Creating a Localization in TopSURV

 

Localization

To set up a survey with localization, tap the Localization button found in the Setup menu:

 

Localization is used for transforming coordinates between a local system and a WGS84 system. The basic approach of calculating the mathematical conversion is to provide pairs of coordinates for each point used for localization in the job.

The Localization screen contains a list of points used for localization, called control points. Their coordinates are known in both systems: Known (Local), hand entered or imported ground coordinates, and Meas Pt (WGS84), points measured with GPS. Each point has a level of reliability specified with the values of the residuals along the horizontal (rH) and the vertical axes (rV) and the Control parameters that shows the status of the point. The horizontal and vertical use of any of the control points can be changed by selecting the line and then tapping on the header of the H Control or V Control. This toggles the display between "used" (yes) and "not used" (no).

Adding Localization Points

To perform a localization in TopSURV, there are three simple steps:

1. You Must have the Known (local) coordinates in the TopSURV field job. These known coordinates are usually keyed in or imported from a text file.

If you are going to import or hand enter new points that are on a local coordinate grid it is important to first have the projection set to NONE (this can be done in the Coordinate System Configuration:

It is also important to set the Coordinate Type to GROUND in the Display Configuration:

Also, be sure that the UNITS are set properly for the coordinates in the Units Configuration:

To enter points by manual input use the Edit Points menu. Enter coordinate values by selecting

2. Physically occupy and measure the existing control points (brass caps, rebar, nails, etc) in the field with your GPS receiver. These control points must have “known” coordinates. It is recommended that these points be collected with an increased epoch count.

3. Pair up the Known coordinates (Local) and the points of the Measured control (WGS84) in the localization menu.

The Add Localization Point screen contains the coordinates of the control points:

• The Known (Local) Point Field contains the name and coordinates of the point in the known coordinate system.

Select the first Known (local) point using the list icon .

Use Horizontal: set if the point should be used for horizontal

Use Vertical: set if the point should be used for vertical localization.

• The Measured Point (WGS84) field contains the name and global coordinates of the control points.

Select the first Measured (WGS84) point using the list icon .

• OK saves the point and opens the Localization screen to display a new point.

Since the WGS84 points were previously measured there is no need to take a new measurement or use the measure button .

Continue to Add control points until you are satisfied with your residuals.

• Remember a general rule of thumb: Always Use 1, 4, or more good control points for a localization.

1 point - is generally good for small projects (1 mile radius or less)

4 points or more - it is always best have your controlling points surround or envelope the worksite. Many surveyors will run a differential level loop through the control points prior to the localization, ensuring a good vertical control.

• Always try to leave a known control point or two out of the localization to use for checks when possible.

Exporting Files From Topcon Tools

To export  points from Topcon Tools to a Coordinate file do the following:

1. From the Job pull-down menu select Export

2. Select Format name: Name, N,E,Z,Code – Coordinates (*.csv):

3. Enter the File Name and check the Advanced options for the the export format:

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Example: If you wanted to export to UTM Zone 12 you would select the Zone from the Projection pull-down under USA; UTM-North: Zone_12:

4. Click Save

To export  points from Topcon Tools to a ESRI Shapefile do the following:

1. From the Job pull-down menu select Export

2. Select Format name: ESRI Shape (*.shp):

3. Enter a Folder Name (all components of the shapefile will be saved in this folder) and check the Advanced options for the the export format:

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Example: If you wanted to export to Arizona State Plane (Central Zone) you would select the Zone from the Projection pull-down under USA; SPC83: Arizona Central:

It is also recommended that you check the Export additional fields box.

Note: Only points, lines, and areas with assigned Codes will export to a shapefile.

4. Click Save

Topcon - Working with Geoid Files

Geoid is a physical reference surface. Its shape reflects the distribution of mass inside the earth. Geoid undulations are important for converting GPS-derived ellipsoidal height differences to orthometric height differences.

Gravity measurements and tide gauges and other quantities are used to determine the geoid. After the geoid is determined, then other surveys, like Global Positioning System (GPS) or differential leveling, can be used to measure surface elevations.

Learn more at: http://www.ngs.noaa.gov/GEOID/

To appropriately use a geoid file with Topcon you will want to install the same geoid file on your computer and controller prior to adding it to the list.

Global geoid files can be opened and truncated in Topcon Link to fit the file to the job area.

Some geoid files can be installed on the controller during TopSURV installation. They are provided to the user as “.gif” files.

In the Conterminous United States GEOID09 Data files can be downloaded directly from the National Geodetic Survey in a PC binary format. This “.bin” format can be used in it’s native format in Topcon Tools, Topcon Link, and TopSURV.

Files can be found at: http://www.ngs.noaa.gov/PC_PROD/GEOID09/dnpc09u.shtml

The geoid model for the Conterminous United States is divided into eight grids that can be selected interactively.

The “.bin” files can be stored anywhere on your PC for Topcon Tools and Topcon Link as long as the directory is identified in the Job Configuration.

The same files that are on your PC will need to be copied to the “Geoids” folder in the TopSURV directory on your Field Controller.

In Topcon Tools:

1. From the Job pull-down menu select Job Configuration…

2. Select Coordinate Systems in the left window pane.

3. Click the Geoids List button to import a geoid model to Topcon Tools. Click Add to open a geoid.

4. On the Open dialog box, choose the proper format name and navigate to the location of the geoid file and click Open to add the new geoid model to the Topcon geoids list.

5. Select the new geoid from the Geoid pull-down.

In Topcon Link:

1. From the File pull-down menu select Configuration...

2. Click the Coordinate Systems in the left window pane.

3. Click Add to open a geoid.

4. On the Open dialog box, choose the proper format name and navigate to the location of the geoid file and click Open to add the new geoid model to the Topcon geoids list.

In TopSURV:

1. To add a geoid file to the drop-down list in the Geoids field of the Coordinate System screen, tap the List button next to this field.

2. On the Geoid List screen press the Add button.

3.Select the proper format: Geoid 99/2003, Australian, Canadian 2000, Canadian 95, Geoid File Format, Mexico 97, Sweden, Denmark, Dutch2004 Files, or Norwegian Files.

4. On the Add Geoid screen, select a Geoid file from the controller directory to view the boundaries of the geoid application.

5. Press OK to return to the Geoid List screen with the geoid file added. This list corresponds to the Geoids drop-down list in the Coord System screen

(Geoid images courtesy of National Geodetic Survey)

Editing Codes in TopSURV

To edit codes and attributes, tap Edit Job > Codes. The Code - Attributes screen displays.

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Remember: Codes already in use cannot be edited or deleted.

1. To add a code, tap the Add button on the right side of the screen. The Cade screen displays. Enter the code name and description (if needed). Select the type of code (from Point, Line, Area) and the layer that the code will be stored to. Set the Code Style to represent points, lines and areas with this code on the selected layer. On the Attributes tab, select a radio button for the prompt for code at the beginning of a line or at every point along the line. Tap OK.

2. To define the attributes for the new code, select the code and tap the Add button on the right side of the screen. Set the name, type, and parameters of the attribute for the code on the Attributes screen. Attribute type indicates whether attribute values can be. Check and enable the Required box to always use the default value of the code. Tap OK.

3. To edit a code or attribute, double-tap the object or select it and tap the corresponding Edit button.

In the Code or Attribute screen, make changes and tap OK.

4. To delete a code or attribute, highlight it in the list and tap the corresponding Del button Codes being used in points and their corresponding attributes cannot be deleted.

5. To export the code library to the selected tile format, select the Export To File option from the Help lcon menu in the upper-left corner of the Code – Attributes screen.

Create a Code Library in TopSURV

TIPS:

1. Create a job just for your Code library. This will allow you to import the codes from job.

2. Export you code library to Topcon XML format and set as the Global Code File.

In TopSURV 8 you can set the Global Code File by: 

1. Tap Configure > Codes  

2. Browse to your Topcon XML file, select the file and tap OK

3. Set other desired settings in the Global Codes Options and tap OK

For more in depth instruction please view the video links.

Import/Export a Code Library

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