'Data file len-rpar.dat: Ray parameters for two-point ray tracing'

 2 -1 -2 -1    0.001  0.0020 /        (ISRFR,ISRFX,ISRFY,NREC,XERR,AERR)
'len-rec.dat' /                       (File with receiver coordinates)
 0.0000 -1.3090  3.1416 -1.3090  0.0000  1.3090    18 30   1 /
/
/
/
/
/

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