Remote Sensing: Definition and Data Collection

Remote Sensing: Definition

• Remote sensing is the science of measurement from a distance, obtaining information about an object using a sensor that is physically separated from the object.
• It involves the acquisition of data from a distance, which can be used in various applications.

Data Collection

• Remote sensing provides a regional view of large areas, allowing for the collection of data over a broad range of territories.
• It offers repetitive looks at the same area, enabling the monitoring of changes over time.
• Remote sensors can "see" over a broader portion of the spectrum than the human eye, and can focus on specific bandwidths in an image or multiple bandwidths simultaneously.

Advantages of Remote Sensing

• Provides geo-referenced, digital data.
• Some remote sensors operate in all seasons, at night, and in bad weather.

Who Uses Remote Sensing and Why

• Geologists use remote sensing for minerals and oil prospecting.
• Geographers use remote sensing to detect changes on the Earth's surface that need to be mapped.
• Environmentalists use remote sensing to detect, identify, and follow the movement of pollutants.
• Foresters use remote sensing to gather information about tree types and disease effects.
• Farmers use remote sensing to monitor crop growth and effects of drought, floods, disease, or pests.
• Ship captains use remote sensing to navigate through northern ice packs.
• Firefighters use remote sensing to track the size and movement of forest fires.

Applications of Remote Sensing

• Military operations
• Geological mapping
• Geomorphology
• Hydrology
• Oceanography
• Vegetation
• Archaeology
• Agriculture
• Urban planning
• Landcover/landuse
• Weather
• Disaster management
• Geological applications: surficial deposit/bedrock mapping, lithological mapping, structural mapping, sand and gravel exploration, mineral exploration, environmental geology, and baseline infrastructure

Passive and Active Systems

• Passive systems detect radiation reflected from the target, while active systems emit radiation towards the target and detect the reflection.
• Radar is an example of active remote sensing, used by police to measure vehicle speed.
• A camera is an example of both passive and active remote sensing, depending on the lighting conditions.

Remote Sensing System

• Aerial photography involves taking photographs of the ground from an airborne platform.
• Photogrammetry involves making measurements and maps from photographs, especially from aerial surveying.
• Photogeology involves using aerial photographs to interpret geologic features.

Remote Sensing Process

• Energy Source (A)
• Radiation and Atmosphere (B)
• Interaction with Targets (C)
• Recording energy by sensor (D)
• Transmission and Reception (E)
• Interpretation and Analysis (F)
• Application (G)