Navigating GOES GeoTiff Images
QUESTION: I download a number of GOES East and West GeoTiff images from this NOAA web page. Can you show me how to annotate these GOES images with continental outlines and map grid lines?
First, I create a map coordinate object by reading the GeoTiff file. In this case, I also return the image so I can display it later on. (The image display can also be driven from keywords to cgGeoMap, but I think it will be more useful to you to see the individual steps in the process.)
file = 'GoesEast04I23451615.tif' map = cgGeoMap(file, IMAGE=image)Next, I create a window to display the image in and display the image with a two-percent histogram stretch.
cgDisplay, XSIZE=900, ASPECT=image cgImage, image, STRETCH=2
Next, I make sure the map object is set up to cover the entire window, and I set up the map projection space.
map -> SetProperty, POSITION=[0,0,1,1], /NOBORDER map -> Draw
And, finally, I draw the continental outlines and map grid lines on the image.
cgMap_Continents, COLOR='dodger_blue', MAP=map cgMap_Grid, COLOR='goldenrod', MAP=map, /LABEL
You see the result in the figure below.
|A GOES East image with annotation.|
Version of IDL used to prepare this article: IDL 7.1.