Teaching remote sensing? Or just want to understand remotely sensed imagery better? The Landsat Thematic Bands web mapping application can serve as a very useful teaching, learning, and research tool. It covers the entire planet and the map is updated daily with new Landsat 8 scenes.
You can access many band combinations and indices by hovering over the tools to the left of the map image and selecting among the following:
- Agriculture: Highlights agriculture in bright green. Bands 6,5,2
- Natural Color: Sharpened with 25m panchromatic band. Bands 4,3,2+8
- Color Infrared: Healthy vegetation is bright red. Bands 5,4,3
- SWIR (Short Wave Infrared): Highlights rock formations. Bands 7,6,4
- Geology: Highlights geologic features. Bands 7,4,2
- Bathymetric: Highlights underwater features. Bands 4,3,1
- Panchromatic: Panchromatic image at 15m. Band 8
- Vegetation Index: Normalized Difference Vegetation Index (NDVI). (Band5-Band4)/(Band5+Band4)
- Moisture Index: Normalized Difference Moisture Index (NDMI). (Band5-Band6)/(Band5+Band6)
The Time tool for different indices at larger scales based on a user-selected location enables examination of changes over years or over seasons. It also provides temporal profiles for NDVI (Normalized Difference Vegetation Index), NDMI (Normalized Difference Moisture Index) and an Urban Index, dating back to 1973. The Identify tool enables access to information on the date, cloud cover, and a spectral profile about each scene. The Bookmark tool allows access to interesting locations such as the “Eye of the Sahara” in Mauritania.
- Landsat Multispectral on AWS – 8-band multispectral 30m resolution image services and functions that provide different band combinations and indices.
- Landsat Pan-sharpened on AWS – Panchromatic-sharpened imagery; 4-band (Red, Green, Blue and NIR); 30m resolution.
- Landsat Panchromatic on AWS – Panchromatic imagery; 15m resolution.
These services can also be accessed through the public Landsat on AWS group on ArcGIS Online. Because you can add these services as layers to your own maps or are adding to maps made by others, or if you are simply using the above web mapping application as a standalone map, you truly have “the world at your fingertips” with these maps and apps. But there is a third option: Use the Unlock Earth’s Secrets page, also useful for instruction, with the above application embedded in it, but also with explanatory text and featured places around the planet as they have changed through time.
Think of the above as solid introductory segments to help your students, customers, or stakeholders see the value in remote sensing. These maps and applications require very little geospatial technology skills to use, but allow you to focus on building remote sensing concepts and principles while exploring some truly engaging content and places.
To dig deeper, delve into the many powerful remote sensing functions available in ArcGIS Desktop. One source for engaging, hands-on activities, is Kathryn Keranen and Bob Kolvoord’s book Making Spatial Decisions Using GIS and Remote Sensing: A Workbook.
Give these resources a try!
Landsat web application in ArcGIS Online.