The purpose of this lab exercise is to introduce the student to geometric correction of digital imagery (see Figure A-

6, in appendix). The lab exercise involves the collection of two sets of reference points from the following sources:

(1) GPS receivers and (2) USGS 7.5 minute topographic maps. The reference points are collected in units of latitude

and longitude and will serve as the ground control points (GCP) and check points (CP). An input image of Blacksburg is matched to the reference coordinates collected above to reduce positional errors. This process is called image registration. -The purpose of this lab exercise is to introduce the student to geometric correction of digital imagery (see Figure A-

6, in appendix).　The lab exercise involves the collection of two sets of reference points from the following sources:　

(1) GPS receivers and (2) USGS 7.5 minute topographic maps.　The reference points are collected in units of latitude

and longitude and will serve as the ground control points (GCP) and check points (CP).　An input image of Blacksburg is matched to the reference coordinates collected above to reduce positional errors.　This process is called image registration.