[collin.harty]

Had some time on the water earlier this week with iNavX and the new iPhone 2.1 software. The course and speed readings seemed much more stable and accurate, and the chart view no longer jumped around the screen nearly as much. Apple's upgraded has improved iNavX's usability considerably. Rich, you must be as pleased as I am.

A friend had a Garmin handheld in the cockpit for comparison, and his course and speed reading were noticeably more stable than those produced by the Apple upgrade, which makes me curious what aspect of the software accounts for this. Is it the inevitable compromise the programmers must make between battery life and the sampling rate on the GPS satellite data?

Collin

[GPSNavX]

I am glad to hear the speed and course are becoming more settled. Currently iNavX must compute speed and course based on current and previous position. In order to do this accurately the iPhone OS 2.1 software must return accurate positions and time stamps for these positions.

Ideally the iPhone OS would compute speed and course so each application did not need to do so.

Apps do not control the GPS sampling rate, instead each time the iPhone OS has a new position, it notifies the App. Once can see the UTC field in iNavX update to see the frequency.