# Chapter15, Ionospheric Propagation¶

## Example No. 15.8.1, page : 15-19¶

In :
fc_E=2.5 #MHz(critical frequency of E-layer)
fc_F=8.4 #MHz(critical frequency of F-layer)
print "For E-layer : "
Nm=(fc_E*10**6)**2/81 #per m**3(Maximum electron density)
print "Maximum electron density = %0.4e per m**3 "%Nm
print "For F-layer : "
Nm=(fc_F*10**6)**2/81 #per m**3(Maximum electron density)
print "Maximum electron density = %0.4e per m**3 "%Nm

For E-layer :
Maximum electron density = 7.7160e+10 per m**3
For F-layer :
Maximum electron density = 8.7111e+11 per m**3


## Example No. 15.8.2, page : 15-19¶

In :
from math import sqrt
Nm_D=400 #electron/cm**3(Maximum electron density)
Nm_E=5*10**5 #electron/cm**3(Maximum electron density)
Nm_F=2*10**6 #electron/cm**3(Maximum electron density)
fc_D=9*sqrt(Nm_D) #kHz(critical frequency of D-layer)
print "Critical frequency for D-layer = %.2f kHz "%fc_D
fc_E=9*sqrt(Nm_E) #kHz(critical frequency of E-layer)
print "Critical frequency for E-layer = %0.3f MHz  "%(fc_E/1000)
fc_F=9*sqrt(Nm_F) #kHz(critical frequency of F-layer)
print "Critical frequency for F-layer = %0.1f MHz "%(fc_F/1000)

Critical frequency for D-layer = 180.00 kHz
Critical frequency for E-layer = 6.364 MHz
Critical frequency for F-layer = 12.7 MHz


## Example No. 15.8.3, page : 15-19¶

In :
from math import sqrt
Eta=0.5 #(refractive index)
N=400 #electron/cm**3(Electron density)
f=sqrt(81*N/(1-Eta**2)) #kHz(frequency)
print "Frequency = %0.2f kHz " %f

Frequency = 207.85 kHz


## Example No. 15.9.1, page : 15-22¶

In :
T=5 #milli-seconds(time period)
c=3*10**8 #m/s#/speed of light
H=1.0/2*c*T*10**-3 #m(Virtual height)
print "Virtual height = %0.2e km  " %(H/1000)

Virtual height = 7.50E+02 km


## Example No. 15.12.1, page : 15-26¶

In :
from math import sqrt
d=2000 #km
H=200 #km
fc=6 #MHz
f_MUF=fc*sqrt(1+(d/2/H)**2) #MHz
print "MUF = %0.3f MHz " %f_MUF

MUF = 30.594 MHz


## Example No. 15.13.1, page : 15-29¶

In :
from math import sqrt
Eta=0.9 #refractive index
f_MUF=10 #MHz
H=400 #km
Nm=(1-Eta**2)*(f_MUF*10**6)**2/81 #per m**3
fc=9*sqrt(Nm) #Hz
Dskip=2*H*sqrt((f_MUF*10**6/fc)**2-1) #km
print "Skip distance or range = %0.2f km " %Dskip

Skip distance or range = 1651.79 km