Google
  Web www.gpspassion.com


GpsPasSion LIVE!
www.flickr.com
This is a Flickr badge showing public photos from GpsPasSion Live !. Make your own badge here.

www.NaviBlog.com



Versions

Links/Liens




Portal/Portail
Rechercher

- -

Polls/Sondages
Sondage
Pour vous guider sur la Route :
GPS Mobile (SEM)
GPS Intégré
Smartphone
Autre
Voter  -  Résultat des votes
Votes : 2317




Club GpsPasSion
Soutenez le site!

USA: (US$)
EUROPE: (€)
Guide Paypal


GpsPasSion Forums
Home | Profile | Register/Enregist. | Active Topics | Search/Recherche | FAQ
Username:
Password:
Save Password
Forgot your Password?

 All Forums
 Advanced Topics
 General Technical Discussions
 SBAS and GPS Accuracy - Side by Side Testing
 New Topic  Reply/Répondre
 Printer Friendly
Previous Page | Next Page
Author Previous Topic Topic Next Topic
Page: of 10

bviator

USA
21 Posts

Posted - 28 mai 2006 :  01:14:46  Show Profile  Reply with Quote
So, the unit you tested is not for sale yet to the general public?

If that is the case, how do you think the current i-blue with Nemerix chipset and version 3.8 will compare as far as accuracy?
Go to Top of Page

gpspassion

94046 Posts

Posted - 28 mai 2006 :  01:23:22  Show Profile  Visit gpspassion's Homepage  Reply with Quote
Correct the SBAS enable M5 I used will be available for purchase in June it seems. The current iBlue is the one I used as the other part of the "Nemerix pair" for non-SBAS, but it's 3.2.7, not 3.8 ? Is there a mention of 3.8 somewhere, if yes that would be a typo I need to fix ;-)

_________________________________________________________________________
Discounts and Assistance/Réductions et Assistance (Club GpsPasSion) / Où commencer?
Go to Top of Page

gpspassion

94046 Posts

Posted - 05 juin 2006 :  22:58:01  Show Profile  Visit gpspassion's Homepage  Reply with Quote
In case you missed it, it is now available - http://www.gpspassion.com/forumsen/topic.asp?TOPIC_ID=57401 ;-)

_________________________________________________________________________
Discounts and Assistance/Réductions et Assistance (Club GpsPasSion) / Où commencer?
Go to Top of Page

gpspassion

94046 Posts

Posted - 07 juin 2006 :  15:35:15  Show Profile  Visit gpspassion's Homepage  Reply with Quote
Interesting link about MSAS http://www.kasc.go.jp/MSAS/index_e.html

_________________________________________________________________________
Discounts and Assistance/Réductions et Assistance (Club GpsPasSion) / Où commencer?
Go to Top of Page

bviator

USA
21 Posts

Posted - 07 juin 2006 :  20:13:13  Show Profile  Reply with Quote
Interesting quote from the article:



"Please be aware that although some of the marketed GPS receivers can process the MSAS test signals, test signals are NOT necessarily valid as GPS augmentation information for some of the marketed GPS receivers."

Go to Top of Page

bviator

USA
21 Posts

Posted - 10 juin 2006 :  03:42:53  Show Profile  Reply with Quote
I will have an i-trek M5 with Nemerix chipset by next week. I also own a SirfII and and a SirfIII gps unit. I would like to do some testing for accuracy, especially repeatability of accuracy on different days with different satellite orientations. I would also like to see what WAAS is doing over here in the U.S. as far as improving accuracy. Of course, I stil have not been able to get WAAS on my Sirf III unit, so that may be a limitation.

Question: I have access to an RTK system, a very high end system (costs over 24,000 US dollars) used in precision agriculture that has accuracy of less than one inch. It utilizes a base station to generate localized correction signals to the mobile unit mounted on farm equipment.
I imagine I could use this equipment to get a somewhat "true" reference point to compare accuracy to the consumer gps units. Would I still need Delorme's GPSPostPro or is there some free software I could use. I do have some aricultural software on my IPAQ that can log points every few seconds over a given amount of time, and can export these points into standard arc shape files. Any suggestions on how best to do this in order to measure accuracy in comparison to the reference point?
Go to Top of Page

gpspassion

94046 Posts

Posted - 10 juin 2006 :  23:25:40  Show Profile  Visit gpspassion's Homepage  Reply with Quote
Oh that sounds like it would do the job fine, if you have an accurate geodetical marker in your area you can make sure it is working properly but I suppose it has some kind of error checking built-in ;-)

_________________________________________________________________________
Discounts and Assistance/Réductions et Assistance (Club GpsPasSion) / Où commencer?
Go to Top of Page

bviator

USA
21 Posts

Posted - 14 juin 2006 :  03:42:32  Show Profile  Reply with Quote
What software (especially inexpensive)can be used to calculate average deviation from a fixed point? I am not too concerned about logging over a period of time nor getting an accurate reference point. But how was GPSPassion able to calculate the average deviation from the fixed point?

I am excited about doing a little more accuracy testing in the field of precision agriculture, and especially encouraged about GPSPassions intitial results on the Nemerix chipset. Great job!

________________________
Haicom 303III (SirfIII)
Globalsat BC-307 (SirfII)
I-Trek M5 (Nemerix)
Holux GM-270
Ipaq 2200 Series
________________________
Go to Top of Page

gpspassion

94046 Posts

Posted - 14 juin 2006 :  10:07:23  Show Profile  Visit gpspassion's Homepage  Reply with Quote
Are you already noticing some increased accuracy with the M5 ? I Used SA Watch see 5 here http://www.gpspassion.com/fr/articles.asp?id=185

_________________________________________________________________________
Discounts and Assistance/Réductions et Assistance (Club GpsPasSion) / Où commencer?
Go to Top of Page

bviator

USA
21 Posts

Posted - 24 juin 2006 :  03:09:10  Show Profile  Reply with Quote
Received my M5 a week ago and love it. First, it got WAAS correction right away. Still no WAAS from my two SirfIII units. My SirfII Globalsat unit is getting WAAS everytime. I have about given up on my Haicom 303III and BT-338. I have done every possible tweak with GPSTweak, SirfDemo, MMSirf, etc.

Back to M5, comparing it to my arc view maps underlayed on the location marker of the gps location, I find it is dead on. As GPSPassion saw in the testing, much less jumping around and wandering of the calculated location. But is this a "true" phenomena or some sort of "static navigation" processing?

The shape file fields boundries I am using as an underlay of my gps postion was measured using a sub-meter gps. It seems darned close. I am looking forward to the fall when I will have time to some testing. I just wish I could get WAAS to work on those SirfIII units for the testing.

________________________
Haicom 303III (SirfIII)
Globalsat BC-307 (SirfII)
I-Trek M5 (Nemerix)
Holux GM-270
Ipaq 2200 Series
________________________
Go to Top of Page

bviator

USA
21 Posts

Posted - 24 juin 2006 :  03:11:30  Show Profile  Reply with Quote
By the way,

The GPSPassion testing article indicated that the Nemerix chipset was actually somewhat more accurate without SBAS enabled. What software does one use to disable SBAS on a Nemerix chipset?

________________________
Haicom 303III (SirfIII)
Globalsat BC-307 (SirfII)
I-Trek M5 (Nemerix)
Holux GM-270
Ipaq 2200 Series
________________________
Go to Top of Page

gpspassion

94046 Posts

Posted - 24 juin 2006 :  03:23:52  Show Profile  Visit gpspassion's Homepage  Reply with Quote
Thanks for keeping us posted. No software I'm aware of to turn SBAS on/off on a Nemerix bsaed receiver.

Good to hear you're getting some good accuray results. Not sure how they do it, but there must be some astute filtering going on to have so little wandering, nothing like SN though that just freezes the position completely. Navigation accuracy on foot is good too, so again no SN.

_________________________________________________________________________
Discounts and Assistance/Réductions et Assistance (Club GpsPasSion) / Où commencer?
Go to Top of Page

Leif

Sweden
141 Posts

Posted - 24 juin 2006 :  13:15:56  Show Profile  Reply with Quote
quote:
What software does one use to disable SBAS on a Nemerix chipset?

From NS1030 GPS Software, Datasheet, NS1030-GPS-SW-ds15 – Rev. 1.5 – November 2005.

$PNMRX114,0,0*xx : disable SBAS functions
$PNMRX114,1,1*xx : enable SBAS functions with normal handling of type 0 messages
(to be used on WAAS satellites, for example).
$PNMRX114,1,0*xx : enable SBAS functions and ignore type 0 messages
(to be used on EGNOS satellites, for example).

So any software that can transmit a user defined NMEA message and add a calculated checksum. SiRFDemo, menu Action, Transmit Serial Message. SirfTech, NMEA, Set.

Go to Top of Page

bitslizer

9 Posts

Posted - 25 juin 2006 :  19:40:32  Show Profile  Reply with Quote
so how to go about calculating the checksum? i assume the *xx is the checksum?

Edited by - bitslizer on 25 juin 2006 19:47:00
Go to Top of Page

Leif

Sweden
141 Posts

Posted - 04 juil. 2006 :  16:01:18  Show Profile  Reply with Quote
You don't have to. SirfTech and SiRFDemo calculates it for you. Just enter the NMEA data that should go between the $ and * and the $, * and checksum is added before transmission.
Go to Top of Page
Page: of 10 Previous Topic Topic Next Topic  
Previous Page | Next Page
 New Topic  Reply/Répondre
 Printer Friendly
Jump To:
GpsPasSion Forums © 2002-2014_GpsPasSion/Manzanite Go To Top Of Page
This page was generated in 0,91 seconds. Powered By: Snitz Forums 2000 Version 3.4.05