Arkansas Canoe Club Forums

Butch Crain wrote:Having floated and waded a few swamps, for me, nothing beats a good topo, a trustworthy compass AND a recent aerial photo.

Oooh - good point on the photos being another great tool. Have you found any good on-line source for high-res aerial photos, relatively recent, available to the general public? Google Earth and most of the others I have stumbled across seem to just not get down to the resolution that I know must be available SOMEWHERE. Free is good, but I'd also be willing to pay for the good stuff.

http://jdmcox.com/" onclick="window.open(this.href);return false;


This is freeware altho I sent him 25 bucks because I do use it quite a bit

you down load real topo sheets and aerial overlays as well

I will lay out a route with it and then upload to my garmin gps on mapsource which is topo but not the good topo

It is a very nice tool

"turn on trail"

that's the command our garmin gave my wife when she was trying to find Frozen Head State Park on the Cumberland Plateau... and the trail was straight down a ravine.

we still laugh about that (when something gets tense, we give the "turn on trail" command to lighten the mood)

Cowper wrote:Have you found any good on-line source for high-res aerial photos, relatively recent, available to the general public? Google Earth and most of the others I have stumbled across seem to just not get down to the resolution that I know must be available SOMEWHERE. Free is good, but I'd also be willing to pay for the good stuff.

I'm kind of old school w/ data and don't need(?) layered GIS, so my mapping is done w/ Terrain Navigator Pro -

http://maptech.mytopo.com/support/coveragesearch.cfm" onclick="window.open(this.href);return false;

The photos they make available are USGS and USDA sourced. The only consistently available scale is 1:12,000 photos from 2009. Urban areas sometimes have (2003) 1:7,200 and even 1:3,600 scale available.

The 1:12,00 photos are generally the same as those available in the freeware Dave mentioned above, with better screen and print resolution. Terrain Pro allows you to view those side by side w/ Google aerials and I honestly can't see a great deal of difference.

TP also allows you to create 3d views from different elevated aspects and "flyover" videos.

Richard is a very wise man.

This thread: serious map nerds only need apply.

I'm a map nerd wannabe - can't seem to rise above above map geekdom

As always the ultimate responsability lies with the user. It's not "death by GPS" it's death by incompetance (or outright stupidity).

A lack of competance with the tool, whether it's a GPS, a topo, or a chainsaw is going to put the user at some degree of risk. Some tools more than others. And if you fall into the outright stupid category (hiking 5 miles into any wilderness with a single plastic bottle of water, no company, no backup plan for finding your way back, etc) then Darwin is going to have his way with you.

Richard wrote:Here is a comparison of MS Streets & Trips, Google Earth and USAPhotoMaps at their highest resolution. This is Hwy 65 crossing the Buffalo.

If you are refering to Garmin MapSource Streets and Trips you are looking at some VERY old data (in tech years). Garmin switched from Streets and Trips to the Navigator series around 2005 and I know with certainty that they updated the US65 bridge and the re-routing of the road north of the river in the 2010.3 map update sometime last spring or summer.

David Mac wrote:A lack of competance with the tool, whether it's a GPS, a topo, or a chainsaw .... And if you fall into the outright stupid category (hiking 5 miles into any wilderness with a single plastic bottle of water, no company, no backup plan for finding your way back, etc) then Darwin is going to have his way with you.

And yet another reason one should consider carrying a chainsaw when hiking alone in the wilderness - in addition to using it to defend yourself against predators, if you find yourself lost in the desert with no water, you'll be able to easily cut open that barrel cactus in your quest for water!

Touche!

Richard wrote:

are refering to Garmin MapSource Streets and Trips

Micro Soft Streets and Trips 2010

Well that explains the problem. It's a microsoft product....

I have to reply on this subject just a bit. If anyone goes completely by a GPS or a map can be in trouble. Technology can and will get you into a fix if you do not have a sense of direction and not knowing at least some about the area you are touring, hiking, etc... I am retired Army and have taught map reading of Topo maps for years along with battlefield geometry. A person would think a military map system would have no mistakes. Wrong.

There are problems with magnetic to true north on map orientation in Germany. The grid declination was off when I was stationed in Germany from 1977 to 1980. It may be fixed by now but what is to say that is not happening here in the Ozarks. I have not used it here myself so I can not say there are problems.

As for a GPS. These are electronic devices that can and will change with the amount battery power. A fresh set of batteries may and sometimes will give you different coordinates as a set of batteries on the low voltage side. You can place 2 or 3 GPS's side by side and get different readings. This is because by the time a circuit is created in electronics the voltages are slightly different between devices and will give a different reading.

An example is while in the Army we tested 3 computers for the computation of shooting a 200lb projectile approximately 12 miles. We used saved data to a hard drive. We moved the hard drive from one computer to the next so we definatley had the same computations. All 3 computers computed different data. Not enough to worry about shooting Artillery with but I have kept that in mind since.

Mapping agencies are flooded with changes in roadways and trails. GPS's use information and calculations that have will be forever input incorrectly into computers. Maps have incorrect information on them as well.

It is sad people have died because they rely on their GPS to get them safe to places. That has also happened before GPS's came along because of incorrect mapping data or someone thinks they know how to use a map. I hope this puts some thoughts to some who thinks every GPS and Map should get you there safe. Not so.