[OSM-talk] Aerial photo offsets

[Paul Norman]

There was some discussion about a True Offset Process
(http://wiki.openstreetmap.org/wiki/True_Offset_Process) awhile back, but
I'm not sure if any code ever got written.

As much as I sometimes talk about offset imagery, it is overall more
accurate than single GPS tracks. Although we can all find examples of bad
bing offsets, I've seen just as many bad GPS tracks. Imagery from other
sources (county GIS departments, etc) tends to be more accurate than any
consumer GPS can be, even in ideal conditions for the GPS.

I'm aware that high-end professional GPS units can be more accurate, but I
doubt anyone is mapping with those. <10cm accuracy is not really necessary
for mapping most features.

I also map mainly in urban settings, where GPS reception is poor and imagery
is good.