When GPS satellite positioning was unavailable, the laser altimetry was corrected using attitude information from an inertial navigation system, and a digital pressure transducer was used to recover vertical positions and accelerations. A data index plot gives an overview of the names and locations of the geographic regions. A data table summarizes the survey specifications, including dates flown and original flight elevations. A list of data processing steps details the procedures used to produce the final maps. GIF and page-sized color postscript plot files can be downloaded for all maps.
All maps are also available for screen viewing .
The authors wish to thank our USGS colleagues Richard Saltus and Kim Oshetski for their assistance in preparing this report, and Robert Arko of LDEO for his assistance with the data processing.