Draw based on GPS or satellite images?

I am looking at an area (http://www.openstreetmap.org/?lat=39.36285&lon=-120.23967&zoom=17) where the streets, and the satellite images, are misaligned.

If I draw further roads, or fix details, should I trust the satellite imagery or the GPS?

What is the way for me to bring the imagery and the map back into alignment? For instance, if I can get an accurate fix of a few points via my GPS, what is the way to then make the satellite image conform to those points? I guess there could be a way to click on those points in the satellite image and manually enter their coordinates, and then have the image correctly re-mapped (with the system inferring the right tranform to remap the photo with minimal distorsion on the terrain). But how is it done in OpenStreetMaps?

Many thanks!


Accurate GPS references taken in an unobstructed area are to be trusted over the satellite imagery. To align the satellite imagery,

In Potlatch - hold the SPACE and drag the background until it lines up
In JOSM - Use the tool on the toolbar on the left side to adjust the selected WMS layer.

The TIGER data in this area looks to me as though it was created from either a pencil sketch or a very old generation GPS or low res satellite imagery.