100 ' ********************************

110 ' *  IBM PC BASIC VERSION A3.30  *

120 ' *  FILE NAME    "REFL"         *

130 ' *  GROUND REFLECTION LOSS      *

140 ' *  1987/10             I.KATO  *

150 ' ********************************

160 KEY OFF:CLS:SCREEN 9

170 COLOR 14

180 DATA "water surface","paddy field","field,dry field",                                "wood,mountains,urban area"

190 FOR I=1 TO 4:READ U$(I):NEXT

200 LOCATE 1,1:PRINT "[ITEM 12]              GROUND REFLECTION LOSS":PRINT:COLOR 7

210 PRINT "The magnitude of ground reflected wave is affected by the variation of the      reflection coefficient due to the variation of the grazing angle and by the     divergent effect of the reflected wave due to the curvature of the earth."

220 PRINT "Hence, the actual reflection coefficient tends to be less than real one,        particularly for the lower antenna height.  It also differs depending upon      frequencies."

230 PRINT "Taking these all into account, attenuation caused by reflection is summarized inthe table below."

240 PRINT "Reflected wave loss(Item 11) will be obtained as a total sum of ground          reflection loss(Item 12), antenna directivity loss(Items 14, 15) and, if any,   ridge diffraction loss(Item 10) and is desirably to be ";

250 COLOR 3:PRINT "more than 10 dB.":COLOR 7

280 PRINT:PRINT TAB(0)STRING$(60,"-")

290 GOSUB 1000

300 LOCATE 15, 1:PRINT "reflection point(F)        2GHz   4GHz   5GHz   6GHz   11GHz"

310 LOCATE 16, 1:PRINT STRING$(60,"-")

320 FOR I=1 TO 4:LOCATE 16+I,1:PRINT U$(I):NEXT

330 LOCATE 17,26:PRINT "    0      0      0      0       0"

340 LOCATE 18,26:PRINT "    2      2      2      2       2"

350 LOCATE 19,26:PRINT "    4      6      6      6       8"

360 LOCATE 20,26:PRINT "   10     14     14     14      16"

370 LOCATE 21, 1:PRINT STRING$(60,"-")

380 COLOR 6:LOCATE 23,10:PRINT "----- menu:  Hit space key -----"

390 COLOR 7:Q$=INKEY$:IF Q$<>" " THEN 390

400 CLS:SCREEN 0:RUN "ME"

1000 ' --------------------

1010 ' *  graph draw sub  *

1020 ' --------------------

1030 YW=INT(50*50/12.74*5)

1040 WINDOW SCREEN(0,-YW)-(100,0)

1050 VIEW(492,196)-(632,318),,5

1060 FOR X=0 TO 100

1070   Y=-(100-X)*X/15

1080   IF X=0 THEN PSET(X,Y) ELSE LINE-(X,Y),2

1090 NEXT

1100 PAINT(50,-50),2

1110 LINE(0,-600)-(10,0),2

1120 LINE(90,0)-(100,-800),2

1130 PAINT( 5,-100),2

1140 PAINT(95,-100),2

1150 LINE( 0,-600)-(100,-800),7  :'A-B

1160 LINE( 0,-600)-( 45,-170),14 :'A-F

1170 LINE(45,-170)-(100,-800),14 :'F-B

1180 LOCATE 15,79:PRINT "B"

1190 LOCATE 17,63:PRINT "A"

1200 LOCATE 21,70:PRINT "F"

1210 COLOR 7: LOCATE 15,65:PRINT "direct wave"

1220 COLOR 14:LOCATE 19,66:PRINT "reflected"

1230          LOCATE 20,66:PRINT "  wave"

1240 COLOR 7:RETURN