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Commit 363546b7 authored by Stuart Sides's avatar Stuart Sides Committed by Jesse Mapel
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New distortion model for LRO LROC NAC (#235)

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include/usgscsm/Distortion.h
+ 3
− 1
View file @ 363546b7
......@@ -10,9 +10,11 @@ enum DistortionType {
RADIAL,
TRANSVERSE,
KAGUYATC,
DAWNFC
DAWNFC,
LROLROCNAC
};
// Transverse Distortion
void distortionJacobian(double x, double y, double *jacobian,
const std::vector<double> opticalDistCoeffs);
......
src/Distortion.cpp
+ 104
− 3
View file @ 363546b7
......@@ -43,6 +43,7 @@ void distortionJacobian(double x, double y, double *jacobian,
}
}
/**
* @description Compute distorted focal plane (dx,dy) coordinate given an undistorted focal
* plane (ux,uy) coordinate. This uses the third order Taylor approximation to the
......@@ -81,6 +82,7 @@ void computeTransverseDistortion(double ux, double uy, double &dx, double &dy,
}
}
void removeDistortion(double dx, double dy, double &ux, double &uy,
const std::vector<double> opticalDistCoeffs,
DistortionType distortionType,
......@@ -89,6 +91,7 @@ void removeDistortion(double dx, double dy, double &ux, double &uy,
uy = dy;
switch (distortionType) {
// Compute undistorted focal plane coordinate given a distorted
// coordinate set and the distortion coefficients
case RADIAL: {
......@@ -102,6 +105,7 @@ void removeDistortion(double dx, double dy, double &ux, double &uy,
}
}
break;
// Computes undistorted focal plane (x,y) coordinates given a distorted focal plane (x,y)
// coordinate. The undistorted coordinates are solved for using the Newton-Raphson
// method for root-finding if the distortionFunction method is invoked.
......@@ -159,6 +163,8 @@ void removeDistortion(double dx, double dy, double &ux, double &uy,
// number of iterations
}
break;
// KaguyaTC
case KAGUYATC: {
// Apply distortion correction
// see: SEL_TC_V01.TI
......@@ -201,6 +207,7 @@ void removeDistortion(double dx, double dy, double &ux, double &uy,
uy = dy + dr_y;
}
break;
// The dawn distortion model is "reversed" from other distortion models so
// the remove function iteratively computes undistorted coordinates based on
// the distorted coordinates, rather than iteratively computing distorted coordinates
......@@ -252,18 +259,41 @@ void removeDistortion(double dx, double dy, double &ux, double &uy,
ux = guess_ux;
uy = guess_uy;
}
break;
// LROLROCNAC
case LROLROCNAC: {
if (opticalDistCoeffs.size() != 1) {
throw "Distortion coefficients for LRO LROC NAC must be of size 1, current size: " + std::to_string(opticalDistCoeffs.size());
}
double dk1 = opticalDistCoeffs[0];
double den = 1 + dk1 * dy * dy; // r = dy*dy = distance from the focal plane center
if (den == 0.0) {
throw "Unable to remove distortion for LRO LROC NAC. Focal plane position " + std::to_string(dy);
}
ux = dx;
uy = dy / den;
return;
}
break;
}
}
void applyDistortion(double ux, double uy, double &dx, double &dy,
const std::vector<double> opticalDistCoeffs,
DistortionType distortionType,
const double desiredPrecision, const double tolerance)
{
const double desiredPrecision, const double tolerance) {
dx = ux;
dy = uy;
switch (distortionType) {
// Compute undistorted focal plane coordinate given a distorted
// focal plane coordinate. This case works by iteratively adding distortion
// until the new distorted point, r, undistorts to within a tolerance of the
......@@ -312,6 +342,8 @@ void applyDistortion(double ux, double uy, double &dx, double &dy,
computeTransverseDistortion(ux, uy, dx, dy, opticalDistCoeffs);
}
break;
// KaguyaTC
case KAGUYATC: {
if (opticalDistCoeffs.size() != 8) {
throw "Distortion coefficients for Kaguya TC must be of size 8, got: " + std::to_string(opticalDistCoeffs.size());
......@@ -377,6 +409,7 @@ void applyDistortion(double ux, double uy, double &dx, double &dy,
}
}
break;
// The dawn distortion model is "reversed" from other distortion models so
// the apply function computes distorted coordinates as a
// fn(undistorted coordinates)
......@@ -388,5 +421,73 @@ void applyDistortion(double ux, double uy, double &dx, double &dy,
dx = ux * (1.0 + opticalDistCoeffs[0] * r2);
dy = uy * (1.0 + opticalDistCoeffs[0] * r2);
}
break;
// The LRO LROC NAC distortion model uses an iterative approach to go from
// undistorted x,y to distorted x,y
// Algorithum adapted from ISIS3 LRONarrowAngleDistortionMap.cpp
case LROLROCNAC: {
double yt = uy;
double rr, dr;
double ydistorted;
double yprevious = 1000000.0;
double tolerance = 1.0e-10;
bool bConverged = false;
if (opticalDistCoeffs.size() != 1) {
throw "Distortion coefficients for LRO LROC NAC must be of size 1, current size: " + std::to_string(opticalDistCoeffs.size());
}
double dk1 = opticalDistCoeffs[0];
// Owing to the odd distotion model employed in this senser if |y| is > 116.881145553046
// then there is no root to find. Further, the greatest y that any measure on the sensor
// will acutally distort to is less than 20. Thus, if any distorted measure is greater
// that that skip the iterations. The points isn't in the cube, and exactly how far outside
// the cube is irrelevant. Just let the camera model know its not in the cube....
if (fabs(uy) > 40) { //if the point is way off the image.....
dx = ux;
dy = uy;
return;
}
// iterating to introduce distortion (in sample only)...
// we stop when the difference between distorted coordinate
// in successive iterations is at or below the given tolerance
for(int i = 0; i < 50; i++) {
rr = yt * yt;
// dr is the radial distortion contribution
dr = 1.0 + dk1 * rr;
// distortion at the current sample location
yt = uy * dr;
// distorted sample
ydistorted = yt;
if (yt < -1e121) //debug
break; //debug
// check for convergence
if(fabs(yt - yprevious) <= tolerance) {
bConverged = true;
break;
}
yprevious = yt;
}
if(bConverged) {
dx = ux;
dy = ydistorted;
}
return;
}
break;
}
}
src/Utilities.cpp
+ 24
− 2
View file @ 363546b7
......@@ -727,6 +727,7 @@ double getSemiMajorRadius(json isd, csm::WarningList *list) {
return radius;
}
double getSemiMinorRadius(json isd, csm::WarningList *list) {
double radius = 0.0;
try {
......@@ -747,8 +748,9 @@ double getSemiMinorRadius(json isd, csm::WarningList *list) {
return radius;
}
// Gets the type of distortion model from the isd. If none is specified defaults
// to transverse
// Converts the distortion model name from the ISD (string) to the enumeration
// type. Defaults to transverse
DistortionType getDistortionModel(json isd, csm::WarningList *list) {
try {
json distoriton_subset = isd.at("optical_distortion");
......@@ -769,6 +771,9 @@ DistortionType getDistortionModel(json isd, csm::WarningList *list) {
else if (distortion.compare("dawnfc") == 0) {
return DistortionType::DAWNFC;
}
else if (distortion.compare("lrolrocnac") == 0) {
return DistortionType::LROLROCNAC;
}
}
catch (...) {
if (list) {
......@@ -877,6 +882,23 @@ std::vector<double> getDistortionCoeffs(json isd, csm::WarningList *list) {
}
}
break;
case DistortionType::LROLROCNAC: {
try {
coefficients = isd.at("optical_distortion").at("lrolrocnac").at("coefficients").get<std::vector<double>>();
return coefficients;
}
catch (...) {
if (list) {
list->push_back(
csm::Warning(
csm::Warning::DATA_NOT_AVAILABLE,
"Could not parse the lrolrocnac distortion model coefficients.",
"Utilities::getDistortion()"));
}
coefficients = std::vector<double>(1, 0.0);
}
}
break;
}
if (list) {
list->push_back(
......
tests/DistortionTests.cpp
+ 61
− 0
View file @ 363546b7
......@@ -214,6 +214,7 @@ TEST(KaguyaTc, testRemoveCoeffs) {
EXPECT_NEAR(uy, 1 + 1 + 2.828427125 + 6 + 11.313708499, 1e-8);
}
TEST(KaguyaTc, testCoeffs) {
csm::ImageCoord imagePt(1.0, 1.0);
......@@ -235,6 +236,7 @@ TEST(KaguyaTc, testCoeffs) {
EXPECT_NEAR(uy, 1.0, 1e-8);
}
TEST(KaguyaTc, testZeroCoeffs) {
csm::ImageCoord imagePt(1.0, 1.0);
......@@ -254,3 +256,62 @@ TEST(KaguyaTc, testZeroCoeffs) {
ASSERT_DOUBLE_EQ(ux, 1.0);
ASSERT_DOUBLE_EQ(uy, 1.0);
}
// Test for LRO LROC NAC
TEST(LroLrocNac, testLastDetectorSample) {
double ux, uy, dx, dy;
double desiredPrecision = 0.0000001;
// Coeffs obtained from file: lro_lroc_v18.ti
std::vector<double> coeffs = {1.81E-5};
removeDistortion(0.0, 5064.0 / 2.0 * 0.007, ux, uy, coeffs,
DistortionType::LROLROCNAC, desiredPrecision);
applyDistortion(ux, uy, dx, dy, coeffs,
DistortionType::LROLROCNAC, desiredPrecision);
EXPECT_NEAR(dx, 0.0, 1e-8);
EXPECT_NEAR(dy, 17.724, 1e-8);
EXPECT_NEAR(ux, 0.0, 1e-8);
EXPECT_NEAR(uy, 17.6237922244, 1e-8);
}
TEST(LroLrocNac, testCoeffs) {
double ux, uy, dx, dy;
double desiredPrecision = 0.0000001;
// Coeff obtained from file: lro_lroc_v18.ti
std::vector<double> coeffs = {1.81E-5};
applyDistortion(0.0, 0.0, dx, dy, coeffs,
DistortionType::LROLROCNAC, desiredPrecision);
removeDistortion(dx, dy, ux, uy, coeffs,
DistortionType::LROLROCNAC, desiredPrecision);
EXPECT_NEAR(dx, 0.0, 1e-8);
EXPECT_NEAR(dy, 0.0, 1e-8);
EXPECT_NEAR(ux, 0.0, 1e-8);
EXPECT_NEAR(uy, 0.0, 1e-8);
}
TEST(LroLrocNac, testZeroCoeffs) {
double ux, uy, dx, dy;
double desiredPrecision = 0.0000001;
std::vector<double> coeffs = {0};
applyDistortion(0.0, 0.0, dx, dy, coeffs,
DistortionType::LROLROCNAC, desiredPrecision);
removeDistortion(dx, dy, ux, uy, coeffs,
DistortionType::LROLROCNAC, desiredPrecision);
ASSERT_DOUBLE_EQ(dx, 0.0);
ASSERT_DOUBLE_EQ(dy, 0.0);
ASSERT_DOUBLE_EQ(ux, 0.0);
ASSERT_DOUBLE_EQ(uy, 0.0);
}
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