Lecture 1 -- Introduction to Remote Sensing

Instructor Information

  • Instructor: Desheng Liu

  • Department: Geography, The Ohio State University

  • Contact: liu.738@osu.edu

  • Course: GEOG 5225: Geographic Applications of Remote Sensing

Lecture Overview

  • Lecture 1 Topics:

    • What Is Remote Sensing?

    • Remote Sensing Process

    • A Brief History of Remote Sensing

    • Remote Sensing Applications

What is Remote Sensing?

  • Definition:

    • "The science and art of obtaining information about an object, area, or phenomenon through the analysis of data acquired by a device that is not in contact with the object, area, or phenomenon under investigation."

    • Source: Lillesand and Kiefer, 2000

Components of Remote Sensing

Scientific Foundations

  • Physical Sciences

  • Mathematics and Logic

  • Social Sciences

  • Biological Sciences

  • Geographic Cartography/Information

  • Surveying Systems

The Remote Sensing Process

Steps in Remote Sensing

  1. Statement of Problem

  2. Data Collection

  3. Data-to-Information Conversion

    • Formulate Hypothesis

    • In Situ Measurements

  4. Image Processing

    • Analog (Visual) Image Processing

    • Digital Image Processing

      • Preprocessing

      • Accuracy Assessment

  5. Presentation and Interpretation

  6. Model Selection

Image Processing Techniques

  • Analog Images:

    • Visual analysis and interpretation

  • Digital Images:

    • Radiometric Correction

    • Geometric Correction

    • Thematic Maps

    • Statistical Analysis (univariate and multivariate)

A Brief History of Remote Sensing

Early Aerial Photography

  1. Balloon Photography:

    • 1858: Gaspard Tournachon (Nadar) photographed the Bievre, France (80m high)

    • 1860: James Black over Boston (365m high)

  2. Kite Photography:

    • 1882: Archibald sent the first aerial photograph from a kite.

    • 1906: George Lawrence captured images of San Francisco after the earthquake.

  3. Pigeon Photography:

    • 1903, photographs taken using carrier pigeons.

  4. Airplane Photography:

    • 1908: First aerial motion pictures over Le Mans, France.

    • World War I: Over one million reconnaissance photos taken for military use.

Space-Borne Imaging

  • 1960s:

    • Launch of various satellites including the MetSat and CORONA spy satellite program.

    • Landsat MSS and Landsat TM launched for land observation (1972 & 1986).

Remote Sensing Applications

Key Applications

  1. Global Land Cover Characterization

    • Classifications include developed land, forests, cropland, water bodies, etc.

  2. Nighttime Lights Mapping

    • Data from Defense Meteorological Satellite Program (DMSP).

  3. MODIS Applications

    • Sea Surface Temperature and Leaf Area Index

  4. Wildfire Mapping

    • Hotspot locations from NOAA/AVHRR data (1989-1999).

  5. Natural Disaster Assessment

    • Case study: Japan earthquake and tsunami (March 12, 2011).

  6. Hydrological Studies

    • Soil moisture, snow depth, and transpiration data from Landsat.

  7. Geological Mapping

    • Case study: Cuprite, Nevada using hyperspectral imagery.

  8. Urban Expansion Studies

    • Urban footprint analysis for Charleston area (1973, 1994, 2030).

  9. Crime Mapping

    • Spatial data on crime incidents with location maps.

  10. Infectious Disease Studies

    • Correlation of sea surface temperature with cholera outbreaks.

  11. Air Pollution Monitoring

    • Analysis of PM2.5 measurements and trends.

Conclusion

  • Remote Sensing is a multifaceted field with applications across various scientific domains and real-world issues, supporting enhanced understanding and decision-making in geography and environmental monitoring.