GPS Toolkit (GPSTk) 1.0 Released

rmach writes "Based on many years of work performed at ARL:UT, we have release GPSTk under the GNU LGPL. GPSTk is a cross platform library and set of applications that provides both fundamental and advanced GPS processing algorithms to the GPS and open source community. A wide array of functions are provided by the GPSTk library, including: RINEX I/O, ephemeris calculation, P-code generation, atmospheric refraction models, and positioning algorithms. GPSTk applications provided more concrete benefits to the user, including: cycle slip detection and removal, calculation of the Total Electron Content (TEC) of the ionosphere, position residual computation, and RINEX file manipulation. The library is about 41,000 SLOC with a COCOMO estimated cost to develop of about $1.3 million. You can also read more about it in the current issue (September '04) of Linux Journal."

Re:It's probably just me, but....

[Espectr0]

SLOC means source lines of code. COCOMO (construction code model) is the name of a method used to estimate costs of development, mostly in person-months needed to finish a project.

Geocaching with Linux

[ylikone]

If you use a GPS for geocaching, there is already a set of GPS tools for the Linux user here [rkkda.com].

Re:Track editing?

[rjstanford]

I highly recommend TopoFusion [topofusion.com]. No relationship other than a very satisfied customer. I got the free version, but paid the very reasonable $40 within a couple of days. Really good software and a very responsive developer.

Re:It's probably just me, but....

[InternationalCow]

All about RINEX: http://www.ngs.noaa.gov/CORS/instructions2/ Cycle slipping is explained here: http://www.gmat.unsw.edu.au/snap/gps/gps_survey/ch ap7/735.htm

Re:Track editing?

[swillden]

I spent two weeks trying to find a way to do this on my Linux box before giving up. I ended up paying out of my rear end to buy expensive Garmin maps and closed source software. Even then, I couldn't mix and match tracks, let alone cut and paste sections of them together to make trail maps.

Depending on exactly what you want to do, there are some in-progress Linux tools that are usable. gpsbabel is a tool that can convert track, route and waypoint files to and from a bunch of different file formats, including the Garmin MapSource files. Some of the file formats are text, so you can do pretty much anything you like by converting to one of those, munging the stuff with your favorite utilities and scripting language, and converting back to MapSource (or whatever).

For visualization and tracking, check out gpsdrive. You can download maps for it from various on-line sites. Rick Richardson's geo-* tools are a bunch of useful bash and (I think, haven't looked lately) perl scripts that do lots of useful things, like making it easy to download maps and stuff. Most of Rick's stuff is focused on geocaching (for which it's really great, BTW, especially in conjunction with gpx2html.

The other feature I've always wanted is to do profile slices of my rides to see climbing and descending rates, especially during races.

I don't know of anything to do this (maybe someone else does?) but if you're a programmer hacking it together yourself wouldn't be too hard, given gpsbabel to convert the data into a mungeable format so you can get the times, positions and altitudes (and I think Rick's code has some stuff for calculating distances).

All in all this toolkit sounds hugely promising, as the last time I looked at SF.net/Freshmeat the capabilities were nearly nil. All I want is a simple import module, track overlay over free downloadable maps, and a track editor...

I don't think this toolkit is what you're looking for. Oh, I forgot to mention, look at gpstrans for transferring data between your Vista and Linux. Works fine, and you don't have to use gpsbabel to get the data in a usable format.

We're off to a bad start here, unfortunately

[Anonymous Coward]

While I salute and thank the developers here for what looks like may be a useful and valuable package, I just downloaded the library and can see that we're off to a rather bad start.

Unfortunately, the whole build process requres "jam" (a tool from perforce.com). Arrrgghh!

That they are using Perforce is a very bad sign. The whole Perforce system is designed by people who didn't understand basic mathematics (as in Set theory), and consequently it's annoying as heck to use.

Give me BitKeeper or Sun's Teamware (if you have a golden key, and can by-pass the license restrictions) anyday. Or even CVS in a pinch.

But requiring Jam in a distribution? Have these folks never, ever heard of "configure" and autoconf?

Hopefully the rest of the code exhibits some technical cluefulness. But right now, I can see that we're off to a bad start.

To the developers: sorry to give you folks a hard time here, but someone really has to on this.

Acronyms and Terms Explained

[n2rjt]

I have a few of these:

GPS = global positioning system (but you knew that)

ephemeris calculation = modeling a satellite's orbit based on a handful of numbers, demonstrated by http://ssd.jpl.nasa.gov/eph_help.html [nasa.gov]

RINEX = Receiver Independent Exchange Format, http://www.ngs.noaa.gov/CORS/Rinex2.html [noaa.gov]

SLOC = source lines of code .. a simplistic and rather poor metric used to gauge the effort required to develop software. http://www.dwheeler.com/sloc/ [dwheeler.com]

COCOMO = an obsolete software development cost model http://www.jsc.nasa.gov/bu2/COCOMO.html [nasa.gov]

Re:Track editing?

[Anonymous Coward]

You can use Radio Mobile [cplus.org] to create the maps. It is designed to calculate radio frequency coverage based on terrain information, but it can be "abused" to create nice maps with different ways of displaying altitude, which is a very nice feature if you're planning bike rides. It also allows you to automatically fetch and overlay maps from MapQuest, MapPoint, Toporama and Terraserver. These maps can then be exported and used in programs like OziExplorer [oziexplorer.com] (shareware) or GPS Trackmaker [gpstm.com] (freeware), both of which can import, overlay and export waypoint and tracklog data. G7toWin [gpsinformation.org] is a great free tool to download, upload and convert GPS data.

Re:Track editing?

[garcia]

GPS Visualizer [gpsvisualizer.com]. This site is free and uses SVG to display maps. You can overlay GPX/LOC or track data (among others) over top of maps.

Re:Track editing?

[parkrrrr]

Oh, I forgot to mention, look at gpstrans for transferring data between your Vista and Linux. Works fine, and you don't have to use gpsbabel to get the data in a usable format.

Depending on what your definition of "a usable format" is, and keeping in mind that GPSBabel [sourceforge.net] has some built-in customization for whatever your favorite xSV file format may be, why not just do gpsbabel -i garmin -f /dev/tty00 -o [your-favorite-file-format] -F [filename] and do everything in one step?

Not that this has anything to do with GPSTk, which is designed to solve an entirely different class of problems.

Wissenbach Map3D does this

[wombatmobile]

When I bought my Garmin Etrex, I wanted to use it to store mountain bike rides and overlay them with maps.

Dave Wissenback's free program [cableone.net] "allows you to plan and record your hiking and mountain bike trips with a Garmin eTrex GPS receiver and share your local knowledge of trails with others. You can also use the program to print topographic maps with these trails, either on a single page or as a mosaic on many sheets of paper. And you can use the program to visualize planned or past trips in 3D by virtually flying across a landscape of colorized aerial photographs draped over a three dimensional terrain model."

Re:vertical tracking.

[Jussi K. Kojootti]

The calculation itself is not difficult, but in many countries getting the data is: At least here in Finland useful elevation datasets cost an arm and a leg.

OSS tools for GIS and Radio Modeling

[Anonymous Coward]

What would be a "killer app" for me would be a OSS tool to do terrain elevation modeling using DTED/DEM/SDTS datasets to do radio network modeling including radio path profiling, LOS profiles including fresnel zone projection. Given GPS coordinates, antennae elevations above ground level (AGL), and frequency and polarization of the radio signal the tool should be able to give path length, azimuth, verticle declination, freznel zone intrusion, etc.

Two so-called "free-ware" (as in cost, not OSS!) that I have used are MicroDEM/Terrabase from Prof. Peter Guth of the Oceanography Department, U.S. Naval Academy http://www.usna.edu/Users/oceano/pguth/website/mic rodem.htm/ [usna.edu] and Radio Mobile http://www.cplus.org/rmw/english1.html/ [cplus.org] by Roger Coudé VE2DBE. Both programs have some powerful features, BUT...

The problems I have with both of the programs:
1) Buggy
2) Windows Only
3) Not OSS
4) Poor/inconsistent UI

Unfortunately, both of these programs appear to be written by folks who have much more skill/knowledge about the subjects (GIS and radio telemetry) than they do about programming.

If they would only release the code under an OSS licensing scheme, perhaps others (professional SW developers?) could clean up (rewrite?) and improve/expand the capabilities. And we could have cross-platform availability to boot!

Re:Wasn't the Precision code classified? (NO)

[spankus]

Actually, Precision Code isn't classified, and it lists how to make it in Interface Spec Document 200 [uscg.gov]

The government encrypts the Pseudo Random Code with an encryption key that makes it hard to track.

Y-code is simply encrypted P Code.

Basically, this software package allows you to increase your accuracy, export and import GPS information, and model the ionosphere (a major source of error using the Coarse Acquisition (civilian) signals.

um, no.

[SuperBanana]

Well, say, you take a project like GnuRadio and make your own GPS receiver.

GPS depends upon measuring the time it takes radio signals to travel less than a meter or two. That's not possible without very specialized electronics. Furthermore- GPS units, at least the kind -you- can buy for a few hundred dollars, don't do any of this bull. They just use WAAS- aka broadcast-via-satellite DGPS.

Sorry to burst your bubble, but not everything can be done in software.

Re:vertical tracking.

[Anonymous Coward]

The southern part of Finland is in the "Shuttle Radar Topography Mission" dataset, which can be downloaded for free. It's a height map with 3 arcsecond resolution (US coverage has 1 arcsecond resolution).

Re:We're off to a bad start here, unfortunately

[rmach]

I agree with your critique. However, this code was extract from various projects using "jam" and there was not time/resources to do anything different. We may consider a change for the future and would welcome any community submissions that would improve the build process.

Re:Great! But....

[rmach]

You can use these processing routines with any hardware that provides access to the "raw" GPS data (range, phase, etal.). All GPS receivers aimed at the survey market allow this including units from Thales, Trimble, Allan Osborne, and others.

Re:How does this help the average GPSer?

[rmach]

I concur that the average GPS user will get no use out of this. However, it is useful in a variety of university, government, and commercial situations. Examples include ionospheric physicist using GPS to study and/or model the ionosphere, advanced GPS users that are trying to exploit GPS by utilizing the raw data, and developers of GPS receivers and GPS processing software.

Re:LGPL!

[rmach]

I would encourage you to re-reading the GPL and LGPL. I have done both and as I read both, the base GPL precludes linking a non-GPL appliction with a GPL library. They say on gnu.org a reason to use the GPL for a library is to give the open source community a competitive advantage over commercial products. They recommend the LGPL if you are wanting to become the defacto standard. Hence our choice of the LGPL for the license.

Re:Dude, where's my phone?

[Doc Ruby]

Yep, AGPS. The cheap, slow AGPS chip gets some GPS data, sends it over the phone's Net connection to a server. That server processes the data, generates the GPS coordinates, and returns it to the phone. The full GPS receivers aren't found in the smartphones, like my T600, because they're too expensive and powerhungry compared with the other features already crowding the phone. So AGPS processing would work with my hardware right now.

Re:Huh?

[spankus]

For the most part...if the accuracy you get from the GPS unit you have is sufficient....you have no need for this.

If however, you have higher accuracy requirements like less than 10m @ 95% then you need some form of augmentation....which this software will help you to acquire.

Here's a list of some of the features and what they'll do for you:

• It will allow you to convert GPS time
• Allow you to break out time and ephemerides
• It includes models for atmospheric (troposphere) and ionospheric delay (largest error source for all-in-view civil receivers)
• Includes a software implementation of RAIM (Receiver Autonomous Integrity Monitoring) which prevents bad satellites from screwing you over
• Computes out a possible ionospheric delay for your receiver
• Allows you to perform residual analysis on your measurements (helps you figure out whether the satellites are hosed or you are)
• and exports and imports data to and from the tool

• hope it helped

Other GPS data tools

[kelk1]

Nice to release these libs. UNAVCO has a nice free tool called teqc [unavco.org], but does not release the source. Also found that link with many interesting things with source code: http://www.ngs.noaa.gov/gps-toolbox/exist.htm Admitedly, all this is not very useful for geocaching ;)

Some more useful tools for mapping

[alphakappa]

If you want to use your gps trakpoints and display them over satellite maps, the best source for maps (in the US) is Microsoft Terraserver which hosts USGS maps. Extracting the maps is another thing. However, there are some really cool tools to do that:

1. USAPhotoMaps [jdmcox.com]. [FREE]This is a very simple interface which can download topology maps (the usual atlas maps), as well as black-and-white satellite imagery (down to 1 m), and color aerial maps (down to 0.25m for select cities.). It can also plot your gps trackpoints on the aerial photos/maps provided the output is in the form of garmin .gpx files, or some other formats. (Thankfully it is very easy to write a tiny program to convert your lat-long to these ASCII formats).
Cons: cannot plot more than one trackpoint on the map.

2. Quakemap [earthquakemap.com]. [Free initially, $9.99 to register]All the above features, plus the ability to plot as many trackpoints as you want plus a much more advanced interface plus the ability to track your gps receiver in real time over a satellite map (provided your receiver gives its output as NMEA). For 10 bucks, you get the ability to store the image files offline so that you can take this on a trip and see your vehicle tracked on cool aerial photos.

There are other tools that can download terraserver maps, but none that has the ease of the above two. (Please correct me if I'm wrong.)

There is an equivalent tool that does the same on OSX, but I can't recall the name.

Is there any tool that can download aerial photos for free for the rest of the world?

Re:Maybe offtopic

[Anonymous Coward]

Thanks to the NASA space shuttle SRTM mission (Feb. 2000) most of the inhabited area of the earth has been been scanned into digital elevation datasets.

All of North America in 3 arc-second (a.k.a 7.5 meter) resolution is available here: http://edcsgs9.cr.usgs.gov/pub/data/srtm/North_Ame rica_3arcsec/3arcsec/ [usgs.gov]

Using various GPS mapping programs your dad should indeed be able to track his location on waterways.

Re:Track editing?

[jfurtner]

Something like GPSMan [ncc.up.pt] will overlay over maps, download from the GPS, and show climb/descent rates and speeds over time and distance, but doesn't download them itself - you have to download and then georeference maps manually (or use a map that's already been referenced).

Written in Tk/Tcl, so it runs on Linux/OSX/Windows/anywhere you can run Tk/Tcl. It's what I've been using since I got a Foretrex. Just a sastified customer..

My problem is most of the free map sites I've found are only relevant to the US and don't show Canada.

JF