I. Intro
Date: 01/18/2023
During the first lab, we went over the knowledge relative to spatial analysis.
II. Type of Resolution
A. Spectral
Spectral resolution refers to the number of bands, as well as the bands’ wavelength ranges in the imagery. This spectral information can be used to identify features or specific phenomena in the image. The higher the spectral resolution, the more bands are available to provide spectral information, meaning more information about features in the imagery.
B. Spatial
Spatial resolution refers to the size of the cell, or pixel. The cell size is the area represented on the ground in the image.
C. Radiometric
Radiometric resolution, often referred to as bit depth, is the range of possible data values that can be stored in each band. It describes sensitivity or brightness values to distinguish features viewed in the same region of the EMS. Visually, this range corresponds to the grayscale values observable in each band. The larger the range of data values, the higher the radiometric resolution. This increases the ability to distinguish features in the imagery with greater detail.
D. Temporal
Temporal resolution refers to when the image was collected and the frequency of collection for the same geographic area. This could include the time of day, date, and time between capture. Collection consistencies allow analysts to look back in time, perform change detection, identify trends, and make predictions about the future. Having more imagery of the same geographic location across time can provide a better understanding of the landscape. A sensor that collects data once every week has a higher temporal resolution than a sensor that collects data once a month. Temporal resolution is determined primarily by the platform type. For example, if the imagery is collected with a satellite it is more likely to collected on consistent cadence, revisiting the same location as the satellite orbits Earth.
III. Composite
A. Natural Color
A natural color band combination is the closest rendition to what is visible with the human eye. In this type of composite rendering, imagery appears the way that you would see features if flying over an area.
B. Color IR
A color infrared composite is a type of false-color IR that helps distinguish between vegetation, urban, and water features. Because the NIR band is displayed in the red color channel, healthy vegetation will appear as shades of red. The vegetation along the river and stream channels (riparian vegetation) is clearly visible as red and magenta colors. Other features, such as different rock types and sand formations, appear with variable colors to help with discrimination.
C. Vegetation Analysis
The vegetation analysis composite is another type of preset false-color IR band combination that you can render in ArcGIS Pro. This band combination highlights vegetation based on its water content and cell structure. Because the NIR band is displayed in the green color channel, healthy vegetation appears as vibrant shades of green.
IV. Getting Started with Imagery and Remote Sensing
It’s an online tutorial made by Esri about ArcGIS Pro.
