On Sat, 23 Mar 2019 18:49:08 -0700, sms wrote:
> My $130 LG tablet sees 18 satellites and gets uses 12 of them and
> crunches the data to narrow down the position. As it locks onto more and
> more satellites the accuracy keeps increasing. Here's a screen shot I
> just took outside where it locked onto 18 satellites within about 30
> seconds, with no A-GPS: <http://oi63.tinypic.com/2dvk46w.jpg
> inside the house, on the first floor, it sees 16 satellites, but the
> signal is weaker
> The same app on my Samsung Note 9 shows 15 satellites in view, and uses
> 12 of them (with much greater signal strength), and the same accuracy (3
> meters). It got a fix much faster, within about 5 seconds, because of A-GPS.
I'm confused by my fast fix test results below based on your suggestions.
I've used GPS since the StreetPilotIII days (before cell phones) where I'm
amazed at not only how quickly, but how well indoors phones & tablets get a
I _think_ part of the fast fix is memory, as, I recall, in the olden days,
if I wanted my GPS to fix faster (in the days before cell phones) I would
enter the location into the GUI.
It _might_ be that your tablet "remembers" where it last was, which enables
it to get such a quick fix? (Dunno. Just asking about that location memory.)
> The app is this one:
> but there are a load of similar apps on the Play Store.
Thanks for that app suggestion.
o Here is some data where I ask knowledgeable people for analysis advice.
The first time I ran it, I was inside my house where this happened...
o I put "GPS status" in my "Map" folder, and then tapped it to start it
o First "GPS status" asked to allow GPS
o Then it popped up a full-page ad (the teeny tiny (x) is at top left)
o Then it asked me to "calibrate the compass"
o Then it said my GPS "seems to be disabled"
o It then popped me into my "off" location in the Android settings
o I turned "Location" on which _defaulted_ (aurrgh!) to "high accuracy"
o I switched it instantly to "Device sensors only (GPS only)"
o Just to be sure, I turned off cellular data & Wi-Fi
(Would airplane mode have worked just the same?)
I then killed & restarted "GPS status", told it to stop showing me the
calibration suggestion, and then it popped up, seemingly instantly, with
the message of 12/17 satellites, 15M error, magnetic field 42uT, etc.
Then I turned on "Airplane Mode", where it acquired a fix, seemingly
Hmmmm.... why so fast?
I decided to pull the sim card, so I did a shutdown & realized that in my
$130 LG Stylo 3 Plus, I have to removed both the battery and microSD card
to get to the SIM card (which I don't normally remove) and removed the SIM
card & powered it back up, still in Airplane Mode.
Putting it back sans both the sdcard and SIM card, the phone asked to turn
airplane mode back on, which I left off.
Tapping the "GPS status" app, it seemed to get a fix in something like two
seconds. with 10/17 satellites, error of 26M, magnetic field of 42.3uT.
I'm puzzled since nospam said the fix takes up to fifteen minutes.
While I'm very aware of what "up to" means, the fix was basically almost
>> So, if one had a powerful dedicated GPS it would be doing a lot of sat
>> data receiving and crunching. A phone (also) uses the info from
>> 'towers'. Some phones and locations can't even get one tower, Some
>> phones and locations can't even get one sat, which would be completely
>> useless for location.
> The phone uses towers for A-GPS, to get a faster satellite fix by
> knowing what satellites to look for based on the location.
> You can't run this kind of an app on an iOS device because iOS doesn't
> give the app access to NMEA data.
> I wonder why you think that a phone's GPS cannot access multiple GPS
> In any case, the bottom line is that you want to avoid buying any tablet
> that lacks a GPS receiver.
I'm confused by my GPS test results below based on your suggestions.
Since you use facts to form basic logic, I can't disagree with _anything_
you've said, where I'm just confused at the moment why my el-cheapo $130 LG
Stylus 3 Plus was able to seemingly "get a fix" inside my house, basically
almost instantly, with airplane mode on, and the SIM card removed.
With nospam insisting that it takes "up to" fifteen minutes to get a fix
o Why was my fix done, seemingly in just a couple of seconds?
NOTE: Alt.Satellite.GPS added for help in answering the basic question.