Interconnecting observations file

INTCOBS

The INTCOBS file is used to define a set of observations in a project, in a sub project or in a blocked partition.

The file can include observations of

Each traditional observation or set of observations can have a sigma record associated with it:

azimuth
distance
direction
orthometric height difference

Sample direction observation

 ----+---|----+----|----+----|----+----|----+----|----+----|----+----|----+----|
  51F16   0.5   0.0 0.0
   1F16 629009 LASH            629008  JADE              0  0  0.00000  .600   
   1F16 629009 LASH            629007  INDIA            60 39 37.56     .6

Direction record

1 - Code used to identify the record type
F16 - type used to identify Sigma group Column(4-6)
629009 - 9 character string used as unique identifier Column(7-15)
LASH - Name 16 character additional identifier Column(16-30)
629008 -9 character string used as unique identifier Column(7-15)
JADE - Name 16 character additional identifier Column(16-30)
0 - Initial direction degrees Column( 56-58)
0 - Initial direction minutes Column( 59-61)
0.00000 - Initial direction seconds Column( 62-70)
.600 - Standard deviation for the direction

Sigma direction record

51 - Code used to identify the record type
F16 - Type used to identify direction sets Column(4-6)
0.5 - Direction pointing standard deviation Column(7-14)
0.0 - Centering error stand point Column( 30-34)
0.0 - Centering error target Column(35-39)

Sample distance observation

 ----+---|----+----|----+----|----+----|----+----|----+----|----+----|----+----|
  52T33   3.0 3.0            0.0  0.0                                   GEODSCAL  
   2T33 629009 LASH            629008  JADE           1   13058.57000   4.934

Distance record

2 - Code used to identify the record type
T33 - type used to identify Sigma group Column(4-6)
629009 - 9 character string used as unique identifier Column(7-15)
LASH - Name 16 character additional identifier Column(16-30)
629008 -9 character string used as unique identifier Column(7-15)
JADE - Name 16 character additional identifier Column(16-30)
1 - indicates distance is a mark-to-mark distance Column(55)
13058.57000 - distance meters Column(56-70)
4.934 - Standard deviation for the distance

Sigma distance record

52 - Code used to identify the record type
t33 - Type used to identify distance sets Column(4-6)
3.0 - Distance standard deviation constant Column(7-14)
3.0 - Distance standard deviation ppm Column(15-19)
0.0 - Centering error stand point Column(30-34)
0.0 - Centering error target Column(35-39)
GEODSCAL - Identifies associated auxiliary parameter for distances with T33 Column(72-80)

Sample azimuth observation

 ----+---|----+----|----+----|----+----|----+----|----+----|----+----|----+----|
  53t56   0.5 0.0 0.0 0.0 0.0
   3t56 629003 EMBER           629006  HOPE           352 37  7.96000  1.269

Azimuth record

3 - Code used to identify the record type
t56 - type used to identify Sigma group Column(4-6)
629003 - 9 character string used as unique identifier Column(7-15)
EMBER - Name 16 character additional identifier Column(16-30)
629006 -9 character string used as unique identifier Column(7-15)
HOPE - Name 16 character additional identifier Column(16-30)
352 - azimuth degrees Column( 56-58)
37 - azimuth minutes Column( 59-61)
7.96000 - azimuth seconds Column( 62-70)
1.269 - Standard deviation for the azimuth

Sigma azimuth record

53 - Code used to identify the record type
t56 - Type used to identify azimuth sets Column(4-6)
0.5 - Azimuth pointing standard deviation Column(7-14)
0.0 - Standard deviation of instrument levelling Column(15_19)
0.0 - Standard deviation of longitude determination column(20-24)
0.0 - Centering error stand point Column(30-34)
0.0 - Centering error target Column(35-39)

Sample orthometric height difference observation

----+---|----+----|----+----|----+----|----+----|----+----|----+----|----+----|
 54t56   0.5                  0.0 0.0 
 14t56 629003    EMBER        629006  HOPE                    7.96000  1.269

14 - Code used to identify the record type
t56 - type used to identify Sigma group Column(4-6)
629003 - 9 character string used as unique identifier Column(7-15)
EMBER - Name 16 character additional identifier Column(16-30)
629006 -9 character string used as unique identifier Column(7-15)
HOPE - Name 16 character additional identifier Column(16-30)
7.96000 - orthometric height difference Column( 56-70)
1.269 - Standard deviation for the height difference

Sigma orthometric height record

54 - Code used to identify the record type
t56 - Type used to identify orthometric height difference sets Column(4-6)
0.5 - Orthometric height difference standard deviation Column(7-14)
0.0 - Rod error Column(30-34)
0.0 - Rod error Column(35-39)

Sample position equation observation

 ----+---|----+----|----+----|----+----|----+----|----+----|----+----|----+----|
  95dop a doppler survey
  96    629005   GATE                   63 53 49.31804 106 23 56.37197  530.0000
  96    629006  HOPE                    63 55 13.06801 106 45  1.25770  430.0000 
  97pov upper 
     1.0                 0.0                 0.0                 0.0     <-- 6 terms
     0.0                 0.0
     1.0                 0.0                 0.0                 0.0     <-- 5 terms
     0.0
     1.0                 0.0                 0.0                 0.0     <-- 4 terms
     1.0                 0.0                 0.0                         <-- 3 terms
     1.0                 0.0                                             <-- 2 terms
     1.0                                                                 <-- 1 terms

Code 95 record

dop - identifies the dataset as being Doppler data (col 4-6)
a doppler survey - is a data set identification - column(7-29)

Code 96 records

629005 - 9 character string used as unique identifier Column(7-15)
GATE - Name 16 character additional identifier Column(16-30)
63 - Latitude degrees
53 - Latitude Minutes
49.31804 Latitude seconds
106 - Longitude degrees
23 - Longitude Minutes
56.37197 -Longitude seconds
530.0000 - Ellipsoid height

Code 97 record

POV - Position Observation stored as Variance
UPPER - Associated matrix is stored in UPPER triangular form

The associated matrix in this case is stored as a simple diagonal matrix of 1.0 meters. The terms are stored in a fixed format of 20 digits per term (A fixed format has a constant number of columns for each term). Each record can have a minimum of 1 term and a maximum of 4 terms. For this matrix, because there are 2 stations and three terms per station, there is a total of 6 terms in the first row. The diagonal term is stored first so the first term is 1.0 the remaining 5 terms are 0.0, so require 2 records to store the 6 terms. (Blank is interperted as 0.0 in this case.)

The second row requires 5 terms, so 2 records, the third 4 terms so 1 record and 1 record for the remaing 3 rows

Sample GEODOP (tape9) position equation input

    95DOP A DOPPLER SURVEY       DOP75    9    2 
    94DOP A SCARER                SCPR 
    97POV UPPER

Code 95 record

A DOPPLER SURVEY - is a data set identification - column(7-29)
DOP75 - is a file name in the sub directory - column (32-34)
9 - indicates a tape9 format Column(40)
2 - indicates read 2 data sets from the file - column(46)

Code 94 record

DOP identifies this auxiliary parameter as belonging to a set of Doppler observations
A SCARER - Unique identifier for the Auxiliary parameter Column(7-15)
SCPR - Identifies the Auxiliary parameter as a sclae parameter Column (32-25)

Code 97 record

PO - Indicates Position Observation
V - Indicates Variance terms in the associated matrix
UPPER - indicates the terms are stored in an upper triangular format

Sample position difference equations

The same position difference expressed as Geographic coordinates, cartesian coordinates and cartesian coordinate difference. In this case the resultant observation equation will be exactly the same.

 91DOP A DOPPLER SURVEY
 96    629005 GATE                      63 53 49.31804 106 23 56.37197 530.0000
 96    629006 HOPE                      63 55 13.06801 106 45 1.25770 430.0000
 97PDV UPPER 
     1.0                 0.0                 0.0                         <-- 3 terms
     1.0                 0.0                                             <-- 2 terms
     1.0                                                                 <-- 1 terms
 91DOP A DOPPLER SURVEY  
 92   629005 GATE                  -794497.430    -2699646.004   5705149.790
 92   629006 HOPE                  -810353.560    -2692450.604   5706200.644
 97PDV UPPER 
     1.0                 0.0                 0.0                         <-- 3 terms
     1.0                 0.0                                             <-- 2 terms
     1.0                                                                 <-- 1 terms
 91DOP A DOPPLER SURVEY                                    
 41   629005    629006             - 15856.130        7195.400     -1050.854    
 97PDV UPPER 
     1.0                 0.0                 0.0                         <-- 3 terms
     1.0                 0.0                                             <-- 2 terms
     1.0                                                                 <-- 1 terms

Code 91 record

dop - identifies the dataset as being Doppler data
a doppler survey - is a data set identification - column(7:29)

Code 96 records

629005 - 9 character string used as unique identifier Column(7:15)
GATE - Name 16 character additional identifier Column(16:30)
63 - Latitude degrees
53 - Latitude Minutes
49.31804 Latitude seconds
106 - Longitude degrees
23 - Longitude Minutes
56.37197 -Longitude seconds
530.0000 - Ellipsoid height

Code 92 records

629006 - 9 character string used as unique identifier Column(7:15)
HOPE - Name 16 character additional identifier Column(16:30)
X coordinate - -810353.560 (Col 36:50)
Y coordinate - -2692450.604 (Col 51:65)
Z coordinate - 5706200.644 (Col 66:80)

Code 41 records

629005 - 9 character string used as unique identifier Column(7:15)
629006 - 9 character string used as unique identifier Column(16:25)
X coordinate difference - - 15856.130 (Col 36:50)
Y coordinate difference - 7195.400 (Col 51:65)
Z coordinate difference - - 1050.854 (Col 66:80)

Code 97 record

PDV - Position Difference observation stored as Variance
UPPER - Associated matrix is stored in UPPER triangular form

The second row requires 5 terms, so 2 records, the third 4 terms so 1 record and 1 record for the remaing 3 rows

Sample GEODOP (tape9) position difference input

 91DOP A DOPPLER SURVEY       DOP75    9    2 
 94DOP A SCARER                SCPR  scale aux.parameter
 97PDV UPPER           <--- 'd' in column 5 indicates position difference

Code 91 record

DOP75 - is a logical file name attached to the job
9 - indicates a tape9 format
2 - indicates read 2 data sets from the file

Code 94 record

A SCARER - Auxiliay parameter identification (Col 7:15)
SCPR - indicates a systematic scale error to solve (Col 32:35)

Code 97 record

POV - Position Observation stored as Variance
UPPER - Associated matrix is stored in UPPER triangular form

Sample partially reduced normals input

Partial reduced normal equations are produced by program Ghost as part of th Helmert block normal equation reduction. As such there is no way of checking the data for correctness.The code 92 records are the right side for the station as shown. The matrix is part of the reduced norml equations which includes the junction stations.

 93PRN PARTIAL NORMAL EQ
 92RHS 629005 GATE                 0.12345282790    0.3569546     0.000256780
 92RHS 629006 HOPE                 0.00012546789   10.8923456     1.000245367
 97RNE UPPER
 0.4273890883482E+04 0.2437562955840E+04-0.1998435290244E+04-0.6225107737697E+03
 0.1426218402441E+04-0.2187795836071E+04 
 0.6821359378078E+04-0.1531313380680E+04-0.1479628114046E+04-0.2907968407862E+05
 0.4460776248055E+04 
 0.1369205364267E+04 0.1146383934886E+04 0.3350223017495E+04 0.5139187627254E+03
 0.1798052821409E+04-0.2781685858370E+03-0.4267060870751E+03 
 0.1857232773571E+04 0.2848964872197E+04 
 0.9436558860551E+03

Code 93 record

PRN - identifies the dataset as being partial normal equation
PARTIAL NORMAL EQ - is a data set identification - column(7:29)

Code 92 records

629005 - 9 character string used as unique identifier Column(7:15)
GATE - Name 16 character additional identifier Column(16:30)
0.12345282790 - Latitude equation right hand side
0.3569546 - Longitude equation right hand side
0.000256780 Ellipsoid height right hand side

Code 97 record

RNE - Partially Reduced Normal Equation
UPPER - Associated matrix is stored in UPPER triangular form

The associated matrix in this case is stored as a upper triangular. The terms are stored in a fixed format of 20 digits per term (A fixed format has a constant number of columns for each term). Each record can have a minimum of 1 term and a maximum of 4 terms. For this matrix, because there are 2 stations and three terms per station, there is a total of 6 terms in the first row. The diagonal term is stored first and requires 2 records to store the 6 terms.

The second row requires 5 terms, so 2 records, the third 4 terms so 1 record and 1 record for the remaining 3 rows

Sample PRN exchange format input

The exchange format was devised as a method of exchanging partially reduced normal equations for the NAD83 adjustment between Canadaa and National Geodetic Survey in Washington. A subsequent revision was used for the NAVD88 adjustment

93PRN EXAMPLE EXCFMT          BLOCK1    1
97RNE

Code 93 record

PRN - Indicate a partially reduced data set (col3:6)
EXAMPLE EXCFMT - Indicates group identifier (col 7-30)
BLOCK1 File name for exchange format file (col 31-38)
1 Indicates exchange format file (col 41)

Code 97 record

RNE Indicates partial Reduced Normal Equations

Sample weighted station adjustment input

The weighted station adjustment input was originally devised for program GALS as a means for combining sets of equations that were too large for the computer at that time. The coordinate values are the currently adjusted values and the matrix is the elements of the covariance matrix associated with the unknowns as ordered by the station coordinates, converted to a weight matrix(inverse). Not all three components are required for this type of observation.

 93PRN example station adj
 96WSA 1001 STATION 1001               N29 5959.851957W 89 5959.734301 1966.2544
 96WSA 1004 STATION 1004               N30  146.853908W 90 14 8.733804
 96WSA 1005 STATION 1005               N30 1147.852079W 90 1458.732385 1924.2763
 97RNE UPPER       8   36    1     
0.3231464658313D+03 0.1069390522836D+03 0.9402132082595D+00 0.3233651567116D+03
0.1062788424866D+03 0.3233707125265D+03 0.1062402801474D+03 0.1146086152309d+01
0.9217684445842D+02 0.6012589059038D+00 0.1071281573108D+03 0.9195778501081D+02
0.1071368061730D+03 0.9194486496761D+02 0.1427203619137D+00
0.2816643143318D+02 0.9354729976487D+00 0.7743717061069D+00 0.8475322539185D+00
0.7856409979040D+00 0.2816167257509D+02
0.3235867621137D+03 0.1064668578710D+03 0.3235903361706D+03 0.1064286867044D+03
0.1140403066601D+01
0.9174708368797D+02 0.1064752721990D+03 0.9173239878167D+02 0.3154009464255d+00
0.3235980721251d+03 0.1064364140798d+03 0.1052411358544d+01
0.9171974252663d+02 0.3266458187867d+00
0.2817443304929d+02

Code 93 record

PRN - Indicates Partially Reduced Normal equations as a weighted station adjustment (col 3:6)
example station adj - identifier for the data set (col 7:30)

Code 97 record

RNE - Indicates partial Reduced Normal Equations
8 Indicates that there are 8 unknowns in this set
36 Indicates the matrix size
1 Indicates there is only 1 block

The associated matrix in this case is stored as a upper triangular. The terms are stored in a fixed format of 20 digits per term (A fixed format has a constant number of columns for each term). Each record can have a minimum of 1 term and a maximum of 4 terms. For this matrix, because there are 3 stations and three terms per stationfor the first and third stations with 2 for the middle, there is a total of 8 terms in the first row. The diagonal term is stored first and requires 2 records to store the 8 terms.

The second row requires 7 terms, so 2 records, the third 6 terms so 2 records until 1 record each for the last stations unknowns

Sample position correction constraint input

Sometimes it may be required to constrain one or more unknowns for a station rather than fixing them. The result should be the same as far as the coordinates are concerned, but you now have the covariance from the constrained station for analysis purposes.It is straightforward to produce these equations using program CNSTRT

C
 93PRN CONSTRAINT 
 92RHS 7193002                       0.0            0.0           
 97RNE UPPER
              1.0E20
              1.0E20

Code 93 record

PRN - Indicates Partially Reduced Normal equations as a constraint (col 3:6)
CONSTRAINT - identifier for the data set (col 7:30)

Code 92 records

RHS - Reduced Right Hand Side
7193002 - 9 character string used as unique identifier (col 7:15)
0.0 - Indicates the reduced right hand side term of 0.0 for latitude (col 36:50)
0.0 - Indicates the reduced right hand side term of 0.0 for longitude (col 51:65))

Code 97 record

RNE - Indicates partial Reduced Normal Equations

Note: The term 1.0e20 indicates a small variance 1.e-20. This along with the term of 0.0 means that the unknown will not take a correction

Sample auxiliary parameter constraint input

Sometimes it may be required to constrain one or more unknowns for an auxiliary parameters to a predetermined value(s). One or more auxiliary parameters can also be constrained to the same value(s) as another auxiliary parameter. The constrain equation is based on the PRN record set.

Auxiliary parameters can be constrained to any value by using a constraint equation in the adjustment. There are two steps to follow when constraining an auxiliary parameter:

Add the auxiliary parameter's initial value to the auxiliary parameter identification record (code 94 or code 8) in the BLKCORD file.
Add a partially reduced normal equation or constraint equation to the INTCOBS file with the following format:

 93PRN CONSTRAINT
 92RHSMCRWV    MICROWAVE         PR    0.0
 97RNE UPPER                              0.0
     4.0E12

Code 93 record

PRN - Indicates Partially Reduced Normal equations as a constraint (col 3:6)
CONSTRAINT - identifier for the data set (col 7:30)

Code 92 records

RHS - Reduced Right Hand Side
MCRWV - 9 character string used as unique identifier (col 7:15)
PR - Indicates the auxiliary parameter class (col 32:35)

0.0 - Indicates the reduced right hand side term of 0.0 for auxiliary parameter (col ), computed as negative of initial value of auxiliary parameter (metres for translations, radians for rotations and ppm for scale) times the weight

        Type                  Class     Value
        ---------------------------------------------------------
        Constant scale         CS       0.0
        Proportional scale       PR     0.0
        Space system scale     SCPR     -(Initial PPM) x (Weight)
        Rotations              ROT      -(Initial Rad) x (Weight)

Code 97 record

RNE - Indicates partial Reduced Normal Equations

0.0 - Indicates the sum of VtPV (col 43:62), computed as square of initial value of auxiliary parameter (metres for translations, radians for rotations and ppm for scale) times the weight

        Type                  Class     Value
        ------------------------------------------------------------
        Constant scale         CS       0.0
        Proportional scale       PR     0.0
        Space system scale     SCPR     -(Initial PPM)**2 x (Weight)
        Rotations              ROT      -(Initial Rad)**2 x (Weight)

Note: The term 4.0E12 is the weight for the auxiliary parameter corresponding to a standard deviation of 0.5 ppm (inverse of square of standard deviation). To fix the parameter, use a very large weight (e.g., 1.0E20, corresponding to a standard deviation of small standard deviation of 1.0E-10 ppm). Menu

Sample auxiliary parameter equivalencing input

Treating two or more auxiliary parameters as the same parameters in the solution is referred to as equivalencing. The auxiliary parameters are combined using constraint equations. One constraint equation is required to combine (equivalence) two auxiliary parameters. To combine more then two, write as many constraint equations as there are auxiliary parameters to combine: the first constraint equation combines two auxiliary parameters; the second constraint equation combines either of the first or second with a third parameter; the third constraint equation combines either of the first three with a fourth parameter; and so on until all parameters appear in at least one constraint equation.

 93PRN CONSTRAINT
 92RHSMCRWV1   MICROWAVE 1       PR    0.0
 92RHSMCRWV2   MICROWAVE 2       PR    0.0
 97RNE UPPER
    1.0E20              1.0E-20
    1.0E20

Code 93 record

PRN - Indicates Partially Reduced Normal equations as a constraint (col 3:6)
CONSTRAINT - identifier for the data set (col 7:30)

Code 92 records

RHS - Reduced Right Hand Side
MCRWV - 9 character string used as unique identifier (col 7:15)
PR - Indicates the auxiliary parameter class (col 32:35)
0.0 - Indicates the reduced right hand side term

Code 97 record

RNE - Indicates partial Reduced Normal Equations

Revised 20 Dec 98 by Mike Craymer
Revised 18 Oct 01 by Mike Craymer