Class for linear expansion of track parameters in vicinity of vertex.
The measurement equation is linearized in the following way:
F_k= D_k (x_k - x_0k) + E_k (p_k - p_0k) + F^0_k
where F_k are the parameters at perigee nearest to the linearization point, x_k is the position of the vertex, p_k the track momentum at the vertex, and F^0_k is the constant term of expansion. D_k and E_k are matrices of derivatives, denoted hereafter as “positionJacobian” and “momentumJacobian” respectively.
LinearizedTrack() = default¶
inline LinearizedTrack(const BoundVector ¶msAtPCA, const BoundSymMatrix &parCovarianceAtPCA, const BoundSymMatrix &parWeightAtPCA, const Vector4 &linPoint, const ActsMatrix<eBoundSize, 4> &posJacobian, const ActsMatrix<eBoundSize, 3> &momJacobian, const Vector4 &position, const Vector3 &momentum, const BoundVector &constTerm)¶
Constructor taking perigee parameters and covariance matrix of track propagated to closest approach (PCA) of linearization point, position and momentum Jacobian and const term.
paramsAtPCA – Parameters at point of closest approach
parCovarianceAtPCA – Parameter covariance matrix at point of closest approach
parWeightAtPCA – The weight at the point of closest approach
linPoint – Linearization point
posJacobian – Position jacobian
momJacobian – Momentum jacobian
position – Position at point of closest approach
momentum – Momentum at point of closest approach
constTerm – Constant term in taylor expansion
- LinearizedTrack() = default¶