Hello. I noticed that when my gps antenna is rotating rapidly the elevation shown on the display is changing [MEDIA=youtube]3l8u1qm_0Og[/MEDIA] this happens also when only the antenna is moving. I would like to have an explanation of why this is happening, how does the gps calculate elevation, and also how can I receive a gps satellite signal from a single satellite and display it on my scope or computer with 100 ns accuracy. thanks.