set grid mxtics mytics xtics ytics lt 7, lt 0 set key bottom right # Constants pi=acos(-1.0) filter_loss=2.415484 # Absolute number, not dB. Loss of sun on the VIS filter. vis_yield=0.83 # Quantum yield of SFH203 at 640nm (wavelength of HPWT-BD00) nir_yield=0.88 # Quantum yield of SFH203F at 875nm (wavelength of HSDL42?0) # Losses of lenses on 640nm, in dB # Will be used for receiver sensitivity calculation l60v=-0.63 l75v=-1.71 l80v=-0.71 l90v=-0.85 l100v=-0.37 l130v=-0.45 # Losses of lenses on 875nm, in dB # Will be used for receiver sensitivity calculation l60i=-1.54 l75i=-6.20 l80i=-1.78 l90i=-1.89 l100i=-2.00 l130i=-2.37 # Data for reference receiver reference_intensity=15.53 # dBTq/sym/sr, launch intensity reference_loss=l130v # dB, lens loss reference_dia=0.13 # meter, dia of input aperture of reference receiver reference_visibility=4000.0 # meter, visibility of reference track reference_distance=1400.0 # meter, distance of reference track # length in meters, visibility in meters. Positive. In dB. db_per_m(vis)=17.0/vis extinction(length,vis)=length*db_per_m(vis) # Spread attenuation. Positive. Length in meters. spread(length)=10*log10(length**2) # Going to computer reference sensitivity reference_dist_db=10*log10(reference_distance**2) refsen=reference_intensity-spread(reference_distance)-\ extinction(reference_distance,reference_visibility) print "reference sesitivity=",refsen," dBTq/sym/m^2" set xlabel "Distance [km]" set ylabel "Required Launch Intensity [dBTq*sym^{-1}*sr^{-1}]" # Positive. How big [dB] the launch intensity must be. # Length is in meters. demand(length,sens,visibility)=sens+spread(length)+extinction(length,visibility) # Computation of sensitivities [dBTq/sym/m^2] of various receiver heads # Gain in dBTq/sym/m^2 for VIS receivers # low sensitivity = sensitive # high sensititivy = insensitive vis_sens(dia, loss)=refsen-20*log10(dia/reference_dia)+(reference_loss-loss)/2 # Gain in dBTq/sym/m^2 for NIR rceivers nir_sens(dia, vis_loss, nir_loss)=vis_sens(dia,vis_loss)+(vis_loss-nir_loss)/2+\ 5*log10(vis_yield/nir_yield)-5*log10(filter_loss) sens60v=vis_sens(0.06, l60v) sens75v=vis_sens(0.075, l75v) sens80v=vis_sens(0.08, l80v) sens90v=vis_sens(0.09, l90v) sens100v=vis_sens(0.1, l100v) sens130v=vis_sens(0.13, l130v) print "sens130v=",sens130v sens60i=nir_sens(0.06, l60v, l60i) sens75i=nir_sens(0.075, l75v, l75i) sens80i=nir_sens(0.08, l80v, l80i) sens90i=nir_sens(0.09, l90v, l90i) sens100i=nir_sens(0.1, l100v, l100i) sens130i=nir_sens(0.13, l130v, l130i) set terminal postscript portrait enhanced color solid set output set style line 1 lt 16 lw 1.5 set style line 2 lt 1 lw 1.5 set style line 3 lt 2 lw 1.5 set style line 4 lt 3 lw 1.5 set style line 5 lt 4 lw 1.5 set style line 6 lt 5 lw 1.5 set style line 7 lt 16 lw 3 set style line 8 lt 1 lw 3 set style line 9 lt 2 lw 3 set style line 10 lt 3 lw 3 set style line 11 lt 4 lw 3 set style line 12 lt 5 lw 3 set xrange [0.2:2] set xtics 0.2 set mxtics 4 set yrange [4:21] set ytics 1 set mytics 5 scale=1000 v=4000 set title "Required launch intensity vs. distance (4km visibility = 4.25 dB/km)" plot demand(x*scale,sens60v,v) title "60mm red" ls 1, \ demand(x*scale,sens75v,v) title "75mm red" ls 2, \ demand(x*scale,sens80v,v) title "80mm red" ls 3, \ demand(x*scale,sens90v,v) title "90mm red" ls 4, \ demand(x*scale,sens100v,v) title "100mm red" ls 5, \ demand (x*scale,sens130v,v) title "130mm red" ls 6, \ demand(x*scale,sens60i,v) title "60mm 875nm" ls 7, \ demand (x*scale,sens75i,v) title "75mm 875nm" ls 8, \ demand(x*scale,sens80i,v) title "80mm 875nm" ls 9, \ demand (x*scale,sens90i,v) title "90mm 875nm" ls 10, \ demand(x*scale,sens100i,v) title "100mm 875nm" ls 11, \ demand (x*scale,sens130i,v) title "130mm 875nm" ls 12 v=2000 set xrange [0.2:1.4] set xtics 0.1 set mxtics 5 set title "Required LED flux vs. distance (2km visibility = 8.5 dB/km)" replot v=1000 set xrange [200:900] set xtics 100 set mxtics 5 scale=1 set xlabel "Distance [m]" set title "Required LED flux vs. distance (1km visibility = 17 dB/km)" replot set xrange [150:550] set xtics 50 set mxtics 5 v=500 set title "Required LED flux vs. distance (500m visibility = 34 dB/km)" replot set xrange [100:300] set xtics 20 set mxtics 4 v=200 set title "Required LED flux vs. distance (200m visibility = 85 dB/km)" replot set xrange [60:180] v=100 set title "Required LED flux vs. distance (100m visibility = 170 dB/km)" replot set xrange [45:100] set xtics 5 set mxtics 5 v=50 set title "Required LED flux vs. distance (50m visibility = 340 dB/km)" replot