3.- ENCUESTA SOBRE LA ESTRUCTURA Y ACTIVIDAD DE LAS UNlDADES DE MEDIA ESTANCIA Y CONVALECENCIA
3.3. RESULTADOS
This tutorial demonstrates how to analyze and reduce survey data.
In the following exercises, you will use the Survey Command Window to query survey data. Then, you will look at two ways to reduce the survey data.
You can reduce survey data by:
■ Adjusting a traverse loop using the standard compass rule method or other adjustment methods.
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■ Using the network least squares adjustment method.
Each method produces slightly different results. The standard compass rule adjustment method adjusts the traverse loop and sideshots. The least squares method adjusts each of the observations so that the sum of the residuals is at a minimum.
NOTE Before performing the steps in this tutorial, you must have already created the survey database Survey 1 and imported the field book file Survey-1.fbk. For more information, see the Survey Setup (page 129) and Importing and Viewing Survey Data (page 144) tutorials.
For more information, see the AutoCAD Civil 3D Help topic Survey Analysis and Output.
Exercise 1: Querying Survey Data
In this exercise, you will use the Survey Command Window to perform a query on the survey data.
You will use the Inverse Points command to determine the direction and distance between two points.
For more information, see the AutoCAD Civil 3D Help topic Survey Command Window.
This exercise continues from the Importing and Viewing Survey Data (page 144) tutorial.
Specify the survey database settings
1 Open Survey-3.dwg, which is located in the tutorial drawings folder (page 819)
This drawing contains the survey network that was created in the Importing Field-Coded Survey Data (page 136) exercise.
2 In Toolspace, on the Survey tab, expand the Survey Databases collection.
3 If the database Survey 1 is not open (that is, it is not displayed with a next to it), right-click and click Open For Edit.
NOTE By default, to save on resource usage, when you start AutoCAD Civil 3D, all survey databases are displayed in a closed state.
4 Right-click Survey 1. Click Edit Survey Database Settings.
5 In the Survey Database Settings dialog box, expand the Survey Command Window property group. Specify the following parameters:
■ Point Course Echo: Yes
■ Figure Course Echo: Yes
■ Point Coordinate Echo: Yes
■ Figure Coordinate Echo: Yes
■ Command Echo: Yes
These settings determine what information will be displayed in the Survey Command Window.
6 Click OK.
Query data using the Survey Command Window
1 On the Survey tab, expand the Networks collection. Right-click Survey Network 1. Click Survey Command Window.
2 In the Survey Command Window, click View menu ➤ Zoom To Point.
3 In the Enter Point dialog box, enter 1. Click OK.
The drawing zooms to point 1.
4 Click Point Information menu ➤ Inverse Points.
5 In the Point Information - Inverse Points dialog box, enter:
■ Start Point: 1
■ Ahead Point: 2 6 Click OK.
The following information, which describes the location of each point and the direction and distance between the points, is displayed in the command output area:
!
! POINT 1 NORTH: 5000.0000 EAST: 5000.0000 EL:
263.6500
!
! Distance: 300.000 Course: N 72-56-33 E
!
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! POINT 2 NORTH: 5087.9995 EAST: 5286.8036 EL:
259.9600
7 Close the Survey Command Window.
To continue this tutorial, go to Exercise 2: Performing Traverse Analysis (page 150).
Exercise 2: Performing Traverse Analysis
In this exercise, you will reduce some of the survey data using the traverse analysis Compass Rule adjustment method.
The Compass Rule is a method of corrections. It assumes that the closing errors are as much due to errors in observed angles as by the errors in measured distances. The closing errors in latitude and departure are distributed according to the ratio of the length of the line to the total length of the traverse.
For more information, see the AutoCAD Civil 3D Help topic Traverses.
This exercise continues from Exercise 1: Querying Survey Data (page 148).
Set up a traverse
NOTE This exercise uses Survey-3.dwg with the modifications you made in the previous exercise.
1 In Toolspace, on the Survey tab, expand the Survey Databases ➤ Survey 1 ➤ Networks ➤ Survey Network 1. Right-click the Traverses collection.
Click New.
2 In the New Traverse dialog box, for Name, enter Traverse 1. Click OK.
3 On the Survey tab, in the list view, right-click Traverse 1, and click Properties.
4 In the Traverse Properties dialog box, specify the following parameters:
■ Initial Station: 1
■ Initial Backsight: 1000
■ Stations: 2,3,4,5,6
■ Final Foresight: 6000 5 Click OK.
Run a traverse analysis
1 On the Survey tab, in the list view, right-click Traverse 1. Click Traverse Analysis.
2 In the Traverse Analysis dialog box, specify the following parameters:
■ Horizontal Adjustment Method: Compass Rule
■ Vertical Adjustment Method: Length Weighted Distribution Use the default values for the other properties.
3 Click OK.
The analysis runs, and the following files are displayed in the ASCII text editor:
■ Traverse 1 Raw Closure.trv: Displays the horizontal closure and angular error.
■ Traverse 1 Vertical Adjustment.trv: Displays a report of raw and adjusted elevations from the vertical adjustment methods.
■ Traverse 1 Balanced Angles.trv: Displays the adjusted station coordinates derived from balancing the angular error and horizontal closure with no angular error.
■ Traverse 1.lso: Displays the adjusted station coordinates based on the Horizontal Adjustment Type setting (Compass Rule).
4 Close all the text files.
A dialog box notifies you that you should use the Process Linework command to update the figures with the new traverse information.
Reprocessing the survey linework is a manual process. You will see how to update the linework in the following steps.
5 In the Survey Network Updated dialog box, click Close.
6 In Toolspace, on the Survey tab, under Import Events, right-click Survey-1.fbk. Click Process Linework.
The Process Linework dialog box enables you to reprocess the survey network linework connectivity after you make corrections to the survey data.
When the survey database is updated following a traverse analysis, the following adjustments to the data that references the traverse take place:
■ Observed station points are updated and added to the Control Points collection.
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■ All sides shots from adjusted setups within the traverse are updated.
■ All figures that reference points within the traverse are updated.
■ Any of the above data that is displayed in the current drawing is also updated.
Because you will use this survey database to perform other analyses in later exercises, you will not reprocess the linework.
7 Click Cancel.
8 In Toolspace, on the Survey tab, select the Control Points collection.
Right-click. Click Reset Adjusted Coordinates.
This action resets the adjusted coordinates, enabling you to continue with the next analysis.
To continue this tutorial, go to Exercise 3: Performing Least Squares Analysis (page 152).
Exercise 3: Performing Least Squares Analysis
In this exercise, you will reduce the survey information using the least squares adjustment method.
The least squares method calculates the most probable value for each observation. The values are calculated by adjusting each of the observations simultaneously so that the sum of the squares of the residuals (the difference between measured and adjusted observations) is at a minimum.
For more information, see the AutoCAD Civil 3D Help topic Least Squares Analysis.
This exercise continues from Exercise 2: Performing Traverse Analysis (page 150).
Modify the survey network style
NOTE This exercise uses Survey-3.dwg with the modifications you made in the previous exercise.
1 In Toolspace, on the Settings tab, expand the Survey ➤ Network Styles collection.
This collection contains the existing network styles in the drawing.
2 Right-click the Standard network style. Click Edit.
3 In the Network Style dialog box, click the Components tab.
4 Under Error Ellipse, set the Error Ellipse Scale Factor to 10000.00.
5 Click OK.
Run the least squares analysis
1 In Toolspace, on the Survey tab, expand the Survey Databases ➤ Survey 1 ➤ Networks collection. Right-click the network Survey Network 1. Click Least Squares Analysis ➤ Perform Analysis.
2 In the Least Squares Analysis dialog box, under Input, specify the following parameters:
■ Create Input File: Selected
■ Input File Name: Survey Network 1
■ Network Adjustment Type: 3-Dimensional Use the default values for the other settings.
3 Click OK. If prompted, click Yes to overwrite the existing Network File.
The analysis runs, the network and drawing updates, and the following files are displayed in the ASCII text editor:
■ <survey network>.lsi: Displays the initial station coordinates and elevations. The angle and distance information for each station, as well as the standard errors for angles and distances are also displayed.
■ <survey network>.lso: Displays the results of the calculations as well as the adjusted coordinate information.
4 When you have finished reviewing the least squares calculation data, close the text files.
5 To view an error ellipse, on the Survey tab, select the Survey Network 1 ➤ Control Points collection. In the list view, right-click 2. Click Zoom To.
The drawing zooms to the point and ellipse.
To continue this tutorial, go to Exercise 4: Translating a Survey Database (page 154).
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Exercise 4: Translating a Survey Database
In this exercise, you will translate the contents of a survey database from assumed coordinates to that of known coordinates.
This command is useful when you must move all the data in the survey database from an assumed location to a known location.
For more information, see the AutoCAD Civil 3D Help topic Translating a Survey Database.
This exercise continues from Exercise 3: Performing Least Squares Analysis (page 152).
Examine the contents of a survey database
NOTE This exercise uses Survey-3.dwg with the modifications you made in the previous exercise.
1 In Toolspace, on the Survey tab, expand the Survey Databases ➤ Survey 1 ➤ Networks ➤ Survey Network 1 collections.
2 Click the Setups collection.
In the list view, examine the elevation values of the following setups:
■ Station Point 1, Backsight Point 1000: Instrument Elevation = 263.650
■ Station Point 2, Backsight Point 1: Instrument Elevation = 259.960
■ Station Point 3, Backsight Point 2: Instrument Elevation = 257.438 For this exercise, you will assume that the elevation value for Station Point 1, Backsight Point 1000, which is at Easting 5000 and Northing 5000, is 2.25 greater than the actual elevation.
Translate the survey database
1 In Toolspace, on the Survey tab, select the Survey 1 database. Right-click.
Click Translate Survey Database.
2 In the Translate Survey Database wizard, on the Base Point page, specify the following parameters:
■ Easting: 5000
■ Northing: 5000
On this page, you specify the base point from which the survey network will be moved.
3 Click Next.
On the Rotation Angle page, you specify the base point from which the survey network will be moved. For this exercise, you will not change the rotation of the survey network.
4 On the Rotation Angle page, for Rotation Angle, enter 0.
5 Click Next.
On the Destination Point page, you specify the point to which the survey network will be moved. Notice that you can specify a new Easting, Northing, or Elevation Change value. In this exercise, you will change only the elevation.
6 On the Destination Point page, for Elevation Change, enter -2.25.
7 Click Next.
On the Summary page, you can examine the results of the translation before it is applied to the survey network. If you want to modify the translation, you can use the Back button to return to previous pages on the wizard.
8 Click Finish.
9 In Toolspace, on the Survey tab, click the Setups collection.
In the list view, examine the elevation values of the setups that you examined in Step 2. Notice that the values have been decreased by 2.25.
■ Station Point 1, Backsight Point 1000: Instrument Elevation = 261.400
■ Station Point 2, Backsight Point 1: Instrument Elevation = 257.710
■ Station Point 3, Backsight Point 2: Instrument Elevation = 255.188
To continue to the next tutorial, go to Manually Creating Survey Data (page 155).