METR155 Remote Sensing - Lecture 1

Professor Menglin Susan JinSan Jose State University, Department of Meteorology and Climate Science

Class notes- www.met.sjsu.edu/~jin

Outline of today’s lecture

1. Introduction and Welcome2. Discussion on the “Greensheet” – overview of this class3. Learning Contract4. First Glance on the Power of Remote Sensing from Space5. Get-to-know each other exam

For greensheet, class ppt notes

http://www.met.sjsu.edu/~jin/METR155fall2012.htm

About Professor

1.

2. an effective teacher

3. Approachable, 4. Respectful5. Encouraging

A very good scholar www.met.sjsu.edu/~jin

Research projects: funded by NASA, NSF, Department of DefenseOn land surface climate change, urbanization, remote sensing

20 leading author papers on top journals

GoalMETR155 will help you to know

the Fundamentals of Remote Sensing, Satellite Observations for Climate Change Research,

and gain appreciation of the complexities involved with remote sensing

Homework: 30% (10-12 homework)Midterm Exam(I and II): 40%

Class Participation 5%Final Exam: 25%

Scale: 90+ A, 80’s B, 70’s C, 60’s D, <60 F

Homework will be assigned in class collected in discussions about 1-2 weeks later.

For METR155 Students

Homework: 25% (10-12 homework)Midterm Exam(I and II): 30%

Class Participation 5%Research Project 20%

Final Exam: 20%Scale: 105+ A, 90’s B, 78’s C, 65’s D, <65 F

Homework will be assigned in class collected in discussions on 1-2 weeks later.

Fore METR280 Students (graduate students)

Content

The structure of the course include:

Part 1: Basic theory –radiation, sensor design, orbit

Part 2: Image Processing and RetrievalSkin Temperature,Vegetation IndexCloud Effective radius

Part 3. Application in Climate Research.

See the greensheet for details

Mid-term1

Mid-term2

Research project

Final ExamResearch Report

Lecture Hour: 10:30 – 11:45 PM, Tuesday and Thursday

Place: DH615

Office Hour: Wednesday 11:00 AM -12:00 PMTuesday 1:15-2:15 PM

Place: MSJ’s Office (DH613)

TA: TBD

•I will meet with you for extra office hour whenever you need. •send email for appointment.

References:

•Useful materials will be assigned on webpage/homework/class

Close-to-be TextbookKing, M. D. et al. 2007: Our Changing Planet: The View From Space.

Cambridge; New York : Cambridge University Press,, 2007

Reference BookStephens, G. L. “Remote Sensing of the Lower Atmosphere: An Introduction”Schowengerdt, Robert A.: Remote Sensing Models and Methods for

Image Processing (2nd edition). Academic Press.

Schott, J. R. 1997: Remote Sensing: The Image Chain Approach. Oxford University Press.

Learning Contract

• Instructor– On time and prepared.– Answers questions.– Approachable and friendly.– Fair with assignments and grades.– Genuinely concerned about your learning and

intellectual development.

Learning Contract• Students

– Make every effort to arrive on time; and if late, enter class quietly.

– Preserve a good classroom learning environment by a) refraining from talking when other people

are talking b) turning off cell phones.

– Be courteous to other students and the instructor.– Aware that learning is primarily your responsibility.– Aware of universities policy on academic integrity

and pledge to abide by them at all times. – Have read and understand what plagiarism is and

know how to cite sources properly.

Academic Integrity• Integrity of university, its courses and

degrees relies on academic standards.• Cheating:

– Copying from another’s test, cheatsheet etc.– Sitting an exam by, or as, a surrogate.– Submitting work for another

• Plagiarism:– Representing the work of another as one’s own

(without giving appropriate credit)

Plagiarism• Judicial Affairs

http://sa.sjsu.edu/judicial_affairs/index.html

• Look at the Student Code of Conduct

• Read through SJSU library site on Plagiarism

http://www.sjlibrary.org/services/literacy/info_comp/plagiarism.htm

One World

Why Remote Sensing

• Remote sensing systems are • Instructors area of research

• Wide area of interest with availability of sensor data (Google Earth)

• Examples in this course concentrate on terrestrial and atmosphere remote sensing

• The goal is not to teach remote sensing, but to familiarize with• Jargon/terminology from remote sensing • underlying physics

• Methods introduced here are used in a variety of other fields• Biomedical imaging• Astronomical studies• Industry and manufacturing• Each field has its own idiosyncrasies that will drive the

Strictly speaking, this course is designed to give anintroduction to the topic of remote sensing on earth system and climatology

“Getting Acquainted" Quiz Class Participation

• Write three sentence about Quantum Physics• What is Electromagnetic Spectrum? • What are Transmittance, Absorptance, and

Reflectance?• Why do we need remote sensing from space?• What are the advantages of remote sensing

technique, you feel?• What are the disadvantages of remote

sensing, you feel?

“Getting Acquainted" Quiz answers

Write three sentence about Quantum Physics

Quantum physics is a branch of science that deals with discrete, indivisible units of energy called quanta as described by the Quantum Theory. There are five main ideas represented in Quantum Theory:

• Energy is not continuous, but comes in small but discrete units. • The elementary particles behave both like particles and like waves. • 4. The movement of these particles is inherently random. • It is physically impossible to know both the position and the momentum of

a particle at the same time. The more precisely one is known, the less precise the measurement of the other is.

• The atomic world is nothing like the world we live in.

(courtesy http://library.thinkquest.org/3487/qp.html)

“Getting Acquainted" Quiz answers

• Write three sentence about Quantum Physics

Quantum physics is a branch of science that deals with discrete, indivisible units of energy called quanta as described by the Quantum Theory. There are five main ideas represented in Quantum Theory:

• Energy is not continuous, but comes in small but discrete units. 1 • The elementary particles behave both like particles and like waves. 2 • The movement of these particles is inherently random. 3 • It is physically impossible to know both the position and the momentum of a particle at the

same time. The more precisely one is known, the less precise the measurement of the other is.4

• The atomic world is nothing like the world we live in. 5

• What is Electromagnetic Spectrum? • What are Transmittance, Absorptance, and Reflectance?• Why do we need remote sensing from space?• What are the advantages of remote sensing technique, you feel?• What are the disadvantages of remote sensing, you feel?

“Getting Acquainted" Quiz answers

• What is Electromagnetic Spectrum? The electromagnetic spectrum is the range of all possible

frequencies of electromagnetic radiation • What are Transmittance, Absorptance, and Reflectance?• Why do we need remote sensing from space?• What are the advantages of remote sensing technique, you feel?Large coverage, long-duration, many variables observed

instantaneously, etc

• What are the disadvantages of remote sensing, you feel? Uncertainties remain. For example, clouds/aerosol/atmosphere interruption, surface noise, instrument

design not perfect, retrieval algorithm needs development, etc

More on Quiz

• To ensure the good communication between professor and students, how would you feel that the professor is approachable?

• After each class, how many hours do you to spend to go over class material?

Let’s see

Remote Sensing: Needs and Examples

.

.

1. Why do we need remote sensing from space?

2. What are the advantages of remote sensing technique?

3. What are the disadvantages of remote sensing?

MODIS Snow Observations

See this video at http://www.met.sjsu.edu/~jin/video/GlobalSnow.mpg

Advantages of MODIS snow (pervious video)

• High resolution (1km)

• High Coverage (global)

• Can assess remote regions including mountains and polar regions

• Continuous observations (2-per-day, 10 years)

Fire Observation on Mountain EtnaIn July 2001 Mt Etna on the island of Sicily exploded dramatically into life.

See this video at http://www.met.sjsu.edu/~jin/video/MtEtna.mpg

Himalayas

Land cover,

Elevation

Surface roughness

Snow coverage

Surface temperature

Vegetation

albedo

See this video at http://www.met.sjsu.edu/~jin/video/Himalayas.mov

Katrina

See this video at http://www.met.sjsu.edu/~jin/video/katrina-visir_sm.mov

Clouds and Aerosol

video: Aerosol-GRECE_1

See this video at http://www.met.sjsu.edu/~jin/video/aerosol-GRECE_1.mov

Concept of Remote Sensing

“Remote sensing” is something we do all the time!

Several of the human senses gather their awareness of the external world almost entirely by perceiving a variety of signals, either emitted or reflected, actively or passively, from objects that transmit this information in waves or pulses.

One World

A formal and comprehensive definition of applied remote sensing• Remote Sensing in the most generally accepted meaning refers

to instrument-based techniques employed in the acquisition and measurement of spatially organized (most commonly, geographically distributed) data/information on some property(ies) (spectral; spatial; physical) of an array of target points (pixels) within the sensed scene that correspond to features, objects, and materials, doing this by applying one or more recording devices not in physical, intimate contact with the item(s) under surveillance (thus at a finite distance from the observed target, in which the spatial arrangement is preserved); techniques involve amassing knowledge pertinent to the sensed scene (target) by utilizing electromagnetic radiation, force fields, or acoustic energy sensed by recording cameras, radiometers and scanners, lasers, radio frequency receivers, radar systems, sonar, thermal devices, sound detectors, seismographs, magnetometers, gravimeters, scintillometers, and other instruments.

This is a rather lengthy and all-inclusive definition

make a list of key words in it

• Acquisition/measurement; • data/information; • properties; • phenomenon,...• material; • recording device; • not in contact; • measuring field;• radiation; • instruments.

two more simplified definitions

• First:Remote Sensing involves gathering data and information about the physical "world" by detecting and measuring signals composed of radiation, particles, and fields emanating from objects located beyond the immediate vicinity of the sensor device(s)

• Second:

two more simplified definitions

• Second: (more related to this course)

Remote Sensing is a technology for sampling electromagnetic radiation to acquire and interpret non-contiguous geospatial data from which to extract information about features, objects, and classes on the Earth's land surface, oceans, and atmosphere (and, where applicable, on the exteriors of other bodies in the solar system, or, in the broadest framework, celestial bodies such as stars and galaxies).

Vertical Layers of the Lower Atmosphere

Atmospheric Properties vs. Altitude

This diagram for remote sensingOrbit platform

Radiation, EM specturm

• Electromagnetic radiation behaves in most

circumstances as waves and can thus be characterized as waves.

• See http://users.humboldt.edu/rpaselk/C107.F09/C107Notes/C107nLec13.html

• Labeled sine wave diagram

thermal radiation

• All matter above absolute zero (0 Kelvin = -273°C = - 459.4°F) emits radiant energy in form of electromagnetic waves.

• The basic physical law concerning thermal radiation emission is the Stefan Boltzmann law, which states that that the heat flux emitted by an ideal radiator which is called a blackbody is proportional to the absolute temperature (in K) to the fourth power

•

3 key three additional properties of surfaces which control the radiation heat transfer of a surface - The absorptivity α, transmissivity T and the reflectivity ρ.

thermal radiation (cont.)

• Real surfaces emit less radiation than the ideal blackbody. The ratio of actual emissive power Eb to the emissive power of a blackbody Eb at the same temperature is called the emissivity.

• Furthermore Kirchhoff’s identity rule states that absorbtivity and emissivity are equal at the same wavelength.

aλ=ελ

Besides the sun, al other objects with temperature > 0 K emits radiation at their temperatures

Key components of Remote Sensing

• Sensor

• Object (not contiguous to sensor)

• Radiation (shortwave, infrared, microwave etc)

• Things emits energy (sun, earth surface etc)

Class activity

• • Is there remote sensing here?

Explain in terms of major components

emitted or reflected, actively or passively,

• Senor senses radiance either emitted (from earth surface, atmosphere) or reflected solar radiation

• Sensor can either passively receive radiance from the object or emit radiance to the object first and then receive its reflected signal

Example of passive and active remote sensing

In this figure, which is passive and which is active remote sensing environment

Passive and Active Remote Sensors

• Remote sensing systems which measure energy that is naturally available are called Passive Sensors. (Sun, surface emission, etc)

• Active sensors, on the other hand, transmit short bursts or 'pulses' of electromagnetic energy in the direction of interest and record the origin and strength of the backscatter received from objects within the system's field of view. Passive systems sense low level microwave radiation given off by all objects in the natural environment.

Why need remote sensing in climate change study?

Change in surface temperature in 20th century

Temperature is measured by therometer

World Meteorological Organization (WMO) http://www.wmo.int/pages/index_en.html

Weather station

http://www.nationmaster.com/encyclopedia/Image:Translational-motion.gif

The Land and Oceans have both warmed, but…

1. Evaporation, transpiration (plants)

2. Atmospheric transport (vapor)

3. Condensation (liquid water, ice)

4. Precipitation

5. Surface transport (continental rivers, aquifers and ocean currents)

Earth’s Hydrological Cycle - Schematic

PHYS 622 - Clouds, spring ‘04, lect. 1, Platnick

Precipitation patterns have changed

Importance of remote sensingRemote Sensing allows data in locations that may be

inaccessible or too large for in situ approaches• Interplanetary studies are an excellent example of where remote

sensing is useful• Sample and return missions are expensive and difficult• Apollo missions were last fully successful sample and return missions

(Genesis was partially successful)• Still, remote sensing was critical even in those missions to determine

where best to sample Meteorological applications

• Probably the clearest example with the widest audience and daily impact• Meteorological satellites cover large areas that are inaccessible• Can cover these areas repeatedly to look for changes over time

• National Defense• Resource Mapping

“Getting Acquainted" Quiz answers

• Write three sentence about Quantum Physics

Quantum physics is a branch of science that deals with discrete, indivisible units of energy called quanta as described by the Quantum Theory. There are five main ideas represented in Quantum Theory:

• Energy is not continuous, but comes in small but discrete units. 1 • The elementary particles behave both like particles and like waves. 2 • The movement of these particles is inherently random. 3 • It is physically impossible to know both the position and the momentum of a particle at the

same time. The more precisely one is known, the less precise the measurement of the other is.4

• The atomic world is nothing like the world we live in. 5

• What is Electromagnetic Spectrum? • What are Transmittance, Absorptance, and Reflectance?• Why do we need remote sensing from space?• What are the advantages of remote sensing technique, you feel?• What are the disadvantages of remote sensing, you feel?