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Removed reused temp variables in final position calc

feature/19
Daniel Warner 2011-07-09 19:13:03 +00:00
parent b947802289
commit af949a5dca
1 changed files with 23 additions and 27 deletions
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50
SGP4.cpp
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@ -424,20 +424,15 @@ void SGP4::CalculateFinalPositionVelocity(Eci* eci, const double& tsince, const
const double& x3thm1, const double& x1mth2, const double& x7thm1, const double& x3thm1, const double& x1mth2, const double& x7thm1,
const double& cosio, const double& sinio) const { const double& cosio, const double& sinio) const {
double temp;
double temp1;
double temp2;
double temp3;
const double beta = sqrt(1.0 - e * e); const double beta = sqrt(1.0 - e * e);
const double xn = kXKE / pow(a, 1.5); const double xn = kXKE / pow(a, 1.5);
/* /*
* long period periodics * long period periodics
*/ */
const double axn = e * cos(omega); const double axn = e * cos(omega);
temp = 1.0 / (a * beta * beta); const double temp11 = 1.0 / (a * beta * beta);
const double xll = temp * xlcof * axn; const double xll = temp11 * xlcof * axn;
const double aynl = temp * aycof; const double aynl = temp11 * aycof;
const double xlt = xl + xll; const double xlt = xl + xll;
const double ayn = e * sin(omega) + aynl; const double ayn = e * sin(omega) + aynl;
const double elsq = axn * axn + ayn * ayn; const double elsq = axn * axn + ayn * ayn;
@ -504,38 +499,39 @@ void SGP4::CalculateFinalPositionVelocity(Eci* eci, const double& tsince, const
/* /*
* short period preliminary quantities * short period preliminary quantities
*/ */
temp = 1.0 - elsq; const double temp21 = 1.0 - elsq;
const double pl = a * temp; const double pl = a * temp21;
if (pl < 0.0) { if (pl < 0.0) {
throw SatelliteException("Error: #4 (pl < 0.0)"); throw SatelliteException("Error: #4 (pl < 0.0)");
} }
const double r = a * (1.0 - ecose); const double r = a * (1.0 - ecose);
temp1 = 1.0 / r; const double temp31 = 1.0 / r;
const double rdot = kXKE * sqrt(a) * esine * temp1; const double rdot = kXKE * sqrt(a) * esine * temp31;
const double rfdot = kXKE * sqrt(pl) * temp1; const double rfdot = kXKE * sqrt(pl) * temp31;
temp2 = a * temp1; const double temp32 = a * temp31;
const double betal = sqrt(temp); const double betal = sqrt(temp21);
temp3 = 1.0 / (1.0 + betal); const double temp33 = 1.0 / (1.0 + betal);
const double cosu = temp2 * (cosepw - axn + ayn * esine * temp3); const double cosu = temp32 * (cosepw - axn + ayn * esine * temp33);
const double sinu = temp2 * (sinepw - ayn - axn * esine * temp3); const double sinu = temp32 * (sinepw - ayn - axn * esine * temp33);
const double u = atan2(sinu, cosu); const double u = atan2(sinu, cosu);
const double sin2u = 2.0 * sinu * cosu; const double sin2u = 2.0 * sinu * cosu;
const double cos2u = 2.0 * cosu * cosu - 1.0; const double cos2u = 2.0 * cosu * cosu - 1.0;
temp = 1.0 / pl;
temp1 = kCK2 * temp;
temp2 = temp1 * temp;
/* /*
* update for short periodics * update for short periodics
*/ */
const double rk = r * (1.0 - 1.5 * temp2 * betal * x3thm1) + 0.5 * temp1 * x1mth2 * cos2u; const double temp41 = 1.0 / pl;
const double uk = u - 0.25 * temp2 * x7thm1 * sin2u; const double temp42 = kCK2 * temp41;
const double xnodek = xnode + 1.5 * temp2 * cosio * sin2u; const double temp43 = temp42 * temp41;
const double xinck = xincl + 1.5 * temp2 * cosio * sinio * cos2u;
const double rdotk = rdot - xn * temp1 * x1mth2 * sin2u; const double rk = r * (1.0 - 1.5 * temp43 * betal * x3thm1) + 0.5 * temp42 * x1mth2 * cos2u;
const double rfdotk = rfdot + xn * temp1 * (x1mth2 * cos2u + 1.5 * x3thm1); const double uk = u - 0.25 * temp43 * x7thm1 * sin2u;
const double xnodek = xnode + 1.5 * temp43 * cosio * sin2u;
const double xinck = xincl + 1.5 * temp43 * cosio * sinio * cos2u;
const double rdotk = rdot - xn * temp42 * x1mth2 * sin2u;
const double rfdotk = rfdot + xn * temp42 * (x1mth2 * cos2u + 1.5 * x3thm1);
if (rk < 1.0) { if (rk < 1.0) {
throw SatelliteException("Error: #6 Satellite decayed (rk < 1.0)"); throw SatelliteException("Error: #6 Satellite decayed (rk < 1.0)");