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GPS Toolbox List of modules and programs

To go to one of the below section click the desired link.

(1) GPS related constants and conversion factors

convcon most used conversion constants
gpscon most used GPS constants
pz90con most used PZ-90 constants
sgs85con most used SGS-85 constants
wgs72con most used WGS-72 constants
wgs84con most used WGS-84 constants
xcon main program displaying constants specified in macros convcon, gpscon, pz90con, sgs85con, wgs72con, and wgs84con

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(2) Angle transformations

tadmsrad degrees/minutes/seconds to radians
taraddms radians to degrees/minutes/seconds
xatransf main program executing angle transformations from/to degrees/minutes/seconds to/from radians (by selection)

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(3) Coordinate transformations - Point transformation

tecefgd ECEF to geodetic coordinates (direct method)
tecefgd2 ECEF to geodetic coordinates (iterative method)
tgdecef geodetic to ECEF coordinates
xecef2gd_comp main program executing comparison between two ECEF to geodetic transformation methods
xptransf main program executing transformations from/to ECEF/geodetic to/from geodetic/ECEF coordinates

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(4) Coordinate transformations - Matrix transformation

mbllw GPS body to LLW (Local Level Wander azimuth)
mecefeci ECEF (Earth Centered Earth Fixed) to ECI (Earth Centered Inertial)
mecefenu ECEF (Earth Centered Earth Fixed) to ENU (East, North, Up)
mecefins ECEF (Earth Centered Earth Fixed) to INS (Wander/ North, West, Up)
mecefllw ECEF (Earth Centered Earth Fixed) to (Local Level Wander azimuth)
meciecef ECI (Earth Centered Inertial) to ECEF (Earth Centered Earth Fixed)
menuecef ENU (East, North, Up) to ECEF (Earth Centered Earth Fixed)
menullw ENU (East, North, Up) to LLW (Local Level Wander azimuth)
minsecef INS (Wander / North,  West, Up) to ECEF (Earth Centered Earth Fixed)
mllwb LLW (Local Level Wander azimuth) to  GPS body
mllwecef LLW (Local Level Wander azimuth) to ECEF (Earth Centered Earth Fixed)
mllwenu LLW (Local Level Wander azimuth) to ENU (East North Up)
xmtransf main program generating matrix transformations specified in the above mentioned list (by selection)

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(5) Coordinate transformations - Vector transformation

vbllw GPS body to LLW (Local Level Wander Azimuth)
vecefeci ECEF (Earth Centered Earth Fixed) to ECI (Earth Centered Inertial)
vecefenu ECEF (Earth Centered Earth Fixed) to ENU (East, North, Up)
vecefgd ECEF (Earth Centered Earth Fixed) to Geodetic (latitude, longitude, altitude) for a given position vector and a reference point
vecefins ECEF (Earth Centered Earth Fixed) to INS (Wander / North, West, Up)
vecefllw ECEF (Earth Centered Earth Fixed) to LLW (Local Level Wander azimuth)
vecefp90 ECEF (Earth Centered Earth Fixed) to PZ-90 (Parametri Zemli 1990)
vecefs85 ECEF (Earth Centered Earth Fixed) to SGS-85 (Soviet Geodetic System 1985)
veciecef ECI (Earth Centered Inertial) to ECEF (Earth Centered Earth Fixed)
venuecef ENU (East, North, Up) to ECEF (Earth Centered Earth Fixed)
venugd ENU (East, North, Up)  to Geodetic (latitude, longitude, altitude) for a given position vector and a reference point
venullw ENU (East, North, Up) to LLW (Local Level Wander azimuth)
vgdecef Geodetic (latitude, longitude, altitude) to ECEF (Earth Centered Earth Fixed), for a given position vector specified by the external points in geodetic coordinates
vgdenu Geodetic (latitude, longitude, altitude) to ENU (East, North, Up) for a given position vector specified by the external points in geodetic coordinates
vinsecef INS (Wander / North, West, Up) to ECEF (Earth Centered Earth Fixed)
vllwb LLW (Local Level Wander azimuth) to  GPS body
vllwecef LLW (Local Level Wander azimuth) to ECEF (Earth Centered Earth Fixed)
vllwenu LLW (Local Level Wander azimuth) to ENU (East North Up)
vp90ecef PZ-90 (Parametri Zemli 1990) to ECEF (Earth Centered Earth Fixed)
vs85ecef SGS-85 (Soviet Geodetic System 1985) to ECEF (Earth Centered Earth Fixed)
xvtransf main program executing vector transformations specified in the above mentioned list (by selection)

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(6) Specialized plotting programs

xpbar bar graph for a selected column
xyp1 x-y graph for a selected column
xyp1s x-y graph for a selected column, with statistics
xyp2w x-y graph for two selected columns in two different windows/subplots, with statistics
xyp3w x-y graph for three selected columns in three different windows/ subplots, with statistics
xypc2 x-y graph of the difference between columns (from different  files), with statistics
xypc2rss x-y graph for RSS (root sum square) of the difference of  three columns from two files, with statistics
xypm x-y graph for the selected multiple columns
xyprss x-y graph for RSS (root sum square) of three selected  columns, with statistics
xyprss2w x-y graph for RSS (root sum square) of three selected columns corresponding to position and velocity errors, in two  windows/subplots, with statistics
xypvstd x-y graph for a selected column and the associated envelope (standard deviation), with statistics

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(7) Specialized statistics related functions

cep circular error probable (CEP)
rms root mean square (RMS) of a sample
rms2 modified root mean square (RMS) of a sample (mean of the sample is assumed to be zero)
rss root sum square (RSS) of a three component vector sample
rssxy root sum square (RSS) of a two component vector sample
vep vertical error probable (VEP)
statup running mean, standard deviation and root mean square (rms)
xcepvep main program determining the CEP or VEP of a specified data set
xstat main program testing the macros: rms, rss, rssxy, and statup
xstatc main program determining the mean, standard deviation and rms of the elements of a specified column

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(8) Specialized signal processing and Kalman filter functions

dcmnorm normalization of the direction cosines matrix
genrn random numbers with normal (Gaussian) distribution, with mean and standard deviation specified
gmp1 first order Gauss-Markov sequence
gmp2 second order Gauss-Markov sequence
kfcov Kalman filter covariance matrix by using conventional formulation
kfcova Kalman filter covariance matrix by using alternate conventional formulation
rwalk random walk process
xgenrn main program generating the random numbers with normal (Gaussian) distribution and plotting the generated sequence, histogram, and the normalized auto-correlation sequence
xgmp1 main program generating first order Gauss-Markov sequence and plotting the generated sequence and the normalized auto-correlation sequence
xgmp2 main program generating second order Gauss-Markov sequence and plotting the generated sequence and the normalized auto-correlation sequence
xkfcov main program performing the covariance analysis by using the conventional or alternate conventional Kalman filter formulation
xrwalk main program generating the random walk process and plotting the generated sequence and the normalized auto-correlation sequence

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(9) GPS Time Utilities and related functions

cday determination of the civil day (year, month, day, hour and fraction) from a specified modified Julian day (with fraction)
doy2ymd determination of civil date (year, month, day) from day of year and specified year
gpslsec UTC leap seconds value for a specified year between 1980 and 2059
leapyear determination of the leap year value
mjday determination of the modified Julian day from the civil day (year, month, day, hour and fraction)
timetr determination of GPS time of transmission based on time of measurement (reception)
ymd2doy determination of day of year for a specified civil date  (year, month, day)
ymd2doy2 determination of day of year for a specified civil date  (year, month, day) - different algorithm
ymd2gps determination of (GPS week, GPS roll number, day of week) from (year, month, day)
xgpslsec main program determining UTC leap seconds value for a specified year between 1980 and 2059
xgpstime main program executing GPS time related transformations

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(10) GPS Almanac and other data processing functions

elimcol elimination of a specified column of a two dimensional array
elimrow elimination of a specified row of a two dimensional array
msc2f symmetric matrix storage transformation from compact form (upper triangular part, column-wise, one-dimensional array) to full form (all elements, two-dimensional array)
msf2c symmetric matrix storage transformation from full form (all elements, two-dimensional array) to compact form (upper triangular part, column-wise, one-dimensional array)
selectd selection of the different elements from a specified array
xelimrc main program testing the elimination of a specified row/column (see macros elimrow and elimcol)
xmisdat main program determining the missing data into a specified column of an input data table
xread_sem main program reading SEM almanac data and creating two data files
xread_yuma main program reading Yuma almanac data and creating two data files
xsortrec main program sorting the records based on the elements of a specified column (in ascending order)

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(11) Trajectory and related utilities

gcnav great circle navigation position, velocity, acceleration
geodes geodetic data for a specified departure-destination pair
geoidh WGS-84 geoid height correction
gridwaas generation of longitude-latitude WAAS grid
hpe horizontal position error (range) when latitude and longitude of two points are specified
trajs vehicle trajectory in straight segment with constant speed
xgcdr main program determining great circle dead reckoning trajectory
xgcnav main program determining great circle navigation position, velocity and acceleration
xgeodes main program determining geodesic when the departure and destination points are specified
xgeoidh main program determining WGS-84 geoid height correction, and  executing a contour map
xgridw main program plotting the longitude-latitude WAAS grid
xhpe main program determining the horizontal position error (range)
xppva main program determining acceleration from position/velocity data, and plotting all relevant trajectory information
xppvaj main program determining acceleration and jerk from  position and velocity data, and plotting all relevant trajectory information
xtrajs main program determining the vehicle trajectory with straight segment and constant speed

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(12) Satellite position and velocity computation

svpalm ECEF satellite position based on almanac data
svpeph ECEF satellite position based on ephemeris data
svpvalm ECEF satellite position and velocity based on ephemeris data
xsvpalm main program determining ECEF satellite position based on almanac data
xsvpcomp main program determining RSS satellite position difference based on ephemeris and almanac data, and executing the corresponding graph
xsvpeph main program determining ECEF satellite position based on  ephemeris data
xsvpvalm main program computing the ECEF satellite position and velocity based on almanac data; WGS-84 constants are used
xsvpvcomp main program computing the RSS between ECEF satellite position/velocity based on ephemeris and almanac data; WGS-84 constants are used
xsvpveph main program computing the ECEF satellite position and velocity based on ephemeris data; WGS-84 constants are used

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(13) Elevation and azimuth determination, and satellite visibility

eleva elevation angle and the ECEF unit line-of-sight vector
elevar elevation angle, the ECEF unit line-of-sight vector, and the range
elevaz elevation angle, azimuth angle, the ECEF unit line-of-sight vector, and range
range range between two position points
uverv unit vertical vector for a given ECEF position vector
xelaz main program determining elevation and azimuth angles for specified users, time interval, and all satellites in view
xpelaza main program executing the azimuth-elevation plot for all satellites in view, and the number of visible satellites plot
xpelazs main program executing graphs related to elevation and azimuth angles for a specified satellite and selected used (input file can be generated by xelaz)

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(14) DOPs computation, satellite selection and related functions

dop1 dilution of precision (DOP) quantities when at least 3 line-of-sight unit vectors are specified
dop2 dilution of precision (DOP) quantities when 4 line-of-sight unit vectors are specified
gdopv approximate geometric dilution of precision (GDOP) when four line-of-sight unit vectors are specified
hmat H matrix based on line-of-sight measurements
hmatb H matrix based on line-of-sight and baro measurements
hmatbc H matrix based on line-of-sight, baro and clock measurements
hmatc H matrix based on line-of-sight and clock measurements
svsel4 selection of a set of 4 satellites based on minimum GDOP
svsel5 selection of a set of 5 satellites based on minimum GDOP
svsel6 selection of a set of 6 satellites based on minimum GDOP
wdop1 weighted dilution of precision (WDOP) quantities when at least 3 line-of-sight unit vectors and the corresponding weighting factors are specified