What is GPX?

“GPX, or GPS eXchange Format, is an XML schema designed as a common GPS data format for software applications. It can be used to describe waypoints, tracks, and routes. [...] Its tags store location, elevation, and time and can in this way be used to interchange data between GPS devices and software packages. Such computer programs allow you for example to view your track, project your track on satellite images (in Google Earth), annotate maps, and tag photographs with the geolocation in the Exif metadata.” [Wikipedia]

What does the GPS quality indicator mean?

The GPS quality indicator can be either red, yellow, or green. If red, no accurate GPS information could be obtained (e.g., indoors). No new recording session can be started and no waypoints will be added to a running recording until the status switches to yellow or green. If yellow or green, the GPS coordinates recorded are horizontally accurate to within one hundred or fifty meters of the desired target, respectively. During recording, the precise horizontal accuracy of the latest waypoint recorded is further shown in the upper left corner.

What do all the numbers at the top mean once recording has started?

During recording, the timestamp (top middle) of the latest waypoint recorded and its horizontal accuracy in meters (top left) are shown. The number of waypoints recorded during the active session is further shown in the top right.

Does it work when the iPhone is locked?

Yes, it does. Once started, you can lock your iPhone and GPSRaw continues recording until you unlock your iPhone again and explicitly stop recording.

Does it run in the background on iPhone 3GS and iPhone 4 with iOS4?

Yes, it does. Since GPSRaw 1.1 background processing (a.k.a. multitasking) is supported.

Anything else I should know?

For best results, please make sure that the clock of your camera is in sync with the clock of your iPhone. Furthermore, GPX timestamps are always in UTC format, possibly requiring adjustment by your post-processing software (e.g., setting the GMT offset of your photos).

What software do you recommend for tagging photos with geolocation information?

Freeware that might be worth a look are GeoSetter (Windows) and GPSPhotoLinker (MacOS X). In addition, the new “Places” feature of Aperture 3 reads GPX files, and we can fully recommend Photo Mechanic (Windows and MacOS X versions available).

Do you plan to implement…?

Maybe. Just let us know what you would like to see in a future version — we do listen!

Can I get a promotional code?

Maybe. Promotional codes are available for reviews or as prizes, so let us know what you plan to do and we may be able to help.