Remote Sensing and Data Characteristics

Remote Sensing

The acquisition of information about an object or phenomenon without making physical contact.

Discovery Shuttle

A spacecraft that surveyed 70% of the Earth's surface.

Optimized Management of Natural Resources

The effective use and conservation of natural resources to enhance sustainability.

Reflectance

The portion of radiation that is reflected by a surface, different from the radiation that is emitted.

Passive Remote Systems

Remote sensing systems that collect energy from the sun.

Absorption

The process where a target takes in energy from radiation.

Transmission

The passing of energy through a medium without being reflected or absorbed.

Satellite Sensor System

A system used to collect data through sensors on satellites.

Hyperspectral Non-Imaging Systems

Systems that collect detailed spectral information without creating images.

Biophysical Measurements

Measurements related to the physical properties of biological systems.

NDVI

Normalized Difference Vegetation Index, used to assess the health of vegetation.

Synoptic View

A large-area view of the Earth surface obtained from satellite images.

Repetitive Coverage

The ability to take repeated images of the same regions over time.

Spatial Resolution

The amount of area represented by each pixel in an image. How sharp the image is

Spectral Resolution

The ability of a system to distinguish different wavelengths of energy. You have an image in each color (R, G, B) viewing all these at the same timeyou get this

Radiometric Resolution

The sensitivity of a sensor to detect subtle differences in energy.

Temporal Resolution

The frequency with which images of the same area can be captured. Also know was Revisit time

True Color Image

An image that closely resembles how the scene would appear to the human eye. (400-500nm blue, 500-600nm green, 600-700nm red)

False Color Image

An image that uses color combinations not visible to the human eye to represent data. (500-600nm blue, 600-700nm green, 700-800nm red)

red indcates healthy vegetation

Broad Band Vegetation Indices

Indices such as NDVI that assess vegetation health using broad wavelengths.

Specific Band Vegetation Indices

Indices that analyze specific bands of the electromagnetic spectrum.

Georeferenced Image

An image that has been corrected for spatial distortion and aligned to a coordinate system.

Panchromatic Imagery

Greyscale images that provide high spatial resolution.

Automated Analysis of Satellite Imagery

The use of automated tools to analyze satellite images for various applications.

Conditions for Aerial Photography

no smoke or haze, no clouds or cloud shadows, solar angle 30 degrees above horizon, less than 5 degrees of tilt

Image Geo-Referencing

The process of aligning images to geographical coordinates.

Ortho Imagery Requirements

exterior orientation, camera model, relief displacement, compensating for elevation

Digital Photogrammetry

The use of photography, especially aerial photography, to make measurements.

Thermal Imagery

Imagery used to detect temperature differences and stress in crops.

Energy/Target Interaction

The interaction between energy emitted and the target being observed.

Multispectral Data

Data collected from multiple bands of the electromagnetic spectrum.

Leaf Area Index

A measure of leaf area relative to the ground area.

Chlorophyll Measurement

The assessment of chlorophyll content to determine plant health.

Relief Displacement

The apparent shift in the position of an object in an image due to elevation differences.

Data Selection Criteria

Guidelines used to choose appropriate data for analysis, what size photo, height from the ground

NEAR-Infrared

A portion of the infrared spectrum that is important for assessing vegetation health.

Radiometric Resolution - Sensitivity

The capability of a sensor to differentiate between varying radiation intensities.

Multispectral Imagery

anutomated analysis of satellite imagery for 30 years

Hyperspectral Profile

High-resolution spectral data collected across many narrow wavelengths.

Satellite Revisit Time

The time interval between successive images taken by a satellite of the same area.