Review of Spatial Domain Modal Parameter Estimation Procedures and Testing Methods

As part of the IMAC Technology Center a exhibition of continuously scanning laser, digital image correlation and photogrammetry modal testing will be presented. This paper is the “kick off paper” in a special session on these optical testing methods which offer the possibility of very high spatial resolution with 3 to 6 degrees of freedom at each spatial point and which have tremendously reduced requirements for sensor arrays and cabling systems used in a large modal test. The testing procedures for conducting test using these technologies will have to be adjusted to accommodate the scanning procedures. Many of the testing procedures of the past may be very well suited for these scanning methods and need to be reviewed. In particular methods based upon using spatial information in the initial stages of extracting modal parameters. This paper presents a review of spatial domain modal testing parameter estimation and testing procedures. A spatial domain testing method developed in the late 80’s and early 90’s (Spatial Sine Testing -SST) will be review in more detail since it appears to be well suited for these optical scanning methods.