  The main objective of this paper is to assess the estimation of track
condition parameters using onboard micro-electro-mechanical-system (MEMS)
accelerometers. A prototype of an onboard data acquisition system was designed
and installed on a track recording car (TRC) and a measurement campaign was
conducted on an extensive portion of the Brisbane Suburban railway network.
Comparison of the accelerometer-based results vs TRC recordings have shown that
accelerometers installed on the bogie are the best compromise between proximity
to the source and insensitivity to impulsive noise. It was found that two
vertical bogie accelerometers (left and right) provide a good quantitative
estimate of vertical alignment and that strong correlations with TRC
measurements exist for lateral MEMS accelerometer measurements (horizontal
alignment). These findings suggest that two bogie MEMS accelerometers with
vertical and lateral measurement axes are effective in estimating geographical
distributions of vertical/horizontal alignment.
