Thanks for your helpful advises @ABraun , at the moment I do not have good internet access…
I am looking forward to give access to the version I finally used during my thesis, some minor things have changed. One more hint, if you have trouble with the matlab export, because some of the objects do not have the same length, choose a large radius in order to include all points, export the csv and make a spatial subset in R with a polygon you have prepared in google earth for example. I have to use this workaround during the presentation of SBAS results, because of the much higher density of measurement points.