DryTroposphereModel.icc

#include <cmath>
#include <isce3/core/Constants.h>
#include <isce3/core/Ellipsoid.h>
#include <isce3/core/Vector.h>
 
namespace isce3 {
namespace focus {
 
CUDA_HOSTDEV
inline double dryTropoDelayTSX(const isce3::core::Vec3& p,
                               const isce3::core::Vec3& llh,
                               const isce3::core::Ellipsoid& ellipsoid)
{
    constexpr static double c = isce3::core::speed_of_light;
    constexpr static double ZPD = 2.3;
    constexpr static double H = 6000.;
 
    // get unit vector from target in the direction of the radar platform
    auto x = ellipsoid.lonLatToXyz(llh);
    auto r_hat = (p - x).normalized();
 
    // get unit vector normal to ellipsoid at target location
    auto n_hat = ellipsoid.nVector(llh[0], llh[1]).normalized();
 
    // cosine of the incidence angle at the target location
    double cos_theta = r_hat.dot(n_hat);
 
    return 2. * ZPD * std::exp(-llh[2] / H) / (c * cos_theta);
}
 
} // namespace focus
} // namespace isce3