The aim of the project is to determine the center-to-limb variation of the photospheric wave spectrum. In principle this is an improved project of an investigation performed by M. Stix and H. Wöhl more than 20 years ago (Solar Phys. 37, 63 (1974)). By using MDI-SOI data it is intended to improve the statistics a lot. In addition these data will allow to determine the CLV of the ridges in the k-omega-diagram.