CompassData's team of experienced mapping technicians can create a complete GIS dataset from scratch, verify the accuracy and completeness of an existing GIS dataset, collect Ground Control to rectify aerial and satellite imagery, or locate cell towers to comply with E911 requirements and enhance the capability of your Computer Aided Dispatch (CAD) system. CompassData has an existing archive of over 15,000 photo-identifiable ground control points for orthorectification that are available off the shelf and at a great price.