GPS Systems

[Hospital_Rocket]

I am looking to buy a GPS receiver and was wondering if anyone wanted to share their experience with these beasties.

1) What brand is best? The big names seem to be Garmin and Magellan.

2) How sophisticated should it be for GP rocketry use?

3) Any experience with those Bluetooth and USB connected receivers?

4) Is the mapping/color ability woth the additional money?

I've been trolling eBay and keep seeing the Magellan GPS2000 for around $50 to $75. Would this be a good investment/

Thanx

A

 

[edwardw]

I have a Garmin GPS Map 76S. No color, but it has a map on it. I also use National Geographics program for my state (has all the quad maps of the state) to plan my routes. It is mainly my backpacking GPS. I like the 'Sight N Go' feature. Lets you sight a bearing and it will keep you on track while walking toward it for a rocket. Also, I would look at one that you can attach an antenna to, they get better signal strength.

Edward

 

[bobkrech]

Al

I suggest a Garmin with a WAAS. A GPS V deluxe is a great deal for a portable mapping unit. Street pice is ~$250.

I also suggest you check out https://gpsinformation.net/ as the one stop place for GPS info in the web.

The Garmin GPS 15 is the best receiver for a rocket https://www.garmin.com/products/gps15h/

Bob Krech

 

[BHP]

Al,

I have a Garmin eTrex Vista. I like it. I use the Sight-n-Go feature for rocket recovery which draws a virtual line from where you're standing to where you see you rocket land. This aids in walking to recover the downed rocket by allowing you to get back on that line while traversing around obstacles. The technique is better described in the November '03 Extreme Rocketry magazine (issue #31).

There is also the activity of Geocaching in which you locate hidden caches using your GPS receiver and coordinates found online here: https://www.geocaching.com/
This is a fun, family (or not) activity which also helps develop skills in using the receiver.

The Vista is a bit expensive but it has the Sight-n-Go feature I wanted. Additionally, I think a GPS receiver is one of those tools that you'd wish you had spent the extra money for more features after you use it for a while.

The GPS infonet Bob K. mentioned is a great place to get info. There is a lot there.

As for "which is the best?" is a little like asking which rocket motors are best - they all have their pros and cons. I think the best solution is to decide how much you want to spend and what features you may want/need and then go from there.

Good luck in deciding!

Pete

 

[Hospital_Rocket]

While I got your attention, has anybody looked at or tried those Compact Flash (CF) adapters that turn a Pocket PC Device like an IPAQ into a GPS?

A

 

[11bravo]

Originally posted by Hospital_Rocket
While I got your attention, has anybody looked at or tried those Compact Flash (CF) adapters that turn a Pocket PC Device like an IPAQ into a GPS?

A

Nope, no one has.

As for which GPS to get, like everything else, it depends on what you plan to use it for.
If you want to be able to customize and upload your own maps (important to me), then by all means get a mapping one.
The Garmin GPSMap 76S is a great choice for this. The S at the end indicates that it has a built in barometric altimeter and a compass. Kind of odd to think really, but most GPS don't actually have a compass. They know where you are, but not which way you are facing; to get an idea of that, you have to move and they can tell you which way you are moving. Then they can display an electronic "compass".
If the alt and compass are not important to you, by looking around you can usually find the Garmins without the "S".
Color? Not important to me. May be to you if you look around and see one and just got to have it. We all do that.
External antenna? If you want to use it in you car, this maybe very important. My parent's Chevy Venture van apparently has some sort of coating on the windshield that completely blocks the GPS signal. With out an external antenna, no workie. My '89 Jeep does not. If you are only going to be hiking/walking, or boating, or 4 wheeling or something and aren't worried about the car thing, units with external antennas cost more and why?
WAAS Wide Area Augmentation System is a method of correcting atmospheric distortion of the signal to give more accurate positioning. Without it (or with it turned off) most receivers will give you about 10-15 meter accuracy, with DGPS about 5-7 meters, and with WAAS roughly 3 meters. This means if you stand at a spot in your yard and get a position fix with the GPS, that grid coordinate will be inside a circle centered on you with a radius of 3 meters, more or less. Frequently it will be a much smaller circle than that. Though it will also occasionally be larger.
I have an older Lowrance (when I got it, they were the only ones with the Military Grid system in them, and I was in the military) that I love for what it will do.
Next one will probably be a Garmin GPSMap 76.
The link to gpsinformation.net has been run for years by some guys named Joe Mehaffey, Jack Yeazel, and Dale DePriest. It is one of the most complete resources on any subject that I have ever found on the web. One could literally spend many, many hours spread over many, many days digging through there. They are great at answering questions as well, if you can't find it on their site; at least they used to be.

Greg

 

[UhClem]

I recently discovered that the Sight-N-Go feature of my Garmin Etrex Vista no longer works correctly. I believe that this is the result of upgrading the firmware to version 3.60 (I am not sure what version shipped with the unit.) It worked before I upgraded the firmware but doesn't work now.

The problem is when I select "Set Course" the course is not anchored to the current location but floats as you walk about. I think that it is projecting a waypoint 34.5 miles away and then navigating to that waypoint.

I sent an E-mail to Garmin and recieved the non-usefull response of giving the unit a master reset (four finger salute). Along with defective (three finger) instructions on how to perform the reset.

So if you own a Vista, don't upgrade the firmware if you like Sight-N-Go.

 

I have a Garmin e-trex. It's a good huntin' fishin' GPS. It also is good for rocket finding. The e-trex does not have the site-n-go feature others have mentioned, but you can still use it to find rockets.

To find rockets with it, I watch it come down, and get a bearing with a regular magnetic compass. Then, I punch the bearing in to the unit, and project a course for a mile or however far away I think it is, and walk until I find it. Easy. It will get you close enough to hear your beeper.

Last year, I flew my Executioner on a G-64, and she landed DEEP in the 8ft tall CORN a long ways off. I have lost several rockets to CORN, but not this time! My GPS walked me right to it. I most certianly would have lost it if it had not been for my e-trex. The e-trex costs about ~100 bucks, and that one save nearly paid for it right there.

 

[BHP]

The magnetic compass bearing entered into the unit also works as you well know. Another method involves watching the rocket fall and as it does line yourself up with an object between you and the point where the rocket lands. You then draw a virtual bearing line between yourself and the object you've aligned yourself with that is also on the same line as your rocket. You can then walk that line to recover.

(Boy, that is more difficult to write than to mentally visualize. Does what I've written make sense?)

I've found rockets in corn that I don't think I'd have found without the GPS receiver also. They're another tool in the arsenal.

Pete

 

[Adam Selene]

Is "Sight-N-Go" a garmin trade name? is there a similar feature for magellan units? it seams like everyone here likes garmin. i'd prefer a magellan unit and i'd like the Sight-N-Go and an electronic compass, waas and maybe an altimeter. any recomendations?

Al, did you ever end up getting one?

 

[BHP]

Yep, Sight-n-Go is a Garmin name for the feature.

All the features you are looking for are in the eTrex Vista. Can't speak for the Magellan models. My first GPS was a Magellan (purchased in '95 or '96) and it wasn't very good. That experience turned me off to the brand. I'm sure they're much better now.

 

[Daedalus]

Originally posted by Hospital_Rocket
I've been trolling eBay and keep seeing the Magellan GPS2000 for around $50 to $75. Would this be a good investment

The GPS2000 is a very old and basic model. They are also large compared to more modern designs.

I have one and it normally works OK for general use. The system only works to whole seconds whilst Geocache coordinates are to 1/10 seconds so a little guesswork/pacing is needed for the last few feet.

The key thing with the GPS2000 is it only uses 3 or 4 satelites for positioning, modern ones use 12 and so are more accurate. The GPS2000 can take some time to acquire satelites and loses lock quite easily. I would sugest only using 2D mode rather than 3D. If it does not have a good enough signal for 3D it should revert to 2D - usually it just looses lock altogether.

How were you intending to use it to locate a rocket? If it is just to keep you walking in a roughly straight line I would think most GPSs are OK. I had never thought of using it like that. I like the idea of onboard GPS to transmit a grid reference back to you, enter it into your GPS and walk straight up to the model (or at least a good position to start the search).