BUGFIX in pup.c

src/pup.c

@@ -71,7 +71,7 @@ printf("MYID: %i; ntr_start: %i; ntr_end: %i; ns_start: %i; ns_end: %i; ntr: %i,
     row = vector(1,nx_pot);
     row_im = vector(1,nx_pot);
 		
-	dtr=(recpos[1][ntr_glob]-recpos[1][1])/(ntr_glob-1)*DH;
+	dtr=fabs((recpos[1][ntr_glob]-recpos[1][1])/(ntr_glob-1)*DH);
     if (VERBOSE==1) {
 		fprintf(FP,"\n Receiver sampling was calculatet to dtr: %f m \n ",dtr);
     }