AI Remote Sensing Study Summary Sheet PDF

**Study Summary Sheet: W25 GIS2103 - Introduction to Remote Sensing** **1. Key Concepts of Remote Sensing** - **Definition:**\ Remote sensing involves the use of sensors to collect data about Earth\'s surface from a distance, such as satellites, drones, or aircraft. - **Purpose:**...

**Study Summary Sheet: W25 GIS2103 - Introduction to Remote Sensing** **1. Key Concepts of Remote Sensing** - **Definition:**\ Remote sensing involves the use of sensors to collect data about Earth\'s surface from a distance, such as satellites, drones, or aircraft. - **Purpose:** - Identify and map objects or features on Earth. - Provide input data for geospatial and imagery analysis (Exploitation). - **Process:** - Sensors capture data (heat, light, sound, etc.). - Data is processed to derive geographic or physical properties (e.g., geolocation, dimensions). **Conduction** is the transfer of heat through direct contact between particles of a solid without the movement of the material itself. **Convection** is the transfer of heat through the movement of fluids (liquids or gases) caused by temperature differences. Three active **2. Operational Environment** - **Definition:**\ A composite of conditions, circumstances, and influences affecting decisions and operations, including: - Natural (terrain, weather) - Man-made (urban infrastructure, military installations) - Domains: land, air, sea, space, cyberspace. **3. Active vs. Passive Remote Sensing** - **Active Sensors:**\ Emit their energy (e.g. Sonar, Radar, LiDAR) and measure the reflected signal. Can operate in any weather or time. - **Test Question:** Three types of Active Sensors - **Passive Sensors:**\ Measure natural energy (e.g., sunlight) reflected or emitted by objects. Dependent on external energy sources like sunlight. **4. Types of Imagery** - **Still Digital Images:**\ Captures electromagnetic energy, represented as pixels with attributes (e.g., brightness, color).\ Examples: Handheld devices, satellite images. - **Motion Imagery:**\ Continuous frames collected over time, useful for observing dynamic behaviors (e.g., at 24+ fps for full motion video). - **Vertical Imagery:**\ Captured directly above; often ortho-corrected for true spatial representation. - **Oblique Imagery:**\ Taken at an angle, presenting a natural perspective; harder to georeference. - **Stereo Imagery:**\ Creates 3D representation using two perspectives, based on parallax differences. **5. Imagery Exploitation and Applications** - **Purpose of Exploitation:** - **F-DAMM**: Forecast, Detect, Assess, Map, Monitor. - Analyze and interpret imagery for geospatial insights. - **Tools Used:** - Image space analysis (features displayed in original clarity). - Precision positioning for exact geolocation of objects. - Software includes ESRI ArcGIS Pro, Drone2Map, NV5 Geospatial ENVI. **6. Sensors and Performance Parameters** - **Definition of Sensor:**\ Devices responding to stimuli (e.g., heat, light) to transmit measurable impulses. - **Performance Parameters:** - Spatial resolution, spectral resolution, and signal-to-noise ratio define sensor effectiveness. - Optimal parameters depend on study requirements (e.g., weather, surface type). **7. Biophysical Variables and Environmental Context** - **Man-Made vs. Natural Environments:** - **Man-Made:** Urban and military settings. - **Natural:** Terrain and weather factors. - **Influences on Remote Sensing:**\ Environmental characteristics, such as land cover or atmospheric conditions, impact sensor readings and analysis. **8. Image Space Analysis** - **Advantages:** - Preserves original clarity without resampling. - Intuitive interpretation in oblique/perspective imagery. - Accurate mapping and editing capabilities integrated with geodatabases **Study Summary Sheet: W25 GIS2103 L1 - Electromagnetic Radiation (EMR) Principles** **1. Introduction to EMR Principles** - **Energy Transfer in Remote Sensing:** - The Sun\'s energy is emitted, travels through space, interacts with the Earth\'s atmosphere and surface, and is captured by remote sensors. - These interactions affect the radiometric quality of data, necessitating preprocessing and interpretation. - **Energy Transfer Mechanisms:** - **Conduction:** Direct transfer via molecular collisions (e.g., heating a pan). - **Convection:** Movement of energy via fluid motion (e.g., rising warm air). - **Radiation:** Transfer via electromagnetic waves, essential for remote sensing as it operates in a vacuum. **2. Models of Electromagnetic Radiation** - **Wave Model:** - EMR propagates as waves with electric and magnetic fields perpendicular (90 degrees) to each other. - Properties: - **Wavelength (λ):** Distance between wave crests, measured in micrometers (µm) or nanometers (nm). - **Frequency (ν):** Number of wave cycles per second (Hertz, Hz). - **Relationship:** c=λ⋅νc = \\lambda \\cdot \\nuc=λ⋅ν (speed of light, ccc, is constant at 3×1083 \\times 10\^83×108 m/s). - **Stefan-Boltzmann Law:** Total radiation emitted by an object depends on its temperature. - **Wein\'s Displacement Law:** Dominant wavelength (λmax\\lambda\_{max}λmax​) inversely related to temperature. - **Particle Model:** - Quantum theory explains the behavior of matter and energy at very small scales, describing particles as having both wave-like and particle-like properties. - EMR consists of photons, discrete packets of energy. - **Quantum Theory:** Q = h x n whereas Q = Energy of a photon h = is Plank's constant n= frequency of radiation - **Photon Emission:** Electrons absorb energy, move to higher orbits, and release photons when returning to lower orbits. At very high temperatures, atoms heat up so much that their electrons break free, leaving behind positively charged ions. These free electrons and ions create radiation in the ultraviolet and visible light spectrum as electrons change energy levels. When free electrons return to atoms, they emit smooth, continuous radiation instead of specific colors. Interactions between free electrons and nuclei also produce radiation at all wavelengths. This type of continuous radiation is typical of plasma, like the Sun\'s hot surface. **3. Electromagnetic Spectrum** - **Characteristics:** - The Sun emits a continuous spectrum, including visible, infrared, and ultraviolet light. - The Earth\'s atmosphere selectively absorbs and transmits energy (e.g., atmospheric windows for visible light). **4. Atmospheric Energy-Matter Interactions** - **Refraction:** - Bending of light as it passes through layers of varying density (described by Snell's Law). - Errors due to refraction are predictable and correctable. - **Scattering:** - Redistribution of EMR due to atmospheric particles. - Types: 1. **Rayleigh Scattering:** Small particles; short wavelengths (e.g., blue sky). 2. **Mie Scattering:** Larger particles; visible light (e.g., polluted sunsets). 3. **Non-Selective Scattering:** Very large particles; all wavelengths (e.g., white clouds). - **Absorption:** - EMR is absorbed and converted into other energy forms. - **Absorption Bands:** Spectral ranges where certain gases (e.g., H2\_22​O, CO2\_22​) absorb energy. - **Atmospheric Windows:** Regions where energy is transmitted effectively, crucial for remote sensing. - **Reflectance:** - Radiation bounces off surfaces, governed by the laws of reflection. - Reflectance is predictable and essential for interpreting remote sensing data. **5. Key Remote Sensing Principles** - **Blackbody Radiation:** Blackbody radiation is the emission of light and heat from an object that absorbs all incoming radiation and re-emits energy based solely on its temperature. - The Sun (6,000 K): Emits in the visible spectrum (peak at 0.48 µm). The sun is a blackbody; the Sun is considered a blackbody because it emits a continuous spectrum of radiation that closely matches the theoretical blackbody radiation curve for its temperature. - The Earth (300 K): Emits in the infrared spectrum (peak at 9.66 µm). - **Scattering and Absorption Impact:** - Scattering can reduce image contrast. - Absorption creates gaps in the spectrum, requiring remote sensors to operate in atmospheric windows. **Coniferous trees:** are evergreen trees with needle-like leaves that produce cones, such as pines and firs. **Deciduous trees:** are trees that shed their broad leaves annually, such as oaks and maples. **Schrödinger\'s model:** introduced quantum numbers to describe the behavior and position of electrons in atoms In ENVI, the value in parentheses next to a band in the Data Manager typically represents the **wavelength** of that band. It indicates the central wavelength of the spectral band ENVI: WEEK 1 INCLASS A screenshot of a computer Description automatically generated