GPS & Map Reading

Submitted: Wednesday, Feb 18, 2004 at 08:03

ThreadID: 10613 Views:2372 Replies:6 FollowUps:4

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Brent.n

Hello everyone, i am interesded in leaning more about GPS and map reading techniques, are ther any courses that i can do around sydney or step by step outline on the internet.

Thanks

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Reply By: Kiwi Ray - Wednesday, Feb 18, 2004 at 09:04

Wednesday, Feb 18, 2004 at 09:04

Hi Brent
Try a boating navigation book
you will need to set up the GPS to the Aussie grid system I am not sure what the number is Aus68?
I use true north and track up on mine
Ray

AnswerID: 47171

Reply By: Member - Anne - Wednesday, Feb 18, 2004 at 09:12

Wednesday, Feb 18, 2004 at 09:12

Hi Brent,
You can buy an excellent book from the Exploroz shop called GPS Vehicle Navigation in Australia. I have seen the course material for a GPS course, and this book is clearer and easier to understand. Probably cheaper than a course too!
Happy navigating!

AnswerID: 47172

Reply By: Member - Cocka - Wednesday, Feb 18, 2004 at 10:45

Wednesday, Feb 18, 2004 at 10:45

Go for the book ' GPS Navigation in Aust ' - it's excellent & easy to understand. Available here on Ex Oz
He explains the whole satelite system, maps, GPS, computers, navigating etc - facinating stuff.

I have the Garmin II Plus GPS receiver and have just fitted an external aerial to the vehicle and wired in a continuous power suppy cigy socket so that when turning the ignition off I don't shut off the GPS, it only draws milli amps. The receiver does take batteries but they soon burn up if you forget to turn it off. I also use the same GPS on my boat for fishing off shore. It is referred to in the above book and I also recomend the Garmin as it has all the bells and whistles to do the job properly.

Geoscience Australia also produce a small comprehensive "Natmap" Map Reading Guide - How to use Topographical Maps for $2.oo. Try : www.ga.gov.au

Map World in Willoughby Rd, Crows Nest also worth a visit.
Good luckCarpe Diem

AnswerID: 47179

Reply By: Mike - Wednesday, Feb 18, 2004 at 12:28

Wednesday, Feb 18, 2004 at 12:28

Brent.n
a trap for young players is when taking readings(Lat and Log) from maps they usually use a co ordinate system AUS66. and GPSystems use as a default the WGS 84 system. To this will give an error in readings of approx .07 West and .09 South, or approx 160 meters in both directions.
regards
Mike

AnswerID: 47187

Follow Up By: Member - Cocka - Wednesday, Feb 18, 2004 at 15:05

Wednesday, Feb 18, 2004 at 15:05

Yep, this is correct Brent. But all will be revealed in the book if you buy it.
They also talk about the UTM - universal transverse mercator - grid system which is so much easier than lat/long and should be part of good GPS receiver software. Trouble is not many maps use it except for the topo maps.
WGS84 (World Geocentric System 1984) is the world wide standard now adopted in Aust. but most Aust maps will now show the GDA format of 1994.
The old AGD66 system on some maps varies from the UTM grid (measured in meters) & GDA (measured in degrees,mins,secs) co-ordinates by approx 200 mts in a north easterly direction (which is what Mike said).
CheersCarpe Diem

FollowupID: 309173

Follow Up By: Roachie - Wednesday, Feb 18, 2004 at 15:47

Wednesday, Feb 18, 2004 at 15:47

Cheeeeez......
UTM............WGS84..............GDA...............AGD66

Now I remember why I gave up trying to understand my Etrex!! However, it does sit quietly on the dash, plugged into a 24/7 cigi socket on the A pillar ready to tell me my speed and direction!!

One of these days I might get my big fat head around what all that stuff means..... It just seems to me that none of the maps I use have any useable reference data points on them.
Cheers,
Roachie

FollowupID: 309182

Follow Up By: Member - Ruth D (QLD) - Wednesday, Feb 18, 2004 at 20:47

Wednesday, Feb 18, 2004 at 20:47

Cocka, can I book in for lessons?These are Diamantina Barra
GO HARD OR GO HOME

FollowupID: 309240

Follow Up By: Old Soldier - Wednesday, Feb 18, 2004 at 22:19

Wednesday, Feb 18, 2004 at 22:19

That is partly correct.

The bottom line is ALL official topo survey maps have the datum system they are using contained in the marginial information.

Your GPS should be set accordingly - otherwise you are wasting your time, and if you were planning any accurate navigation with it - forget it.

You might as well throw it in the nearest rubbish bin.

I know I'll probably get jumped on for this, but I've said it before and I will say it again.

Before contemplating any serious work in the bush with a GPS you should go and learn basic navigation with a pencil, compass and protractor.

That way if your GPS "spits the dummy" [and anything man made can do just that] you won't become a statistic.

regards

DennisN

FollowupID: 309260