Craig's Hut

Whoops...... here is the web address http://www.kosciuskohuts.org.au/GPS.htmls

Most topographic 1:25k maps are divided up by the UTM grid under the WGS84 datum by default these days. Have been for ages. The old DGM coordinates are merely provided for those people that haven't managed or bothered to convert to the new system yet ;)

Actually they haven't been under WGS84 for ages and most maps in Australia still aren't.

The most common datums have been AGD66 then GDA94, GDA94 is very close but not WGS84 although for 4WD gps can be assumed to be the same.

If you need to give a location to an aircraft it will normally need to be in WGS84 ddd mm.mm format.

Actually - you're correct. I was a bit quick typing WGS84 there - as most maps that I have are indeed based on the ADG66 datum still.

Inspector posted this followup
"Actually they haven't been under WGS84 for ages and most maps in Australia still aren't"

You know/have a record of the datum of “most maps in Australia”?? With all due respect you have to be kidding (even though you may be correct…by educated guess or pure chance?).

Best you define “ages” and “most”.

I have recently looked at (ie calibrated for OziExplorer) 330 x 50K maps from NW WA and "most" are WGS84...so it got me wondering about the basis/validity of your statement.

Cheers
Greg

Explorer

I'm from up the NW of WA and the only maps that I have are 1:250K scale. Which ones have you gotten hold of and calibrated.

Regards

Moneypit

Moneypit - I am doing a DVD, under licence, of all the 1:50 000 scale Defence Topographic Maps available from Geoscience Australia covering the Kimberley area - which is a subset of these maps
GeoScience Australia 50K map index in pdf

Hoepfully I will be finished soon and product will be avaialble for sale from exploroz shop before Christmas (I hope). In total there will be 438 maps in OZF format for use with OziExplorer - all calibrated and ready to go. The DVD will also have 3 sec elevation data for use with OziExplorer 3D.
Cheers
Greg

No, I dont have a record of datums in australia. but the basis for the majority of maps in Australia is drawn from government mapping (ie Geoscience Australia.) and they work to standards

The intergovernmental Committe on survey and mapping states on its web site
[i]" The Geocentric Datum of Australia (GDA) is a coordinate reference system that best fits the shape of the earth as a whole. It has an origin that coincides with the centre of mass of the earth, hence the term 'geocentric'.

Following a resolution of the Intergovernmental Committee on Surveying and Mapping (ICSM) in 1988, it is being progressively implemented throughout Australia as the preferred datum for all spatial information.
It is considered to be the most effective datum as it provides:

* compatibility with satellite navigation systems, such as the Global Positioning System (GPS)
* compatibility with national mapping programmes already carried out on a geocentric datum,
* single standard for the collection, storage and dissemination of spatial information at global, national and local levels.

GDA replaces the Australian Geodetic Datum (AGD) which has been in place since 1966. The AGD provided a reference system that best fitted the shape of the earth in the Australian Region but its origin did not coincide with the centre of mass of the earth. National datums were commonly non-geocentric before satellite based navigation systems were established in the early 1970's. "[/i]

The actual difference between GDA94 and WGS84 is negligible for our (handheld GPS) purposes.

Yeah know all that , but just pointing out that you may be a little off the mark with your statement that "most" maps are not WGS84. As I stated "most" (ie greater than 50%, easily) of the maps covering the Kimberley (some produced as late as 2003, by Defence Mapping not Geoscience Australia) at 50K scale ARE WGS84. Look its no big deal, I was just curious as to how you reached the conclusion. Like you obviously have, I to would have assumed that all new maps produced in Australia since the introduction of GDA94 would now be in this datum, but based on my experience this is not the case.
Cheers
Greg

Explorer

Have you arrived at what sort of price are you looking at for the set.

Moneypit

Moneypit
Still finalising those details so wont make a public statement as yet, though as a guide total price divided by the number of maps will be less than 50 cents per map.
Cheers
Greg

Not sure what you mean there Truckster? I thought it was a recent addition...colourbond roof seems to suggest so. Was there a previous hut before the film?

How long ago was the movie? I havent seen a map anywhere that doesnt have it marked.

I have one without it