Open Source TOPO map/GPS software...

Cartography, maps, navigation, GPS and more.
stan72
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Re: Open Source TOPO map/GPS software...

Post by stan72 » January 11th, 2012, 11:29 am

Koda wrote: It seems to me that any application can calculate accurately but its the device and/or user error that creates inaccuracies?
I mean that GPS devices almost always add some noise to the data, then when you calculate EG from the raw data you sum many small errors and obtain a big error in the final result.
Koda wrote: Stan, is there a way your program can eliminate any large error spikes (like brief loss of satellite reception or other)?
Spikes like here: http://gpsfly.org/a/1303 ? Those are clearly errors, it would be interesting to see how to detect and remove them.

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Koda
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Re: Open Source TOPO map/GPS software...

Post by Koda » January 11th, 2012, 11:57 am

stan72 wrote: Spikes like here: http://gpsfly.org/a/1303 ? Those are clearly errors, it would be interesting to see how to detect and remove them.
Ignore anything outside of an average range in the line? Software like GPSPrune can select track points/elements and edit delete them. I have not tried this yet though to verify how it works. It may be more prudent for the end user to use something like that to clean up the track before uploading to any web application like GPSFly. This is out of my area of expertise, as I am just an end user myself.

Thank you for your work and public use of GPSfly. I see its a favorite for a few hikers here at PH's. I added it to my list because its well done, and the fly thru is way cool. One suggestion I would ask is to add the TopOSM mapset for topography. MyTopo would be ideal but they are not free.... ArcGIS would work here to. Open street map for cyclists would be a great tool for that user group too. I think the mentioned map layers can be added for free... I don't really know.
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retired jerry
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Re: Open Source TOPO map/GPS software...

Post by retired jerry » January 11th, 2012, 12:18 pm

The Garmin Mapsource software allows you to edit out points.

You could look at the distance moved per time for successive points but it would be tricky.

Sometimes, there'll be a point quite a bit off, and then a succession of points that gradually get back to the valid position. So where do you switch from editing out points and back. The first point is way off, which is easy, but it's more difficult to determine when you're back to good.

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retired jerry
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Re: Open Source TOPO map/GPS software...

Post by retired jerry » January 11th, 2012, 12:32 pm

Like this example
locklost.jpg
I was walking up this road above Riley Horse Camp

I lost lock at Cast Creek TH 2

After I walked up the road, to a point just above the center of the picture, it reacquired but it was offset to almost the bottom of the picture.

Then it continued along parallel to my actual path for a while, but with a large offset.

Then, it "realized there was a large offset" so it gradually got back to the true position.

On the way back on the same road, it was just fine.

Difficult to get a piece of software to figure that out.

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retired jerry
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Re: Open Source TOPO map/GPS software...

Post by retired jerry » January 11th, 2012, 12:43 pm

elevation is from barometer, so unaffected.

some GPSes do elevation from satelite, which would be affected

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CampinCarl
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Re: Open Source TOPO map/GPS software...

Post by CampinCarl » January 11th, 2012, 1:58 pm

Super geeky stuff about where GPS is headed with respect to horizontal and vertical accuracy:

http://www.gpsworld.com/gis/gss-weekly/ ... racy-10016

I like this quote:

"No other conclusion can be drawn but that in the future, as soon as 2014 and as late as 2020, high-accuracy GPS receivers (cm-level in both horizontal and vertical) will be in the hands of anyone with a few hundred dollars to spend. This will be consumers as well as professional geospatialists."

Cool, I'll put a new GPS on my wish list for about 2015 :D

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CampinCarl
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Re: Open Source TOPO map/GPS software...

Post by CampinCarl » January 11th, 2012, 2:01 pm

Not to mention the increasing availability of LiDAR data to base digital elevation models on:

http://www.oregongeology.org/sub/lidard ... /index.htm

:ugeek:

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Koda
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Re: Open Source TOPO map/GPS software...

Post by Koda » January 12th, 2012, 10:11 pm

Koda wrote:I am wondering if anyone here on PH knows of any open source (or freeware) TOPO map programs?

Ideally, I would like to find something that works similar to the National Geographic TOPO program with USGS 24,000 scale maps... and of course connects with my GPS (Garmin Rhino 130).

I currently use an old National Geographic TOPO upgraded to version 4.0... which transfers way-points, but does not download tracks/routes to any GPS. Overall, I have never been happy with the interface and functionality of the NG TOPO program and actually think its a rip off since I still have to buy NF maps for road navigation.... The level 4 (100K series) maps are a joke for forest road navigation, the only usable maps are the level 5 (7.5 series) but I am finding the trails on the maps being more and more outdated. which leads me to two other questions: 1) is the brand new NG TOPO worth upgrading? 2) is the $125.00 Garmin TOPO West CD worth buying?

*edit to add the following list of electronic mapping applications...
Software:
  • Viking, Viking is a free/open source program to manage GPS data.
  • Prune, GpsPrune is a free/open source application for viewing, editing and converting coordinate data from GPS systems
  • http://www.topofusion.com/, proprietary software with GPX output. Windows OS only :(
  • http://www.easygps.com/, EasyGPS is the fast and easy way to upload and download waypoints, routes, and tracks between your Windows computer and your Garmin, Magellan, or Lowrance GPS. Free :) Windows only :(
  • http://www.gpsbabel.org/, the ULTIMATE GPS file translator filetype converter utility. Up/Download to any GPS device.
  • Google Earth, what? your not using this already..?
Web Browser Utilites: Smartphone GPS Applications Complete Maps and Misc: I'm certain there are more feel free to add your favorite. Some of these I have used or tried, the majority I have not... Will update the list as I find more.
enjoy
edit to add the smartphone applications list.
lightweight, cheap, strong... pick 2

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Koda
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Re: Open Source TOPO map/GPS software...

Post by Koda » January 12th, 2012, 10:16 pm

CampinCarl wrote:Super geeky stuff about where GPS is headed with respect to horizontal and vertical accuracy:

http://www.gpsworld.com/gis/gss-weekly/ ... racy-10016

I like this quote:

"No other conclusion can be drawn but that in the future, as soon as 2014 and as late as 2020, high-accuracy GPS receivers (cm-level in both horizontal and vertical) will be in the hands of anyone with a few hundred dollars to spend. This will be consumers as well as professional geospatialists."

Cool, I'll put a new GPS on my wish list for about 2015 :D
This will be interesting. I updated the list to show smartphone GPS applications, I'm wondering in light of the new technology if it will be necessary to buy a dedicated GPS device? (I notice Garmin is entering the smartphone market)
lightweight, cheap, strong... pick 2

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Eric Peterson
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Re: Open Source TOPO map/GPS software...

Post by Eric Peterson » January 13th, 2012, 7:04 am

:? Wow, Back Country Navigator really works on Android SmartPhones?

Downloading the demo now and I guess I will find out!

I have a LG smartphone and wonder if it will work with GPS when there is no cell
coverage, like over on the Wilson River Trail.
Last edited by Eric Peterson on January 13th, 2012, 7:24 am, edited 1 time in total.

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