Research on DEM surface deformation detection without control points;

A data processing method for the precision surveying of ballastless track high-speed railway is put forward:first, choosing the compatible points in the control network by quasi-stable adjustment, then, adjusting the control network with the adjustment model of indirect observation in which the Baarda gross errors detection and Helmert variance component estimation are used.

The Application of Robust Estimation to the Gross Error Detection and Adjustment Calculation;

The paper introduces three gross error detection algorithms based on regular DEM,namely the method that applies constrains to the slopes and to the changes in slope at each point,the parametric statistical method and the one based on principal components analysis.

The paper introduces two gross error detection algorithms based on regular DEM,namely the method that applies constrains to the slopes and to the changes in slope at each point,and the parametric statistical method by Felicísimo.

Off-axis use of Cassegrain telescope in heterodyne detection system;

A fiber Bragg grating temperature sensor based on heterodyne detection;

This paper reported a CO 2 laser scanning imaging demo system adopting the technology of scanning transmit, the same antenna for receiving and transmitting, heterodyne detection etc.