Quick Tips for Using COLUMBUS

Input File Samples

This section is intended to demonstrate, by example, how to create input files that can be read into COLUMBUS. All keywords used within these files are described in Appendix A of the User Manual. Please refer to this resource for additional information. (The User Manual may be downloaded from the Best-Fit Computing Web site at no charge.)

All keywords begin with the $ character. To embed comment lines anywhere in the file, begin the line with the exclamation point (!). These lines are ignored when the file is read into COLUMBUS.

Sample input files

• 1D Vertical Network
  
  
• Local NE (north, east) or NEE (north, east, elevation) adjustment
  
  
• 2D PLSS network from a recorded bearing distance plat
  
  
• Mixed Terrestrial/GPS Network with scalers and overridden covariance elements
  
  
• Network using terrestrial observations
  
  
• Network with centering errors, covariance scaler, and GPS baselines
  
  
• Network with PPM factor and overridden Standard Deviations
  
  
• Datum Transformation

1D Vertical Network

In this example, we have a simple vertical network consisting of six stations and seven height difference observation sets. The only station with a known height is BOB. This station is to be held fixed in 1D during the adjustment. Setting it to be fixed in 1D is part of the six-step process for performing network adjustments in COLUMBUS.

!***** BEGIN OF ASCII (Text) INPUT FILE *****
!
!
! See demo file "VERTICAL.TXT" instructions on adjusting a similar network
!
!
!
! If you do not want to provide the $DATUM record in your files, simply
! select the active datum (in this case, NAD 83) before loading the file.
! In the case of 1D Vertical networks, the datum specified has no effect
! on a network adjustment, therefore any datum you declare will be fine.
! All data within COLUMBUS must be associated with a datum.
$DATUM
  NAD 83
  6378137.000000
  298.257222101

! If you do not want to provide the $UNITS record in your files, simply
! select the active units (in this case, meters, degrees, DD.MMSS format)
! before loading the file. For 1D Vertical networks, only the linear units
! are applicable (in this example it is set to meters).
$UNITS
  M
  D
  1

! The $STATION_TYPE_FOR_OBS record is new beginning with version 3.5.1.135.
! It allows you to tell COLUMBUS what type of station to create when the
! station type is not found in the file. If an observation (in the file below)
! references a station name that is not defined (by its type, e.g., height
! type, geodetic type, utm type, etc.), then COLUMBUS will create this station 
! type when the file is loaded. A station type created in this way will be 
! assigned coordinates of ZERO. 
$STATION_TYPE_FOR_OBS
1D_VERT

! The one and only height control station.
$HEIGHT_COMPACT; BOB; 260.04050; 0.00000

! The height difference records weighted by standard deviation.
$HGTDIFF_COMPACT; BOB; CINDY; 2.56916; 0.002
$HGTDIFF_COMPACT; BOB; GABE; -0.44714; 0.003
$HGTDIFF_COMPACT; CINDY; DEBRA; 5.09749; 0.0025
$HGTDIFF_COMPACT; CINDY; FAYE; -1.98974; 0.0015
$HGTDIFF_COMPACT; DEBRA; ED; -3.82921; 0.0035
$HGTDIFF_COMPACT; ED; FAYE; -3.26777; 0.0007
$HGTDIFF_COMPACT; FAYE; GABE; -1.02169; 0.0009

!***** END OF ASCII (Text) INPUT FILE *****

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Local NE (north, east) or NEE (north, east, elevation) adjustment

In this example, we have a simple network consisting of four stations and four observation sets representing a square parcel. The purpose of this adjustment is to establish Local NE (or NEE) coordinates for Stations B, C, and D.

Station A has known coordinates. This station is to be held fixed in 2D (for a Local NE adjustment) or 3D (for a Local NEE adjustment).

This type of adjustment should only be performed in a limited area (a few square kilometers) to eliminate projection distortions. For projects that cover a larger area, please use one of other 2D/3D adjustment models.

The examples below applies only to COLUMBUS 3.6 or later. Earlier versions of COLUMBUS use a different input format.

!***** BEGIN OF ASCII (Text) INPUT FILE *****
!
!
! See demo file "NEE.TXT" instructions on adjusting a similar network
!
!
!
! To perform a 2D or 3D local NEE (north, east, elevation) adjustment, be
! sure to change the View to Local NE or Local NEE.

! If you do not want to provide the $DATUM record in your files, simply
! select the active datum (in this case, NAD 83) before loading the file.
$DATUM
  NAD 83
  6378137.000000
  298.257222101

! If you do not want to provide the $UNITS record in your files, simply
! select the active units (in this case, meters, degrees, DD.MMSS format)
! before loading the file.
$UNITS
  M
  D
  1


! The $STATION_TYPE_FOR_OBS record is new beginning with version 3.5.1.135.
! It allows you to tell COLUMBUS what type of station to create when the
! station type is not found in the file. If an observation (in the file below)
! references a station name that is not defined (by its type, e.g., height
! type, geodetic type, utm type, etc.), then COLUMBUS will create this station 
! type when the file is loaded. A station type created in this way will be 
! assigned coordinates of ZERO. In this example, we do not need the 
! $STATION_TYPE_FOR_OBS, because we have defined all the required station
! types with the $LOCAL_NEUE_COMPACT records.
$STATION_TYPE_FOR_OBS
3D_NEU


! In this sample, Station 'A' is held fixed in 2D or 3D, depending on the
! adjustment context (Local NE or Local NEE) respectively.
! $LOCAL_NEUE_COMPACT; STA NAME; N; E; Up; Elev
$LOCAL_NEUE_COMPACT; A; 10000.0; 10000.0; 0.0; 1000.0
$LOCAL_NEUE_COMPACT; B; 9999.800; 11499.070; 0.0; 1052.460
$LOCAL_NEUE_COMPACT; C; 11709.619; 11499.170; 0.0; 1082.453
$LOCAL_NEUE_COMPACT; D; 11697.686; 10000.178; 0.0; 911.337


! Azimuth, zenith angle, and chord distance to backsight station 'D'.
$AZ_COMPACT; A; D; 0.0000; 0.001; 93.0000; 25.000; 1700.000; 0.01; 0; 0

! Horizontal angle, zenith angle, chord distance records.
$HOR_COMPACT; A; B; D; 90.0000; 20.0; 88.0000; 25.0; 1500.000; 0.01; 0; 0
$HOR_COMPACT; B; C; A; 90.0000; 20.0; 89.0000; 25.0; 1710.000; 0.01; 0; 0
$HOR_COMPACT; C; D; B; 89.3230; 20.0; 96.3100; 25.0; 1508.770; 0.01; 0; 0

!***** END OF ASCII (Text) INPUT FILE *****

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2D PLSS network from a recorded bearing distance plat

In this example, we have a simple 2D geodetic network consisting of six stations and seven PLSS bearing-distance observation sets that represent the perimeter of the east half of a section. The purpose of this adjustment is to establish latitude and longitude for PLSS corners using record data and one or more control points. These adjusted positions (lat/long) might be used "as-is" or they may be transformed to State Plane, UTM or Local NEU for use in GIS systems or to facilitate a search for lost corners in the project area.

The only station with known geodetic coordinates is "1". This station is to be held fixed in 2D during the adjustment. Setting it to be fixed in 2D is part of the six-step process for performing network adjustments in COLUMBUS. The average project height in the area is 6000 feet, which is set up in the Options | Network Options | Network Settings dialog prior to adjustment.

!***** BEGIN OF ASCII (Text) INPUT FILE *****
!
!
! See demo file "BEAR2D.TXT" instructions on adjusting a similar network
!
!
!
! To perform a 2D geodetic adjustment at an average project height, be
! sure to change the View to 2D geodetic and enter the average project
! height in the Options | Network Options | Network Settings dialog.

! If you do not want to provide the $DATUM record in your files, simply
! select the active datum (in this case, NAD 27) before loading the file.
$DATUM
  NAD 27
  6378206.400000
  294.978698214

! If you do not want to provide the $UNITS record in your files, simply
! select the active units (in this case, chains, degrees, DD.MMSS format)
! before loading the file.
$UNITS
  C
  D
  1

! The $STATION_TYPE_FOR_OBS record is new beginning with version 3.5.1.135.
! It allows you to tell COLUMBUS what type of station to create when the
! station type is not found in the file. If an observation (in the file below)
! references a station name that is not defined (by its type, e.g., height
! type, geodetic type, utm type, etc.), then COLUMBUS will create this station 
! type when the file is loaded. A station type created in this way will be 
! assigned coordinates of ZERO. 
$STATION_TYPE_FOR_OBS
2D_GEO

! The one and only geodetic control station.
$GEO_COMPACT; 1; 44.2621; 0.0; -105.0458; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0; 0

! The remaining records are bearing and distance records. Distances and
! standard deviations are in chains. Since the PLSS bearings are usually
! average bearings (between each station), they should be rotated to true
! bearings during an adjustment. To do this, be sure to enable the Rotate
! Bearings checkbox in the Options | Network Options | Network Settings dialog.
$BEAR_COMPACT; 1; 2; 0.2400; 15.0; NE; 40.270; 0.01
$BEAR_COMPACT; 1; 92; 89.1800; 15.0; SW; 39.790; 0.01
$BEAR_COMPACT; 10; 98; 0.0310; 15.0; NE; 40.297; 0.01
$BEAR_COMPACT; 2; 10; 89.2110; 15.0; SW; 40.024; 0.01
$BEAR_COMPACT; 2; 3; 0.2400; 15.0; NE; 40.270; 0.01
$BEAR_COMPACT; 3; 98; 89.2400; 15.0; SW; 40.260; 0.01
$BEAR_COMPACT; 92; 10; 0.0320; 15.0; NE; 40.302; 0.01

!***** END OF ASCII (Text) INPUT FILE *****

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Mixed Terrestrial/GPS Network with scalers and overridden covariance elements

In this example, we have a simple geodetic network consisting of six stations and both GPS and terrestrial observation sets. We have scaled some of the chord distances and all GPS vectors. Some observations have not been measured, and they are denoted by the "NOOBS" entries. Lastly, we have overridden variance elements of the covariance matrix for each GPS baseline.

!***** BEGIN OF ASCII (Text) INPUT FILE *****
!
!
! See demo file "MIXED.TXT" for instructions on adjusting a similar network
!
!
!
! If you do not want to provide the $DATUM record in your files, simply
! select the active datum (in this case, NAD 83) before loading the file.
$DATUM
  NAD 83
  6378137.000000
  298.257222101

! If you do not want to provide the $UNITS record in your files, simply
! select the active units (in this case, meters, degrees, DD.MMSS format)
! before loading the file.
$UNITS
  M
  D
  1

! The $STATION_TYPE_FOR_OBS record is new beginning with version 3.5.1.135.
! It allows you to tell COLUMBUS what type of station to create when the
! station type is not found in the file. If an observation (in the file below)
! references a station name that is not defined (by its type, e.g., height
! type, geodetic type, utm type, etc.), then COLUMBUS will create this station 
! type when the file is loaded. A station type created in this way will be 
! assigned coordinates of ZERO. 
$STATION_TYPE_FOR_OBS
3D_GEO

! The one and only geodetic control station
$GEO_COMPACT; MACK; 40.0; 0.0; -90.2; 0.0; 1033.07; 0.0; -33.07; 0.0; 1000.0; 0.0; 2.0; 0.0; -2.5; 0.0

! Azimuth, zenith angle, chord distance records.
$AZ_COMPACT; 5010; TIN CUP; NOOBS; NOOBS; 89.36158; 0.5; 39879.3; 0.3; 0.0; 0.0
$AZ_COMPACT; BEND; TEMPE; NOOBS; NOOBS; 90.06146; 1.0; 63289.7; 0.4; 0.0; 0.0
$AZ_COMPACT; BENTLY; 5010; 149.4917; 1.0; 89.55325; 0.5; 42784.35; 0.4; 0.0; 0.0
$AZ_COMPACT; TEMPE; 5010; 80.374; 0.5; 89.52; 0.6; 58127.0; 0.3; 0.0; 0.0
$AZ_COMPACT; TEMPE; MACK; NOOBS; NOOBS; 90.0221; 0.6; 66334.1; 0.3; 0.0; 0.0
$AZ_COMPACT; TIN CUP; 5010; NOOBS; NOOBS; 90.4513; 1.0; 39878.9; 0.5; 0.0; 0.0

! Scale all chord distances in the $HOR_COMPACT records
$S_CRD
 0.9999

! Horizontal angle, zenith angle, chord distance records.
$HOR_COMPACT; 5010; BEND; TIN CUP; 148.4843; 1.7; NOOBS; NOOBS; NOOBS; NOOBS; 0.0; 0.0
$HOR_COMPACT; 5010; BENTLY; MACK; 7.2913; 1.7; 90.27387; 0.5; 42784.15; 0.3; 0.0; 0.0
$HOR_COMPACT; 5010; MACK; TEMPE; 61.2636; 1.7; 90.2351; 0.5; 70141.3; 0.3; 0.0; 0.0
$HOR_COMPACT; 5010; TEMPE; BEND; 66.2808; 1.7; 90.39183; 0.5; 58126.6; 0.3; 0.0; 0.0
$HOR_COMPACT; BEND; 5010; TEMPE; 57.2107; 1.2; 89.3937; 1.; 57354.0; 0.4; 0.0; 0.0
$HOR_COMPACT; BEND; TIN CUP; 5010; 12.4321; 1.2; NOOBS; NOOBS; NOOBS; NOOBS; 0.0; 0.0
$HOR_COMPACT; BENTLY; MACK; TEMPE; 93.0702; 1.5; NOOBS; NOOBS; NOOBS; NOOBS; 0.0; 0.0
$HOR_COMPACT; BENTLY; TEMPE; 5010; 68.0134; 1.5; NOOBS; NOOBS; NOOBS; NOOBS; 0.0; 0.0
$HOR_COMPACT; MACK; 5010; BENTLY; 11.2212; 1.; NOOBS; NOOBS; NOOBS; NOOBS; 0.0; 0.0
$HOR_COMPACT; MACK; BENTLY; TIN CUP; 19.4754; 1.; 90.19495; 1.; 28276.75; 0.5; 0.0; 0.0
$HOR_COMPACT; MACK; TEMPE; 5010; 50.1921; 1.; 90.3329; 1.; 66334.0; 0.5; 0.0; 0.0
$HOR_COMPACT; TEMPE; 5010; BENTLY; 43.0244; 0.5; NOOBS; NOOBS; NOOBS; NOOBS; 0.0; 0.0
$HOR_COMPACT; TEMPE; BEND; 5010; 56.1052; 0.5; NOOBS; NOOBS; NOOBS; NOOBS; 0.0; 0.0
$HOR_COMPACT; TEMPE; BENTLY; MACK; 25.1128; 0.5; 90.0401; 0.6; 58487.2; 0.3; 0.0; 0.0

! Turn chord distance scaling OFF (scale by 1.0)>
$S_CRD
 1.0

! Scale all height differences in the $HGTDIFF_COMPACT records
$S_HGTDIFF
 0.999988

! Height difference records.
$HGTDIFF_COMPACT; BEND; BENTLY; 399.63; 0.03
$HGTDIFF_COMPACT; BENTLY; TEMPE; -199.9; 0.05
$HGTDIFF_COMPACT; TEMPE; MACK; 299.94; 0.02
$HGTDIFF_COMPACT; TIN CUP; 5010; -400.09; 0.04

! Turn height difference scaling OFF (scale by 1.0)
$S_HGTDIFF
 1.0

! Scale all GPS X, Y, Z components in the $GPS_COMPACT records
$S_X
 1.000001

$S_Y
 1.000001

$S_Z
 1.000001

! Override current covariance values with new variance values. Off-Diagonal
! elements will be forced to zero.
$G_X_VAR
 0.000025

$G_Y_VAR
 0.000030

$G_Z_VAR
 0.000035

! GPS baseline records.
$GPS_COMPACT; 5010; TIN CUP; 28524.0; 17563.7; 21638.55; 0.32; 0.0; 0.245; 0.0; 0.0; 0.18;
$GPS_COMPACT; BENTLY; 5010; 21472.25; -23765.6; -28365.25; 0.02; 0.0; 0.045; 0.0; 0.0; 0.08;
$GPS_COMPACT; BENTLY; TIN CUP; 49995.7; -6202.0; -6726.7; 0.18; 0.0; 0.245; 0.0; 0.0; 0.32;
$GPS_COMPACT; MACK; 5010; 42807.35; -35643.35; -42625.7; 0.045; 0.0; 0.080; 0.0; 0.0; 0.1225;
$GPS_COMPACT; MACK; BENTLY; 21334.7; -11877.05; -14259.75; 0.02; 0.0; 0.045; 0.0; 0.0; 0.08;
$GPS_COMPACT; MACK; TIN CUP; 71330.0; -18079.2; -20986.6; 0.1225; 0.0; 0.180; 0.0; 0.0; 0.245;

!***** END OF ASCII (Text) INPUT FILE *****

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Network using terrestrial observations

In this first example, we have a simple geodetic network consisting of four stations and six azimuth/zenith/chord observation sets. The only station with known geodetic coordinates is "AJAX". This station is to be held fixed in 3D during the adjustment. Setting it to be fixed in 3D is part of the six step process for performing network adjustments in COLUMBUS.

!***** BEGIN OF ASCII (Text) INPUT FILE *****
!
!
! See demo file "TERRONLY.TXT" for instructions on adjusting a similar network
!
!
!
! If you do not want to provide the $DATUM record in your input file, simply
! select the active datum (in this case, NAD 83) before loading the file.
$DATUM
 NAD 83
 6378137.000000
 298.257222101

! If you do not want to provide the $UNITS record in your input file, simply
! select the active units (in this case, meters, degrees, DD.MMSS format)
! before loading the file.
$UNITS
 M
 D
 1

! The $STATION_TYPE_FOR_OBS record is new beginning with version 3.5.1.135.
! It allows you to tell COLUMBUS what type of station to create when the
! station type is not found in the file. If an observation (in the file below)
! references a station name that is not defined (by its type, e.g., height
! type, geodetic type, utm type, etc.), then COLUMBUS will create this station 
! type when the file is loaded. A station type created in this way will be 
! assigned coordinates of ZERO. 
$STATION_TYPE_FOR_OBS
3D_GEO

! The one and only geodetic control station
$GEO_COMPACT; AJAX; 40.0; 0.0; -108.0; 0.0; 3000.0; 0.0; 0.0; 0.0; 3000.0; 0.0; 0.0; 0.0; 0.0; 0.0

! The remaining records are azimuth, zenith angle, chord distance records.
$AZ_COMPACT; AJAX; BLANCA; 21.0124; 3.0; 82.4930; 5.0; 1998.660; 0.015; 3.0; 3.0
$AZ_COMPACT; BLANCA; DONNER; 198.1553; 3.0; 85.5135; 5.0; 2685.140; 0.012; 6.0; 7.0
$AZ_COMPACT; CASTLE; AJAX; 293.5820; 3.0; 129.2659; 5.0; 788.750; 0.005; 2.0; 3.0
$AZ_COMPACT; CASTLE; BLANCA; 4.1326; 5.0; 96.5034; 5.0; 2119.234; 0.007; 0.0; 0.0
$AZ_COMPACT; DONNER; AJAX; 10.2700; 3.0; 122.0930; 5.0; 831.400; 0.008; 20.0; 21.0
$AZ_COMPACT; DONNER; CASTLE; 56.5830; 3.0; 85.4926; 5.0; 818.300; 0.009; 10.0; 11.0

!***** END OF ASCII (Text) INPUT FILE *****

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Network with centering errors, covariance scaler, and GPS baselines

In this example, we have a simple geodetic network consisting of four stations and six GPS baselines. We have established both a centering error correction and a covariance scaler for the first three baselines.

!***** BEGIN OF ASCII (Text) INPUT FILE *****

! If you do not want to provide the $DATUM record in your files, simply
! select the active datum (in this case, NAD 83) before loading the file.
$DATUM
  NAD 83
  6378137.000000
  298.257222101

! If you do not want to provide the $UNITS record in your files, simply
! select the active units (in this case, meters, degrees, DD.MMSS format)
! before loading the file.
$UNITS
  M
  D
  1

! Geodetic stations defined here
$GEO_COMPACT; FOBART; 39.45; 0.0; -89.30; 0.0; 1531.88; 0.0; -32.51; 0.0; 1499.37; 0.0; 0.0; 0.0; 0.0; 0.0
$GEO_COMPACT; FOZZIE; 40.0; 0.0; -90.20; 0.0; 1033.07; 0.0; -33.07; 0.0; 1000.00; 0.0; 0.0; 0.0; 0.0; 0.0
$GEO_COMPACT; FRANK; 39.30; 0.0; -89.50; 0.0; 1131.59; 0.0; -32.13; 0.0; 1099.46; 0.0; 0.0; 0.0; 0.0; 0.0
$GEO_COMPACT; FREDDY; 39.50; 0.0; -90.05; 0.0; 933.25; 0.0; -32.72; 0.0; 900.53; 0.0; 0.0; 0.0; 0.0; 0.0

! Turn ON the AT and TO station centering error estimates for the first three GPS baselines.
! AT horizontal error = 0.005m. AT vert error = 0.004m
! TO horizontal error = 0.007m. TO vert error = 0.008m
$CENTERING_GPSSET_SD;  0.005;  0.004;  0.007;   0.008

! Scale the covariance matrix by 1.5 for the first three GPS baselines. The covariance
! matrices will be scaled as each is loaded into COLUMBUS.
$S_XYZ_COV
1.5

$GPS_COMPACT; FOZZIE; FOBART; 71330.0; -18079.2; -20986.6; 0.1225; 0.0; 0.18; 0.0; 0.0; 0.245
$GPS_COMPACT; FOZZIE; FRANK; 42807.35; -35643.35; -42625.7; 0.045; 0.0; 0.08; 0.0; 0.0; 0.1225
$GPS_COMPACT; FOZZIE; FREDDY; 21334.7; -11877.05; -14259.75; 0.02; 0.0; 0.045; 0.0; 0.0; 0.08

! Turn OFF the AT and TO station centering error estimates for the remaining three GPS baselines.
$CENTERING_GPSSET_SD;  0.0;  0.0;  0.0;  0.0

! Scale the covariance matrix by 1.0 for remaining three GPS baselines (effectively turning scaling off)
$S_XYZ_COV
1.0

$GPS_COMPACT; FRANK; FOBART; 28524.0; 17563.7; 21638.55; 0.32; 0.0; 0.245; 0.0; 0.0; 0.18
$GPS_COMPACT; FREDDY; FOBART; 49995.7; -6202.0; -6726.7; 0.18; 0.0; 0.245; 0.0; 0.0; 0.32
$GPS_COMPACT; FREDDY; FRANK; 21472.25; -23765.6; -28365.25; 0.02; 0.0; 0.045; 0.0; 0.0; 0.08

!***** END OF ASCII (Text) INPUT FILE *****

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Network with PPM factor and overridden Standard Deviations

In this example, we have a simple geodetic network consisting of four stations and six terrestrial observation sets. We have established both a PPM factor (for chord distances), and we have overridden the standard deviation for each observation within the first three observation sets.

!***** BEGIN OF ASCII (Text) INPUT FILE *****

! If you do not want to provide the $DATUM record in your files, simply
! select the active datum (in this case, NAD 83) before loading the file.
$DATUM
  NAD 83
  6378137.000000
  298.257222101

! If you do not want to provide the $UNITS record in your files, simply
! select the active units (in this case, meters, degrees, DD.MMSS format)
! before loading the file.
$UNITS
  M
  D
  1

! Geodetic station with known and/or approximate coordinates
$GEO_COMPACT; AJAX; 40.0; 0.0; -108.0; 0.0; 3000.0; 0.0; 0.0; 0.0; 3000.0; 0.0; 0.0; 0.0; 0.0; 0.0
$GEO_COMPACT; BLANCA; 40.01; 0.0; -107.5930; 0.0; 3249.98; 0.0; 0.0; 0.0; 3249.98; 0.0; 0.0; 0.0; 0.0; 0.0
$GEO_COMPACT; CASTLE; 40.00; 0.0; -107.5936; 0.0; 3502.13; 0.0; 0.0; 0.0; 3502.13; 0.0; 0.0; 0.0; 0.0; 0.0
$GEO_COMPACT; DONNER; 39.59; 0.0; -108.0; 0.0; 3443.48; 0.0; 0.0; 0.0; 3443.48; 0.0; 0.0; 0.0; 0.0; 0.0

! The remaining records are azimuth, zenith angle, chord distance records.

! Apply a PPM factor of 7.0 ppm to the first three observation set chord distances
$PPM_CHORDDIST;  7.0

! Override the standard deviation for the azimuth, zenith angle, and chord distance
! in the first three observation sets. The new values will be:
! azimuth SD=10.0 seconds, zenith angle SD=15.0 seconds, chord distance SD=0.025m
$G_AZ_SD
 10.0

$G_ZEN_SD
 15.0

$G_CRD_SD
 0.025

$AZ_COMPACT; AJAX; BLANCA; 21.0124; 3.0; 82.4930; 5.0; 1998.660; 0.015; 3.0; 3.0
$AZ_COMPACT; BLANCA; DONNER; 198.1553; 3.0; 85.5135; 5.0; 2685.140; 0.012; 6.0; 7.0
$AZ_COMPACT; CASTLE; AJAX; 293.5820; 3.0; 129.2659; 5.0; 788.750; 0.005; 2.0; 3.0

! Turn OFF the PPM factor for the remaining chord distance observations
$PPM_CHORDDIST;  0.0

! Turn OFF the standard deviation settings above so that the actual standard deviation
! used for observation below will be the values defined in each $AZ_COMPACT record.
! Set to zero to turn off.
$G_AZ_SD
 0.0

$G_ZEN_SD
 0.0

$G_CRD_SD
 0.0

$AZ_COMPACT; CASTLE; BLANCA; 4.1326; 5.0; 96.5034; 5.0; 2119.234; 0.007; 0.0; 0.0
$AZ_COMPACT; DONNER; AJAX; 10.2700; 3.0; 122.0930; 5.0; 831.400; 0.008; 20.0; 21.0
$AZ_COMPACT; DONNER; CASTLE; 56.5830; 3.0; 85.4926; 5.0; 818.300; 0.009; 10.0; 11.0

!***** END OF ASCII (Text) INPUT FILE *****

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Datum Transformation

In this example, we have coordinates defined in two different datums. Using the common control from both datums (CARBON, CHANEY, FORT LEWIS and LA PLATA), we want to develop datum transformation parameters (three-, four-, or seven-parameter model) in order to transform the WGS 84 Stations 12, 14, and 15 to NAD 27 coordinates. This is how the input file could be set up.

!***** BEGIN OF ASCII (Text) INPUT FILE *****

$DATUM
  NAD 27
  6378206.400000
  294.978698214

! If you do not want to provide the $UNITS record in your files, simply
! select the active units (in this case, meters, degrees, DD.MMSS format)
! before loading the file.
$UNITS
  M
  D
  1

! Here are the control station NAD 27 coordinate values. Because the height
! component is not known, we set them to zero. The same will be done for the
! WGS 84 control stations.
$GEO_COMPACT; CARBON; 37.1356084; 0.007; -107.533388; 0.007; 0; 0; 0; 0; 0; 0.007; 0; 0; 0; 0
$GEO_COMPACT; CHANEY; 37.0111309; 0.008; -107.5812206; 0.008; 0; 0; 0; 0; 0; 0.008; 0; 0; 0; 0
$GEO_COMPACT; FORT LEWIS; 37.1543314; 0.01; -108.0133505; 0.01; 0; 0; 0; 0; 0; 0.01; 0; 0; 0; 0
$GEO_COMPACT; LA PLATA; 37.0217492; 0.009; -108.0953187; 0.009; 0; 0; 0; 0; 0; 0.009; 0; 0; 0; 0

$DATUM
  WGS 84
  6378137.000000
  298.257223563

! If you do not want to provide the $UNITS record in your files, simply
! select the active units (in this case, meters, degrees, DD.MMSS format)
! before loading the file.
$UNITS
  M
  D
  1

! Here are the WGS 84 control stations. Their heights have been set to zero,
! because we do not know the heights of the NAD 27 control stations.
$GEO_COMPACT; CARBON; 37.135609168; 0.001; -107.533612965; 0.001; 0; 0.001; 0; 0; 0; 0.001; 0; 0; 0; 0
$GEO_COMPACT; CHANEY; 37.011131526; 0.001; -107.581444698; 0.001; 0; 0.001; 0; 0; 0; 0.001; 0; 0; 0; 0
$GEO_COMPACT; FORT LEWIS; 37.15433187; 0.001; -108.013576145; 0.001; 0; 0.001; 0; 0; 0; 0.001; 0; 0; 0; 0
$GEO_COMPACT; LA PLATA; 37.021749242; 0.001; -108.095544828; 0.001; 0; 0.001; 0; 0; 0; 0.001; 0; 0; 0; 0

! These WGS 84 stations will be transformed to NAD 27 using the transformation
! parameters computed from the control stations in both datums.
$GEO_COMPACT; 12; 37.13329; 0.0205; -107.5557; 0.043; 2072.08; 0.028; 0; 0; 2072.08; 0.028; 0; 0; 0; 0
$GEO_COMPACT; 14; 37.134819; 0.013; -107.58401; 0.022; 2191.49; 0.021; 0; 0; 2191.49; 0.021; 0; 0; 0; 0
$GEO_COMPACT; 15; 37.082649; 0.0168; -108.01202; 0.038; 2303.01; 0.023; 0; 0; 23.01; 0.02; 0; 0; 0; 0

!***** END OF ASCII (Text) INPUT FILE *****