Lab 8 - Thermal and Multispectral Analysis using ERDAS and ArcMap

      After reviewing the use of histograms and learning to combine multiple images in this case obtained using LANDSAT ETM+, we practiced converting the multiple images into a composite using the Composite Bands tool in ArcMap of the Layer Stack tool in ERDAS.  We also reviewed items from past lectures and applied them during our analysis phase.  This included the use, in ERDAS, of multiple views, histogram editing, and using the Discrete DRA tool.  We used symbology in ArcMap and altering color band layer associations in ERDAS during our Multispectral analysis.

      I noticed an area in the Midwestern portion of the image which caught my eye due to both its shape and coloration.  By using the ETM Composite image I created from the ETM layers 1-8, I had the basic image ready to adjust.  Again, I prefer to work in a geodatabase so I imported each layer into the ETM.gdb and stored the ETMComposite there as well.  While running various comparisons made different areas of the image stand out, using the stretch symbology and reviewing each layer, visually I prefer the multispectral imagery.  I set Red to layer 4, Green to layer 2 and Blue layer 6 (the thermal layer).    As I panned around the image I noted a feature south of Guayaquil which was within an urban area, oval in shape with a bright green outline and dark red center.  This became my AOI.

I noted that by using the Stretched symbology the object was most visible in layers 1-3.  Band 6 did not illustrate central red blurs fading to yellows and then surround blues.  I knew the red blurs were potential hot spots, assumed the fading to yellow was a blend of greens and blues and that the outer more distant blues were urban areas.  By switching to the RGB composite symbology as described in the first paragraph, the shape and heat signature were much more clear.  I suspected that this could be some sort of civic area or sports arena.  Knowing the incredible following of Fútbol (soccer) I began to lean toward this area being a stadium.  The coordinate value obtained from the information icon in ArcMap  (Coordinate System WGS 1984 UTM Zone 17N, Projection Transverse Mercator, Linear Unit Meter, Angular Unit Degree, Datum WGS 1984)  is 79°55'29.684” W, 2°9.956"S.  I noted this on the map.  Wanting to confirm my theory, I entered those coordinates into Google earth and discovered that the location was in fact a sports arena known as Estadio Monumental Isidro Romero Carbo AKA Estadio Banco Pinchincha which is in the parish of Tarqui in Northern Guayaquil, Ecuador.