| Author | Message | ||
| captain ron (Captain_ron)
Rating: N/A |
Recieved it today and installed in laptop with no hitches. played with it a little But need to do some reading of the instructions. looks pretty cool. Don't know how acurate it is. I used it in the house in the back room. it showed me on the street behind me but my buddies hand held does the same. he took his out side and it showed a very slight differance in longitude which was correct as he was a few feet north of me. his elevation showed us at 19 ft mine showed us at 40 ft. mines was wrong. I'll play with it some more tonight. | ||
| Donald Lee Schwanke (Dontx)
Rating: N/A |
The one I had in my airplane would allow me to drive on the taxiways without looking out the window. I think you will find the accuracy of most any of them satisfactory. | ||
| Bryce Gaston (Busted_knuckle)
Rating: N/A |
Don ??? Driving a Taxi down the runways with out looking out the window!!!??? Where'd ya get yer "Hack" license at Tijauna?  Knuckle | ||
| james dean boggs (Jd_boggs)
Rating: N/A |
If I remember correctly, there is an accuracy udate you need to get from Delorme. I had a similar problem until the update. I forgot what is called but Delorme has an online link on the main tab which takes you right to the update. Remember to connect the laptop to an internet connection. | ||
| JW Smythe (Jwsmythe)
Rating: N/A |
Cap't Ron, I didn't give any advice in the previous thread, 'cause I don't have any great advices on what's available. Most of the receivers are just as good as each other. It's the softwares which you have to get to fit your application. All any of them do is read data being received from the satellites, calculate your position based on that data, and spit it back to you in NEMA format. Well, most of them do that. Some use their own formats, and don't play well with other vendors programs. http://ve2.ele.etsmtl.ca/ve2wmg/gps/full/nema.htm From that page, a string will look something like: $GPGGA,180432.00,4027.027912,N,08704.857070, W,2,07,1.0,212.15,M,-33.81,M,4.2,0555*73 Each field is split with a comma "," $GPGGA isn't a field, it's a header. 1 is time, in UTC hhmmss.ss 2 and 3 are latitude 4 and 5 are longitute 6 is the quality of the data 7 is how many satellites were used (0-12) 9 and 10 are your altitude It's all pretty useless to an individual, unless you have a map in front of you, and are looking to plot your coordinates by hand. All the exciting stuff is done by the software, which is where the real competition is, and I have absolutely no advice. There are a couple different signals sent down. One is for general use, which is what we use. There is an error built into the system, so you can't track your real position with too much accuracy. I believe it's 9 meters. Any two GPS receivers, even if in the identical place, could have a difference of up to 9 meters. You can do differential GPS, which takes GPS readings from several points, and uses the variation to establish true coordinates. The US Government uses a different frequency, which is accurate to inches, I believe. This error was built into the system intentionally, to keep the "enemy" from using "our" system to attack "us". For example, if you know the coordinates of a target (say, the whitehouse) by standing in front of it with a GPS receiver, the cold-war enemy could have made a long range missile (say, cruise missile) go to exactly those coordinates. With 9m of variation, it could miss, or at very least not hit exactly where they expected. The stupid part of this is, if the enemy was going to bother launch one, why not a dozen, and each one hit somewhere randomly in that 9m of space. I could be wrong on the 9m, and I know they did decrease the error margin a few years ago, but it's still there, and you'll still see a difference. I played with one in my car once, and would track my driving. Sometimes it would show me just a few feet off the road, and sometimes I'd be dead on. GPS does work on low power radio waves, so you'll get blocked reception from buildings, trees, and even heavy cloud cover. Be aware of that, you may lose your GPS reception if it's too cloudy! If it's nasty out you won't be able to depend on the GPS to tell you where to turn. You should already know where you're going, without the GPS. A guy I worked with once worked for a GPS mapping software company. They'd send teams of two out on road trips. They'd mark the coordinates for various intersections and places, to ensure their mapping software would show you in the right places. People get upset when their car tells them to turn left in 5 feet, when they're still 1/2 mile from the turn. I plan on at least one computer in the front of my bus hooked up to at least one GPS receiver, and a 17" LCD monitor. I have one old GPS receiver here, and a whole office full of hardware that can work it, but no good mapping software. I always wanted to put one in my car, but there's no "good" place to put a screen in the front of my car, even a little one. I have a couple friends who did do this, and they set them up with XM radio, and can play a whole collection of MP3. It's all touch screen, so it's pretty slick. I probably won't go with the touch screen. I'll just have a small keyboard and mouse in the front, and pull over to change destinations, or have my girlfriend key in changes. | ||
| captain ron (Captain_ron)
Rating: N/A |
I have run into a problem, When I pan to a different area of the map it snaps back to the original spot where I'm located. How can I fix this or am I doing something wrong? | ||
| Kerry Carlson (Kerryc)
Rating: N/A |
You have it set to "center on GPS". I beleive the button is on the right side of the screen. Turn it off and you will be able to scroll where ever you want | ||
| wec4104 Rating: N/A |
A few more notes regarding accuracy.. Prior to May 2000, the Government used a system to intentionally degrade the accuracy reducing the chances of the system being used against us for military purposes. The Clinton Administration passed a bill to turn off the artifically induced inaccuracies, and this took affect May 1, 2000. (Although the Gov't retains the ability to turn it back on as neccessary, and can do so by region of the country.) My understanding is that Delorme and other GPS units can now use the full accuracy of the broadcasted signals. Most systems quote accuracies around 10 meters, which is about 10 times better than when the signal was scrambled. I believe that is only what they quote for accuracy in the Lat / Long directions, and does not necessarily apply to elevation. | ||
| captain ron (Captain_ron)
Rating: N/A |
Well I took her for a test drive today. What a sexy voice she has. Kind of cool the way she tells me to turn, I'm off route and she's recalculating route. we porposely went off route to see what it would do. because of my general and not acurate destination it did not do a very good job of getting us back on track but next time I will put in presice location. also poi does not seem to have stores on it that I can find like it claimes. when I opened the drop down window it does not have a catagory for stores. | ||
| Tim Strommen (Tim_strommen)
Rating: N/A |
In the U.S., there are a few ways that GPS accuracy is being improved: WAAS: (Wide Area Augmented System) which is a ground and satellite based error correction system used in many COTS (Commerial Off The Shelf) GPS receivers. This system is run by the FAA, and uses very precisely located GPS receiver stations located around the country that pick up the signal and send it to a master station. From there the actual location is compared to the GPS derrived location and an error value is determined. This in turn is sent up to two local satellites that send the correction signal to us. LAAS (Differential GPS): (Local Area Augentation System) is a ground based VHF system also run by the FAA. This system again uses very accurately located GPS receivers which send their position information to a local computer that calculates the error and trasnmits it to GPS receivers within a 30 mile radius. Differential GPS can also be done by coastal based receivers for maritime use but both Aviation and Maritime systems are typically subcription based, and requires a special Differential VHF receiver. Some of you may have seen surveyors out there with GPS receivers. These are typically Trimble GPS units and the acuracy is claimed to be around +/- 20mm H/V (or just a little under and inch off). Here's the FAA Website for the GPS programs they are running right now. Cheers! -Tim | ||
| niles steckbauer (Niles500)
Rating: N/A |
If you know any on who needs a 12 volt WAAS differential beacon reciever - I gots one - never used Magellan - FWIW | ||
| Chris 85 RTS Rating: N/A |
I have the same setup. It was able to show me which lane of a 3 lane highway I was in. |