A decade of operations with the laser traffic control system: paradigm shift and implied development directions

The Laser Traffic Control System (LTCS) is a software solution to the problem of laser beam avoidance, using priority based collision resolution and an optional built-in laser shutter command interface. LTCS uses static site survey information, dynamic telescope pointing and control data, and a configurable "rules" scheme, to monitor laser beam geometry (Rayleigh and LGS) and warn or prevent undesired emission at participating institutions. LTCS was developed for use on Mauna Kea in 2001, but through collaborative efforts with multiple institutions, has since been enhanced and installed at several sites around the world. Functional implementations, either operational or in prototype form, exist for Mauna Kea, La Palma, Cerro Pachon, Cerro Paranal, and Haleakala. Since the last LTCS SPIE update in 2006, many important features have been added. There has also been some new site testing activity that has resulted in lessons learned and the development of new analysis/test tools. Finally, an important lasing operations paradigm shift has emerged on Mauna Kea and is anticipated for Paranal. The trend is clearly away from static collision priority rule determination, toward dynamic "negotiated" priority determination. The implications of this paradigm shift, discussion of forced collision test results and lessons learned, and a status update on development activities since the last update will be presented in the paper.