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  1. #46
    DevilsPGD
    Guest

    Re: fanboy nonsense about netbook vs. iPad debunked

    In message <140620101139259894%[email protected]> nospam
    <[email protected]> was claimed to have wrote:

    >In article <[email protected]>, John Navas
    ><[email protected]> wrote:
    >
    >> That's because it's (cheaper) A-GPS (Assisted GPS),
    >> which isn't as accurate as (mor expensive) standalone GPS.

    >
    >absolute nonsense. assisted gps gets a fix faster and just as accurate.


    Faster, absolutely, IF internet connectivity is available.

    It's only "just as accurate" if you happen to be in an area with a
    reasonable number of wifi access points.

    However, if the only wifi access point in range is the Airport Express
    you carry with you for use in wired-only hotels, you'll get a previous
    location that Airport Express was seen (possibly a different country)



    See More: fanboy nonsense about netbook vs. iPad debunked




  2. #47
    nospam
    Guest

    Re: fanboy nonsense about netbook vs. iPad debunked

    In article <[email protected]>, DevilsPGD
    <[email protected]> wrote:

    > >> That's because it's (cheaper) A-GPS (Assisted GPS),
    > >> which isn't as accurate as (mor expensive) standalone GPS.

    > >
    > >absolute nonsense. assisted gps gets a fix faster and just as accurate.

    >
    > Faster, absolutely, IF internet connectivity is available.


    which is pretty much anywhere. otherwise it works like any standard gps
    device.

    > It's only "just as accurate" if you happen to be in an area with a
    > reasonable number of wifi access points.


    nope. the assisted part enables it to get a fix in seconds instead
    minutes by getting the gps ephemeris data from the cellular system
    instead of downloading it from the gps satellites. once it has a fix,
    it's just as accurate as anything else.

    > However, if the only wifi access point in range is the Airport Express
    > you carry with you for use in wired-only hotels, you'll get a previous
    > location that Airport Express was seen (possibly a different country)


    not necessarily.



  3. #48
    John Navas
    Guest

    Re: fanboy nonsense about netbook vs. iPad debunked

    On Mon, 14 Jun 2010 14:47:20 +0000, in
    <[email protected]>, Larry <[email protected]>
    wrote:

    >John Navas <[email protected]> wrote in
    >news:[email protected]:
    >
    >> Then it's a poor GPS receiver.
    >> Better GPS receivers (e.g., SiRF) have no such hassles.

    >
    >I'm surprised at you, John. GPS isn't a problem for receivers, by its
    >very analog nature, GPS requires a CLEAR, UNOBSTRUCTED, DIRECT PATH to
    >the birds.
    >
    >GPS works on the time it takes the signal to move from the bird to the
    >receiver....Anything that upsets that timing path, trashes the timing
    >and trashes the fix. It's pure physics.
    >
    >If you have a multipath signal from the bird, a weak or no direct
    >signal, the time it takes the pulse train to arrive from the bird is
    >LONGER by microseconds. The path from 8 is really long, the path from
    >12 is shorter, but still not direct. The path from 10 is direct but
    >fades in and out. The path from 13 is direct and strong. The
    >convergence of all these multiple odd length timing paths, makes the
    >calculation each second horribly wrong. And I can prove it to you.
    >
    >Go to any fast food joint you like that has a roof loaded with AC units,
    >preferably one with a steel roof to block all the direct signal to make
    >the problem worse. Pick one on a busy highway near a busy airport so we
    >don't have to wait to see the effect of the passing trucks/cars/planes
    >and reflective other buildings like hotels around the restaurant.
    >
    >Sit in the middle of the restaurant and boot up any GPS. Set the
    >display in very close so only the restaurant and surrounding properties
    >are on the display. Set tracking to on so we can watch the trail.
    >
    >Set and watch it. The fix is constantly in motion because the only
    >signal the GPS is receiving is a reflected signal soup off nearby
    >objects, moving vehicles, passing airplanes you can see out the windows,
    >but no good fix through the blocking roof. It's very easy to see the
    >fix sucks.


    Such issues are not uncommon with earlier receivers, but are greatly
    mitigated by newer more sophisticated high-sensitivity receivers; e.g.,
    SiRFstarIII: <http://en.wikipedia.org/wiki/SiRFstar_III>

    I'm writing this in a coffee shop, and my GPS has a solid accurate fix.

    --
    Best regards,
    John

    Navas' Sailing and Racing in the San Francisco Bay Area
    http://sail.navas.us



  4. #49
    SMS
    Guest

    Re: fanboy nonsense about netbook vs. iPad debunked

    On 14/06/10 7:47 AM, Larry wrote:
    > John Navas<[email protected]> wrote in
    > news:[email protected]:
    >
    >> Then it's a poor GPS receiver.
    >> Better GPS receivers (e.g., SiRF) have no such hassles.
    >>
    >>

    >
    > I'm surprised at you, John. GPS isn't a problem for receivers, by its
    > very analog nature, GPS requires a CLEAR, UNOBSTRUCTED, DIRECT PATH to
    > the birds.


    The steel roof of a car is an effective shield. Sometimes, depending on
    the direction you're going, a GPS mounted low in the car in front of the
    dash (rather than on the dash) can pick up enough satellites to work,
    but often not.

    When I had a GPS for my Toshiba E750 PDA (on a compact flash card) you
    could use the antenna as needed. If you were outside you didn't bring
    it, but you left it in the car. You could also buy a CF extension cable
    so you could place the whole CF receiver away from the CF slot and up on
    the dash. Of course back in those days, the Toshiba PDA also had a full
    USB host port, so you could also use a USB GPS receiver on a cable. It's
    just amazing that seven years ago a small, non-x86 PDA could have a full
    host USB port, a Compact Flash slot and an SD slot, but you get none of
    that connectivity on the much larger iPad.



  5. #50
    SMS
    Guest

    Re: fanboy nonsense about netbook vs. iPad debunked

    On 14/06/10 8:42 AM, nospam wrote:
    > In article<[email protected]>, Larry
    > <[email protected]> wrote:
    >
    >> My puck stays in the car, plugged into a cig lighter USB charger when the
    >> car is running. I think I took it out to show a guy with an iPhone and no
    >> GPS about a year ago. There's a cover on my dash and the puck is under it
    >> to keep it out of the sun. The heat doesn't seem to bother it.

    >
    > which means it won't work outside of the car. that's a huge drawback.
    >
    >> Why would you carry it, unless you're going for a walk in a strange city?

    >
    > location aware software.


    I'd much rather have just the external antenna left in the car than the
    whole USB puck. That's how the old CF GPS for my PDA worked. When you
    were outside, the internal antenna worked fine, when you were inside the
    steel car, and you had your PDA sitting in a cradle in front of the
    dash, you plugged in the antenna.

    What you're seeing with all these after-market vehicle GPS systems is
    that you have to have them on the dash (or mounted to the windshield).
    In California, they finally passed a law permitting the GPS to be
    attached to the windshield (effective January 2009) but it's still
    illegal to place it front and center (which is where most people place
    it). You can get a fine for "obstructed windshield" but I don't think
    it's enforced much. Unfortunately, only CA and NJ have these laws, so
    most of the GPS makers dropped their external antenna ports knowing that
    most people will ignore the rather than start messing with antennas.

    When I used to use the Motorola Professional Hands Free Car Kits, they
    mounted in a very good location with the bracket usually just to the
    right of the radio. When you put your phone into the hang-up cup it
    connected the speakerphone and an external antenna. I liked not having
    cords running everywhere for charging and speakers. The external antenna
    greatly boosted the range of the phone.






  6. #51
    SMS
    Guest

    Re: fanboy nonsense about netbook vs. iPad debunked

    On 14/06/10 8:59 AM, DevilsPGD wrote:
    > In message<140620101139259894%[email protected]> nospam
    > <[email protected]> was claimed to have wrote:
    >
    >> In article<[email protected]>, John Navas
    >> <[email protected]> wrote:
    >>
    >>> That's because it's (cheaper) A-GPS (Assisted GPS),
    >>> which isn't as accurate as (mor expensive) standalone GPS.

    >>
    >> absolute nonsense. assisted gps gets a fix faster and just as accurate.

    >
    > Faster, absolutely, IF internet connectivity is available.
    >
    > It's only "just as accurate" if you happen to be in an area with a
    > reasonable number of wifi access points.
    >
    > However, if the only wifi access point in range is the Airport Express
    > you carry with you for use in wired-only hotels, you'll get a previous
    > location that Airport Express was seen (possibly a different country)


    Assisted GPS is much less accurate and depends on connectivity to the
    network. However it can be faster, at least at start-up. You would not
    want to depend on it for road trips that happen to leave an urban area
    that's for sure, but you never know what some people will do. I recall
    pointing out to someone once that one of the less major, but still well
    used, routes through the Sierra Nevada (CA 88) had only CDMA and AMPS
    cellular coverage and they explained that they were aware of this and
    that they planned their travels to avoid roads that lacked cellular
    coverage for Cingular.



  7. #52
    Dennis Ferguson
    Guest

    Re: fanboy nonsense about netbook vs. iPad debunked

    On 2010-06-14, SMS <[email protected]> wrote:
    > On 14/06/10 8:59 AM, DevilsPGD wrote:
    >> In message<140620101139259894%[email protected]> nospam
    >> <[email protected]> was claimed to have wrote:
    >>
    >>> In article<[email protected]>, John Navas
    >>> <[email protected]> wrote:
    >>>
    >>>> That's because it's (cheaper) A-GPS (Assisted GPS),
    >>>> which isn't as accurate as (mor expensive) standalone GPS.
    >>>
    >>> absolute nonsense. assisted gps gets a fix faster and just as accurate.

    >>
    >> Faster, absolutely, IF internet connectivity is available.
    >>
    >> It's only "just as accurate" if you happen to be in an area with a
    >> reasonable number of wifi access points.
    >>
    >> However, if the only wifi access point in range is the Airport Express
    >> you carry with you for use in wired-only hotels, you'll get a previous
    >> location that Airport Express was seen (possibly a different country)

    >
    > Assisted GPS is much less accurate and depends on connectivity to the
    > network. However it can be faster, at least at start-up. You would not


    That isn't true in general. Assisted GPS can mean many things, you need
    to read the data sheet for the hardware to find out what it actually does.

    The product brief for the GPS receiver Apple uses (the Infineon version,
    at least, I think the iPad has a Broadcomm-labeled version instead) says
    this

    Multiple-mode operation
    – Ms-based (calculation of position in mobile handset)
    – Ms-assisted (calculation of position in base station)
    – Autonomous (no assistance by network)
    – Enhanced autonomous (using four day assistance data)

    which seems like it has all bases covered. There's no reason at all to
    think that would be "less accurate" either.

    The reason you only get GPS with 3G seems to be that the particular
    GPS hardware Apple has used to date is a peripheral chip for the Infineon
    baseband unit. The control software runs in the baseband unit, and
    the GPS chip leaches off the baseband chip's clock, so if there isn't
    a 3G baseband chip in the system there's nothing to solder the GPS
    unit to.

    Dennis Ferguson



  8. #53
    John Navas
    Guest

    Re: fanboy nonsense about netbook vs. iPad debunked

    On Mon, 14 Jun 2010 13:08:36 -0500, in
    <[email protected]>, Dennis Ferguson
    <[email protected]> wrote:

    >On 2010-06-14, SMS <[email protected]> wrote:


    >> Assisted GPS is much less accurate and depends on connectivity to the
    >> network. However it can be faster, at least at start-up. You would not

    >
    >That isn't true in general. Assisted GPS can mean many things, you need
    >to read the data sheet for the hardware to find out what it actually does.
    >
    >The product brief for the GPS receiver Apple uses (the Infineon version,
    >at least, I think the iPad has a Broadcomm-labeled version instead) says
    >this
    >
    > Multiple-mode operation
    > – Ms-based (calculation of position in mobile handset)
    > – Ms-assisted (calculation of position in base station)
    > – Autonomous (no assistance by network)
    > – Enhanced autonomous (using four day assistance data)
    >
    >which seems like it has all bases covered. There's no reason at all to
    >think that would be "less accurate" either.
    >
    >The reason you only get GPS with 3G seems to be that the particular
    >GPS hardware Apple has used to date is a peripheral chip for the Infineon
    >baseband unit. The control software runs in the baseband unit, and
    >the GPS chip leaches off the baseband chip's clock, so if there isn't
    >a 3G baseband chip in the system there's nothing to solder the GPS
    >unit to.


    The inaccuracy of the iPhone GPS can easily be demonstrated by comparing
    reported positions to actual positions. I've often seen errors of
    hundreds of feet, making it unusable for critical marine navigation.

    --
    Best regards,
    John

    If the iPhone and iPad are really so impressive,
    then why do iFans keep making excuses for them?



  9. #54
    nospam
    Guest

    Re: fanboy nonsense about netbook vs. iPad debunked

    In article <[email protected]>, SMS
    <[email protected]> wrote:

    > I'd much rather have just the external antenna left in the car than the
    > whole USB puck. That's how the old CF GPS for my PDA worked. When you
    > were outside, the internal antenna worked fine, when you were inside the
    > steel car, and you had your PDA sitting in a cradle in front of the
    > dash, you plugged in the antenna.


    that would be nice but not enough people find it to be a limitation. i
    think it's tomtom who makes a gps cradle which has its own gps that
    talks to its app (which is a piece of **** but that's another story).



  10. #55
    nospam
    Guest

    Re: fanboy nonsense about netbook vs. iPad debunked

    In article <[email protected]>, SMS
    <[email protected]> wrote:

    > Assisted GPS is much less accurate and depends on connectivity to the
    > network.


    nope. assisted gps means it can get a fix faster. after that, it's
    exactly the same as any other gps.

    > However it can be faster, at least at start-up.


    right, that's the whole point.

    > You would not
    > want to depend on it for road trips that happen to leave an urban area
    > that's for sure, but you never know what some people will do.


    of course you would. it works just fine.

    > I recall
    > pointing out to someone once that one of the less major, but still well
    > used, routes through the Sierra Nevada (CA 88) had only CDMA and AMPS
    > cellular coverage and they explained that they were aware of this and
    > that they planned their travels to avoid roads that lacked cellular
    > coverage for Cingular.


    which has nothing to do with gps.



  11. #56
    John Navas
    Guest

    Re: fanboy nonsense about netbook vs. iPad debunked

    On Mon, 14 Jun 2010 13:05:16 -0400, in
    <[email protected]>, Todd Allcock
    <[email protected]> wrote:

    >At 14 Jun 2010 07:15:05 -0700 John Navas wrote:
    >
    >> >Well, to be fair, the GPS is only included with the iPad 3G, ...

    >>
    >> That's because it's (cheaper) A-GPS (Assisted GPS),
    >> which isn't as accurate as (mor expensive) standalone GPS.

    >
    >The GPS chips in the iPad 3G and other GSM devices are "real" standalone
    >satellite GPS and do not require a cellular connectivity. The reason
    >it's only included in the 3G model is because the GPS chip is integrated
    >in the 3G chipset, much like most GSM phones with internal GPS.


    It's A-GPS:
    <http://artoftheiphone.com/2008/06/10/iphone-3g-what-is-assisted-gps/>
    <http://gizmodo.com/5015930/giz-explains-what-you-didnt-know-about-the-iphone-3gs-gps>

    --
    Best regards,
    John

    "Assumption is the mother of all screw ups."
    [Wethern’s Law of Suspended Judgement]



  12. #57
    nospam
    Guest

    Re: fanboy nonsense about netbook vs. iPad debunked

    In article <[email protected]>, John Navas
    <[email protected]> wrote:

    > The inaccuracy of the iPhone GPS can easily be demonstrated by comparing
    > reported positions to actual positions. I've often seen errors of
    > hundreds of feet, making it unusable for critical marine navigation.


    i've seen errors of hundreds of feet with various gps devices,
    including garmin and tomtom. it all depends on how many satellites it
    sees. it's not a flaw with the iphone, despite your repeated bashing.



  13. #58
    nospam
    Guest

    Re: fanboy nonsense about netbook vs. iPad debunked

    In article <[email protected]>, John Navas
    <[email protected]> wrote:

    > >> >Well, to be fair, the GPS is only included with the iPad 3G, ...
    > >>
    > >> That's because it's (cheaper) A-GPS (Assisted GPS),
    > >> which isn't as accurate as (mor expensive) standalone GPS.

    > >
    > >The GPS chips in the iPad 3G and other GSM devices are "real" standalone
    > >satellite GPS and do not require a cellular connectivity. The reason
    > >it's only included in the 3G model is because the GPS chip is integrated
    > >in the 3G chipset, much like most GSM phones with internal GPS.

    >
    > It's A-GPS:


    which is as he said, a real gps, but assisted. maybe you should read
    the links you cite.



  14. #59
    Dennis Ferguson
    Guest

    Re: fanboy nonsense about netbook vs. iPad debunked

    On 2010-06-14, John Navas <[email protected]> wrote:
    > On Mon, 14 Jun 2010 13:08:36 -0500, in
    ><[email protected]>, Dennis Ferguson
    ><[email protected]> wrote:
    >
    >>On 2010-06-14, SMS <[email protected]> wrote:

    >
    >>> Assisted GPS is much less accurate and depends on connectivity to the
    >>> network. However it can be faster, at least at start-up. You would not

    >>
    >>That isn't true in general. Assisted GPS can mean many things, you need
    >>to read the data sheet for the hardware to find out what it actually does.
    >>
    >>The product brief for the GPS receiver Apple uses (the Infineon version,
    >>at least, I think the iPad has a Broadcomm-labeled version instead) says
    >>this
    >>
    >> Multiple-mode operation
    >> – Ms-based (calculation of position in mobile handset)
    >> – Ms-assisted (calculation of position in base station)
    >> – Autonomous (no assistance by network)
    >> – Enhanced autonomous (using four day assistance data)
    >>
    >>which seems like it has all bases covered. There's no reason at all to
    >>think that would be "less accurate" either.
    >>
    >>The reason you only get GPS with 3G seems to be that the particular
    >>GPS hardware Apple has used to date is a peripheral chip for the Infineon
    >>baseband unit. The control software runs in the baseband unit, and
    >>the GPS chip leaches off the baseband chip's clock, so if there isn't
    >>a 3G baseband chip in the system there's nothing to solder the GPS
    >>unit to.

    >
    > The inaccuracy of the iPhone GPS can easily be demonstrated by comparing
    > reported positions to actual positions. I've often seen errors of
    > hundreds of feet, making it unusable for critical marine navigation.


    I've noticed that. While this might say something about Apple's antenna
    design skills, or about Infineon's hardware (the iPad seems to have replaced
    it), or Broadcomm's navigation software, or the RF environment inside a
    cell phone in general, it has nothing at all to do with Assisted GPS. Even
    the most precise autonomous unit can benefit from assistance data when that
    is available, even if it can run without it.

    Dennis Ferguson



  15. #60
    nospam
    Guest

    Re: fanboy nonsense about netbook vs. iPad debunked

    In article <[email protected]>, Dennis
    Ferguson <[email protected]> wrote:

    > > The inaccuracy of the iPhone GPS can easily be demonstrated by comparing
    > > reported positions to actual positions. I've often seen errors of
    > > hundreds of feet, making it unusable for critical marine navigation.

    >
    > I've noticed that.


    i haven't.

    it starts off coarse and then gets more accurate, just like other gps
    devices. the other night, the maps app had the dot approximately where
    i was in the house, in from the road. at most, it was about 10 feet
    off, and that was *inside* the house.

    on the other hand, the driving apps have crappy snap-to-road
    algorithms. if you're on a parallel frontage road, it sometimes gets it
    wrong. i've seen that on garmin gps devices too but not as often.

    > While this might say something about Apple's antenna
    > design skills, or about Infineon's hardware (the iPad seems to have replaced
    > it), or Broadcomm's navigation software, or the RF environment inside a
    > cell phone in general, it has nothing at all to do with Assisted GPS. Even
    > the most precise autonomous unit can benefit from assistance data when that
    > is available, even if it can run without it.


    true. it has to do with how many gps satellites it can see.



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