! 3D Geodetic adjustment using GPS observations and ellipsoidal heights.
! Apply GPS rotation and scaling to compute station SAND


! Define datum
! Datum Name; Semi-Major Axis; 1.0 / Flattening
_DATUM; NAD 83; 6378137.000000; 298.257222101


! Define the Units used in this file
! M - meters, U - US Feet, I - International Feet, C - Chains
! D - DMS, DD - Decimal Degrees, G - Grads (Gons), 
! Note: Lat and Lon must always be in DMS format (e.g., 100-30-40.1234 is entered as 100.30401234)
_UNITS; M; D


! Grid zone
_ADJUST_GRID; ILLINOIS,W,1202,TM


! Station 'HORSE' to be fixed in Lat(north), Lon(east), Hgt.
_LAT_NORTH_FIX;	HORSE
_LON_EAST_FIX; HORSE
_HGT_FIX; HORSE


! Station 'SKY' to be fixed in Lat(north), Lon(east), Hgt.
_LAT_NORTH_FIX; SKY
_LON_EAST_FIX; 	SKY
_HGT_FIX; SKY


! Station 'SNAKE' to be fixed in Lat(north), Lon(east), Hgt.
_LAT_NORTH_FIX; SNAKE
_LON_EAST_FIX; SNAKE
_HGT_FIX; SNAKE


! Indicates the type of adjustment
_ADJUST_3D_LATLONHGT


! Use ellipsoid height field (for each station) instead of ortho height field during adjustment
_ADJUST_USE_ELLIPHGT


! Define if unknown stations (referenced by observations) should be created at Adjust Time.
! Unknown stations are those not defined in the _STA_COORD record (see below).
_ADJUST_CREATE_MISSING_STATION


! All variances (squared standard deviation) will be multiplied by this value prior to adjustment
_ADJUST_APRIORI_FACTOR; 1.0


! Perform no more than this number of iterations when solving the adjustment. Most networks will
! converge within two to seven iterations when input data contains no major blunders. 
_ADJUST_MAX_ITER; 10


! Consider the adjustment completed, when the current iteration moves station coordinates less than
! this value (from the previous iteration).
_ADJUST_CONVERGE_CRITERIA; 0.001


! Confidence level for reporting - 95%
_ADJUST_CONFIDENCE_LEVEL; 0.95


! Compute and apply rotation and scale corrections to GPS observations 
_ADJUST_GPS_SCALE;
_ADJUST_GPS_ROT_N;
_ADJUST_GPS_ROT_E;
_ADJUST_GPS_ROT_U;


! Coordinate definition for control station HORSE, SKY and SNAKE
!           Name;  Lat;    Lon;     OrthoHgt;   EllipHgt;   North; East; NorthSD; EastSD; HgtSD;  CorrNE; CorrNH; CorrEH; DeflNS; DeflEW
_STA_COORD; HORSE; 40;     -90.20;  1033.07584;  999.99994; 0.;    0.;   0.0001;  0.0001; 0.0001; 0.;     0.;     0.;     0.;     0.
_STA_COORD; SKY;   39.45;  -89.30;  1531.8815;   1499.3725; 0.;    0.;   0.0001;  0.0001; 0.0001; 0.;     0.;     0.;     0.;     0.
_STA_COORD; SNAKE; 39.30;  -89.50;  1131.5913;   1099.4643; 0.;    0.;   0.0001;  0.0001; 0.0001; 0.;     0.;     0.;     0.;     0.


! GPS observations
!             AT Name; TO Name;  dx;       dy;         dz;        xx;      xy;  yy;    xz;  yz;  zz (upper diag column order)
_OBS_GPS_SET; HORSE;   SKY;      71330.;   -18079.2;   -20986.6;  0.1225;  0.;  0.18;  0.;  0.;  0.245
_OBS_GPS_SET; HORSE;   SNAKE;    42807.35; -35643.35;  -42625.7;  0.045;   0.;  0.08;  0.;  0.;  0.1225
_OBS_GPS_SET; HORSE;   SAND;     21334.7;  -11877.05;  -14259.75; 0.02;    0.;  0.045; 0.;  0.;  0.08
_OBS_GPS_SET; SNAKE;   SKY;      28524.;    17563.7;    21638.55; 0.32;    0.;  0.245; 0.;  0.;  0.18
_OBS_GPS_SET; SAND;    SKY;      49995.7;   -6202.;     -6726.7;  0.18;    0.;  0.245; 0.;  0.;  0.32
_OBS_GPS_SET; SAND;    SNAKE;    21472.25; -23765.6;   -28365.25; 0.02;    0.;  0.045; 0.;  0.;  0.08