GPS reception problems

[BlackBuzzard]

Using my Etrex Summit in heavily forested  parks I often get little to no signal.   I like to do loop hikes and finding my way back to point of origin just does not work like it does in the desert.


Questions:  are there GPS's that would work in heavily forested (foliage) terrain?  Is my older unit (6 yrs or so) inferior to newer ones in terms of signal reception ability?

I'd buy a new one in a heart beat, but only if I know it will do the job I ask.


BlackBuzzard

[jeffblaylock]

Is my older unit (6 yrs or so) inferior to newer ones in terms of signal reception ability?

Yes. I had an Etrex Summit until it was forcibly parted from me on the side of Casa Grande, and it seldom locked onto a signal in forested areas or canyons. And I never got a signal while inside a house. I now have a Garmin 60CSx, which has a "high-sensitivity antenna." and it gets a signal indoors. I have not tested it sufficiently in the wild, but I expect it to perform well.

This thread covers the 60CSx if you're interested. There are other models with the higher sensitivity receptors, but even a more stripped-down version will probably have better reception than the old Summits.

[badknees]

You have the older version of the Summit which does not have the high sensitivity receiver. The newer Garmins have the SiRF high-sensitivity GPS receiver. This is by far much more sensitive than the pre SIRF models. I can actually get a 3D position inside my house with the GPS60CSX.

In some models, the addition of an external antenna will improve reception, however I believe the Summit unit does NOT have an external jack.

Check out a review of the 60CSX vs the older 60CS (without SIRF)

  http://patrick-roeder.de/reviews/garmin_gpsmap_60CSx.htm

I have used my 60CSX on trails with heavy cover, trees and in narrow canyons with great success. Of course there are limitations related to satellite constellation visibilty, but the new SIRF receivers are a vast improvement over the previous generation.

I believe the move to the higher sensitivity receivers was driven by the auto navigation systems in the "canyons of cities"

Some of your problem can be solved by the application of $$'s. Sorry.

[SHANEA]

Some of your problem can be solved by the application of $$'s. Sorry.

Yep, I had the same problem with the Etrex VISTA with super lousy reception.  I got fed up with it and purchased the 60CS - before the CSx was available.  Outstanding reception, has a jack for external antenna which I have, etc.  Absolutely no complaints with my 60CS.    Didn't like the little "joy stick" on the Vista either and the small display and lack of color.  Haven't found a good reason to upgrade to the 60CSx yet.

[presidio]

The lower end units have trouble with aerial obstructions, much like the first units did with sequential reception rather than parallel reception of signals. Heavy tree cover is too much for some units.
 
If you want the best reception, get a unit with the SiRF processor, and WAAS capability for best accuracy. If using in a vehicle, get a unit with an external antenna connector and plunk an antenna on the roof or hood. Typically, the Garmins (at least) in the upper price range will give you all this combined.

However, recognize that a very thick canopy is going to degrade the signal somewhat in any case regardless of the unit used.

[BlackBuzzard]

I was good and lost for about 1 hr yesterday, trying to complete my loop without gps.  Terrain was very rocky and trees were tall and thick.

The area of interest (state game lands #211, saint anthonys wilderness in PA) has several mountain ranges rising about 800ft off the valley floor.

I dont need precision.......I just want it to work +/- 70ft in thick, tall tree canopy.  Light weight is important, preferably without external antenna.

My old Garmin Summit works on the dash of my truck, but does not like canopy.

I guess I could order one, try it out, and return it if it fails to deliver.






BlackBuzzard

[presidio]

has several mountain ranges rising about 800ft off the valley floor.

Ummm....those would be 'hills'. However, if you are in a narrow valley where your view of the sky is limited, reception and accuracy will be degraded or impossible. A tree canopy will just make that situation worse.

Light weight is important, preferably without external antenna.

The higher end units have an external antenna connector. You don't have to have one plugged in as the internal antenna will work fine. The external antenna is merely recommended for better reception/accuracy when the unit is in a vehicle.

[LandCruisers4Life]

Using my Etrex Summit in heavily forested  parks I often get little to no signal.   I like to do loop hikes and finding my way back to point of origin just does not work like it does in the desert.


Questions:  are there GPS's that would work in heavily forested (foliage) terrain?  Is my older unit (6 yrs or so) inferior to newer ones in terms of signal reception ability?

I'd buy a new one in a heart beat, but only if I know it will do the job I ask.


BlackBuzzard

My Lowrance GlobalMap 100 works in heavy coverage, and is about 8 years old now. The Lowrance units are the leaders in reception - all other companies have tried to match and copy Lowrance's 12 parallel channel technology, but do not quite cut it yet. In fact, if I had to replace my older unit, I'd still have to go with Lowrance today. I'm getting ready to put a Lowrance large screen unit in my 4wd truck as well for easy viewing.