Digital Mapping falls short
Submitted: Thursday, Feb 05, 2009 at 21:44
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Willem
Busy doing some serious research on tracks and seismic and shot lines and if it wasn't for Google Earth I would be lost, pun intended.
Admittedly I only have the early version of Hema Great Desert
Treks but I have Natmap Raster 2008 and it is still way behind in proper mapping details especially in remote areas.
For instance the maps would show some of the seismic tracks but not show others. I have been able to find a number of new seismic tracks by painstakingly going along the Google earth image on the screen. This may make travel to remote areas a lot easier or more difficult depending on the terrain
Cheers
Reply By: x - Friday, Feb 06, 2009 at 11:26
Friday, Feb 06, 2009 at 11:26
G'day Willem,
I agree that Google Earth is revolutionising mapping.
I am finding that I am spending many nights combing over GE and dropping markers on tracks, shot lines etc in preparation for trips.
By the time I actually drive there I feel I have spent many days there already!
Roll on high resolution imaging of the whole country. It makes such a difference to track visibilty.
I have also imported GE downloads into Ozi. I find the terrain view maps thus created to make the Natmap rasters look very ordinary. It would be good to have mobile internet access in remote areas to allow live mapping. Satellite connection is too pricey for me.
Bob
AnswerID:
347802
Reply By: Member - Toolman (VIC) - Friday, Feb 06, 2009 at 17:35
Friday, Feb 06, 2009 at 17:35
The reason the NATMAP products do not show all "shot Lines" as you refer to them(known as Seismic lines in NATMAP) is for what they consider to be a very sound reason. They are not just overlooked.
I can't recall the exact details so don't quote me but the story goes something like this, in the 1970's as I recall a lad drove down a seismic line that was shown on the map, for whatever reason. He got lost, his vehicle broke down, and he perished. Seismic lines are not always very
well defined and many soon became overgrown unless they were used as tracks. It doesn't take much to leave a mark on the earth that an aerial photograph would pick up. Maps have a fair lag from the time of aerial photography to the final publication of the map and also the time between publication and revision can be many years.
Following a fair bit of questioning from parliamentarians, the coroner and others, a fair amount of introspective reflection and after a fair bit of s@#t hit the fan, the decision was made to only show those lines that were clearly visible and were likely to be visible for a fair amount of time. There are thousands of these seismic lines out there and many just fade away over time. Some remain as they may have been driven over periodically.
Again if I recall correctly the post 1997 edition of the 250K NATMAP maps had new specifications written and this specification revision revisited the issue of seismic lines and even more of them were removed.
I love Google Earth and wished we had it when I was making maps but a word of caution using it. You need to be aware of the age of the satellite image and allow for the age of the image when gathering information. I've found images that are 8 years old. The reason we get to view them for free is because they are dated images. Also be aware that the geo-coding of the Google Earth images also can be a bit inaccurate. Be especially careful where there is no road network to compare the image to because then you'll not know just how good the geo-coding really is.
Toolman
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Follow Up By: Willem - Friday, Feb 06, 2009 at 18:02
Friday, Feb 06, 2009 at 18:02
Thanks for the explanation Toolman.
It might have been the Annetts incident northwest of the CSR in the 1970's when those two
young fellas perisihed out there.
I have taken some waypoints for using seismic tracks. I know that the referencing may not be all that accurate but it will show where approximately a point of reference is.
I discovered some buildings in a very remote area which may be left overs from exploration days as the tracks in the vicinity look very overgrown.
Cheers
FollowupID:
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Follow Up By: equinox - Friday, Feb 06, 2009 at 20:57
Friday, Feb 06, 2009 at 20:57
Willem,
The James Anetts and Simon Amos incident took place in 1986-87.
Remember it
well. Sad story, they were only a couple of years younger than me.
Anetts Amos Story
Cheers
Alan
FollowupID:
616124
Follow Up By: Willem - Friday, Feb 06, 2009 at 21:10
Friday, Feb 06, 2009 at 21:10
Just goes to show that the older you get the more confused you get....LOL
Yeah, one cannot be too careful out there in the never~never
Thanks for the correction
Cheers
FollowupID:
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Follow Up By: Member - Toolman (VIC) - Saturday, Feb 07, 2009 at 07:18
Saturday, Feb 07, 2009 at 07:18
Thanks for the correction, That sounds like the sad incident I was referring to. The 70's and 80's just seem roll up together in the memory banks for me these days.
Toolman
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