I select “Path” and use many more waypoints to project a more accurate route. It comes out close enough in both. .
Thanks , that is pretty much what I am trying to do , you have a really interesting blog I will spend some good time on it.
How do you figure you can only trace a straight line? If you press the mouse button while dragging you’ll get a continuous curve. However, I usually zoom in a reasonable amount and use short straight segments. If you go in close enough and pay attention to where you’re actually likely to paddle it works out very close to reality.
I route plan using Google Earth for the 440 mile Yukon River Quest and the Yukon 1000 mile races . I normalize from known GPS measured total distance. On the YRQ, although advertised as 440 miles, I have on each of 5 different races measured an actual distance of 426 miles with very little variance. I have created a calculation spreadsheet of waypoints and projected arrival times at any of them that I choose. With it my pit crew knows where I am at any moment. I have waypoints placed at specific points on the river (594 waypoints to Dawson City), In addition to mathematically normalizing the overall distance, I use straight line segments and add about 10% to each to account for what really happens at turn points.
I measure river miles using sufficiently small straight line segments on Google Earth or BaseCamp, which will almost certainly yield a result that is somewhat too small since you criss-cross the river to find the best line. I personally don’t care about that difference, but if you’d like to be more precise, you could use GPS (has inaccuracies itself) or known distances to figure the average fudge factor you need to add for a more accurate measurement, which will depend on the characteristics of the river. If it was me, I’d start with the 10% that Yukon Paddler figures for his trips.
You can also use the mouse to “draw” the entire path instead of using individual segments, but it’s more difficult than you think, at least for me.
Thanks so much to all of you , I will had way more way point and do segmentation , I normally travel by motorcycle so I don’t really care about the exact amount I will do in a day but on a canoe this seems pretty important to me .
Appreciate your help.
Remember one thing about Google Earth… it is NOT Real-Time!
I paddled the Colorado with some people, one guy had a mapping GPS on his deck and was lost because what he saw on G-Earth did NOT match what he saw around him. I told him that G-Earth was years old and the river had changed since then but he insisted it was real-time and he should be bale to see us on the river.
At the next beaching, I told him to zoom in on his house and see how old it was. G-Earth showed him a winter-scene with an old car he had sold 5 years ago.
Google-Earth is a guide only, NEVER trust it for more than the basics.
You make a good point. There’s a wetland I often paddle in the spring where the access is a creek running into it. With the spring melt and flooding, the bottom section of the creek often takes different paths into the wetland and satellite imagery is not very useful. It’s interesting to look back at the historical imagery and see all the different configurations that used to exist.
agree with you , I only use Google for the distances then , the area I will canoe are pretty remote and without cities so its not really important what it look like .But a good point , I have travelled in Africa and Asia and a dirt road on G map is now a nice road so time change …
Most maps I use on GE of the Yukon River are 2-3 years old, the date is shown on the bottom of the page… The topo maps (both Canadian and US) are decades old and virtually useless. There are many cases of oxbows that in reality exist that are drawn on the topo maps where they do not exist, or that exist and have been formed since the date on the topo map. I have traveled that river and verified and re-verified the usefulness of GE map plots 5 times so far. I know of some channel differences in certain locations, but those differences are very few. GE maps have helped me pick the best shortcuts and efficient lines of travel around thousands of islands and channels to do very well in the Yukon races.
Thanks , good to know that you are still using them for general purpose , part of the plan for me is to leave when the river is fairly low , so I can avoid to get lost in the plentitude of islands and little river path. Anyway I will be using paper map , the google earth is only for the prep , to help me calculate food supply/ paddling time for few weeks at time. I use this company to find difficult to get maps http://geospatial.com/
In my power boat cruising the ICW the boat often cruises across dirt on the map display on the chart plotter. Some out of the way places don’t get updated much.
You can also use BirdsEye satellite imagery with Garmin Basecamp or Homeport. Requires a $30 subscription (to a single Garmin handheld), downloads are slow. Sometimes the BirdsEye is better than GE, and sometimes not (usually not). I like having the option and to download some images to my handheld for areas requiring high detail. I read somewhere that urban areas are updated each year, more remote areas are probably less current.
Thanks I will check them since I do not know them. I am not sure they are doing Brazil and the Amazon basin .