pro db_ftc,ur,fbc,ftc,stc

; v1 tries to map out the nadir and azimuth angle contours as a function of 
;    station topocentric position

dstc=stc
lng_srt=-110.5005d0
lng_end=-110.4990d0
lat_srt=31.7995d0
lat_end=31.8015d0
ndice=100d0
dlng=(lng_end-lng_srt)/ndice
dlat=(lat_end-lat_srt)/ndice
n_plot  =dblarr(fix(ndice)+1,fix(ndice+1))
ph_plot =dblarr(fix(ndice)+1,fix(ndice+1))
lng_plot=dblarr(fix(ndice)+1,fix(ndice+1))
lat_plot=dblarr(fix(ndice)+1,fix(ndice+1))
j=0
for lng=lng_srt,lng_end,dlng do begin
  i=0
  for lat=lat_srt,lat_end,dlat do begin
    lng_plot(j,i)=lng
    lat_plot(j,i)=lat
    dstc(0)=lng
    dstc(1)=lat
    duma=tc(ur,fbc,dstc)
    n_plot(j,i)=duma(0)
    ph_plot(j,i)=duma(1)
    i=i+1
  endfor
  j=j+1
endfor

wset,0
contour,n_plot(0:99,0:99),lng_plot(0:99,0:99),lat_plot(0:99,0:99),$
  levels=[10,20,30,40,50],c_labels=[1,1,1,1,1]
oplot,[ftc(0),stc(0)],[ftc(1),stc(1)],psym=2
stop
wset,1
contour,ph_plot(0:99,0:99),lng_plot(0:99,0:99),lat_plot(0:99,0:99),$
  levels=[-20,-10,0,10,20],c_labels=[1,1,1,1,1]
oplot,[ftc(0),stc(0)],[ftc(1),stc(1)],psym=2

stop
return
end

;plot,lng_plot,lat_plot,psym=3,$
;  xrange=[lng_srt,lng_end],xstyle=1,$
;  yrange=[lat_srt,lat_end],ystyle=1
;oplot,[ftc(0),stc(0)],[ftc(1),stc(1)],psym=2