Where to start discussions about cartography?

Cartography, maps, navigation, GPS and more.
Adventure Mapper
Posts: 70
Joined: October 18th, 2012, 7:37 am

Where to start discussions about cartography?

Post by Adventure Mapper » October 18th, 2012, 8:32 am

I see that there is a lot of discussion about GPS, GIS, cartography, and maps that is spread across the topics. I'm interested in learning and contributing on this subject. I have a lot of experience making maps for wilderness exploration. Cartography is like photography or botany or geology or archeology, it enhances the wilderness experience. Would it be possible to concentrate the communication on this subject under "Gear and Goodies"? It would be similar to "Photography". This would be a place to discuss the ways to use LiDAR data that is available for many places in Oregon and Washington. It might also be a place where off-trail hikers can learn where to get property boundary data and load this into their GPS receivers.

Hope I put this question in the right place. I'll post some example maps and start some discussion about cartography for wilderness exploration if there is a good place in the forums.

raven
Posts: 1531
Joined: May 28th, 2008, 10:03 pm

Re: Where to start discussions about cartography?

Post by raven » October 18th, 2012, 9:33 pm

A dedicated forum under Gear and Goodies sounds good to me - and good for my interests as a lurker. However, there's more to the subject than mere cartography, so I suggest calling the new forum "Maps and Navigation".

Adventure Mapper
Posts: 70
Joined: October 18th, 2012, 7:37 am

Re: Where to start discussions about cartography?

Post by Adventure Mapper » October 19th, 2012, 9:17 am

Indeed it would be good to cover equipment such as GPS receiver, compass, and altimeter. Also, Geographic Information System (GIS) software and data formats may be of interest.

Navigation skills would also be included. I have a few hand drawn maps from Russ Jolley and it is interesting to compare his estimates of where his trails were with the accurate GPS track. He was really good where there are distinctive land forms but some places he was pretty far off.

Map errors are also interesting. Does anyone know why trails along the top of the Oregon side of the gorge are so inaccurate? It seems unlikely they were moved. Some errors are corrected in some GIS information I've gotten but I don't know who is doing the updating or how it is done because the metadata has not been brought along with the trail data.

Are people interested in entering trails in Open Street Map (OSM) ( http://www.openstreetmap.org/ )? I see some trails in the gorge have been entered but they appear to be derived from lines on inaccurate USGS maps rather than from recent GPS tracks. I don't think off-trail routes should be revealed on publicly available maps but signed and maintained trails should be in the right place. It would be good if Portland Hikers updated OSM with accurate information about the true state of back roads.

I have attached a custom map that is entirely derived from LiDAR data. The same area of a 1:24000 USGS topo is included for comparison. I won't go into detail about the features of the custom map but it allows navigation through cliffs to a unique viewpoint. I expect that many folks who post on "Off-trail Trip Reports & Lost Trails" will be interested in how to get LiDAR data and use it to make highly accurate and detailed maps.
Attachments
LiDAR.jpg
from LiDAR data
10 ft. contours - 100 ft. grid
TOPO.jpg
from 1:24000 USGS topo

User avatar
IDratherbehiking
Posts: 551
Joined: May 7th, 2010, 11:20 pm
Contact:

Re: Where to start discussions about cartography?

Post by IDratherbehiking » October 19th, 2012, 10:48 am

I suggest calling the new forum "Maps and Navigation"
I really like that idea!

Welcome to PH.org, Adventure Mapper!

User avatar
Don Nelsen
Posts: 4377
Joined: May 28th, 2008, 10:03 pm
Location: Vancouver, WA

Re: Where to start discussions about cartography?

Post by Don Nelsen » October 19th, 2012, 11:59 am

I agree, too, good idea.

Also, I think you are correct that the trails that are so far off on the OR side haven't been re-aligned, for the most part. (some have, like Wyeth and the trail from Franklin Ridge down to Oneanto Cr.) I think most simply were not surveyed very accurately. It says on the map for a couple of them "loc app": an abreviation for "location approximate." I've field checked most of the worst by criss-crossing through the forest where the map says they are and found nothing - 425 east of Oneonta, 430 from Nesmith to Tanner Cr. are a couple of the worst.

I'd like to know how you put your GPS track on the Lidar map you posted, too, looks really good.

Don
"Everything works in the planning stage" - Kelly

"If you don't do it this year, you will be one year older when you do" - Warren Miller

Adventure Mapper
Posts: 70
Joined: October 18th, 2012, 7:37 am

Re: Where to start discussions about cartography?

Post by Adventure Mapper » October 19th, 2012, 1:13 pm

Don Nelsen wrote: I've field checked most of the worst by criss-crossing through the forest where the map says they are and found nothing - 425 east of Oneonta, 430 from Nesmith to Tanner Cr. are a couple of the worst.
Don
When those USGS maps were made it didn't matter much if the location was correct as long as the order and count of junctions and stream crossings was correct. Now that people are using GPS receivers for off-trail navigation the correct location of trails is more important.

My wife and I found the problems with the trail east of Oneonta when we had bushwhacked up out of Horsetail Creek expecting to find the trail right on the rim. It was getting late and we needed something we could follow out with headlamps. We did find the trail in time but only after wandering around and hacking through vine maple thickets.

I discovered the errors east of Nesmith more than 10 years ago on a backpack to Talapus with my kids. We tried to shortcut the climb up and down Nesmith and go past that lake that is really just a swamp. When we didn't cross the trail where it showed on the map the kids were worried. We kept heading south and found the trail but it's hard to know how far to go before giving up.

If you know where the trails really are it would be great if you entered them in Open Street Map (OSM) http://www.openstreetmap.org/ . With so many hikers carrying good GPS receivers now it should be possible to make a very accurate public map of the Oregon side of the gorge.

User avatar
Koda
Posts: 3466
Joined: June 5th, 2009, 7:54 am

Re: Where to start discussions about cartography?

Post by Koda » October 19th, 2012, 1:25 pm

Adventure Mapper wrote: Are people interested in entering trails in Open Street Map (OSM) ( http://www.openstreetmap.org/ )?
yes, I would love to see more quality open source maps available and would encourage this. OSM has developed its own open source topographic map set... right now its limited to only the US called TopOSM. I added a gpx track to it once but it didnt seem to take regardless if I could figure it out I would upload every trail. The quality of TopOSM is outstanding too... as it appears to be using lidar shading.

Take a look here: http://www.toposm.com/us/index.html?zoo ... ayers=B0TT

What I don't understand is why TopOSM does not include trails, yet OSM does but OSM has terrible topography I would not use.
lightweight, cheap, strong... pick 2

User avatar
Koda
Posts: 3466
Joined: June 5th, 2009, 7:54 am

Re: Where to start discussions about cartography?

Post by Koda » October 19th, 2012, 1:43 pm

Adventure Mapper wrote: I have attached a custom map that is entirely derived from LiDAR data.
have you played with the layer stacking in the Hillmap utility? You can stack different layers on each other adjusting their transparency, the CaltopoHillshade layer looks like lidar imagery...

many custom maps can be made from this.


here is one layering topography, satellite imagery, and lidar shading
lightweight, cheap, strong... pick 2

Adventure Mapper
Posts: 70
Joined: October 18th, 2012, 7:37 am

Re: Where to start discussions about cartography?

Post by Adventure Mapper » October 19th, 2012, 2:02 pm

I wasn't familiar with TopOSM but I'll check it out and try to enter a .gpx. The rendering is good but I don't think it is based on LiDAR data. The contours are 50 ft. LiDAR is usually more than accurate enough to make 10 ft. contours. I checked some locations where I'm pretty sure there is no LiDAR data vs. some where there is data and I couldn't see a difference.

OSM is really a database of vector information. It can be overlaid on any base map including topo maps. Also, it is more likely to have good data on roads. If there isn't already an OSM editor that shows topo maps then it is likely that someone will make one. OSM is the best bet for a place where your data entry efforts will not be wasted in the long run.

Adventure Mapper
Posts: 70
Joined: October 18th, 2012, 7:37 am

Re: Where to start discussions about cartography?

Post by Adventure Mapper » October 19th, 2012, 2:04 pm

Don Nelsen wrote: I'd like to know how you put your GPS track on the Lidar map you posted, too, looks really good.
Don
It's all done in GIS programs. Adding the GPS track is easy. Making the map requires the following:
- getting LiDAR data
- generating 10 ft. contours from the "bare earth" part of the data
- "slope shading" the bare earth elevation model to show impassible cliffs
- subtracting "bare earth" from "first return" to get height of trees and then shading the result in green
- processing the bare earth elevation model to find places where water will accumulate enough to make small streams that don't show on topo maps

The computer does the work but the user interfaces to the GIS programs use some terminology that must be learned.

If you send me a square kilometer in the gorge near the river or somewhere in the Yacolt burn I can return a simple LiDAR hillshade as a .KMZ. You will be able to put it in Google Earth and overlay tracks.

Post Reply