What's the lowdown on GPS units?
Question:
Probably been discussed a million times here but… I was wondering what’s the current feelings on GPS units? 1) Are they worth it? 2) Will the $200 Magellan do fine, or is a more expensive unit neccessary? 3) Any brand considered better than the others? 4) Any brands ot definitely avoid? Any help, opinions, experiences would be appreciated. I’m thinking about getting one next year. ==Jim McGuigan Power Switching & Conversion Systems== ==Hanover, PA Baltimore / Washington Field Service== == == ** Especially for the oversensitive moron on USENET: ** ** GOD, COUNTRY, NOTRE DAME **
Response:
: Probably been discussed a million times here but… : : I was wondering what’s the current feelings on GPS units? : : 1) Are they worth it? : 2) Will the $200 Magellan do fine, or is a more expensive unit : neccessary? : 3) Any brand considered better than the others? : 4) Any brands ot definitely avoid? : : Any help, opinions, experiences would be appreciated. I’m thinking http://www.fys.uio.no/~kjetikj/fjellet/GPS1.html http://www.nmaa.org/navtech.com/garmin.htm#gar40 self.Hunting buddies of mine have the Garmins and love them.Vey helpful during bow season.You can track without fear of getting lost in big woods.Some of the holes I hunt are big and its easy to get turned around after dark. As I learn more about them,my buddies that hunt and fish,hanglide love the Good Hunting David — + + + "No free man shall ever be debarred the use of arms. The strongest + + reason for the people to retain the right to keep and bear arms is, as + + a last resort, to protect themselves against tyranny in government. + + – Thomas Jefferson, proposed Virginia constitution, June 1776. + + 1 Thomas Jefferson Papers, 334 (C. J. Boyd, Ed., 1950) +
Response:
= Probably been discussed a million times here but… = = I was wondering what’s the current feelings on GPS units? = = 1) Are they worth it? Depends upon your point of view. They are handy. = 2) Will the $200 Magellan do fine, or is a more expensive unit = neccessary? Do spend some time in the newsgroup, sci.geo.satellite-nav, before you buy the Magellan. Incidentally, according to a recent card from Navtech, Garmin now have a new, lower-cost, model, the GPS-38 (or maybe it was GPS-39, I can’t find the card, now) for just under $200. = 3) Any brand considered better than the others? See also earlier posts about the Eagle Accunav Sport. = 4) Any brands ot definitely avoid? See earlier comment about reading sci.geo.satellite-nav. = Any help, opinions, experiences would be appreciated. I’m thinking = about getting one next year. — Best, Charlie "Older than dirt" Sorsby "I’m the NRA!"
Response:
writes: >: Probably been discussed a million times here but… >: >: I was wondering what’s the current feelings on GPS units? >:
A hunting buddy totes a Magellan 45 (I think). It’s been helpful sometimes, but a real pain in the ass other times. It’s more precise than my (pretty good) compass work, but not nearly as reliable. The big problem seems to be frequent difficulty (maybe 25% failure) acquiring four satellites. That problem, the pal alleges, has to do with high altitude…which makes no sense at all to me. So my question is this: If somebody’s really skilled at using a GPS (I’m assuming that I can blame my pal for being inexpert), can you count on it most of the time? 75% is far from adequate, in my book. This is a tempting technology, but it is really irritating to interrupt hunting attitude while somebody struggles with the gizmo. Or is this problem one that has to do with the operator or the specific GPS? Anybody else with high-altitude GPS problems? JK
Response:
> So my question is this: If somebody’s really skilled at using a GPS > (I’m assuming that I can blame my pal for being inexpert), can you > count on it most of the time? 75% is far from adequate, in my book. > This is a tempting technology, but it is really irritating to interrupt > hunting attitude while somebody struggles with the gizmo.
Don’t blame your pal. Blame his machine. I don’t know too much about the Magellan 45 (isn’t it a Garmin 45?), but I’ll bet it isn’t a parallel-channel receiver. Most older GPS units and most cheaper ones can only "look" for one satellite at a time. Once the unit locks on to a satellite it receives almanac data and knows where to look for the other satellites. Once a set of satellites are tracked it flips through the set for about a second on each one. Almanacs are good for about a week. If your single channel unit is off for more than a week or you move a long distance with it off you have to start all over (cold start). It can take over 10 minutes to get a full almanac so if your unit is only a single channel receiver and your almanac is old or bad, you can expect 10+ minutes to get a fix. When you and your hunting buddy don’t get a fix, are you both standing between the antenna and the sky? Are you leaving it on for 10 minutes? Are there a lot of leaves on the trees above you? A parallel-channel receiver like my Eagle AccuNav is far better at getting a position fix. It uses Rockwell’s GPS chip set and can track 5 satellites at a time. I’ve never failed to get a position fix (0% failure) with it. As soon as one satellite is tracked, the other 3 or 4 lock in quickly. Usually it stays locked on the 4 best ones it can "see" and switches around on the 5th channel. The only time I’ve waited 10 minutes to get a fix is the first time I turned it on out of the box. It is never off more than a week however. Sitting on the couch watching TV it gets a postion fix in 15 seconds or so (wood roof). At work it can never get a fix (tin roof). The only problem with the parallel-channel receivers is battery usage. The AccuNav needs 6 AAs and goes through them pretty fast. So its a trade off. High battery usage vs. reliable, quick position fixes. To solve the battery problem I bought a couple of sets of Renewal batteries for hunting and a cigarette lighter adapter cable for the boat. The parallel-channel receivers also cost a little more. I view the cost problem sort of like the Dodge problem. Yes, a Dodge initially costs less but remember your first Dodge is nobody’s fault, your second Dodge is your own damn fault. > Or is this problem one that has to do with the operator or the specific > GPS? Anybody else with high-altitude GPS problems?
About the high-altitude problem. How many GPS units do you think you could sell to commercial airlines if they didn’t work at their cruise altitude? — – Matt Rein
Response:
– Hide quoted text — Show quoted text – >writes: >: Probably been discussed a million times here but… >: >: I was wondering what’s the current feelings on GPS units? >: >A hunting buddy totes a Magellan 45 (I think). It’s been helpful >sometimes, but a real pain in the ass other times. It’s more precise >than my (pretty good) compass work, but not nearly as reliable. The big >problem seems to be frequent difficulty (maybe 25% failure) acquiring >four satellites. That problem, the pal alleges, has to do with high >altitude…which makes no sense at all to me. >So my question is this: If somebody’s really skilled at using a GPS >(I’m assuming that I can blame my pal for being inexpert), can you >count on it most of the time? 75% is far from adequate, in my book. >This is a tempting technology, but it is really irritating to interrupt >hunting attitude while somebody struggles with the gizmo. >Or is this problem one that has to do with the operator or the specific >GPS? Anybody else with high-altitude GPS problems? >JK
JK– Do you happen to remember what the terrain and tree-cover was like in the places where your buddy told you his GPS was failing due to high-altitude? I’d bet most of those times were when there was a heavy canopy of tree foliage overhead, blocking the signal from the satellites which the GPS uses to determine location of itself WRT the surface of the earth. You are right, altitude should have no effect on the reliability of a GPS. But in many units, tree cover does. Chris Fulton
Response:
Anybody else with high-altitude GPS problems? > JK John,
Go to news group sci.geo.satellite-nav and you’ll learn more than you reckoned to.
Response:
= A hunting buddy totes a Magellan 45 (I think). It’s been helpful [...] = problem seems to be frequent difficulty (maybe 25% failure) acquiring = four satellites. That problem, the pal alleges, has to do with high = altitude…which makes no sense at all to me. = = So my question is this: If somebody’s really skilled at using a GPS = (I’m assuming that I can blame my pal for being inexpert), can you = count on it most of the time? 75% is far from adequate, in my book. [...] = Or is this problem one that has to do with the operator or the specific = GPS? Anybody else with high-altitude GPS problems? John, First, don’t forget to also check out sci.geo.satellite-nav; lots of knowledgeable folks there last time I checked in. As to high altitude, the only thing that I can think of that high altitude may imply is mountains that could block one or more signals. Not restricted to high altitude but something found in the mountains is forests which can attenuate the signals. The Eagle Accunav Sport has been given good marks here (in rec.hunting) in such circumstances. Something that I’ve wondered about is this: As I understand it, while 4 satellites are needed for a three-dimensional fix (e.g. lat, long, and altitude), 3 are adequate for a two-dimensional fix. If my understanding is correct, why are the GPS receivers not set up so that, if the fourth satellite can’t be locked in, it gives lat-long (or equivalent) only? It seems to me that having a two- dimensional fix and no altitude is better than having no fix at all which seems to be what you get if the fourth satellite can’t be locked in. What am I missing? Any ideas? — Best, Charlie "Older than dirt" Sorsby "I’m the NRA!"
Response:
– Hide quoted text — Show quoted text -> So my question is this: If somebody’s really skilled at using a GPS > (I’m assuming that I can blame my pal for being inexpert), can you > count on it most of the time? 75% is far from adequate, in my book. > This is a tempting technology, but it is really irritating to interrupt > hunting attitude while somebody struggles with the gizmo. >Don’t blame your pal. Blame his machine. I don’t know too much about the >Magellan 45 (isn’t it a Garmin 45?), but I’ll bet it isn’t a parallel-channel >receiver. Most older GPS units and most cheaper ones can only "look" for one >satellite at a time. Once the unit locks on to a satellite it receives >almanac data and knows where to look for the other satellites. Once a set of >satellites are tracked it flips through the set for about a second on each >one. >Almanacs are good for about a week. If your single channel unit is off for >more than a week or you move a long distance with it off you have to start all >over (cold start). It can take over 10 minutes to get a full almanac so if >your unit is only a single channel receiver and your almanac is old or bad, >you can expect 10+ minutes to get a fix. >When you and your hunting buddy don’t get a fix, are you both standing between >the antenna and the sky? Are you leaving it on for 10 minutes? Are there a >lot of leaves on the trees above you? >A parallel-channel receiver like my Eagle AccuNav is far better at getting a >position fix. It uses Rockwell’s GPS chip set and can track 5 satellites at >a time. I’ve never failed to get a position fix (0% failure) with it. As >soon as one satellite is tracked, the other 3 or 4 lock in quickly. Usually >it stays locked on the 4 best ones it can "see" and switches around on the >5th channel. The only time I’ve waited 10 minutes to get a fix is the first >time I turned it on out of the box. It is never off more than a week however. >Sitting on the couch watching TV it gets a postion fix in 15 seconds or so >(wood roof). At work it can never get a fix (tin roof). >The only problem with the parallel-channel receivers is battery usage. The >AccuNav needs 6 AAs and goes through them pretty fast. >So its a trade off. High battery usage vs. reliable, quick position fixes. >To solve the battery problem I bought a couple of sets of Renewal batteries for >hunting and a cigarette lighter adapter cable for the boat. >The parallel-channel receivers also cost a little more. I view the cost >problem sort of like the Dodge problem. Yes, a Dodge initially costs less >but remember your first Dodge is nobody’s fault, your second Dodge is your own >damn fault. > Or is this problem one that has to do with the operator or the specific > GPS? Anybody else with high-altitude GPS problems? >About the high-altitude problem. How many GPS units do you think you could >sell to commercial airlines if they didn’t work at their cruise altitude? >– >- Matt Rein
I would like to know how close you can get back to a marked spot. I am considering getting a GPS for relocating lake structure as well as hunting. — Ben Blakely
Response:
– Hide quoted text — Show quoted text – >writes: >: Probably been discussed a million times here but… >: >: I was wondering what’s the current feelings on GPS units? >: >A hunting buddy totes a Magellan 45 (I think). It’s been helpful >sometimes, but a real pain in the ass other times. It’s more precise >than my (pretty good) compass work, but not nearly as reliable. The big >problem seems to be frequent difficulty (maybe 25% failure) acquiring >four satellites. That problem, the pal alleges, has to do with high >altitude…which makes no sense at all to me. >So my question is this: If somebody’s really skilled at using a GPS >(I’m assuming that I can blame my pal for being inexpert), can you >count on it most of the time? 75% is far from adequate, in my book. >This is a tempting technology, but it is really irritating to interrupt >hunting attitude while somebody struggles with the gizmo. >Or is this problem one that has to do with the operator or the specific >GPS? Anybody else with high-altitude GPS problems? >JK
I bought a Garmin 45 from Cabela’s about a year ago. The thin work like a charm on the water or anywhere out in the open. But if I got any kind of a canopy of trees overhead, it lost its signals. It was totally, totally useless in the timber. (The reason I bought it). So I sent it back and bought an Eagle Accu-Nav. Boy what a difference. I promise I’m not lying, this thing works in my living room… it picks up 4 satellites while im sitting on my couch. The reason, I’ve since found out, is that it has a parallel receiver. Which means it has 5 or so receivers instead of one. Cheaper GPSs have to cycle around each satellite to triangulate. A parallel receiver stays locked on once it aquires a satellite. But it does cost a lot more. We duck hunt way out in flooded timber. If you’ve ever hunted in timber you know how easy it is to get lost. I used this Eagle each time we hunted there this season. It took us right to our beaver lodge each time. (and back out also 
)
Response:
: : : >writes: : >> Does Eagle have a web page???????I could not find it.I did find info at http://www.fys.uio.no/~kjetikj/fjellet/GPS1.html#buying Good site…. Good Hunting David — + + + "No free man shall ever be debarred the use of arms. The strongest + + reason for the people to retain the right to keep and bear arms is, as + + a last resort, to protect themselves against tyranny in government. + + – Thomas Jefferson, proposed Virginia constitution, June 1776. + + 1 Thomas Jefferson Papers, 334 (C. J. Boyd, Ed., 1950) +
