Remote Sensing for Environmental Sciences

1. Introductory Remarks on Remote Sensing.- 1.1 Application Areas of Remote Sensing.- 1.2 Sensing Systems.- 1.3 Remote Sensing and Spectral Constraints.- 2. Aerospace Photography.- 2.1 Introduction.- 2.2 Characteristics of Photographic Process.- 2.2.1 Sensitometry — General.- 2.2.2 The Characteristic Curve.- 2.2.3 Development Control.- 2.2.4 Exposure Control.- 2.2.5 Film Speed.- 2.2.6 Reciprocity Law Anomalies.- 2.2.7 Density Measurement.- 2.2.8 Measurement of Color.- 2.2.9 Tone Reproduction Theory.- 2.2.10 Spectral Sensitivity.- 2.2.11 Resolution.- 2.2.12 Granularity.- 2.2.13 Dimensional Stability and Mechanical Properties.- 2.3 Cameras and Films.- 2.3.1 Cameras (General).- 2.3.2 Aerial Cameras — Common Features.- 2.3.3 Optical System.- 2.3.4 Calibration.- 2.3.5 Image Motion.- 2.3.6 Hand Held Cameras.- 2.3.7 Special Cameras.- 2.3.8 Film (General).- 2.3.9 Aerial Photographic Materials.- 2.3.10 Black-and-White Camera Films.- 2.3.11 Color Camera Films.- 2.4 Photographic Attributes of Earth Sciences.- 2.4.1 Agriculture.- 2.4.2 Geography and Geology.- 2.4.3 Hydrology and Oceanography.- 2.4.4 Anomalies, Atmospheric.- 2.4.5 Factors Affecting the Photo Image.- 2.4.6 Image Formation on Color Film.- 2.4.7 Processing of Color Film.- 2.4.8 Photo Systems, Choice.- 2.4.9 Image Enhancement Procedure.- 3 Infrared Sensing Methods.- 3.1 Introduction.- 3.2 The Infrared Radiation Field.- 3.3 Fundamentals of Measurement.- 3.4 Methods of Measurement.- 3.4.1 The Single Element Radiometer.- 3.4.2 Imaging Radiometers.- 3.4.3 Multi Wavelength Channel Radiometers.- 3.4.4 Spectrometers.- 3.4.5 Interferometers.- 3.5 Applications.- 3.6 Data Interpretation Error Sources.- 3.7 Expectations of the Near Future.- References.- 4 Laser Applications in Remote Sensing.- 4.1 Introduction.- 4.1.1 Scope and Definitions.- 4.1.2 Technical Approaches.- 4.2 Fundamentals of Physical Processes Involved.- 4.2.1 Specular Reflection and Elastic (Non-resonant) Scattering.- 4.2.2 Inelastic and Resonant Scattering.- 4.2.3 Resonant Absorption.- 4.2.4 Doppler Effects.- 4.2.5 Polarization.- 4.3 Instrumentation.- 4.3.1 System Concepts.- 4.3.2 System Configuration.- 4.3.3 Lasers.- 4.3.4 Photodetection.- 4.3.5 Eye Safety.- 4.3.6 Viewpoint of Remote Sensing.- 4.4 Applications.- 4.4.1 General.- 4.4.2 Backscattering Techniques — Non-resonant Elastic Scattering.- 4.4.3 Inelastic and Resonant Backscattering.- 4.4.4 Resonant Absorption.- 4.4.5 Doppler Techniques.- 4.4.6 Polarization.- References.- 5 Radar Methods.- 5.1 General Aspects.- 5.1.1 Introduction.- 5.1.2 Resolution.- 5.1.3 Image Build-up; Flight Procedure.- 5.1.4 Parallax.- 5.1.5 Image Correction.- 5.1.6 Registration of the Radar Signals.- 5.2 Backgrounds.- 5.2.1 Introduction.- 5.2.2 The Radar Equation.- 5.2.3 Ground Returns.- 5.3 Applications.- 5.3.1 Introduction.- 5.3.2 Geography.- 5.3.3 Geology.- 5.3.4 Vegetation Studies.- 5.3.5 Sea, Coastal and Oceanographic Studies.- 5.4 Conclusion.- References.- 6 Passive Microwave Sensing.- 6.1 Principles of Passive Microwave Remote Sensing.- 6.1.1 Physical Fundamentals of Microwave Radiometry.- 6.1.2 Semitransparent Media.- 6.1.3 The Effects of the Atmosphere.- 6.2 Instrumental Aspects of Microwave Radiometry.- 6.2.1 The Sensitivity of a Microwave Radiometer.- 6.2.2 Other Types of Radiometers.- 6.2.3 Angular Resolution and Range of Passive Microwave Sensing.- 6.2.4 Realisations of Microwave Radiometers.- 6.3 Emissive Properties of Materials on the Surface of the Earth.- 6.3.1 Plane Surfaces of Homogeneous Materials.- 6.3.2 Heterogeneous Media.- 6.3.3 Rough Surfaces.- 6.3.4 Various Investigations on Emissivities.- 6.4 Remote Determination of Atmospheric Constituents by Their Microwave Spectra.- 6.4.1 The Absorption Coefficients of the Line Spectra.- 6.4.2 Determinations of Height Profiles.- 6.5 Passive Microwave Remote Sensing of Water, Ice and Snow.- 6.5.1 Investigations of Water Surfaces.- 6.5.2 Investigations of Ice and Snow.- 6.6 Investigations of the Soil, Vegetation and Geological Features.- 6.7 Investigations of the Atmosphere and of Meteorological Features.- 6.7.1 Sounding of Atmospheric Constituents from Molecular Line Radiation.- 6.7.2 Observation of Meteorological Features.- References.- 7 Applications of Gamma Radiation in Remote Sensing.- 7.1 The Natural Gamma-radiation Field.- 7.2 Gamma-ray Detector Systems.- 7.3 Operational Procedures.- 7.3.1 Background Radiation.- 7.3.2 Height Correction.- 7.3.3 Calibration and Spectral Stripping.- 7.4 Applications.- 7.4.1 Mineral Exploration.- 7.4.2 Geological Mapping.- 7.4.3 Water-equivalent Snow Measurements.- 7.4.4 Soil Moisture Measurement.- 7.4.5 Monitoring Nuclear Facilities.- 7.5 Future Prospects.- References.- 8 Sonar Methods.- 8.1 Introduction.- 8.2 Propagation of Acoustic Energy.- 8.2.1 General.- 8.2.2 Absorption Losses in Water.- 8.2.3 Beam Bending in Water.- 8.2.4 Propagation in Air.- 8.3 The Sonar Equation.- 8.3.1 Transducers and Arrays.- 8.3.2 Noise and Reverberation.- 8.3.3 Signal to Noise Ratio and Signal to Reverberation Ratio.- 8.3.4 Interference Signals in Air.- 8.4 Factors Affecting Resolution in a Sonar System.- 8.4.1 General.- 8.4.2 Range Resolution.- 8.4.3 Bearing Resolution.- 8.4.4 Doppler Effect in Sonar.- 8.5 Applications.- 8.5.1 Echo Sounding.- 8.5.2 Sonars with Fixed Beams.- 8.5.3 Mechanically Rotated Sonar Array Systems.- 8.5.4 Side-scan Sonars.- 8.5.5 Sub-bottom Profiling Systems.- 8.5.6 Sonars with Sectors Scanned Electronically.- 8.5.7 Remote Sensing Application of Sonar in Air.- References.- 9. Digital Picture Processing.- 9.1 Introduction.- 9.1.1 General Remarks.- 9.1.2 Relation between Image and Real Scene.- 9.1.3 Enhancement and Filtering.- 9.2 The Elements of an Image Data Processing and Analysis System.- 9.2.1 Data Acquisition Subsystem.- 9.2.2 Data Handling Subsystem.- 9.2.3 Data Preprocessing Subsystem.- 9.2.4 Data Storage and Retrieval Subsystem.- 9.3 Geometric Corrections.- 9.3.1 Linear Transformations.- 9.3.2 Quadratic and Higher Order Transformations.- 9.3.3 Reference Marks.- 9.3.4 Image Gridding.- 9.3.5 Image Registration.- 9.3.6 Geometric Correction Concepts.- 9.4 Image Enhancement and Filtering Processes.- 9.4.1 Enhancement Processes.- 9.4.2 Image Smoothing.- 9.4.3 Image Sharpening.- 9.4.4 Matched Filters.- 9.4.5 Ratio Mapping and Generalization of Image Combination Procedures.- 9.4.6 Pseudocolor Transformation.- 9.5 Feature Extraction and Classification.- 9.5.1 Spectral Features.- 9.5.2 Spatial Features.- 9.5.3 The Decision Process.- 9.5.4 The Decision Criteria.- 9.5.5 Unsupervised Classification.- 9.5.6 Recognizing of Bridges, Rivers, Lakes, and Islands.- 9.6 Appendix 1: The Image Signal in Spatial and Frequency Domain.- 9.6.1 Signals in the Spatial Domain.- 9.6.2 Signals in the Frequency Domain.- 9.7 Appendix 2: Numerical Example for Texture-context Features.- References.- Color Plates.