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