GPS Marks for SA

[brenton 637]

I,m not very good with the computers but i,m wondering if anyone can post the links to some of the gps sites like Marinenews.com or fishnet.com they have plenty of good general marks for SA i have them on my comp but don,t know how to post the links or is that not kosher. cheers brenton

[coonta kinta 1]

http://www.fishnet.com.au/forums/index.php?http://www.sportsfish.com.au/Default.aspThere u r brenton. Cant find the marinenews one. Had a link on the other computer but I cant seem to find on google today {SMILIES_PATH}/huh.gif

[brenton 637]

Good one Coonta I,ll try and get the kids to show me how to post the other linkshttp://www.marinews.com/fishing_gps_listing.php?sid=38#http://www.fishnet.com.au/information/gps/adela.txthttp://www.users.on.net/~abowie/wreckGPS.htm and there we go.Just remember that these marks off the net and cannot be guaranteed but will give you somewhere to start. cheers brenton

[Guest dabilda]

Just thought I'd add this one.SA fishing.net http://home.iprimus.com.au/mtaj/index1-1.htmlAlso has links to other fishing sites (including Strike & Hook) and many other topics.DaBilda

[Raw 0]

Just thought I'd add this one.SA fishing.net http://home.iprimus.com.au/mtaj/index1-1.htmlAlso has links to other fishing sites (including Strike & Hook) and many other topics.DaBilda

Flicking through that link I see under Outer Harbour the following note[The following locations require WGS 84 Systems to have an ajustment of 0.08 southward and 0.08 westward to agree with AGD 66 points below.]Are the coordinates below this note AGD66? Do I adjust these values by 0.08 southward and 0.08 westward if I am using WGS84?Could somebody please explain what this is trying to say? What should I do to use these values below this note?

[Guest dabilda]

G'day Raw,The 0.08 adjustment should be already made in your GPS settings. I have a Garmin GPS72 and there is an option in one of the settings menu's where that has been done in the factory. I put them all in as WGS84 and on my mapping software they all look pretty right.Although, to date most marks in any of the sites or books I have not yet used my GPS to get to, so I can't say how spot on they are. I find looking at my maps as often as I have I can just go out and the anchored boats tell me where each mark is. As I've said before, I use these marks as a starting point to get me in a general area, from there I rely much more on what my sounder shows than the GPS.DaBilda

[bruce 0]

They are in AGD66 if I read it right, and entering them in WGS 84 like DB did will put them approx. 200 metres out.The adjustment of .08 W and .08 S will give you the same marks in WGS 84 datum.The best way to solve your problem is quite simple. Go into settings on your GPS and change the datum to AGD66. Enter the coordinates straight in, and once complete, go back into settings, and change the datum back to WGS84. The unit will convert the marks precisely, eliminating any guess work.

[bruce 0]

Also Brenton, the way to post a link is simply right click on the web address in the browser above, and copy. Then simply paste it into word, or else straight into the post you are making.Cheers mate.

[Guest dabilda]

I stand corrected. Just re-visited and found what you meant Raw and as Bruce said, those bottom 7 are AGD66.Enter as Bruce suggested.DaBilda

[Raw 0]

Thanks now I see what my problem was as I was adjusting these coordinates by 0.08 southward and 0.08 westward as I understood the note to mean and ending up 400 metres out? The adjustment should be around the other way and after reading the note many many times it now says to me this is the adjustment that goes into a GPS set to WGS84 so as to display these coordinates once on the mark.Now isn't this the wrong way around as first the marks have to be input into the GPS to be able to find the marks in the first place.So what is the purpose of this 0.08 southward and 0.08 westward adjustment then? Why not simply say the following marks are AGD66 and leave it at that?

[Guest GNSS]

Not sure I understand why those adjustments are listed like that either? It's like putting the cart before the horse, a bit backwards?

[Guest GNSS]

Either the person responsible for that site does not read this forum or they don't understand the issues otherwise they would have changed the wording to better reflect the intent.

[bruce 0]

All it means is that the .08 west and .08 south, is the difference between WGS 84 and AGD66, which is spot on.The first marks listed are WGS84, and the second lot are AGD66.Between the two lists of marks it says "The following locations require WGS 84 Systems to have an adjustment of 0.08 southward and 0.08 westward to agree with AGD 66 points below. Just for fun, if you've got GPS software on your puter, put in the same mark in WGS84 and also in AGD66 datums. The AGD66 mark will be exactly 205 metres NE of the WGS84 mark.

[Guest GNSS]

So given that the first marks are WGS84 and the second lot AGD66 then the wording with relation to WGS 84 systems and adjustment is very obscure and frankly a waste of confusion and I must reiterate the wording is confusing.

All it means is that the .08 west and .08 south, is the difference between WGS 84 and AGD66, which is spot on.

As for .08 west and .08 south being the difference between WGS 84 and AGD66 as being "spot on" then I would suggest this is simply not the case. For this area "approx 205 metres" is about right but certainly not "exactly 205 metres" as 205 metres in no ways can be equated to 0.08 west and 0.08 south.

The AGD66 mark will be exactly 205 metres NE of the WGS84 mark.

As previously mentioned "exactly" should not be used in conjunction with the distance of 205 metres as for 1 it is not exact and 2 the difference between AGD66 and WGS84/GDA94 does varyHowever to call the "AGD66 mark will be exactly 205 metres NE of the WGS84 mark" is really highlighting how confused you are with relation to the difference between AGD66 and WGS84. For the record it is the WGS84 mark that will be approx NE of the AGD mark.

[bruce 0]

I will agree to disagree with you and stand by my comments. OK, maybe not EXACTLY 205 metres, but certainly within 5 metres, and should sufficiently address the original poster's question I reckon. Move on shall we bugs?

[Guest GNSS]

Certainly not even within 5 metres. Bruce what you need to do is address your comments not try and defend them as you are going to find that extremely difficult to do if you continue on in this manner.FYI 0.08W & 0.08S in real terms is a bit more than GPS accuracy, but certainly no even close to 5 metres.As for you standing by your comments? Are you still going to stand by your statement that AGD is NE of WGS84? You certainly need to retract that one!

[bruce 0]

Bugs/GNSS/Raw, all you have done on 2 websites now is bicker with lots of different people in GPS threads, and I honestly can't be bothered discussing this any further. Apologies Brenton, my posts to you were genuinely trying to help.

[Raw 0]

Now I'm even more confused than ever. So is AGD NE (assume that to be north-east) of WGS or is WGS NE of AGD? A lot of conflict here so which is right?

[Guest dabilda]

Now I'm even more confused than ever. So is AGD NE (assume that to be north-east) of WGS or is WGS NE of AGD? A lot of conflict here so which is right?

There is a very easy way to work this out for yourself Raw,Set your GPS to AGD66 and enter one of those marks. Then set your GPS to WGS84 (this will convert that mark to WGS84) then enter that same mark again. Once done look at your map screen and see where the 2 marks are, measure the distance between them and direction.Let us know the results.

[Raw 0]

Isn't there a simple black and white answer to this? Which is north-east of what?Who can tell me which way it is?

[Fishie 98]

You shouldn't refer to AGD66 as just AGD as this will create more problems as there is also AGD84

[Guest dabilda]

You shouldn't refer to AGD66 as just AGD as this will create more problems as there is also AGD84

In this instance the marks in question are AGD66, hence that is the datum mentioned.

[Raw 0]

DaBilda, Then for Glenelg Dredge i make agd66 205m at 216 degrees from the wgs84 equiv. Is that what you get?

[squidley 0]

group hug group hug :-)

[Raw 0]

DaBilda, Then for Glenelg Dredge i make agd66 205m at 216 degrees from the wgs84 equiv. Is that what you get?

Hang on, so if that is what i get then how come Bruce reckons agd66 is 205 metres NE of wgs84 ?? NE is totally in the opposite direction.

[Raw 0]

If i use the adjustment of .08 southward and 0.08 westward as suggested then i make adg66 191 metres at 218 degrees from the wgs84m position. So why aren't they the same?

[Guest GNSS]

Looks like some are getting the hang of it? I'm impressed.Now how about you coming back Bruce and rectify / retract your inexcusable and confusing comments. You are supposed to lead by example not totally confuse people.Will be interesting to see if Bruce actually has enough manners to do his ?

[goat herder 0]

I wouldn't bother replying either to someone who comes across as a complete PEANUT! : ;D :DHow about YOU tell us all how it works GNSS, as it's clear that you are the expert on the subject?? :icon_lol: Sounds like there's a lot we could learn from such a knowledgable individual about the subject matter at hand. Sounds like your alter-ego wants some clarification too..?? : PEANUT! :D ;D Cheers,GH

[spratrat 0]

Can't see why Bruce has been chosen to "lead by example" when all he's doing is contributing.I'd have to agree that from the mathematical ability and command of english displayed, you already know your own answers so why persist ???

[Guest GNSS]

If sprat and the goat would like to discuss the actual topic of this thread then please feel free to show your intelligence.Please feel free to review the previous material and act appropriately.Probably the major item that was being discussed was the direction that agd66 is from wgs84 coordinates and it appears that some now are not prepared to stand by or gone completely silent on their statements .If you pair feel you can contribute to what the duiscussion what about then please do so. I await your valued unconfusing input

[goat herder 0]

The topic seems to be "GPS Marks in SA. :-\ And I'll be the first one to admit I am not an expert on the subject - I've had a GPS unit for less than a year and still learning the caper. ;DYOU, on the other hand GNSS, seem to have an infinite knowledge of the subject, so perhaps YOU should explain to us all how it works, instead of sitting back and sniping at anyone who dares to offer their input. ::)I have no doubt that you are more than qualified to share with us your (up until now..) untapped knowledge and clear things up once and for all! Unless you are just full of it & unable to explain the process afterall, and you are just looking for confrontation.. :icon_e_wink: I look forward to your explanation of the subject matter at hand. 8)Cheers,GH

[spratrat 0]

http://www.hydro.gov.au/important-info/gps-chart-datums.htmGood enough ??http://www.cosports.com/index.php/tool/tools/latlongHere is a converter for those without access to a GPS or Computer :)IMO,That should be sufficient "Subject Matter" to appease any enquiring mind :)

[David Ciaravolo 34]

If sprat and the goat would like to discuss the actual topic of this thread then please feel free to show your intelligence.If you pair feel you can contribute to what the duiscussion what about then please do so.

Firstly the Actual TOPIC of this thread as started by BRENTON is and i Quote:

wondering if anyone can post the links to some of the gps sites like Marinenews.com or fishnet.com they have plenty of good general marks for SA i have them on my comp but don,t know how to post the links or is that not kosher.

It is fine to do this.AND notice that Brenton who Already Had the Marks wanted help SHARING THEM. This is what S&H is all about!!GNSS: for someone who came with the 11th word on this topic you are mightily worked up about it, especially considering the ongoing argument has nothing to do with the original topic. You may be right but it is largely irrelevant, and your approach is bordering on what is acceptable (too personal).

Now how about you coming back Bruce and rectify / retract your inexcusable and confusing comments. You are supposed to lead by example not totally confuse people.Will be interesting to see if Bruce actually has enough manners to do his ?

Bruce has no responsibility to lead by example any moreso than other forum members so this statement seems unreasonable, in addition as moderator of this section i have reviewed the post and NOTHING Bruce has said is INEXCUSABLE; if an error was made it will be considered a mistake and not an intentional act to mislead.NOW I AM NO EXPERT ON GPS & MAP DATUMS however this is how i see it;WSG84 and AGD66 are DATUMS for MARINE CHARTS - Conversions are required when wishing to plot the positions onto a Chart, for example now GPSs normally reference horizontaly using the WGS84 datum and many (older) charts are in AGD66 (WSG84 & AGD66 are different spherical measures of the earth). Positions recorded on your GPS or (from a website) in WGS84 will need a conversion in order to be referenced on a ADG66 Marine Chart. The Chart will inform you what degrees of change are required in order to reconsile your WGS84 data correctly.If you are using the GPS for Navigation Solely (not using a chart,), Storing the Position in your GPS reciever with the correct corresponding datum selected should allow you to find the spot, so I fail to see the relevance of working out a conversion for your GPS, as most units will alow you to choose the Datum to use. For Further info visit:http://www.amsa.gov.au/Shipping_Safety/Navigation_Safety/Positions_and_horizontal_datums_on_paper_and_electronic_charts/FINALLY this is not the place to criticise the AUTHORS of OTHER WEBSITES. Take it up with them in PRIVATE. Also take up Private issues with other members (regarding responsibilities and integrity) via Personal Messages, that way you get to say your piece and work out your differences with dignity.Sorry for this Brent, but i this this post was hijacked long ago!

[Guest GNSS]

Yes and pity when it was hijacked that the info provided was incorrect but then some people apparently are prepared to accept this.So come on you lot at least if you stuff up then have the manners to fix it as otherwise somebody might actually think you know what you are talking about and in cases like this this is far from the truth.

[Guest GNSS]

As mentioned previously the wording of WGS correction should be rectified as it is misleading and also it is not correct. Now if users here are prepared to post these other sites then obviously they will come into the discussion and especially in this case as there certainly is some modifications to be made so as to be less confusing and second actually use the correct numbers.