GPS - prijem signala, problemi, resenja...

Član
Učlanjen(a)
15.04.2011
Poruka
1.374
Kolege, utvrdio sam da je problem do mog note 3. Stavio sam na sto jedan pored drugog moj note 3 i suprugin j5 prime, u isto vreme pokrenuo nextgen israel na oba uredjaja i njen j5 je na prom spratu zgade koja ima 6 spratova, 2m od prozora uhvatio za 15-ak sek 10 satelita i preciznost lociranja je bila visoka, dok moj note 3 nikako nije uspevao da uhvati satelite, tj jedva ih je ucitavao, pa se pojavi po 2-3 satelita koja uhvati i to je sve, a j5 cak do 10 i precizno odradi lociranje.

Definitivno je problem rom koji koristim. Cak sam gledao i root folder etc gde ja nisam imao oba gps fajla, dok je ona na j5 imala oba gps fajla. Prekopirao sam fajlove gps.cfg i gps.conf u moj note 3 u folder etc i lociranje je bolje, ali i dalje nije kao sto je nekad bilo.

Jedan od zakljucaka je da je nextgen zahtevniji sto se tice prijema gps signala nego sto je slucaj sa primom jer mi primo super radi, a kao sto znate od skoro sam poceo da se igram sa nextgenom jer mi se konacno dopao pa sam pozeleo malo vise da ga testiram i da mozda potisnem primo na drugo mesto.

Danas sam odradio backup roma koji koristim i backup svih programa sa podesavanjima preko titanium backupa pa cu najverovatnije da pronadjem neki drugi rom koji nema ovaj problem i da ga instaliram i da vratim sve apk koje sam imao preko titanium backupa.

Evo mozete da vidite na slici o kojim se fajlovima radi koje sam izvadio iz systema j5 i prebacio na note 3
53928c2e9b17b9d33b312bdc6fdfbc69.jpg
 
Učlanjen(a)
15.08.2014
Poruka
932
Lepo je videti da veliki broj članova ima volju da se bavi i teorijom. Međutim, da bi se neko bavio naukom mora da poseduje i neko obrazovanje a i neophodno predznanje. Nije mi namera da nekoga povredim, ali je u ovoj diskusiji bilo previše nepreciznosti, bolje rečeno, amaterskog pistupa i paušalnih ocena nečijeg (ne)znanja.
Takođe, ovo je tema NextGen i možda bi bilo korisno da se otvori nova, specijalno namenjena ovoj oblasti. Pa da se možda i čitava diskusija prebaci u tu novu temu.

Najpre, evo korektnog teksta iz koga se može dosta toga naučiti u vezi sa lociranjem u navigacijama.
Assisted GPS
From Wikipedia, the free encyclopedia


Assisted GPS
Assisted GPS (abbreviated generally as A-GPS and less commonly as aGPS) is a system that often significantly improves startup performance—i.e., time-to-first-fix (TTFF), of a GPS satellite-based positioning system. A-GPS is extensively used with GPS-capable cellular phones, as its development was accelerated by the U.S. FCC's 911 requirement to make cell phone location data available to emergency call dispatchers.
Description
Standalone/self-ruling GPS devices depend solely on information from satellites. A-GPS augments that by using cell tower data to enhance quality and precision when in poor satellite signal conditions. In exceptionally poor signal conditions, for example in urban areas, satellite signals may exhibit multipath propagation where signals skip off structures, or are weakened by meteorological conditions or tree canopy. Some standalone GPS navigators used in poor conditions can't fix a position because of satellite signal fracture, and must wait for better satellite reception. A GPS unit may need as long as 12.5 minutes (the time needed to download the GPS almanac and ephemerides) to resolve the problem and be able to provide a correct location.

An assisted GPS system can address these problems by using external data. Utilizing this system can come at a cost to the user. For billing purposes, network providers often count this as a data access, which can cost money depending on the plan.

To be precise, A-GPS features depend mostly on an internet network or connection to an ISP (or CNP, in the case of CP/mobile-phone device linked to a Cellular Network Provider data service). A mobile (cell phone, smart phone) device with just an L1 front-end radio receiver and no GPS acquisition, tracking, and positioning engine only works when it has an internet connection to an ISP/CNP where the position fix is calculated offboard the device itself. It doesn't work in areas with no coverage or internet link (or nearby BTS towers, in the case on CNP service coverage area). Without one of those resources, it can't connect to the A-GPS servers usually provided by CNPs. On the other hand, a mobile device with a GPS chipset requires no data connection to capture and process GPS data into a position solution, since it receives data directly from the GPS satellites and is able to calculate a position fix itself. However the availability of a data connection can provide assistance to improve the performance of the GPS chip on the mobile device.

Assistance falls into two categories:

  1. Mobile Station Based (MSB): Information used to acquire satellites more quickly.
    • It can supply orbital data or almanac for the GPS satellites to the GPS receiver, enabling the GPS receiver to lock to the satellites more rapidly in some cases.
    • The network can provide precise time.
  2. Mobile Station Assisted (MSA): Calculation of position by the server using information from the GPS receiver.
    • The device captures a snapshot of the GPS signal, with approximate time, for the server to later process into a position.
    • The assistance server has a good satellite signal, and plentiful computation power, so it can compare fragmentary signals relayed to it.
    • Accurate, surveyed coordinates for the cell site towers allow better knowledge of local ionospheric conditions and other conditions affecting the GPS signal than the GPS receiver alone, enabling more precise calculation of position.
As an additional benefit, in mobile station assisted implementations, the amount of processing and software required for a GPS receiver can be reduced by offloading most of the work onto the assistance server.

A typical A-GPS-enabled receiver uses a data connection (Internet or other) to contact the assistance server for aGPS information. If it also has functioning autonomous GPS, it may use standalone GPS, which is sometimes slower on time to first fix, but does not depend on the network, and therefore can work beyond network range, and without incurring data usage fees. Some A-GPS devices do not have the option of falling back to standalone or autonomous GPS.

Many mobile phones combine A-GPS and other location services including Wi-Fi Positioning System and cell-site multilateration and sometimes a hybrid positioning system.[4]

High Sensitivity GPS is an allied technology that addresses some of these issues in a way that does not require additional infrastructure. However, unlike some forms of A-GPS, high-sensitivity GPS cannot provide a fix instantaneously when the GPS receiver has been off for some time.

Basic concepts
Standalone GPS provides first position in approximately 30–40 seconds. A standalone GPS needs orbital information of the satellites to calculate the current position. The data rate of the satellite signal is only 50 bit/s, so downloading orbital information like ephemerides and the almanac directly from satellites typically takes a long time, and if the satellite signals are lost during the acquisition of this information, it is discarded and the standalone system has to start from scratch. In A-GPS, the network operator deploys an A-GPS server, a cache server for GPS data. These A-GPS servers download the orbital information from the satellite and store it in the database. An A-GPS capable device can connect to these servers and download this information using mobile network radio bearers such as GSM,CDMA, WCDMA, LTE or even using other wireless radio bearers such as Wi-Fi. Usually the data rate of these bearers is high, hence downloading orbital information takes less time.

Modes of operation
A-GPS has two modes of operation:

Mobile Station Assisted (MSA)
In MSA mode A-GPS operation, the A-GPS capable device receives acquisition assistance, reference time and other optional assistance data from a mobile service provider. The mobile service provider continuously logs GPS information (mainly the almanac) from the GPS satellites using an A-GPS server in its system. With the help of the above data (the data received from the mobile device and the data already present in A-GPS server) the A-GPS server calculates the position and sends it back to the A-GPS device.
Mobile Station Based (MSB)
In MSB mode A-GPS operation, the A-GPS device receives ephemeris, reference location, reference time and other optional assistance data from the A-GPS server. With the help of the above data, the A-GPS device receives signals from the visible satellites and calculates the position
Dakle, neki članovi su pogrešno zaključivali. Da ne bih provocirao nepotrebnu polemiku, ipak moram, istine radi, da ukratko samo naglasim :
1. Osnovno je da A-GPS, kako i ime govori "Assisted GPS", služi da popravi lociranje, tj. ova funkcija podržava i poboljšava osnovno, čisto GPS lociranje. Prema tome, kolega koji preporučuje da se ova opcija obavezno isključi jer "smeta lociranju" je neozbiljno. Ova opcija ubrzava i poboljšava lociranje. I veoma je korisna.
2. Lociranje neke pozicije se obavlja pomoću GPS satelita i popravlja GSM mrežom, to je A-GPS, kao i internetom koji je na raspolaganju isključivo preko GSM mreže. Dakle i tu je jedan kolega pogrešio kada je pomenuo postojanje nekih "baznih WiFi stanica". Tako nešto ne postoji.
3. Tako je nesrećni skrinšot kolege @nislija30, da se lociranje popravlja i WiFi signalom, napravio najveću zbrku. Nažalost, isti teskt je na mnogim telefonima, pa i na mom. WiFi, u tumačenju kako ga većina razume, nema nikakvog značaj na lociranje. Uostalom, nelogično je da će moj kućni WiFi, koga ostvaruje internetski signal dobijen telefonskim paricama, na bilo koji način popraviti lociranje. U tom smislu kolega @BlackBeetle nije pogrešio. Pogrešio je samo u tvrđenju da se mogu koristii ili samo GPS ili samo GSM. I neoprezno je izjavio da se celularna mreža ne može isklučiti osim vađenja SIM kartice. Tu je kolega @Bocky72 ispravno objasnio da se to jednostavno odrađuje izborom Airplane mod, tj. "Profil letenja".
4. Ja bih se samo priključio zaključku koji je kolega @akineki napisao. Problem kod kolege @toda81 je posledica lošeg hardvera konkretnog telefona. U tom smislu je i kolega @Bocky72 bio u pravu.
 

WOB

Član
Učlanjen(a)
11.08.2009
Poruka
859
Znači, da zaključimo:
- imao si dobar uređaj, koji odlično radi
- zatim si uređaj sam "podesio" tako da radi loše
- sada ćeš da tražiš i pokažeš nam rešenje problema

Msm, nemo' se ljutiš, ali ... ?
 
Član
Učlanjen(a)
07.05.2013
Poruka
382
@toda Imas negde gps.conf koji je BD sredio za nasa podrucja, pa zameni. Ili edituj svoj. Plus...permissions na oba gps fajla sa screenshota...cini mi se da nije kako treba.
 
UREDNIK
Učlanjen(a)
07.03.2011
Poruka
3.044

Prilozi

  • gps.conf.zip
    1,4 KB · Pregleda: 18
Član
Učlanjen(a)
15.04.2011
Poruka
1.374
Pokusao sam da rasklopim tel, ali mi nije poslo za rukom. Nsao sam neke klipove na youtube gde pokazuju sta moze da bude problem kada je gps u pitanju i kako se resava taj problem. Nisam smeo previse da povucem onu plastiku koa sto stoji na klipovima jer me je strah da ne pukne tako da sam samo malo zategao srafcice.

Evo mojih rezultata u stanu, a sutra cu probati i van pa cu okaciti i te rezultate




226dafe94b5ecaf9f6c2a260d5c8aaa9.jpg


Ne znam koja je fora i sa ovim gps utc vremenom jer mi se ne slaze sa satom. Da li se vama slaze?

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Ovo su klipovi sa youtube gde sam video kako resavaju problem sa gps prijemnikom i kontaktima:


 
Poslednja izmena:
Učlanjen(a)
10.09.2012
Poruka
349
Moj predlog ti je da u sys.txt aktiviraš Glonass. Aktiviraćeš ga tako što obrišeš ; u liniji gde ti je napisano ispred Glonass.
Ja sam brisanjem dobio stalno uključen prijem i sa tih satelita. Inace UTC je vreme po kojem rade neke firme, leti je 1 h a zimi 2 h razlika. Zovu ga kod žene u firmi Univerzalno vreme po naški. ...
 
Učlanjen(a)
05.12.2015
Poruka
1.272
Moj predlog ti je da u sys.txt aktiviraš Glonass. Aktiviraćeš ga tako što obrišeš ; u liniji gde ti je napisano ispred Glonass.
@nislija30 druze interesantna tema da li milis na:
[interface]
show_glonass=1
Kod mene u sys uopste ne postoji ta linija za glonass ali mi u info o satelitima NextGen ipak prikazuje glonass.
Sad pitanje da li to znaci da ih koristi iako u sys nema podesavanja za glonass ili ih samo prikazuje u info ali ih u stvari ne koristi?
Screenshot_20170627-114630.png
 
Učlanjen(a)
10.09.2012
Poruka
349
Ne koristi ih ako ne aktiviraš u sys.txt uklanjanjem ; ispred komade koju si naveo.
Ako je nemaš upiši je.
Na slici ti je prikazan glonass jer si kliknuo na prikaži. U prethodnom postu ti je drugačija slika....

I još nešto, telefoni novijih generacija imaju i BDS (BEIDOU ) I Galileo, ali ih aplikacije ne podržavaju na žalost
 
Član
Učlanjen(a)
15.04.2011
Poruka
1.374
Da li treba da stoji 1 ili 0? Pise ako se uzme 1 nece raditi glonas.

Evo kako je kod mene u primo:


[interface]
skin="ui_android"
capture_to_jpeg=1
extra_settings=1
save_checksum=0
maxzoom2d=6000000 show_scroll_button=0
show_glonass=0 ; don't use "1" - not works GLONASS vga=0 ;use this entries for full HD and QHD:


Da li je to dobro ili mora 1 da se upise umesto 0?

Послато са SM-N920C уз помоћ Тапатока
 
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