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Locus Map - help desk Topic Question Locus Map (Android)

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Category Locus Map (Android)

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Position on LoMap "behind" of reality

Pusztai Miklós shared this question ago

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Hi!

I use Locus Map Pro with LoMaps installed. I used it when I ridden motorcycle, and I observed that the position showing on map was always behind of real circumtances. As an example, riding in the village I rode near the marginal roads who intersected the main roads, but showing real position on LoMap cca. 20 metres before thqt road. Then I already was away from that marginal road when in LoMap showing that I am near that road.

I have to mention that I use Locus on my Samsung Galaxy S5 device.

How can I resolve this delayed displaying on Locus?

The same question

Replies (3)

Menion ●

Good day Pusztai,

without screenshot or video showing this problem, it is harder to give precise answer.

Locus Map display location on the map immediately it is received from Android system itself. In most cases, there exists small delay that is caused by full path it took till received data are transformed into visible point on the map. It may be up to one second.

How long is delay you see on the map? Also what about other map applications that use GPS? Just asking if this "problem" isn't just how your GPS works.

You may also try to tap on menu > settings > GPS & Location > Reset A-GPS data. This, when connected to internet, should force your system to re-download some data necessary for fast GPS work.

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Pusztai Miklós ●

The delay was aprox. 3-4 second when riding motorcycle.

But now I made an reset in the Locus t the menu of the the A-GPS datas. I will try the Locus on motorcycle riding again.

I have to mention, that I used before the standard Googlemaps and doesn't encountered any delay-problem.

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Menion ●

Hello,

hmm 3-4 seconds is far away from maximum acceptable value.

From technical point of view, I cannot explain this on side of Locus. This app, as mentioned before, does not use any optimizations for received coordinates/location so there is no reason for any serious delay.

I really suggest to confirm same behavior (expected) on any other mapping/navigation app. I'm almost sure, result will be same.

Mentioned reset of A-GPS data is mainly useful for initial obtain of location (GPX fix), anyway once fixed, it should not cause any big difference and definitely not such "lags". Anyway give it a try please and we will see. Thank you.

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Libor Poutnik Striz ●

I notice similar time delay regularly, but I suppose it is not Locus specific. I think it is a general problem of many Android navigation applications. Many of them do not apply any sort of the time extrapolation of the current positions ( based e.g. on the last 2 positions, their timestamps and current time.

It can be easily noticed during fast motion, if a position jumps per second basis, instead of more or less continuous motion.

There could be even implemented compensation of processing delay.

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Menion ●

This is correct. There is currently no extrapolation based on current movement & used "vehicle". Such feature was considered few times and with your help of accelerometer and your suggestions :), it is definitely doable (expectation). Anyway I always decide not to do it. One of most precious substance is battery energy. One/per/second map refresh has huge advantage = it is very battery friendly.

Btw. this improvement already has own topic: http://help.locusmap.eu/topic/improving_gps_position_with_gyroscope_and_accelerometer

Question for me remains if delay noticed by @Pusztai is expected maximum 1 second delay ( Locus Map "problem" ), or it's a longer delay ( most probably problem in device ).

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Libor Poutnik Striz ●

I agree the power friendliness is much more important in slow foot or bike scenario.

OTOH, for fast car motion and the phone plugged into the car USB charger, it makes more sense. If one drives through a city with dense web of crossroads, the delayed positions can confuse the driver, if he/she does not count with a correction.

BTW, is doable a selective screen update of the position pointer, possible being a layer above a maps ?

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Menion ●

Hi Libor,

yes, I absolutely agree, good point. Device plugged into charged of course does not suffer by battery problems ( except it suffer with overheating :) ), so there such feature make sense ( in car it make double-sense, because of tunnels etc. ).

What exactly you mean "selective screen update of position pointer"? Fluent update of current position is of course doable, I just worry about framerate & performance. My quite old map rendering system is not best in terms of performance, you know.

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Libor Poutnik Striz ●

I mean the rendering of the map/screen would remain at the usual rate,

but the location placement on this background would be rendered with higher rate, based on extrapolated position. But I am not familiar with Android coding, so I have no idea if this can be done efficiently in LocusMap context.

To avoid overheating, it is good to use fully charged phone to avoid extra heating due charging, especially in hot summer days.

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Hallgeir Gjesdal ●

Norway got a lot of tunnels, and more to come. Longer and more complex.

When navigating by car, i always use navigon app. It does animate speed in tunnel and tell you how long to exit of tunnel or to turn right in a tunnel intersection/roundabout. It hardly miss by 100 m in a 3 km tunnel. Clever indeed!

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Menion ●

Most probably not. Imagine whole screen as one huge raster image, that needs to be prepared before every draw is executed.

Anyway I do not know exact numbers here so I'm not saying it is not possible. Also worst on performance/refresh rate are visible points (mainly geocaches with extra symbols + waypoints) compare to map itself, so maybe I'll give it a try and measure impact more precisely then just "guess".

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