Including a new arrival time into the location of hypocentre: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Input: POWERN... Exponent describing the self-affine random medium. TTERR1... Travel-time error at travel time equal to 1 unit. T... Arrival time at the receiver. TERR... Standard deviation of the arrival time. TREF... Optional reference arrival time. Need not be specified. $1... Gridded travel time from the receiver. $2,$3,$4... Temporary files to accumulate intermediate results. Output: $2,$3,$4... Updated temporary files. Travel-time variances are calculated from POWERN and TTERR1. Travel-time covariances are not calculated and are deemed zero, which may result in underestimation of variances of hypocentral coordinates. For example refer to wb2-loc.h. TDIF=T-TREF TDIF=TDIF-$1 TTERR=$1**POWERN TTERR=$1*TTERR TTERR=TTERR1*TTERR A=TTERR*TTERR AA=TERR*TERR A=A+AA A=1./A B=A*TDIF C=$2*TDIF C=C-$3 CC=C*C C=0.000001*A C=MAX(C,$2) C=CC/C $2=$2+A $3=$3+B C=C/$2 C=A*C CC=$4*$4 C=C+CC $4=SQRT(C)