For those of you viewing the 4-band NAIP image services in ArcGIS Desktop, you can put the 4th band to work and view the imagery as Color Infrared (CIR).
First to get the 4-band NAIP image service into ArcGIS Desktop (I’m using 10.2.2), click on the Add Data button and select “GIS Servers” from the “Look in” pulldown menu. Then double click on “Add ArcGIS Server” in the list.
You will be asked what you would like to do, so select “Use GIS services” and click the Next button. Then in the Server URL input field, enter the following:
Click the Finish button and the image service will be added to your list of GIS Servers.
Double click on it to reveal the folders. Double click on the NAIP folder to list the different image services. Double click on one to add as a layer in ArcMap.
What you are currently viewing is Natural Color or RGB. You are viewing 3 of the 4 bands, or the Red, Green, and Blue bands. Here is a nice graphic of the visible spectrum:
Together the 3 bands make the natural color image. Right click on the NAIP layer in ArcMap and select Properties. Click on the Symbology tab to view the bands being used.
Note the image service was initially setup with a Minimum-Maximum stretch. Depending on the imagery, you can fiddle with the stretch to make the colors more pleasing. The setting here seems to make the imagery a little more brighter, though I like it better with it set to “None”.
Now for the fun. You need to shift around the bands to view the imagery in CIR. To do that, there is a pulldown for each of the bands. Make the Red channel Band 4, the Green channel Band 1, and the Blue channel Band 2. Band 3 is not used.
Click OK or Apply to view the Color Infrared.
I think the best part of this is that for LARIAC participants in LA County, we can take advantage of this free source since we did not get CIR imagery this time around. Though this is only 1 meter resolution, it might help out some people that need this information. And besides, it matches the year our latest 4in resolution imagery was taken.
I bet there is a way to “enhance” the CIR imagery with LARIAC’s imagery … that is using high-resolution panchromatic imagery to sharpen multi-spectral imagery. If someone wants to do that, please do a writeup using LARIAC imagery and NAIP! -mike