Methods for aligning measured data taken from specific rail track sections of a railroad with the correct geographic location of the sections

A method for aligning measured track data collected from a railroad track to correct geographic location information for geometric parameters in the measured track data comprising steps of:

• (a) obtaining track geography data for use as reference data in data alignment;
• (b) reconstructing the track geography data to simulate in form and in coverage of length the measured track data to be aligned;
• (c) cross-correlating the reconstructed reference data to the measured track data to identify a relative misalignment value between the data types;
• and
• (d) using the value identified through comparison to correct the geographic location information contained in the measured track data.

In a data alignment process for aligning measured track data collected along a length of railroad track to a reference data set for the same length of track, a method for coarse estimation of odometer error manifest along the track length of measured track data and refining the coarse estimate to produce a final estimate used in correcting the actual odometer error manifest in the measured track data comprising steps of:

• (a) creating a plurality of simulated data sets from the measured track data, each data set simulating a different odometer error value, each value taken at a different predetermined interval point along a predetermined maximum error range applied to the measured track data set, the range having a zero interval point at center thereof;
• (b) cross-correlating each of the simulated data sets against the.reference data set at each interval point along the maximum range allowed obtaining a coefficient value for each of the simulated data sets;
• (c) identifying a single best coefficient value from those obtained in step (b) that defines a best alignment to data contained in the reference data set;
• and
• (d) repeating steps (a) through (c) using a smaller range having smaller intervals, the smaller range centered over the range interval in the first range of the measured track data associated the best coefficient identified.

In a data alignment process for aligning measured track data collected along a length of railroad track to a reference data set for the same length of track, a method for estimating a value of odometer error manifest along the track length of measured track data comprising steps of:

• (a) cross-correlating the entire set of measured track data to the entire set of reference data to identify a relative misalignment value;
• (b) filtering the measured track data set to remove references to certain geometric features;
• (c) dividing the length of the measured and reference data sets into smaller portions;
• (d) cross-correlating the smaller portions of measured data against associated portions of reference data to find relative misalignment values for each portion;
• (e) using line regression, fitting a line through the found misalignment values plotted sequentially for each correlated data portion on a graph;
• and
• (f) determining the magnitude and direction of slope of the fitted line indicative of the magnitude and direction of the actual calibration error manifest in the measured track data.