Field Methods in Remote Sensing

1 Problems and Objectives in Remote Sensing Field Work 1(11) Problems Encountered in Field Work 1(4) Defining Objectives 5(5) Planning Field Work Based on Objectives Statement 10(2) 2 Sampling in the Field 12(14) Sampling from Aerial Photographs or Thematic Maps 13(1) Timing of Observations 13(1) Sampling Patterns 14(6) Comments on Sampling Practicalities 20(1) Number of Samples 21(1) Size of Sample Sites 22(3) Where to Begin Measurements 25(1) 3 Finding Locations in the Field 26(16) Overview of Location-Finding Using GPS 27(6) Preparation for GPS Field Work 33(4) Procedures in the Field with GPS 37(5) 4 Field Spectroscopy 42(17) Fundamentals of Reflectance 42(4) Uses of Field Spectra in Image Analysis 46(3) Assumptions When Measuring Reflectance Spectra 49(2) Field Procedures for Measuring Reflectance Spectra 51(4) Use of Artificial Illumination 55(2) Field Notes for Spectral Surveys 57(2) 5 Collecting Thematic Data in the Field 59(12) Preliminary Preparation 60(1) Reference Information 60(3) Types of Field Work 63(1) Field Work Tasks 64(2) Selection of Physical Features for Observation or Measurement 66(1) Measurement Procedures in the Field 67(1) Measurement Error 68(1) Note Taking in the Field 68(1) Field Preparation Checklist 69(2) 6 Measurement of Vegetation 71(18) Spectral Response of Vegetation 71(5) Which Biophysical Features to Measure 76(2) Timing of Measurements 78(3) Standardization of Mapping Methods 81(1) General Methods of Measuring Vegetation 82(6) Selecting a Measurement Method 88(1) 7 Soil and Other Surface Materials 89(12) Spectral Responses of Earth Materials 89(5) What Soil Features to Measure 94(1) Field Estimates of Soil Characteristics 95(3) Soil Mapping 98(2) Locations of Soil Sample Sites 100(1) 8 Water Bodies and Snow Cover 101(14) Spectral Response of Water 101(2) What Can Be Detected, Measured, and Mapped in Water? 103(1) Timing of Water Measurements 103(2) Field Measurements 105(5) Spectral Response of Snow 110(1) Description of Snow Cover 111(1) Measurement of Snow Cover 111(4) 9 Applying Concepts of Field Work to Urban Projects 115(6) Project Objectives 115(1) Spectral Response in Urban Areas 116(1) Aerial Photographs 116(1) Urban Land Use 117(1) Urban Socioeconomic Studies 117(1) Urban Hydrology 118(3) APPENDIX 1 Selected Bibliography on Field Methods and Related Topics Not Cited in the References 121(10) APPENDIX 2 Field Note Forms 131(12) APPENDIX 3 Metadata Online Resources 143(4) References 147(6) Index 153(6) About the Author 159