From 1621ec61e5d3ab41d57c816f88af6586f8a66de6 Mon Sep 17 00:00:00 2001
From: Joe Taylor <joe@princeton.edu>
Date: Tue, 17 Sep 2024 09:15:23 -0400
Subject: [PATCH] Add sfrx_sub.f90.

---
 lib/superfox/sfrx_sub.f90 | 55 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)
 create mode 100644 lib/superfox/sfrx_sub.f90

diff --git a/lib/superfox/sfrx_sub.f90 b/lib/superfox/sfrx_sub.f90
new file mode 100644
index 000000000..f7a84a36e
--- /dev/null
+++ b/lib/superfox/sfrx_sub.f90
@@ -0,0 +1,55 @@
+subroutine sfrx_sub(nyymmdd,nutc,nfqso,ntol,iwave)
+
+  use sfox_mod
+  use julian
+
+  integer*2 iwave(NMAX)
+  integer*8 secday,ntime8
+  integer*1 xdec(0:49)
+  character*13 foxcall
+  complex c0(NMAX)                    !Complex form of signal as received
+  real dd(NMAX)
+  logical crc_ok
+  data secday/86400/
+
+  fsync=nfqso
+  ftol=ntol
+  nf=0
+  nd=0
+  nv=0
+  fsample=12000.0
+  call sfox_init(7,127,50,'no',fspread,delay,fsample,24)
+  npts=15*12000
+
+  if(nyymmdd.eq.-1) then
+     ntime8=itime8()/30
+     ntime8=30*ntime8
+  else
+     iyr=2000+nyymmdd/10000
+     imo=mod(nyymmdd/100,100)
+     iday=mod(nyymmdd,100)
+     ih=nutc/10000
+     im=mod(nutc/100,100)
+     is=mod(nutc,100)
+     ntime8=secday*(JD(iyr,imo,iday)-2440588) + 3600*ih + 60*im + is
+  endif
+
+  dd=iwave
+  call sfox_remove_ft8(dd,npts)
+
+  call sfox_ana(dd,npts,c0,npts)
+
+  ndepth=3
+  dth=0.5
+  damp=1.0
+
+  call qpc_decode2(c0,fsync,ftol, xdec,ndepth,dth,damp,crc_ok,   &
+       snrsync,fbest,tbest,snr)
+  if(crc_ok) then
+     nsnr=nint(snr)
+     nsignature = 1
+     call sfox_unpack(nutc,xdec,nsnr,fbest-750.0,tbest,foxcall,nsignature)
+  endif
+
+  return
+end subroutine sfrx_sub