The user may wish to examine the relative distortion between two sets of adjusted coordinates. The relative distortion can be thought as the difference in the difference between two station coordinates. This can be expressed as the difference along the line between the stations and at right angles. The total distortion is compared against the input order and flagged if it falls outside the classification standards.
The user is given the option to choose the number of relative distortions to examine up to and including the whole set. The user can select these pairs by choosing a radius and/or a list of station pairs. The user is also given the option to disregard any distortions below a threshold value.
The program collects the number of relative distortions chosen as falling within the 5 classification standards of 20, 50, 100,300 and greater than 300.
If the coordinate records do not contain an order in column 32 the user can input an order for each station or change the existing order before doing the analysis.
======================== Coordinates from 2 files [2] <== Ghost data from two adjustments GHOST coordinate files [G] <== Ghost data input vs adjusted List differences [C] <== Show list of coordinate differences Write MapInfo® diff file [M] <== Coordinate difference file List distortions [D] <== Show list of relative distortions List Station names,order [S] <== View station names, order (distortion class) Change order [O] <== Modify input order Input covariance data [I] <== Import from file(s) saved by GHOST Compute covar diff [V] <== Compare covariance differences MapInfo® station ellipse [E] <== Using first file compute abs ellipses MapInfo® line ellipse [L] <== Compute line ellipse from first file Help [H] <== Select a character for extra help Quit [Q] <== Return to program
===========
The user can get further information on the various options above by entering the letter enclosed in []. Other information is available in the GHOST Help files and the GHOST documentation, for example the layout of the coordinate records.
[menu]
==========================
This option is used when you have saved two sets of coordinates from the same project but with different constraints or options and want to analyze the differences in the coordinates.
For example the first set may be from an adjustment with 1 fixed station and the second set from an adjustment with many fixed stations.
The program will prompt you for a file name and a title for the first set of coordinates and store the coordinates in memory. The program then queries for the second set and stores the matching pairs along with the coordinate difference in terms of distance and azimuth so that you can do the analysis using the other options.
[menu]
============================
This option is used when you want to compare the input set of coordinates with the adjusted set of coordinates in a GHOST adjustment without having to save a set of coordinates.
For example the input coordinates might be an existing set from the data base and you would like to compare them with the adjusted coordinates having added a new project
The program will read the values directly from the STADATA file then store the coordinates and differences in memory so that you can use the other options to do your analysis.
Remember you must be in the directory with the STADATA file
Summary of differences
======================
Maximum Minimum Mean St.dev.
Correction latitude = 0.09981 -1.48556 -0.52647 0.24717
longitude = 1.07758 -1.02650 0.04084 0.34230
elevation = 0.00000 -21.04000 -17.34341 0.68553
Number of differences = 246
[menu]
===============================
This option will tabulate the differences in file COMPOS.LIS
The listing will contain the station identification, the two latitudes, longitudes, elevations, the difference in elevation, the azimuth and distance of the displacement vector between the two sets of coordinates.
The user can select to only list the stations where the distance is above a minimum. The user can select to list only the differences to the terminal without the table of displacement differences.
Listing format
==============
======================================================================================== =========================
The distortion is computed as NEWADJ - OLDADJ
LATITUDE LONGITUDE ELEVATION DIFF AZIMUTH DIST
NO STATION NUMBER OLDADJ NEWADJ OLDADJ NEWADJ OLDADJ NEWADJ (M) (DD.MM) (M
)
=============================================================================================================================
===
1 25750US OTOOLE [1] N48 48 31.96397 31.96517 W117 53 2.20950 2.20716 1252.7890 1252.7890 0.0000 52.18 0.
060
where OLDADJ is the coordinate from the first file
NEWADJ is the coordinate form the second file
=========================
Station char(9) <== Station identification
Shift_dis decimal(10,4) <== Vector diference between coordinates
Shift_az char(17) <== Azimuth of the vector
Shift_lat decimal(10,4) <== Component parallel to latitude
Shift_lon decimal(10,4) <== Component parallel to longitude
Shift_elv decimal(10,4) <== Vertical component
Class char(1) <== Station assigned order (class)
POINT -117.883947 48.808879 <== Station longitude latitude decimal degrees +East
SYMBOL (56, 2387383, 4) <== Symbol id, colour, size
[menu]
============================
This option will tabulate the distortions in the COMPOS.LIS file. The listing will contain the station identifications, the azimuth and distance between the stations, relative distortions in terms of distance and azimuth, and the existing station order compared to the relative distortion.
The relative distortion is defined as the coordinate vector difference of the end points of the line, divided by the distance and expressed in ppm. The coordinate vector difference is found by computing the azimuth and distance between the two sets of coordinates for a station at both ends of the line, then computing the difference between the two vectors.
The relative distortion is compared to the standard classes of 20 50 120 300 ppm
The distance component of the distortion is defined as the component of the vector difference along the line divided by the distance and expressed in ppm.
The azimuth component of the distortion is defined by the component orthogonal to the line divided by the distance between the stations and expressed as an angle subtended at the first station.
Distortion options ================== List distortions [L] All <== Produce the listing Failing/all [F] <== List either all distortions or only those failing the order Maximum radius [R] 3433.815 kil. <== Select stations within this radius Minimum distortion [D] 1.000 ppm <== Disregard distortions below this value Write MapInfo® distr file [M] off <== Produce a MapInfo® file of the distortions Quit [Q]
The user can select to list only the lines where the relative distortion is different from the exsting station order.
Be aware that the process can be very time consuming if the options chosen require comparsion of many lines. For example a large number of stations and a large radius.
==================
The distortion is computed as NEWADJ - OLDADJ
: Distortion: Distortion components : AZIM REL. :95%
STATION NAME STATION NAME DIST AZIM: DIST AZIM: DISTANCE AZIMUTH : DIST DISTOR :C
ONFID
FROM TO (KM)(DDD): (M) (DDD): (M) (PPM) (PPM) (SEC) : RATIO (PPM) :S
PC CL
---------------------------------------------------------------------------------------------------------------------------
-----
1 25750US OTOOLE (1) 20 25705 GLORY (U) 37.975 356 0.048 22 -0.044 1.1 0.6 0.12 0.5 1.3
20 1*
2 25761US OROVILLE (1) 8 25700 ANARCHIST (1) 18.901 347 0.382 57 -0.125 6.6 19.1 3.94 2.9 20.2
50 2>
Terms defined for listing
=========================
1 <== First station in file of stations
25750US <== Station number
OTOOLE <== Station name
(1) <== Assigned order (class)
20 <== Sequence of station in first file
25705 <== Station number
GLORY <== Station name
(U) <== Assigned order (class)
37.975 <== Distance in kilometers between 25750US and 25705
356 <== Azimuth from 25750US to 25705
0.048 <== Vector difference between differences at 25750US and 25705
22 <== Azimuth of vector
-0.044 <== Component along the line
1.1 <== Expressed as ppm
0.6 <== Orthogonal component expressed as ppm
0.12 <== Orthogonal component expressed in seconds
0.5 <== Ratio of orthogonal to along line components
1.3 <== Relative distortion in ppm
20 <== Classification of line is less than 20
1 <== Falls within first order
* <== Disagrees with the assigned orders (in this case the (U))
> better than assigned class
< less than assigned class
Next listing
The program will produce a MapInfo® file of the relative distortions where the relative distortion is divided into 7 groups and a line is given a colour representing a range of values. The line with the largest distortion is coloured red and the line with the smallest distortion is coloured blue.
Station_fr char(9) <== station identification
Order_fr char(1) <== station assigned order (1 2 3 4 U)
Station_to char(9) <== station identification
Order_to char(1) <== station assigned order (1 2 3 4 U)
Distance decimal(10,4) <== distance between stations
Azimuth decimal(10,4) <== azimuth from first station to second
Distortion decimal(10,4) <== Vector difference of positions
Dstr_azim decimal(10,4) <== Azimuth of vector
Along_dist decimal(10,4) <== Component along the line
Along_ppm decimal(10,4) <== Expressed as ppm
Across_ppm decimal(10,4) <== Orthogonal component
Across_sec decimal(10,4) <== Expressed as an azimuth difference
Azi_dist decimal(10,4) <== Ratio azi component / distance component
Rel_distrt decimal(10,4) <== Vector difference / distance in ppm
Line_class integer <== Assigned line classification
LINE -117.883947 48.808879 -117.912156 49.149851 <== mif position
PEN ( 1,20, 2387383) <== line type colour
The user can list to the screen the station names, the input order and the number of line distortions in each class for that station. The line distortions for each classification are counted.
Summary of station distortion analysis
======================================
NO STATION ORDER distortions failing minimum
==================================================
Stations where the distortion is greater than 1.00 ppm
Numb station order 20.0 50.0 120.0 300.0 >
1[ 25750US ] (1) 4 0 0 0 0 <== All distortions are less than 20 ppm
2[ 25761US ] (1) 4 1 0 0 0 <== One distortion is between 20 and 50 ppm
[menu]
===========================
The station order is not always included on the input record or may be incorrect. This option allows the user to change the order on one or all the stations. The default comparison in the distortion analysis is undefined or 500 ppm where the order is undefined. This option allows the user to modify this comparsion.
[menu]
=====================
The program will prompt the user for the file name for each adjustment in turn. The elements from each file for each station pair are saved together in a direct access file.
[menu]
==================
The covariance file(s) is produced by program GHOST using the save covariance option. The file(s) contains the station identification and the covariance elements from the INVERSE NORMAL equations scaled by the variance factor. 21 terms for 3 dimensional stations, 10 terms for 2 dimensional and 3 for 1 dimensional.
[menu]
This option will list the relative covariance differences and write a MapInfo® file containing the two semi major and semi minor axes as well as the differences. The mif file will contain the coordinates for the line, a line pattern and color. The color will represent one of 7 ranges of differences. The smallest difference will be blue and the largest red.
There is a set of files (mid and mif) for the lat long differences (covdif.mif) as well as the elevation difference (covedif.mif)
The difference of the distortion vectors for each matching pair is computed. The difference will be listed to the terminal when it exceeds a selected value.
station station azim s maj s min z diff diff z
The summary of the computed vector differences are listed.
Compare vector difference in standard deviations
Number of records in file = <== Number of records found Number of records compared = <== Matching record pairs found Number of single records = <== No matching record pair found Number of differences > 0.5 = <== Greater than 0.5 meters Number of > 0.001 = <== Between 0.001 and .499 Number of < 0.001 = <== Less than 1 mm
A MapInfo® file is created for the vector difference of the semi major axes as well as one for the z axis differences. The lines are colour coded to reflect the size of the differences in 7 equal ranges. The smallest range is blue and the larest range is red.
Stat_from CHAR(9) <== Station identification Stat_to CHAR(9) <== Station identification Azim_a INTEGER <== Azimuth of semi major axis(system 1) S_Major_A DECIMAL(10,4) <== Length of semi major axis (meters) S_Minor_A DECIMAL(10,4) <== Length of semi minor axis (meters) Z_axis_A DECIMAL(10,4) <== Length of semi z axis (meters) Azim_B INTEGER <== Azimuth of semi major axis(system 2) S_Major_B DECIMAL(10,4) <== Length of semi major axis (meters) S_Minor_B DECIMAL(10,4) <== Length of semi minor axis (meters) Z_axis_B DECIMAL(10,4) <== Length of semi z axis (meters) Diff_sum decimal(10,4) <== Vector difference S_major axis 1-2 Diff_z DECIMAL(10,4) <== Vector difference z axis 1-2
[menu]
The program can write a set of MapInfo® files that contain information about the absolute confidence regions. The station ellipse is represented by a symbol which is colour coded to represent a range of values. The smallest value is represented by blue and the largest by red. The symbol size is increased for the two largest ranges.
Mapinfo® stacov staecov.mif table
Station CHAR(9) <== Station identification
Azim_SM INTEGER <== Azimuth of semi major axis (first)
S_Major_A DECIMAL(10,4) <== Semi major axis
S_Minor_A DECIMAL(10,4) <== Semi minor axis
Sd_lat DECIMAL(10,4) <== Standard deviation latitude (meters)
Sd_lon DECIMAL(10,4) <== longitude
Sd_elev DECIMAL(10,4) <== elevation
POINT -109.589 48.773 <== Longitude and latitude of station
SYMBOL (56,11937070, 5) <== Symbol_id, colour, size
[menu]
====================
The program can write a set of MapInfo® files that contain the relative confidence regions for each set of station covariance in the first file. The line ellipse is represented by a line drawn between the two stations and colour coded to represent the size of the semi major axis (2 dimension) The smallest is coloured blue and the largest red.
If the file is 3 dimensional then another set of MapInfo® files is written for the elevation difference confidence region. The confidence region is represented by a line drawn between the two stations and colour coded to represent the size of the semi major axis. The largest values will be red and the smallest values will be blue.
Stat_from CHAR(9) <== Station identification (from)
Stat_to CHAR(9) <== Station identification (to)
Azim_a INTEGER <== Azimtuh of semi major axis (0-180)
S_Major_A DECIMAL(10,4) <== Semi major axis (meters)
S_Minor_A DECIMAL(10,4) <== Semi minor axis
Z_axis_A DECIMAL(10,4) <== Standard deviation ellevation difference
LINE -109.589 48.773 -109.545 49.101 <== Long and lat of end points
PEN (1,5,4774921) <== width pattern colour
[menu]
====================
1 [ 23600 ] [1] [ 23541US ] [1] [ 23615US ] [1] [ 23616US ] [1]
5 [ 25750US ] [1] [ 25761US ] [1] [ 23501 ] [1] [ 23611 ] [1]
9 [ 23601 ] [1] [ 25708 ] [1] [ 25707 ] [1] [ 25747 ] [1]
13 [ 25706 ] [1] [ 25748 ] [1] [ 25700 ] [1] [ 23540US ] [1]
17 [ 23542US ] [1] [ 23543US ] [1] [ 23612US ] [1] [ 23613US ] [1]
21 [ 23614US ] [1] [ 23617US ] [1] [ 23618US ] [1] [ 23603 ] [1]
25 [ 23619US ] [1] [ 23602 ] [1] [ 23620US ] [1] [ 23621US ] [1]
29 [ 23622US ] [1] [ 23623US ] [1] [ 25751US ] [1] [ 25752US ] [1]
33 [ 25753US ] [1] [ 25754US ] [1] [ 25755US ] [1] [ 36734US ] [1]
37 [ 36731US ] [1] [ 36733US ] [1] [ 25756US ] [1] [ 36735US ] [1]
41 [ 25757US ] [1] [ 25749US ] [1] [ 25758US ] [1] [ 25759US ] [1]
45 [ 25760US ] [1] [ 23500 ] [1] [ 23610 ] [1] [ 23609 ] [1]
49 [ 23608 ] [1] [ 23607 ] [1] [ 23606 ] [1] [ 23605 ] [1]
Terms defined for listing
=========================
1 - Station input sequence
[ 23600 ] - Station number
[1] - Station classification
[menu]