Harry's GPS Suite Forum

I am completely new to data acquisition, I would like to figure out how to read the GPS data(cvs) and compare different lap times.

thanks

Hi,

The CSV files contain kind of 'raw' data LapTimer receives from the sensors. The first row has some description on the columns:

LAPINDEX,DATE,TIME,LATITUDE[degrees],LONGITUDE[degrees],SPEED[km/h],HEIGHT[m],
GPSDIFFERENTIAL[UNKNOWN;2D3D;DGPS;INVALID],GPSFIX[NOFIX;2D;3D;UNKNOWN],SATELLITES,DIRECTION[degree],
HOP,DISTANCEFROMSTART[m],TIMEFROMSTART[s],ACCELERATIONSOURCE[CALCULATED;MEASURED;UNDEFINED],
LATERALG,LINEALG,LATITUDEG[degree],LONGITUDEG[degree],RPM,MAF,OBDSPEED[km/h],THROTTLE

LAPINDEX is a reference to the lap recorded. All GPS fixes belonging to a lap have he same number. DATE, TIME should be straight forward and qualify the fix time. Every time you see square brackets, a unit is given used for the column. In case you see several 'names', the column is a enumeration. A value of zero denotes the first name etc. Example: UNKNOWN;2D3D;DGPS;INVALID. DIRECTION is driving direction. HOP is actually HDOP on accuracy and denotes horizontal distance of delution. 1.0 zero means that with 95% probability the fix is within the best accuracy the sensor can make. DISTANCEFROMSTART and TIMEFROMSTART are the distance traveled / time taken from the lap's start to the current fix. LATERALG and LINEALG are the acceleration data (1.0 = 1 Gravity). Ignore LONGITUDEG and LATITUDEG. The rest of the data is OBD data delivered. MAF is the mass flow factor and denotes the weight if air consumed per second(?). THROTTLE is the position of the throttle (i.e. 1.0 = full throttle).

As this is complicated material that requires some reading, I'd like to forward you to basic readings on GPS. You will find everything in Wkipedia

- Harry

I appreciate this in deep explanation, I just would like to know if there is a software I should use to be able to compare the lap maps. Kind of have them overlapped for quick visual comparison.
also can I display my line according to the track?

BTW thanks for such an awesome application

Hi,

I have no recommendation on external data recording applications. Most of the applications are specific to proprietary sensors, maybe someone of the friends here can help?

You are aware that LapTimer has some lap to lap comparison in the data recordings area (i. e. Lap List -> Lap Details -> Track -> Diagram)? You need to have either the Professional version, the Trainer version, or the Analytics Feature installed to get comparison.

Position on track (i.e. vizualization of your line compared to the track) requires data on the track bounds (and pretty good GPS accuracy). Using Google Earth will not work too good, as the satellite pictures are stretched and shifted a bit most of the time.

- Harry

I am starting to get a hold of it, it is really awesome.

Harry wrote:Hi,
You are aware that LapTimer has some lap to lap comparison in the data recordings area (i. e. Lap List -> Lap Details -> Track -> Diagram)? You need to have either the Professional version, the Trainer version, or the Analytics Feature installed to get comparison.
- Harry

I have Pro version and can see the Diagram for a lap as per your path above. Is there a comparison feature or button to directly compare laps side-by-side or as an overlay? Or is the comparison done manually by moving back and forth between laps or printing the lap diagrams?

Hi,

Navigating the Lap List -> Lap Details -> Track -> Diagram way, you should see both the lap currently browsed (gray) and the reference lap in red.

- Harry

Harry,
I am very interested in being able to see two (or more) GPS breadcrumb displays thru the data section when I am analyzing laps after the session.

When I am on Trainer on my iPad, and I go to LapList-->SelectLap-->DataRecording--> Map -->Charts, and I'm on speed@distance, the "Show Map" feature only highlights a sector (Grey outline gets cover in browndots)

It would really help picking a line to see where the car was on track for each lap (selected vs ref), and being able to zoom the track map and see the actual GPS breadcrumbs of each lap would be great.


Thanks...

Yeah, will require a good GPS (not the internal one) to show something reasonable. Once I have enough test data for the VBOX Sport, I will add something like this. Thanks for proposing.

- Harry