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."
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.
Open Source Java Web Forum with LDAP authentication
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
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.