Maps

could this be it: LINZ has adopted a new Map Projection for its future national mapping. Following wide consultation, LINZ approved on the 1st July 2001 a new projection for it's future national map series. A public announcement is intended to be made shortly. A Transverse Mercator projection in terms of NZGD2000, to be called New Zealand Transverse Mercator (NZTM) (pdf 43KB), will supersede the current New Zealand Map Grid Projection (NZMG), for LINZ 1 :50,000 scale and 1 : 250,000 scale map series. * NZTopo50 series at a map scale of 1:50,000 for the landmass of New Zealand. This new series will replace the current Topomap 260 map series. * NZTopo250 series at a map scale of 1:250,000 for the landmass of New Zealand. This new series will replace the current Topomap 262 map series. Both the current Topomap 260 and Topomap 262 series will be retained until such time as the replacement series are fully implemented. Over the next 12 months, LINZ will develop strategies, standards and the programme for the intended implementation of the new map series. http://www.linz.govt.nz/core/topography/projectsandprogrammes/nzgd2000/index.html

Topo cds are here and not yet installed. Can't wait. If replacement made beneficial for both map users and publishers, it would be great welcome. I would like seeing hiking tracks printed on both sides on paper maps with scale of 1:50,000. Terramap's Tararua recreation area, edition 1, 2002 is rather good covering few extended walks in Tararua Forest Park.

Speaking of maps. Does anyone know whether there is a website I can go to to print maps off? Someone who I was on a course with on the weekend told me about one, but I didnt get the details! And where can you get waterproof paper!?

Don't know about printable waterproof paper but you could achieve the same thing by getting your map printout laminated at print shops for a few dollars.

Part of the change is adoption of the NZGD2000 datum to replace the old NZGD49 datum. This is a good thing as the new datum is almost identical to the world standard WGS84 -- which is what GPS units use. This website now stores all coordinates as NZGD2000 latitudes and longitudes instead of NZGD49 eastings and northings. I think it will be awhile before we see print maps though and it will really be a moot point as we are moving toward digital products and printing maps out as needed rather than spending $12.50 on a big sheet of paper.

What does this mean for my faithful Garmin etrex? At the moment I just set the position format to "New Zealand" and the datum automatically sets to NZGD49. The GPS then reads in grid coordinates which go with my 1:50,000 260 maps. Sweet. On the other hand, my GPS doesn't have NZGD2000, so where does that leave me once I can't get 260 maps? I'll have to shag around with lat/long in degrees and minutes instead of grid coordinates...?! Not sweet!!! Do I have to buy a new GPS or should I be stocking up on maps while I can get them..?! I read your article but couldn't spot anything along the lines of "...and the clear benefit to the map users is..." so I'm viewing this change pretty darkly... Happy to be corrected if I've got the wrong end of things, but it sounds pointless - if it isn't broken, don't fix it.

In the short-medium term I don't think it means anything to you, as maps are still produced as NZGD49. I think the benefit to map users is global standardisation. Another benefit is that your unit will be storing coordinates internally as WGS84 and converting to NZGD49, which likely adds inaccuracy. Can you choose WGS84 with that unit instead of New Zealand? NZGD2000 and WGS84 are identical for tramping purposes. Alternatively, you can possibly define your own datum. Is that option there?

No, unfortunately with the Garmin eTrex once you select "New Zealand" as the position format you can't select anything other than NZGD49 as the datum. Rather short-sighted on the part of the manufacturer I guess. If you're using any of the Lat/Long variations then you can select from any of a number of datums, WGS84 being the default. Oh well, hopefully Garmin might release an update when the time comes. Otherwise yes, it looks like I can define a custom position format, although the user manual doesn't cover that detail - which probably means it requires a deep understanding of the dark art of cartography!! Are you a GPS user? I always carry mine, even on a day walk, just as I always carry a map and compass, although I've never needed to use it for real to find where I am. It's just 'good to have' and useful for marking points of interest and tracking thinks like distance covered, elevation, etc.

Actually having "New Zealand" bound to NZGD49 is not short sighted. It would be meaningless to have anything else. What they mean by "New Zealand" is actually New Zealand Map Grid and this is ALWAYS expressed using NZGD49. On my Garmin GPSMap60CSX it has another option. "New Zealand TM" which is a totally different grid system and it uses WGS84. If your etrex is one of the older yellow ones, I doubt there will be any more firmware updates. NZTM has been in the newer Garmins for quite some time. My old 60CS had it and they stopped firmware updates on those quite a while ago. On the good side, there is no reason why you can't carry on using your current map series. I think the NZTM maps are probably a couple of years away and I am sure you will manage to drop your GPS into a river by then. And anyway I doubt the new grid will only be introduced gradually. I have a large collection of NZMG maps and I certainly have no intention of throwing any of them away just because the numbers on them are a bit different. Someone asked about where you could print out maps on line. Try http://www.nztopoonline.linz.govt.nz/