Tuesday, 6 March 2012

Collecting and displaying GPS tracks

This plot was captured with iNavX on my
iPhone, then emailed to myself, and the
.kml file opened in Google Earth.
If I record a track in iNavX using the background option it seems it will usually keep recording while I do other things, but not always. I'm not sure what switches the recording off, maybe running another app that steals control of the GPS? Once I have a track I can email it to myself as a .kml file and open it in Google Earth. From there the display options would seem to be huge. When emailing a track it also sends it in .gpx format, which should result in a bunch more options. Again, too many choices ;-)

This plot is Google Earth showing a
.kmz file from Navionics on the iPad 
Navionics on the iPad also let me record a track, but it only records while it is the foreground app, which may actually make it more predictable. It draws dotted lines between points while in background. It will also send a track to email as a .kmz file, which can also be opened with Google Earth.

More important perhaps is that Google Earth allows me to load and display both tracks at the same time so I can mix and match. Of course, this means I can't play with the images unless I have net connectivity, but that's probably OK.

X-Traverse provides another way to exchange data between devices and have access to the full chart library purchased through XT on various devices, including iPad, iPhone, Fugawi on PC, etc., although I don't know if it will work with my ancient Fugawi.

Epiphany Moment: My computer doesn't need to know current positions in order to view charts and make plans in great graphical detail and my portable display doesn't need to show great detail in order to provide immediate guidance, as long as the plan can get from the computer to the portable display.