This paper provides a summary of the state of practice of reflectorless precision survey monitoring using a manual total station to track and record movements. Topics covered include instrument selection, achievable accuracy under varying and challenging conditions, sources of error, reflectorless controls and establishing accurate baseline readings. The authors provide their opinion, with respect to when this technology is a valuable alternative to standard surveying and when it is not applicable. Abbreviated case studies from projects located in downtown Toronto, Ontario, Canada, are used to provide examples of practical and technical aspects of reflectorless precision survey monitoring. The abbreviated case studies include monitoring of high voltage transmission towers in an electrical substation with a deep excavation nearby, background measurements on the Head-House at Union Station (a historic structure) over four seasons, and taking measurements of adjacent buildings when access is difficult for target installation. A comparison of precise measurements versus reflectorless measurements used for precision survey monitoring is also included. The authors feel this paper will be a useful reference for determining when to use reflectorless monitoring instead of more standard manual monitoring.

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