Last year the McCarthy Taylor Partnership released a free Windows application for the conversion of a Trimble Calibration File to a Topcon Localization file.
When it comes to machine control for construction sites, here in the UK there are two main manufacturer systems in use. These systems are from Trimble and Topcon.
Both the Trimble and the Topcon Machine Control Systems require a transformation of the GPS information to a local grid information or a national co-ordinate system. This is done by surveyors visiting know points around the site and taking readings and then using specialist software computing a Localization (Topcon) or a Calibration (Trimble) file. This file enables both systems to translate the information from the satellites (Lats, Longs and Heights) to local (or ground) co-ordinate system that the project would be designed with.
The transformation file for the Trimble is called a Calibration and has the file extension of .dc (*NAME*.dc). The transformation file for the Topcon is called a Localization and has the file extension of .gc3 (*NAME*.gc3).
It is quite common for both the Trimble and Topcon (Leica also) systems to be in use on the same site and also using just one base station for the corrections. However, it is not possible to load a Trimble Calibration file (.dc) onto a Topcon machine (.gc3), or to load a Topcon Localization (.gc3) onto a Trimble machine (.dc). This would mean that the transformation file would have to be done twice, once for each manufacturer.
However, there is now a free conversion software from McCarthy Taylor that will convert a Trimble Calibration file into a Topcon Localization file. It is called the LSS-Toolkit and can only be downloaded from their website.
Using the LSS-Toolkit is easy and straightforward. Just open the programme and load your Trimble Calibration File and then select Save Topcon GC3 File. The newly created Topcon Localization file can then be loaded onto a Survey Data Logger or onto the Machine Control Logger ready to go to work once the proposed design has been loaded also.
Remember that it is always prudent to check the GPS equipment daily and the first thing you should do is check a new control point with the new Topcon Localization file installed and then check any freshly equipped machines.