GPS use for hunting

I'm not a GPS expert, but here's my two cents. The hand-held receivers havebasemaps pre-loaded and will allow you to set waypoints (position markers) and to track your movement. I've used these in Colorado's national forests with no problem before buying the topos I wanted. You can use a "backtrack" function to follow your track back to your point or origin or you can select a particular waypoint (such as your vehicle) or the unit can simply provide a route back to your selected waypoint or to another location. These supplemental maps are always (?) proprietary to the receiver manufacturer.

I use a Garmin 60CSx and the instructions made no sense to me when I bought it. I even went out an bought the training video. Not much help to me. Finally, I broke down and went around the neighborhood on a hike with the GPS and the instruction book. After an afternoon of walking myself through the various functions, I became very comfortable with its use. I always have maps of the area I am hunting or atving and in new areas use the maps and compass to ensure I coordinate the compass and the GPS display and the map so I know when the GPS tells me to go east, I have an idea what I am going to encounter in that direction. It also give me a backup should the batteries fail on the GPS and I find I failed to pack extras.

A point to remember: GPS is accurate as heck. Still, as a navigation device, it is only as good as the maps you are using. Keeping your software and maps current will ensure many years of enjoyment. I believe the Garmin 60 series is the best unit out there (it has an external antenna and I get decent signal strength in dense cover), but that's my opinion. Garmin makes some very good units in the entry price ranges (about $150.00).

Just want to add something here on GPSes for hunting. It's my belief the DeLorme earthmate series are the best for the following reasons.

They come with the topo 8.o software giving coverage of the entire US. They come with additional disks that already have the topo maps divided into regions for each state so you can immediately transfer the states you want to an SD card and you're ready to go.

The topo software shows both 2D and 3D views of the topo maps.

With a $30/yr subscription you can download files for anywhere in the US and overlay them on your topo map. This service provides unlimited downloads and allows downloading:
# Hi-Resolution Color Aerial Imagery DOQQ
# USGS 7.5-Minute Quads (not available for use within Street Atlas USA)
# NOAA Nautical Charts (not available for use within Street Atlas USA)
# USGS High-Resolution Cities
# Black & White Aerial Imagery
# 1:50K Canada Topographic Map Sheets

The satellite imagery is a great idea as it allows you to see the cover for the area. Knowing how to get there is great, but being able ton plan where to glass before you go because of knowing where water and cover can be found is even better.


To get a good idea, take a look at this review
http://www.gpsreview.net/delorme-pn-40/

The PN-40's reception has been rated as good as the Garmin 60CSx by people that have used both.

The PN-60 will include features like text messaging via satellite when you are in a remote area with no cell phone coverage (normal in Colorado mountains.) Includes the ability to send an emergency help message.
http://blog.delorme.com/2010/01/06/...d-gps-meets-satellite-communication/#more-674

With 16 GB of on board memory, SPOT communication and a lot of other features, this will not be a cheap unit. But you still have all the mapping and other features with the 20,30, and 40

The handheld units you buy at Dick's, Cabela's, etc are fine for doing what you are looking for in the field. I'd get one that has topo maps that you can load and use in the field. The pre-loaded base maps are basically useless in the field once you get away from known roads, etc. They have no built in references. If you are using them for hunting, hiking, etc. you need topos.

Secondly, these type of units don't have sub-meter GPS. They are accurate to about 30 meters, they will tell you 10 meters, and they can be, but you have to have optimum conditions. If you want anything more accurate, be prepared to pay thousands of dollars. I use the Garmin GeoXT or the Magellan Mobile Mapper CX for our sub-meter pipeline surveys. But for my hunting trips I use a Magellan Explorist 500 with 3-D topos loaded. Works quite well.

Thirdly, folks have the mistaken idea that when you are connected to the satellites that the unit automatically updates the maps so that it will show new roads, features, etc. This is not the case. You either have to purchase updated maps and load them, or with some units have a subscription that allows you to download updates. That's the way my Sky Caddie works for GPS on the golf course. Always make sure you have updated maps.

Most people have no clue how GPS works and some of the inherent inaccuracies. The only way to get highly accurate GPS data is to use a receiver capable of differential GPS. Generally, you are going to get 15 - 30 meter accuracy, which is OK for finding your way out of the woods back to your vehicle. If you get back within 50 feet, you are fine. They will tell you WAAS enabled GPS will get you within 3 meters, or about 10 ft. Maybe. I have checked several WAAS enabled hand held units against differential sub-meter GPS, and it wasn't anywhere near 3 meters. But again, unless you are doing detailed mapping work, it's plenty close enough. But try pinpointing an anomaly on a pipeline with a $200 Garmin, and it's not going to happen.

When I meet with clients to talk about GPS data, I hear all kinds of crazy assumptions about what GPS can do. The elevation on even expensive GPS units is very inaccurate. On a cheap Garmin or Magellan it's basically just a go by. "It is true that GPS elevations are less accurate than the horizontal positions gained from GPS. In fact, GPS elevations generally have two to three times the error of horizontal positions gained from GPS." So the elevation is basically just a go by unless you have base stations established and can triangulate.

A lot of other issues enter into obtaining accurate GPS data. There are times of the day (if you have been out using a unit you may have experienced this) when you can't get satellite reception. When we are doing GPS surveys, this leaves us dead in the water. We also lose synchronization of some of our equipment because of this. Why? Probably something that the government is doing with the satellites.

Wikipedia has a pretty good explanation of GPS. http://en.wikipedia.org/wiki/Global_Positioning_System

The whole point is that GPS is a great tool, but I would also take a good topo map of the area along as well. With the topo and the GPS unit you can do a good job of locating where you are as long as you can get satellite reception. I use a Magellan Explorist 500, knowing full well that it has some inherent inaccuracy, but along with my USGS Topographic map, I'm not likely to get lost.

Halwg said:

The whole point is that GPS is a great tool, but I would also take a good topo map of the area along as well. With the topo and the GPS unit you can do a good job of locating where you are as long as you can get satellite reception. I use a Magellan Explorist 500, knowing full well that it has some inherent inaccuracy, but along with my USGS Topographic map, I'm not likely to get lost.

Click to expand...

And this goes straight back to what you mentioned earlier that you need a unit that comes with topo software. That way you can print out maps for the area you are in and keep them in a waterproof holder. Since you can also get special inkjet paper which is almost impossible to rip and makes the map highly water resistant (highly recommended) it can save money in the long run. There is one caveat. You have to use the ink by the manufacturer, bargain ink will not work well.

Funny you should mention accuracy. All manufacturers list the best possible accuracy with all conditions being close to perfect. Then they call it typical accuracy- huh? :

The PN-20 I have will give you the estimated accuracy when on the satellite page. So far, the best I've seen on it is 8 meters. And it was pretty close to that when I looked at both the topographical features and the imagery overlay.

However, you can do what they call averaging by setting your location as a waypoint. This gets a more accurate reading for that point. Once you start moving again, you're back to the normal accuracy. But if you want to lay a route using averaged waypoints, you can get much better accuracy this way. Usually within 5 meters

All that said, they are still great for marking locations you've glassed as good potential hunting ground, marking the area of good fishing holes and lots of other stuff that doesn't require pinpoint accuracy. They are definitely worth the money.