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<br />APPENDIX B. RESIDUAL GROUND CLUTTER AND
<br />OCCUL Tj~TION BLEMISHES
<br />
<br />The following FORTRAN code provides an aid for hand modification of the hybrid scan and possibly the
<br />occultation files. The program reads from a list of * .STP files (daily storm totals) that is created by a
<br />sorted directory listing written to a file. It then opens each * .STP file and determines the number of
<br />range bins with non-zero values. The operator selects a classification criterion: 1 = 0 to 20,000 bins
<br />(scattered precipitation), 2 = 20,000 to 50,000 bins (moderate precipitation) , 3 = 50,000 to 82,800 bins
<br />(widespread precipitation), or 4 = any number of bins. If the * .STP file matches the selected criterion,
<br />then for each bin the program determines the count of non-zero daily totals, the mean and standard
<br />deviation of the totals, and the minimum and maximum values. Those numbers are output to an 1*2 array
<br />for examination in an image processor.
<br />
<br />Examination of the resulting images can reveal bins that are almost always non-zero, even in clear air;
<br />bins that are excessively suppressed in widespread precipitation; and radials that have uncorrected
<br />occultation. The hybrid scan file can be edited to rise higher above residual ground clutter or sink lower
<br />above "holes" in the * .STP output. New SAA products with the corrected hybrid scan file can be run
<br />through this program to note any improvements or degradations. .
<br />
<br />A procedure for adjusting the occultation file, based on radials that are significantly less than their
<br />neighbors, was pondered but not created. While the amount of correction needed at far ranges can be
<br />calculated, it is difficult to note the range at which the correction should begin.
<br />
<br />$debug
<br />PROGRAM RESIDUAL
<br />C Adds up many days of radar *.STP files for a radar site. Counts number
<br />C of non-zero days at each radar bin, average of non-zero precip and
<br />C standard deviation, minimum and maximum values. The results should give
<br />C guidance on reducing residual ground clutter. There may also be helps
<br />C for adjusting the occultation file.
<br />C Writes image array of 1800 lines by 23::: 1*2 columns. The final two
<br />C columns give the partition style, as does a digit in the file name.
<br />C Updated 23 March 1999 by Ed Holroyd
<br />INTEGER*l LN(460)
<br />INTEGER*2 LINE(230)
<br />EQUIVALENCE (LN,LINE)
<br />CHARACTER NSTA*3,LISTFILE*12,INFILE*12,OUTFILE*12,OUTFILEO*l2(4)
<br />+, MY*1
<br />COMMON/SUMS/SX(360,230),SX2(360,230),NX(360,230),MINX(360,230)
<br />+,MAXX(360,230)
<br />INTEGER*2 NX
<br />DATA LISTFILE/'printer.NNN '/
<br />DATA OUTFILEO/'summary1.NNN', 'summary2.NNN','summary3.NNN'
<br />+, 'summary4.NNN'/
<br />
<br />C
<br />
<br />10 WRITE(6,*)' Type 3 letter station name'
<br />READ (5,11) NSTA
<br />11 FORMAT (A3)
<br />LISTFILE(9:11)=NSTA
<br />OPEN(I,FILE=LISTFILE,STATUS='OLD')
<br />C initialize sums, extremes
<br />DO 12 L=I,360
<br />DO 12 KM=I,230
<br />SX(L,KM)=O.
<br />SX2(L,KM)=0.
<br />NX(L,KM)=O.
<br />MINX(L,KM)=100000
<br />MAXX(L,KM)=0
<br />12 CONTINUE
<br />C select partition style
<br />WRITE(6,13)
<br />13 FORMAT(' Which partition style for echo coverage:'/
<br />+, ' 1 = 0 to 20,000 bins (scattered) '/
<br />+, ' 2 = 20,000 to 50,000 bins (moderate)'/
<br />+, ' 3 = 50,000 to 82,800 bins (widespread) '/
<br />+, '4=all')
<br />
<br />23
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