Racelogic Ltd PerformanceTools Software
02/05/2014
Page 59
Circuit Overlays
A circuit overlay is a file created to map the outer and inner bounds of a circuit, and is a
useful aid in drive-line analysis - comparison of lines taken by different drivers can help to
improve lap times.
NOTE:
A circuit overlay is only a feature that can be used in software post-processing
– it is
not vital that it is created or obtained prior to visiting a circuit unless specific drive line
analysis, that requires the track boundaries, is going to be carried out between lap sessions.
Creating a Circuit Overlay
There are two ways that an overlay file can be created: either by driving around the circuit, or
by creating a .kml file in Google Earth and importing it into PerformanceBox Tools.
Creating an Overlay File by Driving the Circuit
Note: It is best to use an external antenna to get maximum positional accuracy
Power up PerformanceBox and let it acquire satellites for at least 5 minutes.
Drive to the left hand side of the start of the circuit.
Place the antenna on the left hand side of the roof.
Insert the SD card, ready for logging.
Drive round the left hand side of the circuit.
Stop back at the place you started.
Move the antenna from the left hand side of the roof to the right hand side slowly,
being careful not to cover the aerial
– let it see the sky at all times.
Drive at right angles across the track to the opposite side.
Drive round the right hand side of the circuit.
Load the logged f
ile from the SD card using ‘File’ -> ‘Load All’
Save using ‘Save’, select ‘Save as type’ and pick ‘Circuit file’ (‘.cir’).
Creating an Overlay File in Google Earth
TM
Please refer to the Google Earth help files for instructions on creating
paths in the software. Once you have plotted a path along the inside
and outside of your chosen track, it must be saved as a .kml file. This
can then be imported into PerformanceBox Tools by clicking on
TOOLS>Import Data
Once the .kml file has been imported, it can be re-saved as a .cir file for
later use with lap data from the circuit. See page 69 for more
information about importing .kml files.
Loading a Circuit Overlay File
The .cir file can be now be loaded into the Graph screen and viewed in
the Map window. To do this, first load a file logged from the circuit in question, and then click
on the drop-down arrow next to the Load All button. Select Load Circuit Map, and choose the
.cir file you have created:
