ESTPM was been developed to estimate corrections to geodetic positions by interpolating between the position corrections which are known for a number of control stations. ESTPM estimates position corrections at any location within the periphery of control stations with known position corrections. The estimation is done first at the datum level by means of geometric coordinate transformations, then at the regional level with a least-squares complex polynomial for regional trends, and finally at the local level using a covariance function for residual interpolation.
All the matrix and vector dimensions are computed within the program at execution time depending on the amount of data read in and the chosen degree for the complex polynomial. When insufficient central memory is available, a diagnostic message is printed in the output listing giving the amount of additional core required and the execution is aborted.
Program ESTPM was originally written by J.A.R. BLAIS, July 1979 Geodetic Survey Division, Surveys and Mapping Branch Department of Energy Mines and Resources, Canada
Documentation added and modifications by G.A.Wilkinson, July 1986 Surveys and Resource Mapping Branch British Columbia Ministry of Environment
ESTPM was been developed to estimate corrections to geodetic positions by interpolating between the position corrections which are known for a number of control stations. ESTPM estimates position corrections at any location within the periphery of control stations with known position corrections. The estimation is done first at the datum level by means of geometric coordinate transformations, then at the regional level with a least-squares complex polynomial for regional trends, and finally at the local level using a covariance function for residual interpolation.
The datum transformation is optional and a number of datum transformations are available.
At the regional level, a complex polynomial model is used to represent the regional trends in the given correction vectors at the control stations. For a given degree, the complex coefficients of the polynomial are estimated by the method of least-squares. There also is provision for situations where the input degree is too high for the input observational information so that only the lower-order coefficients numerically feasible are estimated and the higher-order coefficients are set to zero.
At the local level the remaining residual corrections at the control stations can be practically eliminated through interpolation with an appropriately calibrated covariance function. The covariance function used in ESTPM is the inverse exponential of the distance, which corresponds to a Gaussian stochastic process. The calibration of the covariance function is done using the input normalized unit distance (RUI) in terms of the spatial dispersion of the control stations. The default value for the normalized unit distance is one tenth of the radial dispersion of the control stations about their centre of gravity.
The analysis of ESTPM results may be simplified by use of the optional graphical outputs. The given correction vectors at the control stations and the estimated correction vectors at grid and other points provide a useful graphical representation of the results for assessment and analysis purposes. These outputs can be displayed using an interactive graphical computer terminal or a CALCOMP plotter.
The estimated coefficients and related information can also be saved or catalogued for future uses. These include the transformation of positions at a later date and/or further graphical analysis especially in overlapping areas.
The optional graphical output is generated using the standard CDC FORTRAN calls to CALCOMP routines for PLOT, AXIS, SYMBOL, and so on. The interactive use ot the program may necessitate minor changes to those CALL statements to conform with the interactive system software.
The system SORT/MERGE is used to find the matching stations on the input files IT2 and IT3. Out of those matching stations, only those within the input grid limits are kept for the modelling. Note that the grid limits are always required for this purpose even when no grid is wanted. The resulting transformations are then applied only to those control stations and the other stations on IT4 within the area defined by the peripheral control stations and the parameter RUE.
Blais, J.A.R. (1979): Least-Squares Estimation of Geodetic Horizontal Control Densification. Presented at the Canadian Geophysical Union Meeting at UNB (June 1979).
Boal, J.D. and Junkins, D.R. (1978): Adjustment of Inertial Survey System Data with Satellite Doppler and Conventional Control. Collected Papers (1978), Geodetic Survey of Canada.
The control information required by ESTPM is read in from two cards:
Card 1: Project Title
Columns 1-80 TITLE Reproduced without any modification in the output
listings and on the plot for identification purposes.
(a80)
Card 2: Control Parameters
Column
1- 2 NS Degree of complex polynomial requested - No Default
99 --> coefficient data is to be read on Unit 11
3 K1 Option variable for datum transformations
to be applied to coordinates on IT3 and IT4 (i1)
0 - no datum transformation - Default
1 - transformation NAD27->NAD83
2 - transformation NAD83->NAD27
3 - transformation MAY76->NAD83
4 - transformation NAD83->MAY76
5 - transformation NAD27->MAY76
6 - transformation MAY76->NAD27
7 - transformation ATS77->NAD83
8 - transformation NAD83->ATS77
9 - transformation ATS77->MAY76
4 K2 Plot option (i1)
0 - no plot - Default
1 - plot with point numbers
2 - plot without point numbers
5 K3 Grid option (i1)
0 - no grid - Default
1 - usual grid
2 - grid symbols without vectors
6-10 GW1 Eastern longitude limit in degrees (f5.1) - No Default
11-15 GW2 Western longitude limit in degrees (f5.1) - No Default
16-20 GN1 Southern latitude limit in degrees (f5.1) - No Default
21-25 GN2 Northern latitude limit in degrees (f5.1) - No Default
26-30 SGD Plot Scale in degrees of latitude per inch (f5.3)
Default = 1 degree per inch
31-35 SCV Plot Scale of vectors in seconds per inch (f5.3)
Default = 1 second per inch
36-40 GRD Spacing of grid in degrees (f5.3)
Default = 1 degree spacing
41-45 RCV Maximum vector length in inches (f5.3)
Default = 3.0 inches
46-50 SBT Size of title letters in inches (f5.3)
Default = 0.21 inches
51-55 SBS Size of symbols in inches (f5.3)
Default = 0.14 inches
56-60 SBI Size of point numbers in inches (f5.3)
Default = 0.07 inches
61-65 RUI Normalized unit distance in terms of radial dispersion
of control stations with respect to their centre of
gravity. Used for interpolation by the covariance
function (f5.3).
Negative value --> no local interpolation.
Default = 0.1 (of radial dispersion)
66-70 RUE Normalized unit distance in terms of radial dispersion
of control stations with respect to their centre of
gravity for extension beyond the peripheral control
stations (f5.3).
Default = 0.1 (of radial dispersion)
71 K4 Option code for output of non-coordinate records
Blank --> Output non-coordinate records
NonBlank --> Do not output non-coordinate records
80 KF Control code for data formats
Blank --> GALS format for data cards.
NonBlank --> Read Format on following card (a80)
Z --> No checking for position codes 4, 5, 6, 04, 05, 06,
and 96. All records assumed to be coordinate records
Card 3: Optional data format read only if Column 80 on Card 2 is non-blank.
Columns 1-80 FMT Data format to be used to read coordinate records (a80)
INPUT !Input
OLDADJ !First set of coordinates of control stations
!Not required when NS = 99
NEWADJ !Second set of coordinates of control stations
!Not required when NS = 99
OLDPOS !Coordinates of stations to be transformed
NEWPOS !Transformed Coordinates of stations from OLDPOS
IPT !Plot file output
ESTPM.LIS !Output
COEFOT.DAT !ASCII file of polynomial coefficients and related data.
!Required only when (degree .eq. 99)
!Created by ESTPM when (degree .ne. 99)
ITQ !Temporary data file
!Used to store coordinates in IT2 & IT3 for
!Input to SORTFILE, called within DATAST
ITR !Temporary sort file. Used only in DATAST.
!Output from SORTFILE
ITS !Temporary file for positions and position
!differences. Written in DATAST and
!read in LSQSLN.
The user is queried for the type of job:
For a batch job the user must include parameters as follows:
The batch submission command would look like:
$ SUBMIT/parameter=(p1,p2,p3,p4,p5,p6,p7) ghost$cmnd:estpm
All files must have the extension .DAT.
The extension must not be entered in the parameter list.
All parameters must be entered and must be in UPPER CASE letters.