View previous topic :: View next topic |
Author |
Message |
dcolumbus3 Occasional Visitor
Joined: Sep 09, 2006 Posts: 2
|
Posted: Sat Sep 09, 2006 8:04 pm Post subject: Waas or not to Waas? |
|
|
I have a a couple of newbie nuvi questions:
1. My nuvi 350 has the option to turn Waas off or on (default is off). Why would I not want Waas to be on? What is the downside of having it always on?
2. Turning Waas on or off does not seem to have any effect on the accuracy of the reading; as indicated on the "satellite" screen, the accuracy of the reading seems to be 15-20 feet regardless of whether Waas is on or off. Shouldn't having Waas on increase the accuracy of the reading?
Thanks in advance for your help. |
|
Back to top |
|
|
Skippy Pocket GPS Verifier
Joined: 24/06/2003 00:22:12 Posts: 2946 Location: Escaped to the Antipodies! 36.83°S 174.75°E
|
Posted: Sat Sep 09, 2006 8:18 pm Post subject: |
|
|
The quick answer is that WAAS (aka EGNOS/SBAS) won't do any harm and it will make your GPS position more accurate under certain conditions.
It has to "see" the WAAS satellite which is in the South East, quite low in the sky.
I don't know if the Nuvi has a satellite screen so it's a bit of guess work to know if it's working. Go to the top of a hill or an open space (big outdoor car park) where you have a good view to the SE and wait 5 or 10 minutes to see if the accuracy improves. When it's working it claims 6 to 12 feet accuracy.
The long answer can be found in this thread. _________________ Gone fishing! |
|
Back to top |
|
|
dcolumbus3 Occasional Visitor
Joined: Sep 09, 2006 Posts: 2
|
Posted: Sat Sep 09, 2006 8:35 pm Post subject: |
|
|
Thank you for the quick and informative reply! :D
I should probably have clarified that I live in Michigan in the US; I wonder if the WAAS satellite(s) are more or less accessible from my location as compared to yours?
The nuvi does have a screen which shows the various satellites and the relative signal strength from each, eas well as a calculated location accuracy (in feet). Perhaps one is for the WAAS satellite; I will check.
So you don't think enabling the WAAS function has any negative effects such as reducing battery life? |
|
Back to top |
|
|
zogman Frequent Visitor
Joined: Sep 05, 2005 Posts: 1417 Location: swindon uk
|
Posted: Sat Sep 09, 2006 11:12 pm Post subject: |
|
|
waas in the states works better than here in the uk....i beleive the sat for waas is higher in the sky in the usa than in the uk...i got down to 2-3 feet at times whilst geocaching there on vacation...in the uk the gps slows down trying to get the waas/egnos sat so i personnely would'nt recommend it here.. _________________ *************************** |
|
Back to top |
|
|
swing Pocket GPS Verifier
Joined: Nov 04, 2003 Posts: 2225 Location: Bedfordshire, UK
|
Posted: Sun Sep 10, 2006 10:19 am Post subject: |
|
|
One downside of having it turned on is slightly reduced battery life, but I don't know by how much. |
|
Back to top |
|
|
Skippy Pocket GPS Verifier
Joined: 24/06/2003 00:22:12 Posts: 2946 Location: Escaped to the Antipodies! 36.83°S 174.75°E
|
Posted: Mon Sep 11, 2006 12:04 am Post subject: |
|
|
dcolumbus3 wrote: | I should probably have clarified that I live in Michigan in the US; I wonder if the WAAS satellite(s) are more or less accessible from my location as compared to yours? |
Sorry, I presumed you were in the UK!
zogman's experience is the same as mine - it works much better in the USA than the UK. Switch it on and enjoy! _________________ Gone fishing! |
|
Back to top |
|
|
Anita Pocket GPS Moderator
Joined: Mar 15, 2006 Posts: 3219 Location: Windlesham, Surrey
|
Posted: Mon Sep 11, 2006 12:15 am Post subject: |
|
|
Skippy wrote: | Sorry, I presumed you were in the UK! |
Wouldn't it be helpful if everybody completed their location in their profile!
I really don't understand the reluctance to do so. _________________ Anita
TomTom VIA 135 - App 12.075
UK map 1130.12368
Samsung Galaxy S21 |
|
Back to top |
|
|
lbendlin Pocket GPS Staff
Joined: 02/11/2002 22:41:59 Posts: 11878 Location: Massachusetts, USA
|
Posted: Mon Sep 11, 2006 2:13 am Post subject: |
|
|
zogman wrote: | waas in the states works better than here in the uk....i beleive the sat for waas is higher in the sky in the usa than in the uk... |
erm - no. They are both in geostationary orbits. But the WAAS birds have a stronger signal.
By the way, South-East was correct. The WAAS birds sit on either side of the american continent, one over the east pacific, the other over the west atlantic.
Be aware that SiRF III and WAAS don't go together very well. WAAS may actually degrade the positional accuracy of a SiRF III fix. _________________ Lutz
Report Map Errors here:
TomTom/TeleAtlas NAVTEQ |
|
Back to top |
|
|
Skippy Pocket GPS Verifier
Joined: 24/06/2003 00:22:12 Posts: 2946 Location: Escaped to the Antipodies! 36.83°S 174.75°E
|
Posted: Mon Sep 11, 2006 10:02 am Post subject: |
|
|
lbendlin wrote: | zogman wrote: | waas in the states works better than here in the uk....i beleive the sat for waas is higher in the sky in the usa than in the uk... |
erm - no. They are both in geostationary orbits. But the WAAS birds have a stronger signal. |
Yes, but the orbit in equatorial and in the UK we are 50 to 60 degrees North so the satellites are fairly low on the horizon compared to the USA where you will typically be 30 to 50 degrees North.
It's interesting that you say the WAAS satellites have a stronger signal - maybe that explains why it's so difficult to get EGNOS to work in the UK even in good conditions. _________________ Gone fishing! |
|
Back to top |
|
|
zogman Frequent Visitor
Joined: Sep 05, 2005 Posts: 1417 Location: swindon uk
|
Posted: Mon Sep 11, 2006 10:34 am Post subject: |
|
|
the sun in the states goes over your head whereas the sun in the uk is lower to the south, so the sats are the same in relation to the sun ..hope that makes sense... 8O _________________ *************************** |
|
Back to top |
|
|
|
Posted: Today Post subject: Pocket GPS Advertising |
|
|
We see you’re using an ad-blocker. We’re fine with that and won’t stop you visiting the site.
Have you considered making a donation towards website running costs?. Or you could disable your ad-blocker for this site. We think you’ll find our adverts are not overbearing!
|
|
Back to top |
|
|
|