This video from Oregon State University is one of the best explanations of how to interpret remotely sensed imagery. It talks mostly about aerial photos, but it applies to other kinds of imagery, too.
Following are notes on infrared imagery.
Here is a link to an infrared photography group on Flickr. It has black and white and false color imagery.
Near Infrared or False Color Maps for Study Sites
In this assignment we will use the NAIP imagery to generate true color and false color maps of our study sites. Here are semi-detailed instructions.
- Go to the PASDA Imagery Navigator (Go to www.pasda.psu.edu and choose Apps & Tools). Navigate to each of the study site points.
- Right click near each study site to bring up the PASDA Download Links. Choose the 2017 Statewide Infrared & Natural Color 4-band (1m). Click here to see what the screen looks like.
- Download the tiff files for NE Waynesboro, NW Iron Springs, and SW Caledonia.
- Extract them to the T drive like we did for the panchromatic imagery.
- Open ArcMap. Load each image layer twice and use the instructions below to make one of them color and one false color.
- Display the study points on the map as we did last week. Click here to download the geodatabase of the study points if you don’t still have it.
- Choose two of the study sites to map.
- Make two 1:9600 maps of each site similar to what we did last week.
- Export your maps as jpg files.
- Write a report on your website that includes your maps.
- Upload a link in Canvas to get credit.
- Answer the questions below in your report.
How to show two colors from one image layer.
The NAIP imagery has both true color and infrared false color in the same file. When downloading the tiff from PASDA you get four bands.
- red is 1
- green is 2
- blue is 3
- near infrared is 4
In ArcGIS the raster property wizard can reassign the bands as needed.
For natural color the display the bands in the symbology are set as:
- red — band 1
- green — band 2
- blue — band 3
Band 4 is not displayed
For CIR or false color, the bands should be shifted.
- red — band 4
- green — band 1
- blue — band 2
Band 3 is not displayed. Try experimenting by showing different combinations or just one layer. As long as the red band is near infrared you can experiment with the others.
Questions to Address in Your Report
- How does the vegetation differ between the two views?
- How does hardwood vs. softwood vegetation compare?
- How do bodies of water compare between the two views?
- What time of year is NAIP recorded? Does this have an effects on what you see?