Update on Enhanced-V Algorithm Development 30 March 2007 Telecon

Enhanced-V Algorithm Inputs AREA file of Low Earth Orbit (LEO) satellite data (currently set up to input 150X150 pixel region), given a line/elem value in image as upper left point of desired region (line/elem/brightness temperature value at each pixel in region is input) Enhanced-V Fabricated Matrix of brightness temperatures (have three different versions), ASCII file of brightness temperatures in matrix

Enhanced-V Fabricated Matrices Developed to best represent what the enhanced-V feature looks like in the imagery Three different matrices were developed – based on results of quantitative parameters of enhanced-V features from 2003 and 2004 enhanced-V seasons (total of 450 cases looked at) (Brunner et al. 2007) GIF images of fabricated enhanced-Vs were created in Paint Shop Pro and Jython code was used to create matrix of brightness temperature values from GIF image (assigned each RGB color value in GIF image to a brightness temperature) Mean/Median Enhanced-V Fabricated Matrix (30X30 pixel matrix) Maximum Enhanced-V Fabricated Matrix (50X50 pixel matrix) Minimum Enhanced-V Fabricated Matrix (15X15 pixel matrix)

Mean/Median Enhanced-V Fabricated Matrix (30X30 pixels) TMIN (coldest cloud top temperature) – 201 K TMAX (warmest cloud top temperature) – 217 K TDIFF (warm-cold couplet) – 16 K DIST (distance between warm and cold location) – 10 KM DISTARMS (averaged distance of both V-arms) – 36 KM ANGLEARMS (angle between both V-arms) – 75 Degrees

Maximum Enhanced-V Fabricated Matrix (50X50 pixels) TMIN (coldest cloud top temperature) – 183 K TMAX (warmest cloud top temperature) – 221 K TDIFF (warm-cold couplet) – 38 K DIST (distance between warm and cold location) – 42 KM DISTARMS (averaged distance of both V-arms) – 162 KM ANGLEARMS (angle between both V-arms) – 123 Degrees

Minimum Enhanced-V Fabricated Matrix (15X15 pixels) TMIN (coldest cloud top temperature) – 221 K TMAX (warmest cloud top temperature) – 226 K TDIFF (warm-cold couplet) – 5 K DIST (distance between warm and cold location) – 3 KM DISTARMS (averaged distance of both V-arms) – 10 KM ANGLEARMS (angle between both V-arms) – 32 Degrees

Enhanced-V Algorithm Cross-Correlation Code: Output * Algorithm takes 150X150 pixel region and steps through this region one pixel at a time while comparing 10.7 micron brightness temperatures to a fabricated enhanced-V matrix of brightness temperatures (looks for a similar pattern in brightness temperature values) * ASCII output file of line/elem/correlation value at every pixel * ASCII filtered output file of line/elem/correlation value of all pixels that exceed a certain correlation value threshold (such as >= 0.5 or <= -0.5, for example)

LEO Enhanced-V Test Cases Three LEO enhanced-V cases selected to test the enhanced-V cross-correlation algorithm The enhanced-V cases are East-West oriented enhanced-Vs and the enhanced-V fabricated matrices are East-West oriented (“simple” case) Planning to test the algorithm on the three cases for each enhanced-V fabricated matrix, generate output files of correlation values and then make a MASK file of the filtered output file (correlation values that exceed a certain threshold) Hopefully, if the correlation code looks good for the East-West enhanced-V cases, then will work on rotating the enhanced-V fabricated matrices in the code to test enhanced-V cases that are not necessarily oriented in just the East-West direction

LEO Enhanced-V Test Case #1

LEO Enhanced-V Test Case #2

LEO Enhanced-V Test Case #3