rfun.f
39 lines
| 1002 B
| text/x-fortran
|
FortranFixedLexer
| r0 | C $Id: rfun.f 3304 2011-01-17 15:25:59Z brideout $ | |||
| C | ||||
| DOUBLE PRECISION FUNCTION RFUN(SR,EL,H) | ||||
| C | ||||
| C jmh - 11/79 ans fortran 66 | ||||
| C | ||||
| C RFUN computes the range to an observation point at a specified | ||||
| C elevation (EL) and distance (H) above a sphere of radius SR. | ||||
| C SR and H should be positive and EL should be in the range | ||||
| C 0.0 to 90.0. | ||||
| C | ||||
| C Input: | ||||
| C SR - radius of sphere (km) | ||||
| C EL - elevation (deg) | ||||
| C H - distance above sphere (km) | ||||
| C | ||||
| C .. Scalar Arguments .. | ||||
| DOUBLE PRECISION EL,H,SR | ||||
| C .. | ||||
| C .. Local Scalars .. | ||||
| DOUBLE PRECISION DTR,SE | ||||
| C .. | ||||
| C .. Intrinsic Functions .. | ||||
| INTRINSIC DSIN,DSQRT | ||||
| C .. | ||||
| C .. Data statements .. | ||||
| DATA DTR/.0174532925199D0/ | ||||
| C .. | ||||
| C | ||||
| IF (SR.LT.0.D0 .OR. H.LT.0.D0 .OR. EL.LT.0.D0 .OR. | ||||
| * EL.GT.90.D0) THEN | ||||
| RFUN = 0.D0 | ||||
| ELSE | ||||
| SE = DSIN(DTR*EL) | ||||
| RFUN = DSQRT(SR*SR*SE*SE+2.D0*SR*H+H*H) - SR*SE | ||||
| END IF | ||||
| RETURN | ||||
| C | ||||
| END | ||||
