Patent ID: 9109898
Filing Date: 2015-08-18
Classification: G01C,G01S

Abstract:
1. A method for corrections of metrology instruments measurements of positions of points of interest measured by beams of radiation propagating through stratified media comprising following steps: a) definition and arrangement of at least one metrology instrument, definition of at least one point of interest, and at least one stratified medium; b) definition and arrangement of at least one measurement setup having the at least one metrology instrument, at least one point of interest, ad at least one stratified medium having a least a portion of stratified medium arranged in between and separating the at least one metrology instrument and the at least one point of interest; c) performance of ray-tracing of at least one ray lunched from that at least one metrology instrument in a direction of an apparent position of the at least one point of interest through at least the portion of the at least one stratified medium and determination of at least one direction of propagation of the at least one ray through the at least the portion of the at least one stratified medium arranged in between and separating the at least one metrology instrument and the at least one point of interest, and measurement of at least one apparent total geometric length from the at least one metrology instrument to the apparent position of the at least one point of interest along the at least one ray; d) calculation of at least one path length of the at least one ray through the at least a portion of the at least one stratified medium using optical properties of the at least one stratified medium, the at least one direction of propagation of the at least one ray, and the at least one apparent total geometric length from the at least one metrology instrument to the apparent position of the at least one point of interest along the at least one ray; and e) determination of coordinates of true position of the at least one point interest using the at least one path length and the at least one direction of propagation of the at least one ray.