Thread: About 37xx converted to 34xx satellites reception accuracy

What version of 37xx did you use in step (2) This could also be important.
Thanks for the TUT !
What files do you have in /.System/GPS now ?

for flash back i've used Caty's procedure and files, firmware 4.5 for 37xx
in GPS folder i've always and only 3 files, any folders

Originally Posted by x-trail

..So I've decided to do a different kind of test to check my converted 3760>3490
...I don't think that there is a real problem with the gps fix, I think there is a problem with the mathematical calculation of accuracy.
...It would be very interesting to have one 3790 and one converted 3490 side-by-side doing Diagnosting Logging for some time.
...Then we would compare their gpx files.

X-trail, its very good considerations, I agree with the approach. As you, I also had already placed in doubt the question of the value of the "accuracy" shown on screen gps. Despite being favorable to the method of dynamic measurement, what actually makes sense when it comes to road gps, contradictorily I did static measurements in order to verify the position indicated in relation to the real position. It turns out that the real position is difficult to measure, and even maps or Google Earth are not good references for accuracy. So I decided to take measurements over a official geodesic landmark, what has scientifically calculated coordinates and altitude.
To make more reliable the comparative test, would be necessary to have the values of measurements corrected (deviations in the troposphere, ionosphere ..) in post processing stages on some server on line of high level, but to do so would have to have the raw values collected before being processed by the gps, and transformed in the standard RINEX format in order to be post-processed. For this would have to make new measurements with the GPS connected to a notebook and program that would collect these data before they are processed by the gps. Sounds crazy, but it's a game very stimulating, I'm learning a lot, and maybe in the end, could at least respond safely the question of accuracy btw the values ​​displayed on the screens of the original and converted 3790, among many other issues that do not fit comment here ..
But I'm slowly walking in these steps, but if anyone has any information on how to extract the data collected from satellite before being processed by the Nuvis / Etrex / Oregons, please let me know. It may be that the .bin format is raw data (gpx is processed), but it is a mere supposition. I have still researching it.
Despite my exaggerated pretensions about accuracy, which go far beyond the needs of the topic, there is no denying that yours proposal of compare tracklogs of the original and modified 3790, with measurements side by side, are ideal for the purpose of comparing the precision "real" BETWEEN the two firmwares. At the first opportunity, I will make that comparison.

Originally Posted by rfb

Angelozip,
Did you saw another big diference in your video from 37XX from the 37XX trasformed in 34XX?
See how long 34XX converted takes to scan the screen. Maybe another big diference from 37XX original "drives" for the 34XX firmware?

Rfb, I also noticed the problem of the image scan (flicker). It can be associated with different graphic driver of new firmware. I'll look more attention to this fact in the next comparison. On the other hand the3790 modified was with a protective film screen of low quality. At the next opportunity I will remove it ...

It's actually very east to check Static GPS Accuracy VS Map and Stability.
Set the unit Navigation to OFF Road (This will switch off Snap to Road) Switch to Norh Up and Switch off 3D Terrain
Walk to an intersection and Zoom + to Max.
Try this at Various Locations.
Of Course if the Map is wrong, then the test is meaningless but it will give you a good indication.
I've tried on 3490 and it's usually spot on, If I cross the road I can see it on the GPS Screen

Originally Posted by lolypop000

@rfb
Do you try tutorial from giuseppe66 for better accuracy?
Do you have now better accuracy?

Hi People!

I'm just installed according the Tutorial from giuseppe66.

The preliminary news is...............................GOOD!
In stationary posistion the accuracy was so much better. The signal power looks better as well.

The image below shows the satelite page with GPS from my windows home. Weather with some clouds.

With 37XX/34XX after Tutorial:
[Only registered and activated users can see links. ]


37XX/34XX before Tutorial:
[Only registered and activated users can see links. ]


Original 37XX:
[Only registered and activated users can see links. ]

Tomorrow I'll be back with the news about normal use on the road with GPS.

[]'s

Rodrigo do you have a similar thread on Nimrag forum? If yes what do other brazilian friends say ? Many users have bad accuracy?
It should be nice to share their results if you can report them