Maps for bushwalkers

[Allchin09]

What do people think of the current maps available for bushwalkers?

I know for NSW at least, the government maps are being produced with less and less features as time goes by, and besides small maps published in bushwalking books, there are hardly any recent dedicated bushwalking maps.

[GPSGuided]

A question of market size. Further, all are going digital. OSM, make your own.

[Allchin09]

So do you think that the market size has decreased over the last few decades?

As for making your own maps, OSM does have good coverage for tracks in some areas but the contours are fairly dodgy and many water features are missing.

[GPSGuided]

I use 3rd party contour overlays for OSM. Otherwise, it's not hard to contribute to missing water features and tracks. I have now try to contribute entries both before and after walks. It's a worthwhile cause.

[icefest]

I'm not sure if you've tried tracing into OSM, but it's not as easy as it sounds. I will trace creeks, rivers and lakes into OSM for areas that I frequent, but it's a huge amount of effort.

In hoping that all of Australia takes tasmaps lead and releases gpx KMZ map data. If that days then allows you to separate water, contours and tracks then my perfect system will be complete. OSM tracks and peaks with state hydrological and elevation data.

EDIT: They are being released as KMZ not GPX.

[GPSGuided]

Yes, it takes a little learning, but not that difficult. Yes, I've done tracks, rivers, lakes, marina and streets.

I was in NSW Lands office the other week and followed up on their supposedly available-by-now digital map release. They said that it has been delayed (hardly surprising) but is still in the pipeline. Not sure of the exact features and functionalities provided but should be something to look forward to. It'd be a dream if it supports gpx format output.

[Allchin09]

GPSGuided - When I visited the maps department last week, the guy their mentioned that they were going to release the digital maps. Apparently they will be the same size as the current 1:25k maps which they produce but at half the cost. He also said that they will be georeferenced, but i'm not exactly sure what they mean by that or how useful it would be.

I will have a fiddle around with OSM and see where I get.

Icefest - What you describe sounds ideal, same it isn't currently possible.

As for paper maps, does anyone use Rooftop Adventure Maps? I've only got one of Tumut and surrounds, but I found it very suitable for bushwalking and I especially liked that many comments that covered the map. Unfortunately there are only two maps that cover areas in NSW, but I believe there are a fair few more for Victoria.

[sthughes]

In hoping that all of Australia takes tasmaps lead and releases gpx map data.

Eh? When? How do I get it?

[icefest]

In hoping that all of Australia takes tasmaps lead and releases gpx map data.

Eh? When? How do I get it?

Here: viewtopic.php?f=3&t=15246

EDIT: They are being released as KMZ not GPX.

[vieve]

Not necessarily for bushwalkers but if you are after some good, detailed maps of walks in Sydney (north side) I recommend the Steps Inc. maps. They have 3 available (all 1:10,000), although none of them have been revised recently:

1) Walking Tracks of the Lane Cove Valley
2) Walking Tracks of Middle Harbour Valley and Northern Sydney Harbour Foreshore - Bungaroo and Roseville Bridge
3) Walking Tracks of Middle Harbour Valley and Northern Sydney Harbour Foreshore - Northbridge and North Harbour

More info here: http://www.step.org.au/maps.php

[sthughes]

In hoping that all of Australia takes tasmaps lead and releases gpx map data.

Eh? When? How do I get it?

Here: viewtopic.php?f=3&t=15246

EDIT: They are being released as KMZ not GPX.

Bugger, had me a little excited there for a second! If they released the GPX data (I mean really released, not copyrighted) it could be used to drastically improve OSM and then we'd have excellent maps for our GPS units as well!

[icefest]

I thought it wasn't that hard to convert from KNZ to GPX. Won't that be possible when they release it sthughes?

[sthughes]

No. The .kmz is essentially an image file with kml georeferencing data zipped together to make a kmz. So basically the actual map data is just an image (i.e raster data) that can't easily be made into gpx (vector) data. And I highly doubt the EULA from Tasmap would allow it's use on OSM anyway. They are very protective of our data.

[GPSGuided]

I recall being told the new NSW digital map product will be released in vector format. Of course, have to wait till we see it to confirm. Fingers crossed.

[Rob Gosford]

What do people think of the current maps available for bushwalkers?

i use Matt's WildWalks maps.........have never got lost.

[Allchin09]

I have used the maps from WildWalks, but they are usually specific to one walk, and generally I can't use them to plan walks of my own.

I like maps to cover a large area as it makes it easier to plan routes of your own.

[perfectlydark]

OSM arent bad for that. Not the best contours and as mentioned previously some water features missing but overall print and laminate and you got yourself a map goin!

[north-north-west]

No. The .kmz is essentially an image file with kml georeferencing data zipped together to make a kmz. So basically the actual map data is just an image (i.e raster data) that can't easily be made into gpx (vector) data.

I could do without the jargon, but I think I'm starting to understand. All this vector/raster/KMZ stuff has me totally bamboozled. But if it's just an image with, I assume, grids overlaid, it can still be used to plot a route just like a paper map, only you can do it on the computer and then print out the result.
(I think VP takes KMZ files, so maybe I can even use the maps in there to plan. We'll see. But the new price for the whole set will be worth it.)

[icefest]

NNW:
This analogy might make the vector/raster bit easier to understand:

Raster maps are like a photo: you zoom in too far and you just see colored squares (pixels).

Vector maps are a giant join the dots puzzle; the lines are redrawn every time you zoom.

This means that raster maps take up more space (every block of color is important) and vector maps use less (only the dot location is important).

[north-north-west]

OK, that makes sense. Thank you.
So the raster maps are easier to generate because they're just images. This also makes sense.
I might leave it there. Any more new information and my brain might overload.

[GPSGuided]

Not sure you can say that. Raster map files are large and every time you scroll the image on the computer, it's a lot of work by the CPU. Raster files are expressed mathematically and images are generated on the run. It's far more efficient on the CPU. So the simple take home message is,

Vector - Fast, efficient, small, sharp. GOOD!
Raster - Slow, inefficient, large, limited resolution but can be simply scanned in. Not so good.

[north-north-west]

I meant that the originals would easier to create. I think. *brain overheating . . .*

[GPSGuided]

You are cracking me up NNW. My brain is hurting too...

[icefest]

I don't entirely agree on the CPU load GPSG.

A complicated vector map is much more resource intensive than a raster map.
This is because it must first be converted to raster for display. and then reconverted at every scrolling and zoom change. As with zip files the greater the compression the more processing is required to unpack them. This is due to the use of more complicated algebra to describe the lines. (If you then add AA you have even more processing requirements)

The main CPU intensive task with raster is the dynamic rescaling, which is often limited by having several different raster images saved. (25k, 50k, 250k 1M).

Increasing the amount of ram caching decreases the processing power needed for each.

TL;DR: there is little advantage CPU-wise when using highly detailed vector maps in comparison to raster.

[GPSGuided]

Guess there are always extremes. Given how efficiently our computers and smartphones can handle vector images (CPU, GPU etc), I'd suggest that by and large, vector is significantly more efficient.

Yes, I have "played" with some seriously large AutoCAD files (ie. Vector) and they can certainly drag my machine right down. But I don't think we are talking about vector files of that level of complexity. For bushwalking maps, vector undoubtedly would win out over raster of any usable resolution. No? A simple comparison is b/n loading of OSM maps and vector maps (Google Maps, Apple Maps), the performance difference is pretty obvious.

[Son of a Beach]

Vector uses WAY more CPU power than raster, for any reasonable map and are therefore slower if there is no other limiting factor. Remember your screen is raster so it has to do much of the same raster processing as well as the vector-to-raster conversion.

I've programmed both and vector is much slower due to its large CPU usage requirements.

Your comparison for online maps would be comparing download times which is more dependent on file size, and of course vector wins there.

Both have their advantages and disadvantages. There are some things that you simply cannot do with vector maps and which are trivially simple with raster (although not anything related to bushwalking, off the top of my head).

[GPSGuided]

I buy that. Maybe the issue should be considered in terms of overall computer performance ie. Storage, read-write etc. In such situation, raster is slower for its data retrieval. A better statement?

[Son of a Beach]

For online maps, yes. For maps stored locally on the machine raster are much faster.

[GPSGuided]

For online maps, yes. For maps stored locally on the machine raster are much faster.

That depends on the resolution, surely! Talking about common top map level of complexity wrt vector and raster.

[Son of a Beach]

For online maps, yes. For maps stored locally on the machine raster are much faster.

That depends on the resolution, surely! Talking about common top map level of complexity wrt vector and raster.

Not dependent on the resolution, so much. More dependent on how much data will need to be loaded and processed in order to display a screenful (or window full) of image. This can vary by many more factors that resolution.

The vast majority of mapping applications use a pyramid of image tiles at a variety of resolutions to overcome the problem of having to load an entire large image in high resolution when zoomed right out. This same process is used to only load portions of an image when zoomed right in.

In my iOS mapping app, for example, raster map images of 2000x4000 pixels load up instantly on that tiny device, whether viewing the entire map zoomed right out, or viewing a tiny portion of the map, zoomed right in. It uses pre-tiled versions of the image, similarly to what many other applications do.

So it is largely up to the application architecture and how it handles the raster.

You cannot get the same efficiencies with vector images, unless you also pre-render them (in which case they are really just rendered rasters). This is what the OSM online mapping uses. Their data is all vector, but the vector data is (mostly) pre-rendered into tiles ready for download as requested.

Even without pre-tiling, some image formats allow the application to access only part of the raster image without having to load/process the entire image.