Thinking about getting a GPS

herman · February 2, 2000, 07:16 PM

I want to get a gps unit to keep track of deer runs and other points of intrest on my property. A friend of mine says that a gps won't work on my property because it is thick cedar swap sorrounded by hills, claims his gps never could pick up a signal in thick cover. Anybody out there using one in the deep woods? Would high price models receive better? Has anybody used the ones that down load to your computer?

mongrel66 · February 2, 2000, 08:28 PM

i use an eagle explorer...base model.the hills on your property wont matter , the overhead cover will.i've used these things in thailand and the philippines and theyre worthless in heavily canopied areas...
i made the choice of the eagle by going into several stores..turning the gps units on next to a window and seeing which one locked on first...the eagle won hands down, so i bought it...if you have an rei store near you , they put out a nice informational pamphlet on them.
they are los to lock on to the sattelites, so if youre under cover forget it.-johnny

STLRN · February 2, 2000, 09:57 PM

GPS (the military version, the PLGR) is one of the items I give classes on here at the School house. Here are a few items that GPS companies don't tell allot of people about.
1) The NAVSTAR sats transmint on 2 bands the first the P-codes can be recieved by everyone, the second the Y-codes can only recieved by systems that have cryto-fills. The P-codes are less accurate than the Y-code, with a military GPS recieving P and Y codes you can get accuracy down to +/- 10 meters on good days.
2) The military at anytime can decide to go to "selective availability" When this happens civilian receivers will be accurate to +/- 1000 to 2000 meters. Those units that recieve Y-codes will not be effective.
3)GPS transmission is LOS, Line of Sight, if your receivers loses LOS of the required number of sats you start loosing accuracy. Normally 3 sats are required for location, 4 for altitude, but many of the newer recievors do parallel tracking, so the more sats you can track the more accurate your position will be. Many types of terrain can block the GPS signals, some examples are a thick canopy of trees, canyon walls, buildings, etc. So in many tyoes of terrain you are SOL.
4. GPS direction should not really be relied upon, it has been found that direction option from GPS receivers can be up to 200 milaradians out (1 milaradion is equal to 1/17.77777778 of a degree). So you should also carry a compass to use as your method to determine direction.
5. Most GPS are battery hogs, constantly tracking satellites will drain your battteries fast, the other option is operating in the "Quick Fix" get your new pos and shut it off.

------------------
God truly fights on the side with the best artillery

jcoyoung · February 3, 2000, 01:58 AM

From what you want to use it for, it sounds like you are looking for the portable handheld variety of GPS units. I currently have a GPS unit that plugs into my laptop. Since others may come to this topic for different applications, I will elaborate.

I have the Delorme Earthmate GPS receiver. (~$150 w/ software) It plugs into the serial port and runs off 4 AAA batteries (eats 'em up pretty fast too). The GPS receiver works with all of Delorme's map software, including AAA Map-N-Go.

Software Available:
Included with the Earthmate package is Street Atlas USA 7.0, which only covers CONUS (Continental United States) but is very detailed. Good for driving around the country.
I bought Delormes Eartha Global Explorer to use for a trip into Canada - what a waste of money. The Eartha software can only zoom in close enough to see major highways.
I bought the AAA Map-N-Go to use in Canada(It also has maps for Mexico). The map quality was between Eartha and SA USA, but it did have these cool multimedia tourist site descriptions.
There is also a a topographical map that is available (Topo USA?). From what I remember, it was pretty expensive.

Earthmate GPS Receiver and Street Atlas USA 6.0
Pretty cool software. It will make a route for you per your preferences (speed, scenic, etc.) The map actually shows an arrow to show the position and direction of travel. It also has verbal directions if you like having an electronic backseat driver.

I'm quite happy with the Earthmate, but I haven't used it in a while (maybe this summer). Excellent co-pilot for driving in strange and mysterious places (like NYC).

[This message has been edited by jcoyoung (edited February 03, 2000).]

Skyhawk · February 3, 2000, 04:51 PM

I have had a Garman Streetpilot for about a year. This unit is more suited to driving needs rather that walking due to short battery life (color display). It has plug-in chips for major metropolitan areas with very detailed information. Price is a little steep though. Otherwise, I like it.

Skyhawk

Jeff OTMG · February 4, 2000, 08:23 PM

Garmin is at www.garmin.com Check out the GPS III Plus. 36 hour battery and high level maps are internal. It will interface with the DeLorme mapping programs or you can down load more detailed maps for the areas that you are interested in from the Garmin software. There is a power cord for use in the car available so you don't chew up batteries, a mounting bracket so it doesn't move around, and a handlebar mount for we motorcylce folk. I got to see the GPS12MAP and it has many of the same features as the III Plus, but it is not on the site.

February 2, 2000, 07:16 PM	#1
herman Junior Member Join Date: September 19, 1999 Posts: 5	I want to get a gps unit to keep track of deer runs and other points of intrest on my property. A friend of mine says that a gps won't work on my property because it is thick cedar swap sorrounded by hills, claims his gps never could pick up a signal in thick cover. Anybody out there using one in the deep woods? Would high price models receive better? Has anybody used the ones that down load to your computer?

February 2, 2000, 08:28 PM	#2
mongrel66 Senior Member Join Date: January 19, 2000 Posts: 122	i use an eagle explorer...base model.the hills on your property wont matter , the overhead cover will.i've used these things in thailand and the philippines and theyre worthless in heavily canopied areas... i made the choice of the eagle by going into several stores..turning the gps units on next to a window and seeing which one locked on first...the eagle won hands down, so i bought it...if you have an rei store near you , they put out a nice informational pamphlet on them. they are los to lock on to the sattelites, so if youre under cover forget it.-johnny

February 2, 2000, 09:57 PM	#3
STLRN Senior Member Join Date: October 28, 1999 Location: USA Posts: 1,163	GPS (the military version, the PLGR) is one of the items I give classes on here at the School house. Here are a few items that GPS companies don't tell allot of people about. 1) The NAVSTAR sats transmint on 2 bands the first the P-codes can be recieved by everyone, the second the Y-codes can only recieved by systems that have cryto-fills. The P-codes are less accurate than the Y-code, with a military GPS recieving P and Y codes you can get accuracy down to +/- 10 meters on good days. 2) The military at anytime can decide to go to "selective availability" When this happens civilian receivers will be accurate to +/- 1000 to 2000 meters. Those units that recieve Y-codes will not be effective. 3)GPS transmission is LOS, Line of Sight, if your receivers loses LOS of the required number of sats you start loosing accuracy. Normally 3 sats are required for location, 4 for altitude, but many of the newer recievors do parallel tracking, so the more sats you can track the more accurate your position will be. Many types of terrain can block the GPS signals, some examples are a thick canopy of trees, canyon walls, buildings, etc. So in many tyoes of terrain you are SOL. 4. GPS direction should not really be relied upon, it has been found that direction option from GPS receivers can be up to 200 milaradians out (1 milaradion is equal to 1/17.77777778 of a degree). So you should also carry a compass to use as your method to determine direction. 5. Most GPS are battery hogs, constantly tracking satellites will drain your battteries fast, the other option is operating in the "Quick Fix" get your new pos and shut it off. ------------------ God truly fights on the side with the best artillery

February 3, 2000, 01:58 AM	#4
jcoyoung Senior Member Join Date: January 20, 2000 Location: Oak Forest, IL Posts: 661	From what you want to use it for, it sounds like you are looking for the portable handheld variety of GPS units. I currently have a GPS unit that plugs into my laptop. Since others may come to this topic for different applications, I will elaborate. I have the Delorme Earthmate GPS receiver. (~$150 w/ software) It plugs into the serial port and runs off 4 AAA batteries (eats 'em up pretty fast too). The GPS receiver works with all of Delorme's map software, including AAA Map-N-Go. Software Available: Included with the Earthmate package is Street Atlas USA 7.0, which only covers CONUS (Continental United States) but is very detailed. Good for driving around the country. I bought Delormes Eartha Global Explorer to use for a trip into Canada - what a waste of money. The Eartha software can only zoom in close enough to see major highways. I bought the AAA Map-N-Go to use in Canada(It also has maps for Mexico). The map quality was between Eartha and SA USA, but it did have these cool multimedia tourist site descriptions. There is also a a topographical map that is available (Topo USA?). From what I remember, it was pretty expensive. Earthmate GPS Receiver and Street Atlas USA 6.0 Pretty cool software. It will make a route for you per your preferences (speed, scenic, etc.) The map actually shows an arrow to show the position and direction of travel. It also has verbal directions if you like having an electronic backseat driver. I'm quite happy with the Earthmate, but I haven't used it in a while (maybe this summer). Excellent co-pilot for driving in strange and mysterious places (like NYC). [This message has been edited by jcoyoung (edited February 03, 2000).]

February 3, 2000, 04:51 PM	#5
Skyhawk Senior Member Join Date: January 20, 2000 Posts: 616	I have had a Garman Streetpilot for about a year. This unit is more suited to driving needs rather that walking due to short battery life (color display). It has plug-in chips for major metropolitan areas with very detailed information. Price is a little steep though. Otherwise, I like it. Skyhawk

February 4, 2000, 08:23 PM	#6
Jeff OTMG Senior Member Join Date: October 15, 1998 Location: OKC, OK & Austin, Tx Posts: 3,707	Garmin is at www.garmin.com Check out the GPS III Plus. 36 hour battery and high level maps are internal. It will interface with the DeLorme mapping programs or you can down load more detailed maps for the areas that you are interested in from the Garmin software. There is a power cord for use in the car available so you don't chew up batteries, a mounting bracket so it doesn't move around, and a handlebar mount for we motorcylce folk. I got to see the GPS12MAP and it has many of the same features as the III Plus, but it is not on the site.