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added MainEx function to expose intermediate values. removed temp var…
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… from Result struct
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@wkozmaNTIA
wkozmaNTIA committed Aug 11, 2019
1 parent 4214a44 commit 8433b5e
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Showing 6 changed files with 216 additions and 185 deletions.
4 changes: 2 additions & 2 deletions include/p528.h
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Original file line number Diff line number Diff line change
Expand Up @@ -116,7 +116,6 @@ struct TroposcatterParams

struct Result {
int propagation_mode; // Mode of propagation
int los_iterations; // **Temp var**

double d__km; // Path distance used in calculations
double A__db; // Total loss
Expand Down Expand Up @@ -163,5 +162,6 @@ int ValidateInputs(double d__km, double h_1__meter, double h_2__meter, double f_
////////////////////

DLLEXPORT int Main(double d__km, double h_1__meter, double h_2__meter, double f__mhz, double time_percentage, Result *result);

DLLEXPORT int MainEx(double d__km, double h_1__meter, double h_2__meter, double f__mhz, double time_percentage, Result* result,
Terminal* terminal_1, Terminal* terminal_2, TroposcatterParams* tropo, Path* path, LineOfSightParams* los_params);

6 changes: 3 additions & 3 deletions src/LineOfSight.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -119,9 +119,9 @@ void LineOfSight(Path *path, Terminal terminal_1, Terminal terminal_2, LineOfSig
if (d__km != 0 && psi != 0)
{
double delta = 0.01;
result->los_iterations = 0;
int los_iterations = 0;

while (result->los_iterations < LOS_ITERATION)
while (los_iterations < LOS_ITERATION)
{
RayOptics(*path, terminal_1, terminal_2, psi, los_params);

Expand All @@ -136,7 +136,7 @@ void LineOfSight(Path *path, Terminal terminal_1, Terminal terminal_2, LineOfSig
psi -= delta;
}

result->los_iterations++;
los_iterations++;
}
}
else
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183 changes: 3 additions & 180 deletions src/Main.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -23,191 +23,14 @@
| + 3 : Troposcatter
|
*===========================================================================*/
int Main(double d__km, double h_1__meter, double h_2__meter, double f__mhz, double time_percentage, Result *result)
int Main(double d__km, double h_1__meter, double h_2__meter, double f__mhz, double time_percentage, Result* result)
{
Terminal terminal_1;
Terminal terminal_2;
TroposcatterParams tropo;
Path path;
LineOfSightParams los_params;

int rtn = SUCCESS;

// reset Results struct
result->A_fs__db = 0;
result->A__db = 0;
result->d__km = 0;
result->los_iterations = 0;
result->propagation_mode = PROP_MODE__NOT_SET;

int err = ValidateInputs(d__km, h_1__meter, h_2__meter, f__mhz, time_percentage);
if (err != SUCCESS)
return err;

// Check for frequency low warning
if (f__mhz < 125)
rtn = WARNING__LOW_FREQUENCY;

double N_s = N_0;
path.a_e__km = a_0__km / (1.0 - 0.04665 * exp(0.005577 * N_s));

/////////////////////////////////////////////
// Compute terminal geometries
//

// Step 1 for low terminal
terminal_1.h_r__km = h_1__meter / 1000;
TerminalGeometry(N_s, path.a_e__km, &terminal_1);

// Step 1 for high terminal
terminal_2.h_r__km = h_2__meter / 1000;
TerminalGeometry(N_s, path.a_e__km, &terminal_2);

//
// Compute terminal geometries
/////////////////////////////////////////////

// Step 2
path.d_ML__km = terminal_1.d__km + terminal_2.d__km; // [Eqn 1]

/////////////////////////////////////////////
// Smooth earth diffraction line calculations
//

// Step 3.1
double d_3__km = path.d_ML__km + 0.5 * pow(pow(path.a_e__km, 2) / f__mhz, THIRD); // [Eqn 2]
double d_4__km = path.d_ML__km + 1.5 * pow(pow(path.a_e__km, 2) / f__mhz, THIRD); // [Eqn 3]

// Step 3.2
double A_3__db = SmoothEarthDiffraction(terminal_1.d__km, terminal_2.d__km, f__mhz, d_3__km);
double A_4__db = SmoothEarthDiffraction(terminal_1.d__km, terminal_2.d__km, f__mhz, d_4__km);

// Step 3.3
double M_d = (A_4__db - A_3__db) / (d_4__km - d_3__km); // [Eqn 4]
double A_d0 = A_4__db - M_d * d_4__km; // [Eqn 5]

// Step 3.4
double A_dML__db = (M_d * path.d_ML__km) + A_d0; // [Eqn 6]
path.d_d__km = -(A_d0 / M_d); // [Eqn 7]

//
// End smooth earth diffraction line calculations
/////////////////////////////////////////////////

double K_LOS = 0;

// Step 4. If the path is in the Line-of-Sight range, call LOS and then exit
if (path.d_ML__km - d__km > 0.001)
{
result->propagation_mode = PROP_MODE__LOS;
LineOfSight(&path, terminal_1, terminal_2, &los_params, f__mhz, -A_dML__db, time_percentage, d__km, result, &K_LOS);

return rtn;
}
else
{
// get K_LOS
LineOfSight(&path, terminal_1, terminal_2, &los_params, f__mhz, -A_dML__db, time_percentage, path.d_ML__km - 1, result, &K_LOS);

// Step 6. Search past horizon to find crossover point between Diffraction and Troposcatter models
int CASE;
double d_crx__km;
rtn = rtn | TranshorizonSearch(&path, terminal_1, terminal_2, f__mhz, N_s, A_dML__db, &M_d, &A_d0, &d_crx__km, &CASE);

/////////////////////////////////////////////
// Compute terrain attenuation, A_T__db
//

// Step 7.1
double A_d__db = M_d * d__km + A_d0; // [Eqn 14]

// Step 7.2
Troposcatter(path, terminal_1, terminal_2, d__km, f__mhz, N_s, &tropo);

// Step 7.3
double A_T__db;
if (d__km < d_crx__km)
{
A_T__db = -A_d__db;
result->propagation_mode = PROP_MODE__DIFFRACTION;
}
else
{
if (CASE == 1)
{
if (tropo.A_s__db <= A_d__db)
{
A_T__db = -tropo.A_s__db;
result->propagation_mode = PROP_MODE__SCATTERING;
}
else
{
A_T__db = -A_d__db;
result->propagation_mode = PROP_MODE__DIFFRACTION;
}
}
else
{
A_T__db = -tropo.A_s__db;
result->propagation_mode = PROP_MODE__SCATTERING;
}
}

//
// Compute terrain attenuation, A_T__db
/////////////////////////////////////////////

/////////////////////////////////////////////
// Compute free-space loss
//

// Step 8
double r_1__km = sqrt(pow(terminal_1.h_r__km, 2) + 4.0 * (a_0__km + terminal_1.h_r__km) * (a_0__km)* pow(sin(0.5 * terminal_1.d__km / a_0__km), 2)); // [Eqn 17]
double r_2__km = sqrt(pow(terminal_2.h_r__km, 2) + 4.0 * (a_0__km + terminal_2.h_r__km) * (a_0__km)* pow(sin(0.5 * terminal_2.d__km / a_0__km), 2)); // [Eqn 17]
double r_fs__km = r_1__km + r_2__km + tropo.d_s__km; // [Eqn 18]

result->A_fs__db = -32.45 - 20.0 * log10(f__mhz) - 20.0 * log10(r_fs__km); // [Eqn 19]

//
// Compute free-space loss
/////////////////////////////////////////////

/////////////////////////////////////////////
// Compute variability
//

// [Eqn 238]
double f_theta_h = 1;

double Y_e__db, Y_e_50__db, A_Y;
LongTermVariability(terminal_1.h_r__km, terminal_2.h_r__km, d__km, f__mhz, time_percentage, f_theta_h, A_T__db, &Y_e__db, &A_Y);
LongTermVariability(terminal_1.h_r__km, terminal_2.h_r__km, d__km, f__mhz, 0.50, f_theta_h, A_T__db, &Y_e_50__db, &A_Y);

// [Eqn 256]
double ANGLE = 0.02617993878;
double K_t__db;
if (tropo.theta_s >= ANGLE) // theta_s > 1.5 deg
K_t__db = 20;
else if (tropo.theta_s <= 0.0)
K_t__db = K_LOS;
else
K_t__db = (tropo.theta_s * (20.0 - K_LOS) / ANGLE) + K_LOS;

double Y_pi_50__db = 0.0; // zero mean
double Y_pi__db = NakagamiRice(K_t__db, time_percentage);

double Y_total__db = CombineDistributions(Y_e_50__db, Y_e__db, Y_pi_50__db, Y_pi__db, time_percentage);

//
// Compute variability
/////////////////////////////////////////////

// Step 9
double A_a__db = -TranshorizonAtmosphericAbsorptionLoss(terminal_1, terminal_2, path, tropo, f__mhz);

result->d__km = d__km;
result->A__db = result->A_fs__db + A_a__db + A_T__db + Y_total__db; // [Eqn 20]

return rtn;
}
return MainEx(d__km, h_1__meter, h_2__meter, f__mhz, time_percentage, result,
&terminal_1, &terminal_2, &tropo, &path, &los_params);
}
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