******************************************************** The LAMBDA-method: Matlab implementation V2.1 ********************************************************Use and Liability-----------------Use of the accompanying LAMBDA software is allowed, but no liability for theuse of the software will be accepted by the authors or their employer, theDelft University of Technology.Giving proper credits to the authors is the only condition posed upon the useof the LAMBDA software. We ask you to refrain from passing the software tothird parties; instead you are asked to pass our (E-Mail) address to them, sowe can send the software upon their request. The reason is, that in this waywe have a complete overview of the users of the software, enabling us to keepeveryone informed of further developments.Implementation--------------The implementation is described in LGR report No 12: `The LAMBDA method forinteger ambiguity estimation: implementation aspects'.  Instead of aiming forutmost efficiency, our goal has been to make an implementation that is clearand that has a one-to-one correspondence to the report.For the accessing scheme of the matrices, we use the standard Matlab2-dimensional array, even in the case where the matrix is symmetric ortriangular.We are sure that still some efficiency can be gained, but for educationalreasons, as well for reasons of easy software maintenance we refrained fromthat.Testing and Updates-------------------We welcome any suggestion for improvement of the code, the in-sourcedocumentation and the description in the report.  We also would like toencourage you to communicate to us about results obtained with the LAMBDAmethod, and comparisons made with other methods.  We would also be muchobliged if you inform us in case you decide to use the method commercially. Assaid before, there are no restrictions on that, other than properlyacknowledging the designers of the method and their employer.At this moment, several implementations in other computer languages (C, C++)have been derived from the original Fortran version; none of them has beenmade public yet however. If you are planning to make a version in an otherlanguage, and would like to make it public, we would like you to contact us,in order to coordinate the efforts.  Updated information about the LAMBDAmethod will be available at http://www.geo.tudelft.nl/mgp/lambda/System requirements:--------------------The routines were written and tested on a PC, running Windows 95, with Matlabversion 5.1. Later on, the routines were also tested using Matlab 5.2 on a PC,running Linux (RedHat 5.2, kernel 2.0.36) as well as on a HP9000, running theHPUX operating system (version B.10.20). Although not tested, it is believedthat the routines will run on any system on which Matlab is installed. As faras known, none of the newer additions to Matlab were used, so it should workon older versions as well. The included demonstration requires graphicalcapabilities, so a windowing-system (either X11 or MS) is necessary for usingthe demonstration.Installation:-------------The software is provided as either a "zip-file", or a compressed unix"tar-file". Extract all files, using your favourite software, to any directoryyou wish. Make sure the directory is in the Matlab path. If necessary, thedirectory can be added to the Matlab path with the following commands,depending on your operating system: 	Unix:	      path (path,'/yourhome/yourdirectory');	VMS:	      path (path,'YOURDISK:[yourhome.yourdirectory]');	DOS/Windows:  path (path,'yourhome\yourdirectory');	Mac:	      path (path,'Yourdisk:yourdirectory:');It might be a good idea to place such a statement in your startup.m file, toavoid the necessity of issuing this command every time you wish to use theroutines. See your local installation of Matlab for instructions of how to dothis.Distibuted files:-----------------amb18.m       Example, based on a kinematic surveychistart.m    M-file to compute the size for the search ellipsoidContents.m    M-file, table of contents for Matlab help systemdecorrel.m    M-file to decorrelate the ambiguitiesgeofree.mat   Example, 2-dimensional, can be used in demonstrationlambda.ps     Documentation, in PostScript formatlambda.pdf    Documention in portable document formatlambda1.m     M-file, main routine, complete version, with optionslambda2.m     M-file, main routine, straigthforward solution, no optionslarge.mat     Example, 12-dimensional, can NOT be used in demonstrationldemo.m       M-file, demonstrationldldecom.m    M-file, LtDL-decompostionlsearch.m     M-file, ambiguity searchreadme.txt    This filesixdim.mat    Example, 6-dimensional, can be used in demonstrationsmall.mat     Example, 3-dimensional, can be used in demonstrationwritemat.m    M-file, write matrices, only used in demonstrationRevision history:-----------------27-APR-2000: First official release of the MATLAB code, named V2.006-MAR-2001: Update, setting the size of the search-ellipsoid             Effected files are "chistart.m", as well as the manual             This version was named V2.1Selected Literature on the LAMBDA method----------------------------------------Teunissen, P.J.G. (1993)    Least-squares estimation of the integer GPS ambiguities.  Invited lecture, Section IV Theory and Methodology, IAG General Meeting,   Beijing, China, August,  also in Delft Geodetic Computing Centre LGR series, No. 6, 16 pp.Jonge de, P.J., and C.C.J.M. Tiberius (1996)      The LAMBDA method for integer ambiguity estimation: implementation   aspects. Delft Geodetic Computing Centre LGR series, No. 12.  Available at "ftp://ftp.geo.tudelft.nl/pub/dejonge/papers/" as  PostScript version: lgr12.psTeunissen, P.J.G. (1995)    The least-squares ambiguity decorrelation adjustment: a method for fast   GPS integer ambiguity estimation.  Journal of Geodesy, Vol. 70, No. 1-2,  pp. 65-82.Teunissen, P.J.G. and Kleusberg, A (1998)    GPS for Geodesy, second enlarged edition, Springer Verlag  See especially chapter 8, GPS carrier phase ambiguity fixing concepts.  More literature can be found on our website, http://www.geo.tudelft.nl/mgp, look for "publications"------------------------------------------------------------------------Peter Joosten                                   Phone..: (31)15-2782713Delft University of Technology                  Fax....: (31)15-2783711Faculty of Civil Engineering and GeosciencesThijsseweg 112629 JA Delft                     The Netherlands                       Email..: P.Joosten@geo.tudelft.nl"One mile of road or railway brings you nowhere,                              one mile of runway brings you everywhere"------------------------------------------------------------------------