[Captivate Android Development] poormkp:
In an earlier post I documented how much better my Captivate’s GPS works when the rear cover is removed, and also posted test results showing improved signal strength when the cover is off vs on. Also that the Da_G fix was initially resulting in faster locks and better accuracy. Now that several days have passed wanted to update my results and add some new information. First off let me say thanks Da_G -- the fix, combined with the Assonance 5.0 ROM, have most definitely improved my GPS. In fact, with the right conditions as outlined below, I would rate the performance as excellent.

Previous to this I always had trouble maintaining locks, and could almost never get Google Maps to work. After implementing the fix I found I could get Maps to work but it was very inconsistent and would frequently lose me. Then I experimented with removing the rear cover, and instantly got improved results. Finally since some others had posted about better results with their car charger plugged in I decided to add that in as well. That’s when everything really came together, with consistently getting not only fast locks, but excellent tracking in Maps, Nav, and CoPilot. Under these conditions I’m seeing no lag, no drift, and working turn-by-turn navigation.

I had not seen a lot of documented evidence on the impact of the cover and charger specifically so decided to do a two-day test to try and prove or disprove. The testing I did included the same route driven four times on day 1, and the same route again driven four times on day 2. For all trips the phone was sitting in the same position, which was in my center-console cup holder. Also the same apps were running during each trip – MyTracks in the background to record the results, and CoPilot in the foreground for visual observation. The four scenarios I wanted to test each day were 1) phone in its normal configuration – cover on as usual. 2) phone with rear cover removed 3) phone still with cover off, but also plugged into car charger, and 4) Repeat of #1 immediately after un-plugging the car charger. The results were as follows:

As seen on the two tracks below, in the normal configuration the tracking was not good either day, tracking me only partially both days. This confirmed the experience I had before the testing.

http://maps.google.com/maps/ms?hl=en&ie=UTF8&msa=0&msid=211929289599497149208.0004990aaa98433d93646&ll=39.788687,-85.896177&spn=0.023479,0.064716&z=14

http://maps.google.com/maps/ms?hl=en&ie=UTF8&msa=0&msid=211929289599497149208.0004991f76e35dac96815&ll=39.788489,-85.896091&spn=0.023479,0.064716&z=14

Tracks for Test 2 are below. With the cover removed you will see the much improved tracking. On Day 1 there were some gaps, while on Day 2 the tracking was pretty good except for some overshoots and rounding at the turns.

http://maps.google.com/maps/ms?hl=en&ie=UTF8&msa=0&msid=211929289599497149208.0004990a78557d84615eb&ll=39.788555,-85.89592&spn=0.023479,0.064716&z=14

http://maps.google.com/maps/ms?hl=en&ie=UTF8&msa=0&msid=211929289599497149208.0004991f7892f2c6e52e2&ll=39.788489,-85.896091&spn=0.023479,0.064716&z=14

The results from Test 3 shown below, were really quite amazing to me. You will notice with the car charger plugged in, the tracking is extremely good. The route is shown exactly as traveled, no overshoots at intersections, and even shows being on the correct side of the road. That result confirmed my good experience with Google Nav and CoPilot the past several days.

http://maps.google.com/maps/ms?hl=en&ie=UTF8&msa=0&msid=211929289599497149208.0004990a7af5726f963c7&ll=39.788423,-85.896091&spn=0.023479,0.064716&z=14

http://maps.google.com/maps/ms?hl=en&ie=UTF8&msa=0&msid=211929289599497149208.0004991f79c7062d63c4d&ll=39.788423,-85.896177&spn=0.023479,0.064716&z=14

I did Test 4 just to delve a bit further into the car charger aspect. Wanted to see if the improvement went away again by removing from the charger, which is what I expected. What happened was yet another surprise. You will see from the two tracks below that after putting the rear cover back on, and doing the route again immediately after unplugging from the charger, performance did NOT revert back to the very poor showing in Test 1. While the tracking was not excellent – went off the road a few times, it was far better than in Test 1 when it was unable to maintain locks most of the time. Below are Test 4 tracks.

http://maps.google.com/maps/ms?hl=en&ie=UTF8&msa=0&msid=211929289599497149208.0004990a80b5722024d68&ll=39.788399,-85.896148&spn=0.023479,0.064716&z=14

http://maps.google.com/maps/ms?hl=en&ie=UTF8&msa=0&msid=211929289599497149208.0004991f7be11d0d0d1eb&ll=39.788621,-85.896263&spn=0.023479,0.064716&z=14

So the conclusions for my GPS are as follows:

1.	Removing the rear cover was in fact beneficial.

2.	Performance did improve with the car charger plugged in.

3.	My phone is able to function extremely well with these conditions in combination with the ROM and tweaks.

4.	Results from test 4 indicate a positive impact of the phone being recently charged via the car charger – suggesting a positive impact from a little extra “juice”, so power levels might be affecting performance as well. After being off the charger for a more extended time, the positive impact goes away.

I apologize for the long post but am hopeful this testing might add to the GPS body of knowledge. Next step for me is to test some additional ROMs to see if I can get to the same results without the rear cover and charger steps. My suspicion is that those steps may only be necessary while in the car – and not if out in open space.