Seismic reflection methods can very well be used in glaciology. How does this method work? What is a CMP gather and how do we convert recorded data into a map of the subsurface? What are important parameters to consider when setting up a survey. I will discuss three field surveys at very different locations in ice: An ice shelf, a local ice dome and a mountain glacier. Each site has its own specific problems and advantages. At all survey sites I will compare two source types: conventional explosives against vibrator data.