Lowrance GPS Question?

Have a few Questions for the ones running there Lowrance units, How slow does the GPS show movement? On my Humminbird units I have to be moving way faster then I need to be when fishing a spot that is pinpoint dead on. Was about ready to throw the Matrix 97 off the boat yesterday. When fishing a key spot that is about as big as a car, Its just way to much of a hassle to stay on those spots.
I know throw out a marker. But when your fishing around other boats and there not catching fish. I don't want to mark them for others. Now I can take my Garmin Hand held and it updates as soon as the boat moves allowing me to know what way to move to get back on top of this single rock thats holding fish.
Been running Humminbirds for a lot of years, started out with a flasher then the first LCD screen they came out with. Always told my self I would not swap. But with Lowrance having it where everything can be shared between both the front and back units. Plus if there GPS will show the boat moving at less them .07 MPH I may be saving my copper for 2 new units. I thought with the Bass Boys drop shotting so much. Humminbird would figure this out and fix there units where they allow us to stay on a spot.
Lost in Pickwick because of a GPS that shows a donut until your moving way faster then I can and still catch fish..

Nothing is going to show you moving at .07MPH. Maybe you meant .7MPH?

The problem with any GPS indicating location at that kind of speed is that you are moving far less than the GPS error between updates. .7MPH is about a foot a second, and consumer GPS isn't accurate enough to even tell which direction you moved.

The GPS error can easily change by a quarter foot per second, even with WAAS and good satellite views, and can be much worse than that in poor reception conditions. That means the GPS is telling your chart that you are moving around in random directions all the time, and the chart display algorithm has to ignore those small movements in order to keep the cursor from dancing around rapidly.

There are some processing tricks that can let the chart track steady movement, but if you make a sudden change with the TM, your position could be way off for a short time. In order to really solve the issue, an inertial measurement system needs to be included in the hardware so the chart would find out where it was from the GPS, and then constantly get feedback on which way it is moving from the IMS. They are coming down in price and size, so you will see it someday.

The old 2000/3000 antennas were terrible at very slow speeds, the 4000 (newest model) is not that bad.I believe it was 5x per sec update. I can get over the waypoints pretty quick.

I could'a swore that my Elite 5DSI GPS said I was moving at 0.5mph ... when I was playing with it on the lake, the ONE time I've been able to take it out & use it. I'm pretty sure I was under TM power, at the time, and not just drifting with the wind (or after taking my foot off the TM switch). I could be wrong, but I remember it being a pretty slow speed that was registering .. and I was impressed with the fact that it even registered.

... cp :cool:

I agree with Catfan. Marine inertial navagition systems aint cheeeeep. I worked on airborn inertial navigation systems in my oher life.

Check out Iphone apps for INS. Don't know how accurate they migh be.

The lowrance with LCG4000 external will track below .4mph as long as you are heading in a relative direction. Sudden changes causes hesitations in position on the map as described by Catfan. Takes the processor time to figure things out. You can add a Fluxgate compass to the nmea2000 for about 800 bucks. It shows which way you are heading instantly and don't care much about you speed.

Ment to add that Interphase Inc. makes a foward loooking sonar that could hlep.

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Originally Posted by CatFan

Nothing is going to show you moving at .07MPH. Maybe you meant .7MPH?

The problem with any GPS indicating location at that kind of speed is that you are moving far less than the GPS error between updates. .7MPH is about a foot a second, and consumer GPS isn't accurate enough to even tell which direction you moved.

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Sorry that should have been .7, But its funny that my hand held can do what a $2000. unit can't even come close to.
Also why can my Hand held show me moving and hold me over a spot the size of most peoples boat. But these units costing 5x more can't?

Guess I just need to do like I did years ago. mark spots on the bank in 3 spots and stay on a ledge in the middle of the lake. Rather then try and use this stupid stuff that can't even tell me I'm on water. Half the time both the 987c SI and the Matrix 97 like to show me up on dry land.

There is a long, long post on here about the donut in HB units. My HDS keeps me on my spots and works down to .4 mph. The Elite 5 that i sold had the same issue as HB, Lowrance's tech told me the HDS and Elite series use different GPS systems.

To really, really stay on top of a brushpile, I think you have to use a marker buoy. Personally I'd rather keep my eyes on the water and my fishing line, rather than back and forth between the line and a GPS. Paint your marker buoys grey, so they aren't so obvious. I also agree the Garmin GPS system is pretty dang good. My 498C is probably 6 or 8 year old technology, and it's dead on getting there. I never rely on it to keep me over a brushpile though.

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But its funny that my hand held can do what a $2000. unit can't even come close to.

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That's true. I always carry my Garmin handheld. I am ordering a ram mount for it.

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Originally Posted by Tracker123

That's true. I always carry my Garmin handheld. I am ordering a ram mount for it.

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I got a Garmin in my tote bag as a backup, but I am pleased with this LCG4000 external Lowrance. It is pretty accurate, but it was a $200 add on to a $2000 almost worked HDS.

:)i have a garmin gpsmap 76csx that i use while fishing and i do like it a lot.but that being said ive found that a commend old little rock that i though down on the ground and then marked a waypiont in the same spot was smarter than the gps. all im saying is that unless you want to pay alot more money i dont think that you will be able a achieve what your wanting unless you use a marker.sorry

I have 2 lowrance and like them ,however I can park on the bank and it will move like I am moving,only way to stay on a small spot is with a marker, thats how I jig over brush

My $3000 HB 1197 "donut" tastes like lazy software programmers...

Rickie

http://www.youtube.com/watch?v=4C3O93OBpJE

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Originally Posted by rnvinc

My $3000 HB 1197 "donut" tastes like lazy software programmers...

Rickie

http://www.youtube.com/watch?v=4C3O93OBpJE

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in this video all of the units are showing coarse readings. the humminbird is reading coarse with the donut .the others with the triangle.if you will look they are all pionting in different dirrections because of the boat going so slow.if he were to speed the boat up thin they all will piont in the same direction . slow back down the same thing will happen.all im asking is look at the video and see. find the best gps expert you can and ask.gps in this range cannot do what you are asking.yes it is possible but not with the tecnology that were using.$$$$$$$$$$$$$

Lowrance HDS owners laugh at our HB "Donut"....

Rickie

Rickie, sent you a PM. The horse died quite awhile ago.

GPS satellites have a small wobble, that, coupled with magnetic interference, frequency interference, weather iterference, reflective interference, etc. mean that there are limitations on their accurace. Even with WAAS, the accurace is only about two meters. Any manufacturer who claims more accuracy than that is exaggerating the ability of their unit. These are limitations of the satellite system, not the receivers we mount on our boats. Nothing these manufacturers do can fix the errors in the satellite system.

Good stuff Ricky. And you don't know where you are going with the donut. The horse will die when they fix it. The new update makes the screen look like an HDS, so maybe the donut will be next. We can only hope.

Do we really have to go through this again? Someone please answer genec's question..


http://www.crappie.com/crappie/fishi...estion-di.html

I know where I am going because I have a Garmin backing up my Lowrance & HB..:)

ShilohRed, watched a video on computer a while back. This Guide in Ohio showed a trick he uses to mark spots and keep low profile. Take some 1in pipe insulation, cut off a 2 or 3 in piece and uses a half ounce weight to anchor it. They were pretty hard to see with the camera guy just looking for them. But if you new general area they were obvious enough to stay on your spot. Lot cheaper than buying new GPSs.

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Originally Posted by Don G

Do we really have to go through this again? Someone please answer genec's question..


http://www.crappie.com/crappie/fishi...estion-di.html

I know where I am going because I have a Garmin backing up my Lowrance & HB..:)

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:yikes:yikes:yikes

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Originally Posted by FAADAN

GPS satellites have a small wobble, that, coupled with magnetic interference, frequency interference, weather iterference, reflective interference, etc. mean that there are limitations on their accurace. Even with WAAS, the accurace is only about two meters. Any manufacturer who claims more accuracy than that is exaggerating the ability of their unit. These are limitations of the satellite system, not the receivers we mount on our boats. Nothing these manufacturers do can fix the errors in the satellite system.

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I think a lot of people are fooling themselves into thinking their GPS is spot on, every time. I've owned Garmin, Lowrance, and Hummingbird, with each one I've seen the coordinates move around with the unit sitting dead still. You can have the boat sitting on the bank, and the boat indicator icon is moving around on the lake map.
I think if folks did a little test, drop a marker buoy in the water, blind themselves to any outside visuals, only the GPS screen, then see how tight they can stay to a marker buoy. I can guarantee they ain't gonna stay tight enough to keep a jig from hanging in a brushpile, and probably not stay within a 10 foot radius.

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Originally Posted by Shellback

I think a lot of people are fooling themselves into thinking their GPS is spot on, every time. I've owned Garmin, Lowrance, and Hummingbird, with each one I've seen the coordinates move around with the unit sitting dead still. You can have the boat sitting on the bank, and the boat indicator icon is moving around on the lake map.
I think if folks did a little test, drop a marker buoy in the water, blind themselves to any outside visuals, only the GPS screen, then see how tight they can stay to a marker buoy. I can guarantee they ain't gonna stay tight enough to keep a jig from hanging in a brushpile, and probably not stay within a 10 foot radius.

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This is true. However, ff you really gotta need to stay on a brush pile with a gps, get a Trimble handheld. It keeps you within an inch of your waypoint.

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Originally Posted by Shellback

I think a lot of people are fooling themselves into thinking their GPS is spot on, every time. I've owned Garmin, Lowrance, and Hummingbird, with each one I've seen the coordinates move around with the unit sitting dead still. You can have the boat sitting on the bank, and the boat indicator icon is moving around on the lake map.
I think if folks did a little test, drop a marker buoy in the water, blind themselves to any outside visuals, only the GPS screen, then see how tight they can stay to a marker buoy. I can guarantee they ain't gonna stay tight enough to keep a jig from hanging in a brushpile, and probably not stay within a 10 foot radius.

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That is true. The Satellite sytem has a margin of error that cannot be overcome by any receiver.

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Originally Posted by FAADAN

That is true. The Satellite sytem has a margin of error that cannot be overcome by any receiver.

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what about L5?

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Originally Posted by Cane Pole

This is true. However, ff you really gotta need to stay on a brush pile with a gps, get a Trimble handheld. It keeps you within an inch of your waypoint.

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You mean this one Tom, Trimble® GPS | GeoXH Handheld | GeoExplorer 6000 I see it's only $7,695.00

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Originally Posted by Shellback

You mean this one Tom, Trimble® GPS | GeoXH Handheld | GeoExplorer 6000 I see it's only $7,695.00

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Yep.

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Originally Posted by Cane Pole

Yep.

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We will have to see how deep Don's pockets are. Maybe he could be the guinea pig tester.

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Originally Posted by Shellback

Rickie, sent you a PM. The horse died quite awhile ago.

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The horse is never dead until HB forces RGecy to remove the "donut" from the HB wish list... ALL SI Models - Unit loses GPS signal at slow speeds - Below .6 mph

Then, and only then, will I give up on HB listening to their customers thru the HB "wish list"...

Maybe all the people who do not believe in HB's "wish list" function of "listening to their customers" should start a "movement" and contact HB with requests to remove the "HB Donut" from the HB "wish list" as (what you say) is a technological impossibility....

(Lowrance would be grateful for the added sales...)

Rickie

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Originally Posted by rnvinc

The horse is never dead until HB forces RGecy to remove the "donut" from the HB wish list... ALL SI Models - Unit loses GPS signal at slow speeds - Below .6 mph

Then, and only then, will I give up on HB listening to their customers thru the HB "wish list"...

Rickie

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I went over there and read that. Saw my old pal moose1am there. He an expert on gps now. ha. He still owes me a truck. I won it fare and square.

MY Ipilot can track a course at .2mph. Stays on the recorded track pretty good too. Wonder how it does this if the accuracy is just 3 metres only 95 percent of the time. Must be something in the algorithm section of the track program. haha DLOP. Just something to ponder fellers. I don't have a HB so I have no futher comments. MIght get one next week though if it is a good deal.

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Originally Posted by rnvinc

The horse is never dead until HB forces RGecy to remove the "donut" from the HB wish list... ALL SI Models - Unit loses GPS signal at slow speeds - Below .6 mph

Then, and only then, will I give up on HB listening to their customers thru the HB "wish list"...

Maybe all the people who do not believe in HB's "wish list" function of "listening to their customers" should start a "movement" and contact HB with requests to remove the "HB Donut" from the HB wish list as a technological impossibility....

(Lowrance would be grateful for the added sales...)

Rickie

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Is that the thread with 1306 views, and only 16 replies? Hmmm? Why would they "force" RCegy to remove the post? Doesn't sound like that many H/B owners are concerned about it.

People get mad about the donut, but with all the HDS features on the HB wish lists you'd think that would create a stink. I guess if you loyal to just the name, you could always just put a sticker on the other brands unit.

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Originally Posted by Cane Pole

what about L5?

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L5 is at least several years out. Even L2 can't give you high accuracy and rapid updates like would be required to see constant slow speed updates.

I kind of think somebody will integrate this little guy with a GPS and make something really nice.

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Originally Posted by CatFan

L5 is at least several years out. Even L2 can't give you high accuracy and rapid updates like would be required to see constant slow speed updates.

I kind of think somebody will integrate this little guy with a GPS and make something really nice.

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I thought L5 was coming 2014? I know they are putting sats up and running them tandem to then existing ones. But, it is the government deal.


Interesting little feller there on that link. I wish I could live forever, but I have seen so much and been part of so much technology. Hard to let it go.

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Originally Posted by Cane Pole

I thought L5 was coming 2014? I know they are putting sats up and running them tandem to then existing ones. But, it is the government deal.


Interesting little feller there on that link. I wish I could live forever, but I have seen so much and been part of so much technology. Hard to let it go.

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It depends on a lot. It takes 24 L5 satellites to begin using it. If the European sats and US sats work together and IF enough of them get launched and IF somebody markets a dual freq receiver, it could be as early as 2014. 2018 is a better guess, because it then there will be enough US sats to run the system. Earlier in its life, the only receivers available probably will be dual-band L1-L5 and will probably be too expensive for fishing boats. But I never imagined I'd see the day that fishing boats would be running $5000 worth of electronics either!

Hello all, my first post here, I got hooked on this site buy the poor mans i-pilot post.

Airmar has the GH2183 GPS & Heading sensor at least it is only 750.00.

I think i-pilot uses very similar setup to the airmar and that is how it can follow a track so closely. I think with the accelerometers and the e-compass you can have additional parameters to incorporate in to the dampening algo's. If you are very confident of where you are now and you get indication you are somewhere else that is not backed up with accelerometers and the e-compass data wait a second (or part there of) till all 3 jive. Street GPS's do this with a road reduction filter, a reference DB of highly accurate surveyed road positions.

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Originally Posted by CarolinaJim

Hello all, my first post here, I got hooked on this site buy the poor mans i-pilot post.

Airmar has the GH2183 GPS & Heading sensor at least it is only 750.00.

I think i-pilot uses very similar setup to the airmar and that is how it can follow a track so closely. I think with the accelerometers and the e-compass you can have additional parameters to incorporate in to the dampening algo's. If you are very confident of where you are now and you get indication you are somewhere else that is not backed up with accelerometers and the e-compass data wait a second (or part there of) till all 3 jive. Street GPS's do this with a road reduction filter, a reference DB of highly accurate surveyed road positions.

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It just want work with my HDS.

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Originally Posted by Cane Pole

I went over there and read that. Saw my old pal moose1am there. He an expert on gps now. ha. He still owes me a truck. I won it fare and square.

MY Ipilot can track a course at .2mph. Stays on the recorded track pretty good too. Wonder how it does this if the accuracy is just 3 metres only 95 percent of the time. Must be something in the algorithm section of the track program. haha DLOP. Just something to ponder fellers. I don't have a HB so I have no futher comments. MIght get one next week though if it is a good deal.

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The quote from Tom above should tell something about this "donut" conversation....

I can understand people not agreeing with my opinions... I'm no expert on these things...

But if Tom says there is technology that will track down to 0.1mph, and he has proof of it...in his electronics...

Why do people keep discounting this possibility that the technology exists for a HB unit to track below 0.5mph...??

Rickie

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Originally Posted by Cane Pole

what about L5?

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I worked with the FAA for many years. I worked on WAAS and GPS design. I retired in '06. As of that time, there was no GPS receiver, even WAAS enabled that could completely eliminate satellite and interference related errors. There is even a worm that wanders around the atmosphere that interferes with GPS accuracy. The faster you are moving, the more accurate it becomes and the slower you are moving the less accurate it becomes. If you are moving extremely slow, you are much more subject to the error. Receivers can average out readings by taking multiple samples and averaging the differences but the error is still there. WAAS uses a stationary antenna at a known location and transmits differential signals that help to compensate for the satellite wobble, drift, intentionally induced errors. (Yes, the military can make GPS totally useless if they want) Even with the WAAS input, there is some error left. Until you can account for such things as reflections, atmospheric interference, electromagnetic interference, and someone getting between the receiver and one of the satellites, you will never have a unit that depends solely on a satellite for it's location.

I worked with Inertial Nav systems in the Air Force and while they are quite accurate, they are mechanical. The usually consist of gyros and accelerometers. Each is a mechanical device and as such is subject to friction and wear.

It appears to me that Humminbird is simply admitting when it is not able to provide precicse data by displaying a circle. Lowrance just makes you feel good.