¥  File Descriptions:

SEASATim.pic - SEASAT radar image of the North-West corner of Belize, in Central America. The area is known as the Rio Bravo. The image was taken in 1978 and shows an area of about 100kmx100km. The white lines outline on the image are the borders with Guetamala, to the West (right side of image) and Yucatan, Mexico, to the North (top part of image). This area was settled by the Mayan civilization over a thousand years ago, and has Mayan ruins dotted all over it.  

SEASATzm.pic - zoom-in of part of SEASATim.pic, showing more detail.

Mosaicim.pic - radar image mosaic using AIRSAR data. P-band HH was colored red, L-band HV green and C-band VV blue to make this Red/Green/Blue overlay of AIRSAR data. The image was taken in 1990 and shows an area of about 50kmx50km. Comparing Mosaicim.pic with SEASATim.pic you should be able to see two things immediately:

	1.  By having different radar wavelengths you can see more features in the radar images. It's the difference between having color versus black and white.

	2.  Between 1978 and 1990 a lot of deforestation occurred. These are the darker blue areas in Mosaicim.pic which have no match in SEASATim.pic. The bright red lines in some of the cleared areas are barbed wire fences which appear very bright at P-band, for some reason.

Lbandful.pic - L-band HH radar image of part of the image seen in the mosaic. This image is upside down when compared with the Mosaicim.pic image but was collected at the same time (April 1990) by the NASA/JPL AIRSAR imaging radar system. The radar was flying parallel to the top of the image and looking down and out to the left. 

Belizkey.pic - key to the radar image shown in Lbandful.pic. This schematic diagram, drawn to the same scale as the radar image, shows the size of the area covered (12.3kmx12.6km) and identifies some features seen in the radar image. Most of the image frame contains broadleaf upland forest, or tropical rain forest (regular). At the top right is a small triangular shaped patch of a type of stunted forest, known as Bajo, which grows on poorly drained clay soils. The Bajo is separated from the upland forest by an escarpment, which rises about 100 feet. The most interesting feature in the image is a ranch known as Gallon Jug, which was settled in about 1985, and contains: farmland (for raising corn and cattle); bare soil fields (just recently plowed); an area of regrowth, where the soil was too poor to support agriculture and the rancher is allowing the forest to grow back again; a recently bulldozed clear-cut, with trees still lying scattered on the ground; and a small coffee plantation. The coffee plantation was an area in the upland forest where the understory and middle canopy vegetation had been cleared, leaving only large trees.  Although some coffee had been planted, the forest floor was generally open. Also shown in the key is a local village where the ranch hands live, and two small lakes: Laguna Verde (green lagoon) and Laguna Seca (dry lagoon). Following the path of a small stream is a patch of flooded forest and marshland. Several dirt roads or tracks are indicated on the key as well.

VegmpByt.pic - vegetation map of the Gallon jug area generated automatically from the AIRSAR data, using all three frequencies and all the different polarizations. 

Comparing the vegetation map with the key shown in Belizkey.pic you should be able to see the following:

	1.  The area of farmland is classified as low vegetation (light green).
	2.  The area of bare soil is classified as no vegetation (blue).
	3.  Most of the upland forest is classified as forest (bright green and yellow).
	4.  The area of regrowth is classified as medium vegetation (dark green).
	5.  The Laguna Verde is classified as no vegetation (blue).
	6.  The Laguna Seca has patches of no vegetation (open water?), medium vegetation (D), and low vegetation (D). These are probably sedge (1 to 2m high) and reeds (less than 1m high) growing above the waterline.
	7.  The coffee plantation and the flooded area have a greater concentration of Forest (D), i.e. double-bounce forest (yellow), than the surrounding forest.
	8. The recently clear-cut area is unclassified (white)

Vegmpkey.pic - key to the vegetation  map shown in VegmpByt.pic. The color codes are:

	Blue - No vegetation

	Light Green - Low vegetation (less than 1m)
	Light Brown - Low vegetation with significant double-bounce

	Dark Green - Medium vegetation (1 to 3m)
	Dark Brown - Medium vegetation with significant double-bounce

	Bright Green - Forest
	Bright Yellow - Forest with significant double-bounce

	Urban - settlements

	White, Grey or Black - Unclassified 

 
Vegmphdr.txt - text file showing the percentage classification of each of the classes seen in the VegmpByt.pic file. 

GroundV1.pic - digitized photograph of upland forest, taken from the ground, looking down from a small rise. Photograph shows rain forest canopy stretching for miles in background, with trees and other foliage in foreground. 

GroundV2.pic - digitized sketch map of a walk (or transect) through a stretch of tropical rain forest within the Gallon Jug image. The image. which was drawn by a botanist, shows trees and shrubs seen along the walk.

LBandRed.STK - LBand AIRSAR image data file containing all polarizations. To display, open the Macsigma0 application by clicking twice on the icon, then select the Open Cmprsd Stokes option under the File menu. Select the HV polarization for display.