File Menu

Selecting the File menu opens the following menu:

SurvNET projects

SurvNET is a project based system. Everything related to processing raw data must be specified in the project settings.

A Project (.PRJ) file is used to store all the settings and files necessary to reprocess the data making up the project. You can create a New project, or Open an existing project. It is necessary to have a project open in order to process the data.

The Save Project As Default can be used to create default project settings to be used when creating a new project. The current project settings are saved and will be used as the default settings when any new project is created. Project settings are covered in the Settings menu sections.

Open and New Traverse Closure File

Some statutes and jurisdictions still require the computation of traditional traverse closures. SurvNet gives the surveyor the ability to compute the closures of multiple traverses within a project as part of the preprocessing of the project raw data. Closures for single or multiple traverses can be computed for a single project. Additionally, GPS closures can be computed for GPS loops. To compute closures you must first create a "Closure" file (.CLS). Closure files define the type of traverse loops that are to be computed and the point numbers that make up the traverse.

There are two options in the FILE menu that are used to create and edit the closure, .cls, files:

Open Traverse Closure File
New Traverse Closure File

After choosing the 'New Traverse Closure File' you will be prompted for a new file name. After choosing a file name the following dialog box is displayed.

First enter the point sequence which defines the traverse in the 'Ordered Traverse Point List' grid field. If you initiate the traverse closure input dialog from the FILE menu (as opposed to running it from the Settings Dialog), you will have the option to pick the points graphically.

Set the check boxes to set whether vertical closure and angle closures are to be computed. Then choose what type traverse is being entered. .

Enter the points that define the traverse. If you check the "Allow graphic pt. pick" box, the graphic window will pop up. You can then pick the points graphically. The points will go into the list separated by commas.

If you manually enter the points, they can be entered in the form:

1,23,30-35,45,23,1

A comma separates the point numbers. You can select a range (30-35) when the points are sequential. You must start with the first backsight point number and end with the last foresight point number. For example, if you have a simple loop traverse with angle closure using points 1, 2, 3 and 4, it will be entered as "4,1,2,3,4,1" where 1 is the first occupied point and 4 is the initial backsight.

You can turn the "Angle Closure" ON or OFF. If the angle closure is ON, you will be shown the total angular error and error per angle point. If the final closing angle was not collected you can turn "Angle Closure" OFF and only the linear closure will be computed.

You can turn the "Vertical Closure" ON or OFF. If the vertical closure is ON, you will be shown the total vertical distance closure.

In order to calculate the traverse closure, you must select the TRAVERSE TYPE. It can be:

Pt. to Pt. Trav. - A point to point traverse is a traverse that starts at a set of known coordinates and ends at another known coordinate. This option assumes you start from two control points and tie into two control points if an angle closure is desired and one control point if only a linear closure is desired. The first backsight distance and last foresight distance if angle closure is ON are not used in computing the linear closure. Following is an example of a pt. to pt. traverse with angle closure.

100,101,2-5

In the above pt. to pt. list Pt 100 is the starting backsight point, Pt. 101 is the starting instrument point. Pt. 4 is the ending instrument point and the foresight to the angle closure point is point 5. If a closing angle was not collected the list would look as follows '100,101,2-4'.

Loop Trav., Int. Az. Ref. - A closed loop traverse that begins by backsighting the last interior point on the traverse. Following is an example.

7,101,2-7,101

In the above example closed loop with angle balance list, point 7 is the backsight point and point 101 is the first occupied point. If the closing angle 6-7-101 was not collected the list would be entered as follows ' 7,101,2-7'

Loop Trav., Ext. Az. Ref. - A closed loop traverse that begins by backsighting an exterior point (point not on the traverse).

100,101,2-7,101,100

In the above example loop with exterior reference and angle balance list, point 100 is the backsight point and point 101 is the first occupied point. If the closing angle 7-101-101 was not collected the list would be entered as follows ' 100,101,2-7,101'

GPS Loop Closure: - GPS loop closures can be computed using this option.

A,E,F,A
In the above example GPS loop, closure will be computed from the GPS loop going from A-E-F-A.

After the closure, .CLS, file has been created the preprocessing project settings need to be updated to include the closure file in the project. Following is a view of the settings screen that defines a closure file to be used in preprocessing. Notice that the check box 'Compute Traverse Closure' is checked and a closure file has been entered in the edit box field. Notice that the 'Edit/Create' button can be used to edit an existing closure file or create a new closure file.

When the data is processed, the closure reports will appear in the RPT and ERR files. Traverse Closures will show the error of closure with and without angles balanced. Following is an example of a closed loop traverse report:

Traverse Closures

=================

Traverse points:

103-118,43-44



Traverse starting and ending on different points;

Compute angle closure.

Compute vertical closure.



 BS         IP         FS             Angle          FS H. Dist.    FS V. Dist.

 103        104        105            173-07'48.5"     310.4916     -7.7483

 104        105        106            167-48'21.5"     253.4909      5.6306

 105        106        107            200-52'46.0"     381.4896      8.4879

 106        107        108            149-09'05.5"     410.5470    -16.6830

 107        108        109            080-42'36.5"     245.5728      9.4221

 108        109        110            174-21'17.5"     175.3846     -5.6971

 109        110        111            201-42'21.5"     367.0014    -11.8161

 110        111        112            171-52'54.5"     237.7806      7.5346

 111        112        113            192-32'53.5"     368.8396     -7.0329

 112        113        114            171-30'59.0"     338.0024    -19.1945

 113        114        115            184-54'03.5"     344.5005     16.3157

 114        115        116            149-20'19.5"     353.8455      7.5562

 115        116        117            202-19'01.5"     390.1117     -9.9180

 116        117        118            112-36'32.0"     293.9931      2.0060

 117        118        43             146-06'36.5"     411.3674     -7.7112

 118        43         44             270-04'01.5"



Closing Az:           S 47-39'47.8"W

Computed Closing Az:  S 47-39'51.3"W



Total angular error:      000-00'03.5"

Angular error per point:  000-00'00.2"

Correct Ending Coordinates, North: 1400952.0140 East: 2241884.7010

Ending Coordinates, North: 1400951.7962 East: 2241884.8180

Error, N: -0.2178 E: 0.1170 Total: 0.2472 Brg:  N 28-14'34.6"W

Distance Traversed: 4882.4190 Closure: 1:19751



Correct Ending Elevation:  948.1710

Ending Elevation:          948.1221

Elevation Error:            -0.0489

Closure After Angle Adjustment



 103        104        105            173-07'48.3"     310.4916     -7.7483

 104        105        106            167-48'21.3"     253.4909      5.6306

 105        106        107            200-52'45.8"     381.4896      8.4879

 106        107        108            149-09'05.3"     410.5470    -16.6830

 107        108        109            080-42'36.3"     245.5728      9.4221

 108        109        110            174-21'17.3"     175.3846     -5.6971

 109        110        111            201-42'21.3"     367.0014    -11.8161

 110        111        112            171-52'54.3"     237.7806      7.5346

 111        112        113            192-32'53.3"     368.8396     -7.0329

 112        113        114            171-30'58.8"     338.0024    -19.1945

 113        114        115            184-54'03.3"     344.5005     16.3157

 114        115        116            149-20'19.3"     353.8455      7.5562

 115        116        117            202-19'01.3"     390.1117     -9.9180

 116        117        118            112-36'31.8"     293.9931      2.0060

 117        118        43             146-06'36.3"     411.3674     -7.7112

 118        43         44             270-04'01.3"

Closing Az:           S 47-39'47.8"W

Computed Closing Az:  S 47-39'47.5"W



Total angular error:      000-00'00.2"

Angular error per point:  000-00'00.0"

Correct Ending Coordinates, North: 1400952.0140 East: 2241884.7010

Ending Coordinates, North: 1400951.7752 East: 2241884.8397

Error, N: -0.2388 E: 0.1387 Total: 0.2762 Brg:  N 30-08'45.6"W

Distance Traversed: 4882.4190 Closure: 1:17679

Following is an example of a GPS loop closure report.

Traverse Closures

=================



GPS Loop Points:

A,E,F,A



GPS Loop Closure;

  Misclosure, X:  -0.0323   Y:  -0.0162   Z:  -0.0105

  Closure error:    0.0376   Perimeter: 20229.3858

  Precision: 1:537594



GPS Loop Points:

C,F,D,B,C



GPS Loop Closure;

  Misclosure, X:  -0.0121   Y:  -0.0101   Z:   0.0002

  Closure error:    0.0158   Perimeter: 41332.9807

  Precision: 1:2622216



GPS Loop Points:

F,D,B,F



GPS Loop Closure;



  Misclosure, X:  -0.0022   Y:  -0.0044   Z:   0.0097

  Closure error:    0.0109   Perimeter: 30814.5047

  Precision: 1:2833226

Following is a view of the closure file that created the above GPS closure report. The 'Vert. Closure', and 'Angle Closure' toggles serve no purpose with GPS loop closures.

Creating ALTA Tolerance Reports

SurvNet provides the ability to generate reports that give the surveyor the information needed to determine if his survey is within ALTA positional tolerances. It is required that the user define which points are to be included in the ALTA testing. The points to be included for ALTA testing are defined in an .Alt file.

There are two options in the FILE menu that are used to create and edit the ALTA, .alt, files:

Open ALTA, Rel. Err. Ellipse File
New ALTA, Rel. Err. Ellipse File

After choosing the ALTA file to be created or edited the following dialog box is displayed.

The above dialog box allows the user to define the points to be included in the ALTA report processing. There are two sections in the .RPT file created through the ALTA reporting. The following report shows the sections of the ALTA report generated by the data in the dialog box. The first section of the report displays only the relative error ellipses between points. The point sequences used in this section come from the list on the right hand side of the above dialog box. The second section of the report performs an ALTA tolerance test and displays only those connections that fall outside of the ALTA tolerances (as set in the ADJUSTMENT tab of the SETTINGS dialog box). The program first checks the specific point sequences defined by the list on the right side of the dialog box. The program then checks all the connections between all the points listed on the left hand side of the dialog box.

When adding points to either section, you can choose the option to Allow graphic pt. pick. This option is only available if you run the ALTA dialog from the FILE menu (as opposed to from the Settings dialog). A graphic window will pop up and you can pick the points graphically that you want to include in the ALTA report.

There can be many connections to check if the point list on the left hand side of the dialog box has a lot of points. The user can limit the number of sequences to be displayed that fail the ALTA test by entering a number in the "Max. Connections to display" field.

Notice that you can enter points based on descriptions in the left hand list box. If you wished to check connections between all points with TP, EIP, MON descriptions, enter the descriptions in the edit field and press the 'Add' button. If TP, EIP, and MON represented traverse points, existing iron pipes and monuments then ALTA testing would be performed on those point types.
After you have created the .ALT point file you need to set a few project settings. These settings define the ALTA tolerances, specify the .ALT file to be used, and define the type of reporting to be generated. The 'Adjustment' tab sheet within the project 'Settings', has a relative error ellipse section where the ALTA report settings are located.

All the ALTA reporting settings reside within the Relative Error Ellipse box.

Note: You do not have to "Enable sideshots for relative error ellipses" to get an ALTA report on sideshots that are selected for the report. All points selected for the ALTA report will automatically be included in the computational process.

The 'Rel. Err. Points File:' check box must be checked, and an .ALT file must be chosen to get an ALTA report. The .ALT file defines which points will be included in the ALTA reporting. See the previous discussion on the creation of the .ALT file if you are unsure of how to create an .ALT file.

Check the 'Include ALTA tolerance report' check box to create the ALTA tolerance checking report section. If an .ALT file has been chosen then the relative error section of the report will always be generated.

Next make sure the appropriate tolerance and PPM has been defined. The ALTA standards define their positional standard as .07 plus 50 PPM. Additionally, the ALTA standards require that the computations be performed to a 95% confidence. The confidence interval is set in the 'Confidence Interval:' edit field.

After the project has been processed the ALTA/Relative Error portion of the report is displayed in the report window under its own tab.

The following is a sample ALTA report:

Relative Error and ALTA Tolerances

==================================



Alta Tolerance Report ,Specific Connections, 95% Confidence Interval

                                        Actual       Allowable   Ratio

 Sta.       Sta.           Dist.        Semi Major   Semi Major  Actual/Allowable  Semi Minor  Max. Err. Az.

 27         500          204.4590      0.0384       0.0802      0.4790            0.0332       N 17-50'50.2"E 

 500        502           66.8572      0.0415       0.0733      0.5658            0.0310       S 86-04'58.5"E 

 34         36           237.9748      0.1340       0.0819      1.6364            0.1340       N 00-00'00.0"E 





All the connections between the following points were checked.

   500,501,502,503,504,505,506,507,508,509,510,511,512,513,514,515,516,517,518,519,520,521,522,523,524,525,526,527,528,529,

   530,531,532,533,534,535,536,537,538,539,540,541,542,543,544,545,546,547,548,549,600,601,602,603,604,605,606,607,608,609,

   610,611,612,613,614,615,616,617,618,619,620,621,622,623,624,625,626,627,628,629,630,631,632,633,634,635,636,640,641,642,

   645,646,647,648,649,650,651,652,653,654,655,656,657,658,659,660,670,671,672,673,674,675,676,677,678,679,680,681,682,683,

   684,685,686,687,688,689,690,691,692,693,694,695,696,700,701,702,703,704,706,712,713,714,715,716,717,718,719,720,721,722,

   723



From the above points the following connections exceeded the tolerance of 0.070 +  50 PPM. at the 95% CI.



Alta Tolerance Report ,All Connections, 95% Confidence Interval

                                        Actual       Allowable   Ratio

 Sta.       Sta.           Dist.        Semi Major   Semi Major  Actual/Allowable  Semi Minor  Max. Err. Az.

 642        692          416.9231      0.1709       0.0908      1.8814            0.1046       S 79-32'05.0"E 

 641        642          491.5046      0.1759       0.0946      1.8597            0.1064       S 78-49'09.6"E 

 640        642          632.6614      0.1775       0.1016      1.7463            0.1053       S 74-34'49.3"E 

 642        673          529.6088      0.1680       0.0965      1.7412            0.1003       S 79-00'20.2"E 

 642        650          704.7900      0.1793       0.1052      1.7037            0.1038       S 82-47'35.7"E 

 640        647          538.1392      0.1640       0.0969      1.6925            0.1074       S 51-54'59.1"E 

 616        640          449.6151      0.1555       0.0925      1.6813            0.1039       S 48-04'33.5"E 

 640        646          840.1672      0.1791       0.1120      1.5994            0.1169       S 22-41'37.8"E 

 541        642          163.9307      0.1234       0.0782      1.5775            0.0599       S 87-42'15.2"E 

 547        642          646.1891      0.1607       0.1023      1.5705            0.0959       S 82-55'56.5"E

If the Ratio Actual/Allowable is 1.0 or less, the positional tolerance of the two points have passed the ALTA standards.

The first part of the report shows the SPECIFIC connections as specified in the ALT file.

The second part shows the ALL CONNECTIONS as specified in the ALT file. It is preceded by the list of selected points. All possible combinations of connections between these points are calculated. Based on the setting Maximum Connections to Display in the ALT file, that number of connections are shown, beginning with the largest Ratio Actual to Allowable. Only the connections that fail the ALTA standards will be shown. If all the points "pass" the ALTA standards, no points will be shown and you will see the message: All connection combinations passed the tolerance test.