Integrated space-time modelling based on correlated measurements for the determination of survey configurations and the description of deformation processes (IMKAD II)

IMKAD II is the follow-on project of IMKAD I, which dealt with the functional modelling of point clouds, the stochastic modelling of the terrestrial laser scanners´ error sources and the analysis of survey configurations for a space-continuous monitoring of deformations. During IMKAD I advanced strategies for point cloud modelling by means of B-spline surfaces were developed, forming the basis for a spatio-temporal deformation model.

IMKAD II continues the research topics of IMKAD I and addresses new topics as well, both based on knowledge gained during IMKAD I.

The first objective of IMKAD II deals with the further development as well as the validation of the functional and stochastic components of a space-continuous approximation model of the measured object’s geometry (WP 1 to WP 4). The second one uses the developed model with regard to a deformation analysis and a non-linear sensitivity analysis including an evaluation of the deformation model (WP 5 to WP 8).

Work Packages

  • WP 1: B-spline modelling by estimated surface parameters
  • WP 2: Extended synthetic covariance matrix
  • WP 3: Design and realization of real-world measurements, validation of stochastic modelling
  • WP 3.1 Design and realization of real-world measurements
  • WP 3.2 Validation of the stochastic modelling
  • WP 4: Optimization of the B-Spline surface’s complexity by model selection
  • WP 5: Identification of undistorted regions, estimation of rigid body movements and 3D strain
  • WP 5.1: Identification of undistorted regions and estimation of rigid body component
  • WP 5.2: Estimation of the strain component
  • WP 6: Non-linear sensitivity analysis for deformation models
  • WP 7: Automated optimization of scanning parameters
  • WP 8: Evaluation of functional modelling – benchmark test


Project partner: Institut für Ingenieurgeodäsie, Universität Stuttgart


State of the project at Research Group Engineering Geodesy

At the moment the surface parameters (u,v) are integrated into the least-squares procedure resulting in a non-linear estimation model. As this extension leads to estimated surface parameters outside the interval [0,1], constraints have to be added to the least-squares adjustment.

In addition, we are currently working on the identification of undistorted regions and estimation of rigid body components.

IMKADII.pngThe parameter grid of a B-spline surface is not affected by a rigid body movement (left). In case a local strain is superimposed, the grid is locally distorted (right).