[Loadstone] SIRF3.2: disfunctional receiver?

Charlie Richardson charlieofalbany at hotmail.com
Tue Feb 6 23:58:35 GMT 2007


One of my other things I've wished that I would have GPS for but didn't 
think paying thousands for it was worth it is finding certain stores on a 
block that all the stores are glass front and look the same to me as a blind 
person.  I usually get to where I think it's close enough, find the door and 
open it and give what I think of as a check.  The paint store smells like 
paint, the hardware store is the next door down and would have a more open 
sound to it, the store before the paint store sells fabrics and is usually 
quiet.

Getting within 10 to 20 feet of these doors is better than my now technique, 
but again wouldn't be worth paying thousands for.

When the weather gets a little warmer or if there's a need to go to one or 
any door front I'll try marking them as check points and going back to them 
later, but so far I had marked intersections and then got access to the 
point share website and now probably have every intersection within 6 miles 
of my intersection of my home.  My guess is you guys found a free source of 
Albany, NY because there isn't an intersection that I haven't found.

It seems that the point marked isn't on a sidewalk, but is probably close to 
being under the traffic signal.  So for bus riding and finding where I am 
this is more than satisfactory.


----- Original Message ----- 
From: <monty at loadstone-gps.com>
To: "General discussion pertaining to the Loadstone GPS program" 
<loadstone at loadstone-gps.com>
Sent: Tuesday, February 06, 2007 4:55 PM
Subject: Re: [Loadstone] SIRF3.2: disfunctional receiver?


> Hi Neill,
>
> In ultimate conditions a GPS receiver using the Sirf Star III chipset can
> achieve accuracy of 10 feet (3 metres).  By "ultimate conditions" I mean
> your receiver must have a very good view of the sky, sky conditions are
> clear, and you have a WAAS/EGNOS fix.  Even without a WAAS/Egnos fix you
> can achieve very good results.  The best way to know what your GPS
> receiver is capable of is to read it's technicle specifications.  In my
> experience most say that you can expect an accuracy of between 10 metres
> and 15 metres.  (aprox 34 - 50 feet)  It is often better than this but
> that might be the worst case scenario.
>
> So, lets say you save a point when your conditions are poor and your GPS
> reciever has an accuracy of 10 metres.  Lets also say that unluckally,your
> GPS receiver thinks it is 10 metres to the left of where you are at
> present.  Later, when you try and find the spot again, you are faced with
> equally poor conditions though this time your GPS receiver thinks it is 10
> metres to the right.  This effectively would mean that you are 20 metres
> from your saved position.  In an absolute worst case scenario using the
> technical specifications of 15 metres accuracy, the above example could
> potentially turn into 30 metres.
>
> Having said all of that most of the time it is considerably better but
> like everything else in this world, there are a lot of variables so
> results can and do vary.
>
> As far as saving points while on the move that might not be a bad idea.
> Why don't you experiment and report your findings to the list.
>
> The "GPS Accuracy" function in Loadstone is simply reporting the value
> your GPS receiver is sending to your phone.  The lower the number the
> better.  This value is based on things such as satelites in view Etc.
>
> It would seam that every GPS manufacturor handles the GPS commands a bit
> differently.  The ones that seam to work across the board are the
> Cold/Warm/Hot resets but the WAAS/EGNOS, and Power-Saving functions really
> are hit and miss.  GPS receivers do not acknowledge weather the command
> worked or not nor do they report the current state.  This is why you have
> On/Off settings both available to you.  This sucks but that is something
> we just godda live with!
>
> I personally found and I think others would agree, once you use Loadstone
> for a while and get to know the capabilities and behaviour of your GPS
> receiver things do get much better.  Plus, we are attempting to make
> improvements to Loadstone all the time!
>
> Best regards,
>   Monty
>
> On Tue, 6 Feb 2007, R. Neill Hadder wrote:
>
>> Hi Monty and all,
>>
>> Thanks for the feedback.  "10 to 20 meters is pretty good" -- Really?  I 
>> was
>> thinking 10 feet or so.  Were my expectations for GPS just way too high,
>> then?  I'd appreciate confirmation of this fact so I can stop scowling 
>> and
>> cursing at the GPS receiver--which, since it resides in my pants pocket,
>> makes for some odd looks in public as well as from my dog.  Since 
>> "maximum
>> approach" defaults to 10m, it seems like less than 10m accuracy is what
>> you're used to, no?  Also, I now really don't understand what the 
>> "accuracy"
>> figure means if it isn't a reflection of correlating my position to the
>> coordinates of a way point.
>>
>>  To answer your question, these are points I've entered myself. One idea
>> that came to me is that I'm entering point data while standing still and
>> thus subject to drift, so I wonder if I'd get better results by entering
>> points while walking.  For example, hit pound sign, then stop, then use
>> "from commencement." I already have static threshhold at 2.
>> On the connection issue, my phone is a 6682.  I suspect the power saving
>> mode was on. I'll see on the way home.That might account for connection
>> problems as well as lack of signal, which is really suspiciously tenuous. 
>> I
>> hope there's a way to eventually place a tick or dynamically update the 
>> menu
>> regarding power save state, since on my menu both options are always 
>> there
>> and I don't know if it's on or off, or really what is happening, if
>> anything, when I enter certain commands.  I suppose that depends on 
>> whether
>> the receiver delivers feedback, of course.
>> --Neill
>>
>>
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