Tight Location Requirements For Geophysical Investigations On Urban Sites Using RTS

For geophysical surveys, the accurate location and documentation of measurement points, lines and features in densely-built areas with limited survey control and sky-view is challenging. Yet in the present day, urban sites containing numerous obstructions are more often the norm for geophysical applications. Historic site information may span generations of data ranging from as-designed drawings to generated 3-D plans. Frequently, each dataset is probably in different coordinate systems with widely differing accuracies. Using a robotic total station (RTS) theodolite for survey location/navigation control has significant advantages over conventional gridding, tick wheel, and global positioning system (GPS) techniques including:<br> Survey-grade X,Y,Z precision<br> In-field verification of positional accuracy<br> Operation wherever line-of-sight can be established<br> Data collection directly in agreed-upon or convenient coordinate systems<br> Locations are continuously streamed by radio-link to geophysical loggers/equipment<br> Remote-control RTS operation<br> Follow-up relocation independent of changing ground conditions<br>Geophysical survey and utility mapping results from five “urban” sites are presented illustrating typical location/navigation problems, collection of high locational accuracy survey data around complex structures, and considerations for survey planning, design, and reporting.