Tuesday 29 March 2016

Review of Alcatel Pop D1 for navigation: 0. History

The day that President Clinton announced that the civilian GPS signal would not be limited by selective availability I ordered a Garmin 12XL.

Image from Smithsonian Institution
In common with many civilian users the previous potential inaccuracy made the concept of GPS very poor value to me. I could use a map well so I didn't see much point in spending a  few hundred pounds for rough data. Without SA though a 12 channel device such as this could achieve real world 10m accuracy which is enough to indicate, for example, which side of a farm a path arises from.

In reality, the navigation facilities of the 12XL made it hard to pre-programme routes due to a limitation of 20 waypoints per route. Mapping software was also costly pre-2000 and it wasn't feasible for me to carry a laptop to review maps on a trip. Thus I tended to use the 12XL as a logger and input a few key waypoints where I anticipated problems. Of course, I also referred to it to get a grid reference when I needed a little encouragement. I also found that I could usually relate it to a map bought overseas either via an official datum/reference system or by a combination of trial and error and use of an unofficial reference formula inputted to the 'user grid'.

Three years ago I moved to using a Holux logger which despite my reservations has been a good workhorse, although recovering the data isn't intuitive. As a pure logger this has no utility in navigation. I also consider that the storage format is excessively 'lossy' resulting in poor detail of recorded tracks.

From the review by DC Rainmaker
Finally, I often run with a Garmin 110, another less-than-cutting-edge piece of kit, which has shown itself to be reliable in all weathers. It can be an aid to navigation by revealing distance travelled which is helpful, where permitted, in orienteering events. It is more reliable than my pacing over rough terrain, that's for sure.

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