NDVI

Measuring Vegetation from Satellite Imagery with NDVI

July 14, 2017By Mark AltaweelSpatial Analysis

Normalized difference vegetation index (NDVI) is a remote sensing technique that uses measurement of vegetation signatures to measure vegetation types and growth.

Mapping Soil Moisture in Ethiopia Using Remote Sensing Techniques

April 29, 2016By Elizabeth BornemanSpatial Analysis

Remote sensing can be used to assess soil moisture across a region. Learn more about two methods NASA has used to map out soil moisture in Ethiopia.

Click and drag the slider bar to compare these LDCM images, which zoom into the area around Fort Collins, Colo. On the left, the image is shown in natural color, created using data from OLI spectral bands 2 (blue), 3 (green), and 4 (red). The image on the right was created using data from OLI bands 3 (green), 5 (near infrared), and 7 (short wave infrared 2) displayed as blue, green and red, respectively. In the left-hand natural color image, the city's elongated Horsetooth Reservoir, a source of drinking water, lies west of the city. A dark wildfire burn scar from the Galena Fire is visible just to the left of the reservoir. The scar shows up bright, rusty red in the false color image.

Most imagery for use in GIS projects consist of satellite images or aerial photographs but it can also include, thermal images, digital elevation models (DEMs), scanned maps and land classification maps. This article examines imagery and how to effectively gather, store, process and interpret it for a variety of different GIS projects.

How Geospatial Technologies Are Being Used to Study Light Pollution

Light pollution is considered to be artificial or anthropogenic introduction of light in what would normally be a night setting. Light pollution has grown significantly throughout the twentieth century as cheap, constant light became more possible in urban areas. However, light pollution has the potential to negatively affect our health, […]

Jason-2 Satellite to Help Improve Maps of Sea Floor

Jason-2 will be collecting data about the sea floor every 5 miles, which will be used to create a high-definition estimate of the average surface height of the ocean in various places around the globe.

Elements of a Map

Maps are the primary tools by which spatial relationships are visualized. Maps therefore become important documents. There are several key elements that should be included each time a map is created in order to aid the viewer in understanding the communications of that map and to document the source of […]

Learn GIS for Free

There are a few online options to learn GIS for free. Take advantage of resources that provide you access to free courses from some of the world’s best universities and institutions. Learn GIS on your own or supplement your existing geospatial education with these free resources.