ROO'S DUMMIES GUIDE TO DOWNLOADING AND ANALYSING DATA

If you've been good speedsailors and read Roo's guide on how to set up your NAVi GPS you'll be ready to download your speeds and claim some glory at your local beach.

Even though the NAVi GT-11 is pretty user friendly it still has a few quirks when it comes to getting it to spit out information. As you will have seen in the setup instructions it can store your speedsailing track log both internally in memory and also at the same time record it to a SD card that hopefully you put into the unit before you went sailing.

SD Card removal

We'll deal with getting the track log off the SD card first. Before removing the SD card make sure the unit is turned off, if you don't it may corrupt the data on the card.

Open the flap on the bottom of the GT-11; find the card in the slot on the left side and push in the SD card and it should spring free.

We are now going to transfer the card to a computer so we can retrieve the data. If your computer has a SD card slot simply insert it and you are ready to go.

For those without a built in reader you will need to buy a SD card reader that will plug into a USB slot on your computer (you can find them at most Harvey Norman/Computer superstores for around $20). Insert the card into the reader then plug it into a free USB slot on the front/side/back of your PC and you are ready to go.

Loading the software

If you haven't already downloaded a copy of RealSpeed, download the compressed .zip file from here http://www.intellimass.com/RealSpeed/Index.htm

Once you have copied or extracted all the included files to a folder, run RSpeed.exe and go to "Tools" in the Menu and select "Register" to find your computers "machine ID" number.
You need to send this number to info@intellimass.com with your name and country, and RealSpeed will send you back a registration ID.
Go to "Tools" in the Menu and select "Register"
Enter the license number into the box below "2. Enter the license number that you received:"
Click "OK" and the program will be fully enabled.

Now you are ready to analyse your tracks and see if Finian should start getting worried!

Opening Speedsailing track logs

Click on "File" in the menu and select "Open"

When the dialog box comes up click on the arrow to the left of the "Look in" box.

Select the drive your SD card is listed as (usually Removable Disk (E:) or (F:))

It will bring up a directory in the box below that says "GPS_DATA"; this is the default directory on your SD card the track files are saved in.

Double click on this directory and the track files will be listed.

The last six digits of the file name indicate the time the file was created; pick the one which corresponds to when you were out speedsailing.

Click "OK"

RealSpeed will now load the file, be patient it may take a few seconds.

Setting up divisions

The first time you use RealSpeed you will need to set up the categories you want it to analyse your data for, otherwise known as "Divisions"

RealSpeed comes with "Divisions" for 2 sec peak, 5 x 10 sec average, 100 m, 250 m, and 500 m, pre-selected.

For the Speed Challenge you will need to add "Divisions" for "1 hour" and "Nautical mile".

To add a "Division" select "Edit" from the menu bar and click on "Add Division"

We'll start with "1 hour", add this as the "Division Name"

Click on "Time" under "calculation method"

Add "3600" in the box next to "Seconds", and add "1" for "Average Runs"

Make sure the box next to "Accumulation Method" is selected; no other boxes should be selected.

Click on "OK" to save

Well now do one for the "Nautical mile" which is 1852 m.

Select "Edit" then click on "Add Division"

Add "Nautical Mile" as the "Division Name"

Click on "Distance" under "calculation method"

Add "1852" in the box next to "Metres", and add "1" for "Average Runs"

Make sure the box next to "Accumulation Method" is selected; no other boxes should be selected.

Click on "OK" to save

The program will retain these setting so you will not have to load them again.

Track log analysis

RealSpeed is a bit of a smart alec; it will do everything for you and even delete the spikes from your tracklog! It also gives you a pretty picture of the path you sailed.

The program loads with four windows visible:
on the top left the "Map" box
one for "Division Results" to the right
another for "Trackpoints" under it
and a "Graph" box across the bottom.

When your tracklog has been loaded from your SD card all the data you need will be presented.

Any spikes that were in your tracklog, usually created when the gps is submerged after a crash, will appear as red spikes in the "Graph" box on the bottom of the screen.

The spikes are not used for the speed calculations that are listed in the "Division Results"

To remove the spikes from the tracklog completely click on "Edit" and select "Delete Invalid". The red spikes should disappear from the "Graph" box.

To save your cleaned file, select "File" from the menu box, click on "Save As"

Save the file with a location name and the date, i.e. "PelicanPoint14052007"

Realspeed will save it as a .gpx file.

Send the .gpx file to your team captain so he can enter the results on the website.

You can also use the .gpx file in GPS Action Replay to play back your sailing session over a digital photo of your location.

Like the NAVi GT-11, RealSpeed has lots of other great features you can experiment with to analyse your data.