WAAS vs. High Sensitivity ?

[carolina canadians]

We have not started geocaching yet, but I am trying to learn what I can before we plunge into it. I'm exploring my options on what GPS handheld to buy, and want to know the accuracy differences between WAAS and High Sensitivity. I've generally been looking at the various Garmin units -- the eTrex units spec "WAAS" and the GPSMAP 60 specs "high-sensitivity receiver". Which gives the most repeatable, most accurate locations?

[+Driver Carries Cache]

We have not started geocaching yet, but I am trying to learn what I can before we plunge into it. I'm exploring my options on what GPS handheld to buy, and want to know the accuracy differences between WAAS and High Sensitivity. I've generally been looking at the various Garmin units -- the eTrex units spec "WAAS" and the GPSMAP 60 specs "high-sensitivity receiver". Which gives the most repeatable, most accurate locations?

 

According to Garmin's website, while they use the words "high sensitivity" the 60CSx is also WAAS enabled.

 

DCC

[+briansnat]

WAAS and high sensitivity are two different things. WAAS in short increases the accuracy of GPS by using ground signals in addition to the sats. Most handheld units today are WAAS enabled.

 

High sensitivity refers to the reception the unit gets. Units without high sensitivity receivers (even ones with WAAS) have difficulty with reception under trees.

 

So the choice is not between WAAS and high sensitivity. Most Garmins sold today have both.

[+StarBrand]

Yup - Accuracy and High Sensitivity are 2 different things.

 

Accuracy is how close you are to the actual coordinates - often reported as the EPE (Estimated position Error). That too is just an estimate and is not to be taken literally. WAAS can improve the accuracy of any unit.

 

High Sensitivity is the ability to "see" and hold the signal from Satellites in situations where the view of the sky is limited or somewhat blocked.

 

All of Garmin's "H model eTrex line is high sensitivity as are the Colorado and 60 and 70 lines. Virtual all Garmin's have WAAS capability.

[+briansnat]

All of Garmin's "H model eTrex line is high sensitivity as are the Colorado and 60 and 70 lines

 

Not all of the 60 and 70 lines have a high sensitivity receiver. The GPS 60, Map 60, GPS 72, GPS 76, Map 76 and Map76S do not. All are still sold by Garmin.

 

The discontinuted 60CS, 60C, 76CS, 76C don't have one either.

[+joranda]

Nothing beats a garmin 60 csx in my book.

[+XopherN71]

Nothing beats a garmin 60 csx in my book. smile.gif

Garmin Colorado blows it away in mine

 

High sensitivity is definitely nice to have since you can throw the GPS in your pocket and it'll still work for example. WAAS I can take it or leave it since I generally don't notice much difference with it on or off anyway.

[+StarBrand]

All of Garmin's "H model eTrex line is high sensitivity as are the Colorado and 60 and 70 lines

 

Not all of the 60 and 70 lines have a high sensitivity receiver. The GPS 60, Map 60, GPS 72, GPS 76, Map 76 and Map76S do not. All are still sold by Garmin.

 

The discontinuted 60CS, 60C, 76CS, 76C don't have one either.

sorry forgot to add the correct letters on those.

[Neos2]

Nothing beats a garmin 60 csx in my book. smile.gif

Garmin Colorado blows it away in mine

 

High sensitivity is definitely nice to have since you can throw the GPS in your pocket and it'll still work for example. WAAS I can take it or leave it since I generally don't notice much difference with it on or off anyway.

WAAS reception varies from one location to the next. It's rare that my unit doesn't get a lock on at least one WAAS signal in southern Indiana--but I noticed while traveling great distances away that the WAAS reception varies. When I do have a WAAS sattellite locked, I get better reception, faster aquisition, etc.

 

You are the first person I've ever heard say they prefer the CO for geocaching-- my local caching buddies that tried them have returned their COs to the store and begun using their 60 CSX units again.

 

They said the loooooonnnnggg lag time on their CO drove them crazy. Apparently the unit goes through some sort of refresh every time you point to a new cache??? They claimed the rest of us were already finding the cache and signing it by the time their units locked onto the cache.

 

I was hoping the CO would be "cacher friendly" by now, so I could get one for my husband for his birthday--but it looks like that may have to wait for Christmas or his next birthday. He likes new toys and he is due an upgrade.

 

If there were a lot of Wherigo caches near us I *might* consider going ahead and getting him a 400t now and dealing with the upgrades etc. But since we just want the best geocaching unit, I believe I'll stick with my 60CSx. It has all the features I use and need and none of the issues the CO still seem to have. I know I am comparing apples to oranges in some ways, since the CO is really designed to be used for Wherigo caches and not general geocaching--but it would be nice to have something that did both well.

 

Anyway, for the OP---If you ask me, the better units to consider right now for geocaching and general navigation are the Garmin HCx units (Legend Hcx, Vista Hcx) and the 60CSx. I love my 60CSx and personally think it's the best unit out there for geocaching right now.

[+HOGFEVER]

Just noticed on my vista hcx setup menu that waas was turned off so if I turn it on I will get a more accurate reading,correct?

[+dakboy]

Just noticed on my vista hcx setup menu that waas was turned off so if I turn it on I will get a more accurate reading,correct?

It's not guaranteed to improve your accuracy.

 

And it's not always needed. My PN-40 was "off" by less than 2 meters on 4 of the 5 caches I found yesterday, with no WAAS corrections locked in.

[+Kohavis]

I won't repeat what several have reiterated here, but I will add that the Garmin "H" chipset is the real deal. Older GPS units needed a clear line of sight to the sky, but the H Garmins still work under trees and even in buildings.

 

Here's a track of 1/2 mile my wife and I put in inside a mall store. I had decided to throw my Venture HC in my pocket before we headed out, just to see if it would track. The building is a typical steel commercial structure. The track is overlaid on a Google Earth satellite image so there is some systemic error seen as a shift to the right, but it's Google imagery error, not GPS error.

 

Google Earth is notorious for shifts in geocache positions (really obvious when you use the Geocaching KML overlay and zoom in or out). You can see the little jog to the left in my pic as we went through the checkout line and headed for the exit. Google Earth shows it as being about 20 ft. outside of the front door when it was really about 6 feet inside of the door. But my point is that it tracked us inside a steel-roofed, steel-framed building with ductwork, conduit, roof machinery, etc. - about the worst possible scenario for a GPSr short of being in a copper mine or something :

 

[+StarBrand]

Just noticed on my vista hcx setup menu that waas was turned off so if I turn it on I will get a more accurate reading,correct?

Yes - however, it rarely actually helps you find a geocache. you have no idea at all if WAAS was used by the hider when they obtained the coords.

[+Prime Suspect]

Just noticed on my vista hcx setup menu that waas was turned off so if I turn it on I will get a more accurate reading,correct?

It will usually help, and never hurt to have it turned on.

 

When you're searching for a cache, you're dealing with a combination of the hider's GPS error, and your GPS error. You have no control over the former, but you can reduce the latter by turning on WAAS.

[+HOGFEVER]

Great info,thanks to all.

[+rtreit]

Here's a track of 1/2 mile my wife and I put in inside a mall store....

 

 

Off-topic, but how do you get those neat directional arrows on the track log?

 

rtreit