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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."
... I don't even remotely understand what this post is about. ARLUT? RINEX? cycle slip detection? TEC? SLOC? COCOMO?
anyone that has worked with GPS and GIS data know the real hard part is fixing and processing all the data. Getting the data into a database in a normalized format is perhaps one of the most challenging parts of building a gps/gis application. luckily companies like NavTech provide good data that is supplemented with their own surveys.
So, uh, like... does this mean I can find a geocache faster?
-- Minds are like parachutes... they work best when open.
Just the other day, I was trying to find a way to calculate the total electron content of the ionosphere.
Unknown host pong.
I'm still not gonna stop and ask for directions.
When I bought my Garmin Etrex, I wanted to use it to store mountain bike rides and overlay them with maps. Easy, right? Bah! 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.
The other featuer I've always wanted is to do profile slices of my rides to see climbing and descending rates, especially during races.
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'm going to be spending the evening trying to get this stuff working, hopefully it will provide a replacement to my current Garmin/Microsoft solution!
I think the importance is that a project of this magnitude and complication was released to the public under a nice license.
(S(SKK)(SKK))(S(SKK)(SKK))
If you use a GPS for geocaching, there is already a set of GPS tools for the Linux user here.
Meh.
It's amazing what guys are willing to go through to avoid getting out of the damn car and asking for directions. ;)
-- "A chicken is an egg's way of making another egg."
Advanced Research Labs: Unreal Tournament?
This sig is only here so people stop skipping the last lines of my posts.
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.
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
RINEX = Receiver Independent Exchange Format, http://www.ngs.noaa.gov/CORS/Rinex2.html
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/
COCOMO = an obsolete software development cost model http://www.jsc.nasa.gov/bu2/COCOMO.html
Check out item 4 (emphasis added):
You should know your way around a command line or terminal. For UNIX users, this is a given. For Windows users, using the command line (referred to as "DOS prompt" sometimes) may be a challenge.
Ouch!
Root-Mean-Square (ie, Richard Stallman) won't like it, of course. The FSF strongly recommends all software be under the GPL, not the LGPL. Myself, I think that's a serious mistake. Private enterprise is not, and never has been, the enemy. It's particularly a mistake when you want a package to become a de facto standard, and then do your best to ensure the private sector can't use it.
I thought I would introduce some politics into what is a rather boring technical /. post.
Please correct me if I'm wrong, but this software is very important. This is the software that normally runs inside the GPS, not for drawing maps, but interpreting the GPS radio signals and calculating the lat/long numbers. Why would this be useful? Well, say, you take a project like GnuRadio and make your own GPS receiver. GnuRadio can demodulate the signals and convert it to data. This software would allow you to take the data you receive with GnuRadio and do something with it.
It seems to me that this is first time that code like this has ever been published under an open license.
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.
c rodem.htm/ and Radio Mobile http://www.cplus.org/rmw/english1.html/ by Roger Coudé VE2DBE. Both programs have some powerful features, BUT...
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/mi
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!
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.
Finally -- a means of writing the software required for my GPS-guided canine shock collar defecation system. Now I can just turn the dog loose and not have to worry about her pooping in a different place every time she gets her dump on.
Shit on the driveway? SHOCK!
Crap in the neighbor's yard? SHOCK!
Crap in mean neighbor's yard? NO SHOCK! (subroutine for OPTIONAL shit locations).
Poop near the mailbox? SHOCK!
Drop a deuce in the back corner of the yard near all the other piles of shit? NO SHOCK!
(C) Copyright 2004 by IronChefMorimoto Pet Waste Management Technologies
IronChefMorimoto
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:
hope it helped
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:
.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).
1. USAPhotoMaps. [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
Cons: cannot plot more than one trackpoint on the map.
2. Quakemap. [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?
"When the only tool you own is a hammer, every problem begins to resemble a nail." - Abraham Maslow (1908-1970)
What you get from YOUR GPS is an autonomous position estimate.
What I get from my array of GPS receivers is a set of observables, including the pseudorange from the code phase measurements, and carrier phase information. When I get done processing, I have a set of baselines, a set of potential delays in the troposphere and ionosphere, doppler shifts for the satellites in view, timing deltas, and information on signal multipath propagation.
When I report something out, I can give horizontal positions with respect to a known coordinate system to about 1 cm (2sigma RMS) and vertical estimates (referenced to the WGS84 ellipsoid) on the order of 2 cm (2sigma RMS). Given a good gravity model, I can estimate geoid height differences to about 3 cm.
Given code phase observables from a satellite-borne receiver, I can make reasonable estimates of the satellite's ephemerides and state vector, provided 3 sets with a temporal spread of about 20 minutes. Given code and carrier data I can derive the state vector in less time and with better accuracy.
I can estimate the amount of precipitable water in a vertical column of atmosphere above a GPS receiver site.
I can make estimates of the ionosphere's total electron count.
There's more.
For the record, I've been doing all of the above, for several years.
Never ascribe to malice that which can adequately be explained by tenure.