Mapping Matters

There were a lot of discussions about camera calibration at the 2011 ASPRS conference in Milwaukee. In particular, the plan by the U.S. Geological Survey (USGS) to discontinue laboratory calibration within the next few years generated considerable concern. However, if I heard correctly, you made the point (during one of the conference events) that once the camera has been calibrated at the factory, then subsequent calibrations may not be altogether that useful. Other error sources, in particular, thermal expansion and contraction that affect the camera focal length during actual flight operations become much more important than the small changes that occur in a camera as it ages. And, a laboratory calibration does not address these other error sources. Could you please elaborate on the direction you believe camera calibration should go in the future? Is in situ calibration a viable alternative?.