trajectories using their height measurements as provided by altimeters (e.g. RADAR altimeters) and their position and attitude provided by orbital positioning systems (e.g. DORIS) and by inertial measurement units (IMU) or star trackers. A third advanced topic of satellite oceanography is the processing of data acquired by SAR systems. Those systems which provide a phase and amplitude are used to get information on sea waves, sea surface state, and wind velocity ... The SAR processing technics call upon complex theoretical notions of signal processing.
This is why, for the introductory course, we have chosen to only study the data produced by imaging sensors that detect visible and infrared light. As this course is aimed at oceanographers and limnologists, it will be illustrated by examples that are specifically related to these fields of research. In addition, as the data acquired are geo-localized (geographical or spatial) and temporal, we will also explain general concepts of digital and mathematical cartography and spatial analysis, which are essential in order to analyze those data.
Whether the images are used to observe land or water bodies (lakes, seas or oceans), and whether the phenomena studied are physical, biological or anthropic, it is essential that students learn the general theory of image processing, regardless of characteristic dimension and time. This is what the theoretical part of the course focuses on. Most of the theoretical concepts are applied through the use of software tools during the supervised practical part of the course.
The course's general outline is as follows :
I. Introduction
1. Definition
2. Brief history
3. Satellite movements
4. Nature of the signal
5. Some satellites and sensors
II. Monogenic image processing
6. Concept of digital image
7. Monogenic image visualization
8. Contrast enhancement
9. Geometric corrections
10. Radiometric corrections
11. Spatial filtering
III. Polygenic image processing
12. Polygenic image visualization - color composites
13. Arithmetic operators and indices
14. Polygenic transformations
15. Image classification
IV. Examples of applications (informational part of the course)
16. Nature of satellite information in oceanography
17. Classification of the shallow water seabed
18. Bathymetry
19. Ocean color (OC)
20. Sea Surface and Lake Surface Water Temperature (SSWT and LSWT)
21. Sea surface height (SSH)
22. Radar imaging and of sea surface state
23. Front detection
24. Analysis of temporal series and teleconnections
Advanced satellite oceanography
This practical course consists in brief theoretical introductions, followed by practical exercises on various techniques related to the observation of water bodies (oceans, seas, lakes), mainly using satellite imaging sensors with low spatial resolution and high radiometric and spectral resolutions that detect visible light, reflective infrared and thermal infrared (AVHRR and MODIS e.g.).
The techniques studied deal with the extraction of biogeophysical parameters from the upper layer of the water column, based on the multi-spectral information recorded by these sensors. The biogeophysical parameters studied are surface temperature (Sea Surface Temperature - SST) and Ocean Color (OC). This one is related to chlorophyll-a concentration, CDOM and suspended mineral particles.
We place emphasis on the qualification of input data as well as on its meaning, on its oceanological or limnological representativeness, and on calculation protocols for bio-geo-physical parameters.
The first topic studied is OC (from MODIS sensor). We illustrate the processes used to create level 2 and 3 products from level 0/1, raw luminance data. Several concepts of physics and geometry are applied (geometric correction, radiometric calibration, reflectance, correction of the effects of aerosols, tests on the water's surface state, cloud detection tests, water turbidity, empirical models used to calculate the concentration of chlorophyll-a, validation of the results, etc.).
The second topic is the calculation and analysis of the SST (from MODIS sensor). We illustrate a calculation process involving the adjustment of an empirical model that establishes a relationship between the brightness temperature recorded by the sensor in various thermal channels and the surface temperature provided by ARC-LAKE data. This is produced by the spatio-temporal aggregation of aligned systematic measures by an Along Track Scanning Radiometer (ATSR) sensor. This procedure is a multi-source data fusion analysis technique allowing spatial resolution refinement.
The third topic is the analysis of a time series of level 3 raster files showing SST. These time series are constituted by Pathfinder data. Those are produced by aggregating measures made by AVHRR sensors embarked on the NOAA's various POES satellites. The first operation consists in product selection, product and documentation downloading, data qualification, organization and management. This operation is followed by the creation of the time series, an PCA extraction from of T-mode inertial matrix and the oceanographical interpretation of the saturation matrix shown as temporal profile and of factorial score images. A regionalization is then realized through a clustering process. Finally the spatially generalized time series are extracted by region and their oceanological interpretation is performed.
Learning outcomes of the learning unit
Introduction to satellite oceanography
* Given the diversity of the students attending this course, the requirements in terms of theoretical knowledge are not as high as could be expected from an expert who designs original solutions. Emphasis is rather placed on practical aspects. Still, students should follow basic scientific standards (rigor and reliability) and our expectations will obviously be tailored to each student's background.
* Understand the data acquisition process and the nature of the information recorded by imaging sensors used to observe water bodies.
* Understand the nature and the oceanological meaning of the data recorded by sensors studied in the course, as well as the different pre-processing levels of the images made available to scientists by the providers.
* Know the main types of processing used for these images.
* Master the functionalities of specific software tools allowing to apply these processes.
* Apply standard processing protocols and understand their limits and how they work.
* Understand why images are processed for oceanological purposes and interpret the oceanological meaning of the processes used
Advanced satellite oceanography
* Understand the nature and the oceanological meaning of the data recorded by sensors studied in the course, as well as the various levels of pre-processing used.
*Apply standard processing protocols and understand their limits and how they work.
* Understand the relevance of these processes' results and interpret their oceanological meaning.
* Learn how to use the features of software application that perform these processes.
Prerequisite knowledge and skills
Introduction to satellite oceanography
The course builds upon basic skills in mathematics, statistics, physics, spatial analysis and mathematical and numerical cartography. Students should also have an interest in computer science and programming.
Students will also be helped by the mindset they have acquired through various scientific courses (mathematics, statistics, physics, spatial analysis, etc.) and technical courses (numerical methods, programming, cartography, etc.) of former secondary education and academic programmes.
Nevertheless, the variety of backgrounds among the students who generally enroll in this course requires that the teaching be adapted. Many refreshers will thus be provided using the black board. In addition, students are given the opportunity at the beginning of each class to ask questions about the content from the previous class. It is therefore up to students to go through their notes every week in order to identify potential points of confusion.
The oceanographical interpretation of the results of the methods used in class will rely on knowledge of lake, sea and ocean hydrodynamics, oceanography and climatology... If necessary, students will search through the scientific literature in order to carry out this interpretation.
Advanced satellite oceanography
The course builds upon the skills acquired during the introductory course on satellite oceanography. All the prerequisites of this introductory course are of course required for the advanced course. Students must also have an interest in using digital tools, as well as basic training and practical experience in programming. However, due to the variety of scientific backgrounds among the students who enroll in this class, the teaching will be adapted to the students' needs.
Students will also be helped by the mindset they have acquired through various scientific courses (mathematics, statistics, physics, spatial analysis ...) and technical courses (numerical methods, programming, cartography, etc.) of their former academic programmes.
The oceanographical interpretation of the results of the methods used in class will rely on knowledge of lake, sea and ocean hydrodynamics, physical oceanography, and climatology... If necessary, students will search through the scientific literature in order to carry out this interpretation.
Planned learning activities and teaching methods
Introduction to satellite oceanography
The theoretical part of the course is given as lectures. We also offer students an exercise book, featuring numerical examples illustrating the various methods studied during the lectures. Their goal is to help students understand the theoretical concepts that we have identified over the years as being the most difficult. Examples of typical solutions are provided. The exercises can be done using the computation or programming tools that are known to the students (Excel, Calc Openoffice, programming languages learned in IT class, scientific calculators, etc.).
The practical part of the course consists in assignments that are mostly completed using Idrisi sofware. It illustrates almost all the methods presented during the theoretical part of the course. Classes alternate between practical work and theoretical lectures. Students are also given standard exercises and datasets similar to those used in the practical assignments, along with the solutions, so that they can autonomously assess their ability to use the software before the exam.
Students are free to use the university's Idrisi license as well as other software applications through the ULg's VPN. For information on how to access these applications, students can visit the following web page: http://www.gitan.ulg.ac.be/cms.
This web site also features the timetable of the class room in building B5a (B5a/4/18 and B5a/2/35). To get access to these rooms, students may contact the Geomatics unit if they wish to practice or advance in their practical assignments.
Advanced satellite oceanography
The theoretical introduction of each topic will consist in a lecture before each exercise. The theoretical concepts and the technical protocol will be explained.
The practical assignment will be done using various software tools (SeaDAS, Idrisi, MATLAB, Octave and/or Python). They will be organized as projects, and supervised at all times by the teaching staff in order for students to self-assess their skills by closely interacting with teachers. These practical assignments will also attempt to foster the students' curiosity and ability to come up with original solutions using free software if possible.
Students are free to use the university's Idrisi license as well as other software applications through the ULg's VPN. For information on how to access these applications, students can visit the following web page: http://www.gitan.ulg.ac.be/cms.
This web site also features the timetable of the class rooms of building B5a (B5a/4/18 and B5a/2/35). Students may contact the Geomatics unit if they wish to practice or advance in their practical assignments.
In addition, they may use other open software resources available online (SeaDAS, R, QGIS, Octave, Python...) to independently develop the specific skills required for this study programme. Whenever possible, we encourage students to install these resources on their own personal computers.
Mode of delivery (face-to-face ; distance-learning)
Introduction to satellite oceanography
The course consists mostly in face-to-face classes. Attendance is thus mandatory, but students can install open software on their laptops and use the ULg's licenses in order to progress as their own rhythm outside of class and the academic environment. Classes are held in room B5a/4/18 or B5a/2/35.
Advanced satellite oceanography
The teaching activities are mostly face-to-face, but students can install open software on their laptops and use licenses available from the ULg, thereby learning at their own pace outside class.
Attendance is mandatory.
Classes are held in rooms B5a/4/18 or B5a/2/35 according to the schedule available at http://www.facsc.ulg.ac.be/cms/c_253095/fr/horaires
Recommended or required readings
Introduction to satellite oceanography
MATHER P.M., 1999. Computer Processing of Remotely-Sensed Images. 2nd edition. Wiley, Chichester, 292 p.
RUSSELL G. CONGALTON & KASS GREEN, 2008. Assessing the Accuracy of Remotely Sensed Data: Principles and Practices. CRC Press, Second Edition.
Platform of Earth Observation (BELSO) : http://eo.belspo.be/ (viewed on 14/8/2014)
Landsat 7 handbook : http://landsathandbook.gsfc.nasa.gov/ (viewed on 14/8/2014)
Landsat 8 documentation: http://landsat.usgs.gov/landsat8.php (viewed on 14/8/2014)
Landsat Science : http://landsat.gsfc.nasa.gov/?page_id=11 (viewed on 14/8/2014)
NOAA documentation: http://www.ncdc.noaa.gov/oa/pod-guide/ncdc/docs/intro.htm (viewed on 14/8/2014)
Advanced satellite oceanography
Students are, of course, encouraged to gather scientific and technical documentation in addition to the material provided in class (online literature, software help resources, online forums, reference books ...).
Assessment methods and criteria
Introduction to satellite oceanography
An ongoing non-certificational self-evaluation is carried out during practical sessions, through close interaction between students and teachers. In addition, students have a book featuring numerical exercises with solutions on the one hand, in order to assess their own theoretical knowledge. They also have access exam-type questions with solutions on the other hand, in order to test their skill in using the Idrisi software application.
The certificational evaluation will consist in an oral exam on the course's theoretical content and in a written practical exam with access to the didactical material on the course (printed version). This practical exam consists in a problem to solve using Idrisi software, similar to those given during practical classes. Each part of the evaluation is worth 50% of the final mark.
This standard evaluation procedure may however be modified in agreement with the students, who will be notified of any change.
The assessment criteria are as follows: clarity, coherence, logic, rigorousness, precision, completeness, brevity, relevance, cross-cutting nature (within the course and between courses), quality of mathematical interpretations (mathematical meaning of the different coefficients of the equation, e.g.), physical interpretations (dimensions and units, order of magnitude - scaling, e.g.) and geographical and oceanographical interpretations (mono and multivariate spatial and temporal interaction and meaning - type - of the variables e.g.).
The critical mind with regard to the data used (qualification, nature, meaning, representativeness, standardization ...) and methodological choices (justification of the choice of methods, adopted thresholds ...) will also be taken into account in the evaluation.
Furthermore, answers will also be evaluated based on the quality and the originality of the graphic illustrations since graphic expression is the scientist's specificity. It further allows demonstrating a good understanding of the phenomenon. Finally, enriching an answer with a rich personal scientific culture will also be considered a factor of excellence in the assessment.
Advanced satellite oceanography
A non-certifying evaluation is carried out throughout practical classes, as a close interaction between students and teachers.
The certificational evaluation will consist in a personal presentation using digital slides, during the January exam session. It will deal with the three topics studied in class, and the teaching staff will ask questions about the presentation.
This standard evaluation procedure may however be modified in agreement with the students, who will be notified of any change.
The assessment criteria are as follows: clarity, coherence, logic, meticulousness, precision, completeness, brevity, relevance, cross-cutting nature (within the course and between courses), quality of mathematical interpretations (mathematical meaning of the different coefficients of the equation, e.g.), physical interpretations (dimensions and units, order of magnitude - scaling, e.g.) and geographical and oceanological interpretations (mono and multivariate spatial and temporal interaction and meaning - type - of the variables e.g.).
Furthermore, answers will also be evaluated based on the quality and the originality of the graphic illustration since graphic expression is the scientist's specificity. It further allows demonstrating a good understanding of the phenomenon.
Finally, enriching an answer with a rich personal scientific culture will also be considered a factor of excellence in the assessment.
Work placement(s)
Introduction to satellite oceanography
None
Advanced satellite oceanography
None
Organizational remarks
Introduction to satellite oceanography
Classes are held according the planning of courses (http://www.facsc.ulg.ac.be/cms/c_253095/fr/horaires). Theoretical lectures alternate with supervised practical work classes. Attendance is mandatory.
Advanced satellite oceanography
Ideally, classes should begin after the introductory course on ocean remote sensing; however, practical considerations related to the MER master mean classes must be held during the first term. This will not be a problem for students in the second year of the master in oceanography, but for students in the MER master this course will have to be held at the end of the term, so that enough progress will have been made in this introductory course. The scheduling, which is unfortunately not ideal, will be determined based on the timetables of students in the second year of the master in oceanography and the MER master, as well as on the availability of computer-equipped classrooms and the teaching staff.
The course will take place in room B5a/2/35 or B5a/4/18 according to the schedule provided elsewhere (http://www.facsc.ulg.ac.be/cms/c_253095/en/horaires).
Contacts
Introduction to satellite oceanography
Yves CORNET, Professor
Geomatics unit, 17 (B5a), Allée du 6 Août, 4000 Liège
Phone #: +32 4 366 53 71
E-mail: ycornet@ulg.ac.be
Web: http://139.165.44.35/cms/index.php
Advanced satellite oceanography
Yves CORNET, Professor
Geomatics unit, 17 (B5a), Allée du 6 Août, 4000 Liège
Phone #: +32 4 366 53 71
E-mail: ycornet@ulg.ac.be
Web: http://139.165.44.35/cms/index.php
Items online
Introduction to satellite oceanography
Remote Sensing of the Oceans, Introduction to satellite oceanography,
Remote Sensing of the Oceans, Introduction to satellite oceanography
Advanced satellite oceanography
Remote Sensing of the Oceans, Advanced satellite oceanography
Remote Sensing of the Oceans, Advanced satellite oceanography