Should I update my GPS?

“If you're interested in checking current Declination from any point in the U.S., you ought to Check this out.

Hope I did this right...
last edited: 9/20/07 8:42:00 PM”

“After checking various points along a planned route in SEKI next June, I've learned the Declination changes about 6'W each year, according to the site linked in my previous post.

I suppose getting this far into it might be viewed as somewhat anal, but what the hell... it's cool to know, and even cooler to use that knowledge effectively. Like Cowboy-Up, and Man-Up, I'm gonna "Trail-Up".

Who's with me?”

“Hello?

Anybody?”

“Where'd they go?

Hey, that's pretty cool...

        Declination = 5° 57' W changing by 0° 4' W/year”

“Yeah thanks for the link Obi, very useful indeed. Just another excuse for me to not use a GPS.”

“I still use a Garmin 12. It does not rely on magnetic declination.”

“Actually, Sticks, the link is most useful for those who DON'T use a GPS... in point-of-fact, declination relates to employing a map and compass, for as bacpac's post implies, a GPS doesn't rely on it.

Perhaps I should say something here for all those who might think me a gear head unable to appreciate the simplicity of navigating with map & compass:

I agree. Using map AND compass is more a means of using and testing one's skills at navigation and map reading, taking and following a bearing, and arriving - with accuracy - at your destination. There would be no greater skill I could master than to navigate so effectively without the use of technology which only adds to my weight concerns, and detracts from a more "natural" approach.

It may well be - for me, as well as those who consider GPS an effective tool - that in the absence of having good navigational skills, a GPS allows more people to enjoy the wilderness, grants them access to appreciate the skill required to evolve to a more natural mode of travel, and thus, I would argue that a GPS ENCOURAGES people to take greater interest in navigation, and in developing their map-reading skills.

I would further argue that the more persistent the use of GPS (for some, anyway), the more likely they would WANT to develop their skill at navigation. Indeed, it seems to me, their reliance on GPS would diminish, most likely, with its use relegated to less frequency, and more for confirmation that one's navigational prowess requires less and less reliance on technology. Just as the internet opened a huge new world of communication options for those who now take it for granted every day, so too has GPS opened a new world for those previously foreign to it.

This, in turn, permits greater appreciation for the beauty of the environment we use such skills to explore.

I sincerely enjoy the more natural approach, and button freak that I am, GPS allows me the opportunity to move closer TO that, all evidence to the contrary.

I hope I've made myself clear.
last edited: 9/22/07 7:06:40 AM”

“I use a GPS, because it is vastly superior to map and compass navigation.”

“obi wan canoli.............I appreciate the link, I also use a formula I learned in the Military. I am in the market for a Garmin 60Csx and will incorporate this technology with my Compass and Map skills.
Knowing how to read a map and apply it correctly is the only way to Navigate, Knowing what the declination angle is in relation to the current year is vitaly important if you want to be serious about map reading.
I prefer to take compass and map reading very serious. I have learned that knowing how and applying, especially in long distance backpacking in areas where there are no trails, is vital. Most who hike these days are always on a trail, All you need to know is how to read with the basic navigational skills. When navigating off trail in a area you have no prior experience.....you need to know how to navigate with precise accuracy, or you are lost before you start.”

“Thanks for the kudos... think I just stumbled across the site, looking for more info., and it's brought another question I'd like an answer to (if there is one)...

My TOPO! software permits, of course, a choice between using UTM, or Lat/Long. Among the latter, there are additional options which allow the choice of the standard A) degrees.minutes.minutes, B)degrees.minutes.seconds, or C)degrees.degrees

UTM seems to be the prevailing favorite, and if it isn't, it's getting more attention these days than when I first bought this software in '99...

Which is more accurate? Which do you use, and why? Is UTM simpler to use due its [Metric] decimal system approach? And in coordinating the use of TOPO! with my GPS, does one approach yield greater reliability over another?

Thanks!”

“I'm sure many readers here are thankful to you, bacpac, for putting me on to a site that should occupy most of my waking hours to peruse, thus keeping me and my postings off of TT...

Thanks for the link!!”

“It seems the lack of a response to my UTM/Lat/Long question is an answer in itself, eh?

Does anyone have any idea, or is it so insignificant that it ain't worth posting?

Or, is it my breath? Maybe I oughta shower more than once a week?

Orrrrrrrr.... nevermind.”

“Sorry Obi I didn't see the question. You need to match the Map Datum and Format to the map you are using. The Map Datum and Format should be listed on the map. They are all accurate and the GPS will handle all the conversions.

If you are manually entering coordinates you need to pay attention, because entering WGS 84 coordinates into a GPS set to NAD27 will put you close, but not where you need to be. If you import coordinates via a utility like Easy GPS it will do all the conversions for you.

USGS maps are Nad 27/UTM. I like UTM, because the scale is in meters. I can identify my distance from an object by taking the difference between the coordinates.

Degrees, minutes, seconds are angular measurements, not distance. GPSinfomation.net should have articles on the differences. Keep reading.”

“Oops, I missed your Q too. What I like about using TOPO! with my Etrex (and it's likely to be similar with other programs) is that you don't have to worry about which datum you're on when transferring waypoints, as long as it's the same for both things. Additionally, what I will do with TOPO! is use the function that prints a grid on the map - I do a 500x500m grid on UTM coords. It makes it real easy to estimate distances just by glancing at the map, and if you accidentally delete all your waypoints and have to re-enter them for a XC route in the field (not that I would have ever done that, of course!), it's easy to get the coords to enter.”

“Thanks, bacpac... that's a good site, lots of info., and helpful too.

Your response prompted me to check my GPS setting for the map datum. Good thing, too... my TOPO! was set differently. Both are now coordinated, so that should prove a bit more accurate.

Would you suppose the waypoints I've created and saved in TOPO are similarly off a bit? Seems to me that would be the case, and thus, would necessitate their deletion and then enter them once more, correctly.”

“If you manually entered the waypoints they will be off. If you downloaded them with EasyGPS or some other transfer protocol they will be OK. The data string includes the map datum.”

“If I made a map from my house and marked grid lines every mile it would look like..

1N, 1E, 1S, 1W
2N, 2E, 2S, 2W
3N, 3E, 3S, 3W...etc.

So 1.5 mile North and 1 mile East from my home would be at coordinates (1.5N, 1E bacpac datum).

If you lived in Memphis and made a map from your house using the same grid structure the same location would be at(75S, 150W Memphis datum).

That is why you would need to know which map datum is used when you enter coordinates.

NAD27 and WGS84 are the most common map datums. They don't use the same grid system, but they are close and they are off by different distances depending on location.”

“hey dude, you married?”

“
Accused speeder to cops: My GPS proves your radar gun is wrong
by Ken Fisher | Published: October 26, 2007 - 10:27AM CT

GPS-based tracking devices don't just help you figure out where you are and where you're going, they might also help you avoid a speeding ticket. Shaun Malone of California is contesting a speeding ticket in that state by arguing that his GPS-based tracking system shows that the officer's radar gun was wrong.

Malone, a 17-year-old who was clocked doing 62 MPH in a 45 MPH zone on July 4 of this year, has more than just a GPS on his side. As the AP reports, his stepfather Roger Rude is a retired sheriff, and is pushing Malone to fight the ticket. (As an aside, how awesome would it be to be Sherriff Rude?)

Ironically, Malone's parents had the GPS system installed in order to track the whereabouts and speed of their son, whom they readily admit has a lead foot. In fact, he has already been grounded for having gone over 70 MPH after the GPS was installed. Nevertheless, Malone's parents say that the data on the day in question shows that their son was not speeding in the vicinity of where the ticket was issued.

While many GPS systems don't log travel details extensively enough to be used as a defense against a moving violation, Malone's car was outfitted with a device that could do just that. According to Rude, all recorded plots on Malone's route show him to be driving under the speed limit. At the same time, Rude says, GPS-systems are clearly more reliable than radar systems, which, while good, are "not an infallible tool" and are subject to human error.

”

“HMMmmmmmmm.

Something like this could've saved me some bucks over the years  (provided that it didn't show I was going *faster* than the radar gun indicated,    LOL).”

“Yeah, I was always guilty.”

“Wonder if that would work in a court of law?”

“Click on the title and check out the rest of the article....”

“I found it easier to "pay" for a speedometer test to "discover" that my speedometer was reading incorrectly. Improper equipment ticket is a non moving violation thus doesn't increase your insurance.”

“data on the day in question shows that their son was not speeding in the vicinity of where the ticket was issued

note they did not say he was not speeding. they said he was not speeding "in the vicinity of where the ticket was issued."

i'll take the word of a police officer trained to use a calibrated radar detector over a punk with a record of speeding whose character is obviously so questionable that his parents have to install a GPS in his car to track his whereabouts.”

“http://gpstracklog.typepad.com/gps_tracklog/2007/08/more-on-the-mag.html

New Magellan with the ability to download NG Topo Maps, now we're talking!”