@article{TUW-120543, author = {B{\"o}hm, Johannes and Schuh, Harald}, title = {Linear Horizontal Gradients vs. 3D Raytracing}, journal = {IVS General Meeting Proceedings}, year = {2006}, volume = {Conception, Chile, January 9-11}, number = {NASA/CP-2006-214140}, pages = {261--263} }