# GPS WAAS users - how often does it work in the woods?

**URL:** <https://boards.straightdope.com/t/gps-waas-users-how-often-does-it-work-in-the-woods/260138>\
**Category:** Factual Questions\
**Created:** [August 16, 2004, 8:52pm UTC](https://boards.straightdope.com/t/gps-waas-users-how-often-does-it-work-in-the-woods/260138 "2004-08-16T20:52:15Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\
**Post date:** [August 16, 2004, 8:52pm UTC](https://boards.straightdope.com/t/gps-waas-users-how-often-does-it-work-in-the-woods/260138/1 "2004-08-16T20:52:15Z")

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If you have a GPS navigation device with WAAS augmentation for better accuracy, and you’re in the woods under tree cover, how often does the WAAS work?

Does it work under heavy foliage, or light, or bare branches in winter? Or none of the above?

How does WAAS reception under foliage compare to GPS reception in general under foliage? As a rule of thumb, is it somewhat more difficult to get the WAAS signal than it is to get ordinary GPS? Or much more difficult, or what?

Thanks!

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**Author:** ![PigBoy](https://avatars.discourse-cdn.com/v4/letter/p/97f17d/32.png) [@PigBoy](https://boards.straightdope.com/u/PigBoy)\
**Post date:** [August 16, 2004, 10:31pm UTC](https://boards.straightdope.com/t/gps-waas-users-how-often-does-it-work-in-the-woods/260138/2 "2004-08-16T22:31:52Z")

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My personal experience working with GPS this summer has been that the WAAS signal is lost if you even go so far as to say bad things about its mother. Just today, for instance, it would come and go as we walked along a sidewalk near regular ol’ trees in people’s yards. So from my experience, it does not work well under foliage. However, I don’t think that reception for the GPS satellites has been much better under tree cover.

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**Author:** ![Tapioca\_Dextrin](https://avatars.discourse-cdn.com/v4/letter/t/3d9bf3/32.png) [@Tapioca\_Dextrin](https://boards.straightdope.com/u/Tapioca_Dextrin)\
**Post date:** [August 16, 2004, 11:03pm UTC](https://boards.straightdope.com/t/gps-waas-users-how-often-does-it-work-in-the-woods/260138/3 "2004-08-16T23:03:13Z")

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WAAS signals are a really hard to get unless you are in absolutely clear terrain. Here’s what [Garmin](http://www.garmin.com/aboutGPS/waas.html) has to say (and they are trying to sell the thing)

> [@](#):
>
> For some users in the U.S., the position of the satellites over the equator makes it difficult to receive the signals when trees or mountains obstruct the view of the horizon. WAAS signal reception is ideal for open land and marine applications.