Unverified Commit f6e516cb authored by Oleg Alexandrov's avatar Oleg Alexandrov Committed by GitHub
Browse files

Speedup in Linescan model by avoiding unneeded computations (#385) 

* Speedup in Linescan model by avoiding unneeded computations

Minor comments changes

* Minor comment addition and code tweak
parent 5f14f4f0

include/usgscsm/UsgsAstroLsSensorModel.h

+4 −2
Original line number Diff line number Diff line
@@ -953,10 +953,12 @@ class UsgsAstroLsSensorModel : public csm::RasterGM, 
                             const double& desired_precision,

                             csm::WarningList* warnings = NULL) const;



  // determines the sensor velocity accounting for parameter adjustments.

  // Determines the sensor position and velocity accounting for

  // parameter adjustments. Use calc_vel = false if the velocity is

  // not needed.

  void getAdjSensorPosVel(const double& time, const std::vector<double>& adj,

                          double& xc, double& yc, double& zc, double& vx,

                          double& vy, double& vz) const;

                          double& vy, double& vz, bool calc_vel = true) const;



  // Computes the imaging locus that would view a ground point at a specific

  // time. Computationally, this is the opposite of losToEcf.

src/UsgsAstroLsSensorModel.cpp

+35 −6
Original line number Diff line number Diff line
@@ -1270,7 +1270,8 @@ csm::EcefCoord UsgsAstroLsSensorModel::getSensorPosition( 
//***************************************************************************

csm::EcefCoord UsgsAstroLsSensorModel::getSensorPosition(double time) const {

  double x, y, z, vx, vy, vz;

  getAdjSensorPosVel(time, _no_adjustment, x, y, z, vx, vy, vz);

  bool calc_vel = false;

  getAdjSensorPosVel(time, _no_adjustment, x, y, z, vx, vy, vz, calc_vel);



  MESSAGE_LOG("getSensorPosition at {}", time)
@@ -1723,10 +1724,11 @@ void UsgsAstroLsSensorModel::losToEcf( 
  MESSAGE_LOG(

      "Computing losToEcf (with adjustments) for"

      "line {} sample {}",

      line, sample)

      line, sample);



  double time = getImageTime(csm::ImageCoord(line, sample));

  getAdjSensorPosVel(time, adj, xc, yc, zc, vx, vy, vz);

  bool calc_vel = false;

  getAdjSensorPosVel(time, adj, xc, yc, zc, vx, vy, vz, calc_vel);

  // CSM image image convention: UL pixel center == (0.5, 0.5)

  // USGS image convention: UL pixel center == (1.0, 1.0)

  double sampleCSMFull = sample;
@@ -1929,7 +1931,8 @@ void UsgsAstroLsSensorModel::getAdjSensorPosVel(const double& time, 
                                                const std::vector<double>& adj,

                                                double& xc, double& yc,

                                                double& zc, double& vx,

                                                double& vy, double& vz) const {

                                                double& vy, double& vz,

                                                bool calc_vel) const {

  MESSAGE_LOG("Calculating getAdjSensorPosVel at time {}", time)



  // Sensor position and velocity (4th or 8th order Lagrange).
@@ -1938,6 +1941,31 @@ void UsgsAstroLsSensorModel::getAdjSensorPosVel(const double& time, 
  double sensPosNom[3];

  lagrangeInterp(m_numPositions / 3, &m_positions[0], m_t0Ephem, m_dtEphem,

                 time, 3, nOrder, sensPosNom);



  // Avoid computing the velocity and adjustments, if not needed, as those

  // take up at least half of this function's time. Note that if the

  // adjustments are non-null, need to compute the velocity in order

  // to find the adjusted position.

  if (!calc_vel) {

    bool has_adj = false;

    for (size_t it = 0; it < adj.size(); it++) {

      if (adj[it] != 0) has_adj = true;

    }

    if (!has_adj) {

      xc = sensPosNom[0];

      yc = sensPosNom[1];

      zc = sensPosNom[2];

      vx = 0.0;

      vy = 0.0;

      vz = 0.0;



      MESSAGE_LOG("getAdjSensorPosVel: postition {} {} {}"

                  "and velocity {} {} {}",

                  xc, yc, zc, vx, vy, vz)

        return;

    }

  }

  

  double sensVelNom[3];

  lagrangeInterp(m_numPositions / 3, &m_velocities[0], m_t0Ephem, m_dtEphem,

                 time, 3, nOrder, sensVelNom);
@@ -2015,14 +2043,15 @@ std::vector<double> UsgsAstroLsSensorModel::computeDetectorView( 
  MESSAGE_LOG(

      "Computing computeDetectorView (with adjusments)"

      "for ground point {} {} {} at time {} ",

      groundPoint.x, groundPoint.y, groundPoint.z, time)

      groundPoint.x, groundPoint.y, groundPoint.z, time);



  // Helper function to compute the CCD pixel that views a ground point based

  // on the exterior orientation at a given time.



  // Get the exterior orientation

  double xc, yc, zc, vx, vy, vz;

  getAdjSensorPosVel(time, adj, xc, yc, zc, vx, vy, vz);

  bool calc_vel = false;

  getAdjSensorPosVel(time, adj, xc, yc, zc, vx, vy, vz, calc_vel);



  // Compute the look vector

  double bodyLookX = groundPoint.x - xc;