The Line Database Manager (LDM) is used to create survey lines, routes (polylines) and points for use in planning, conducting and processing a survey. These entities can also be imported from various formats. Once created they can be exported to various formats.
Line Database Manager - Program Status
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At time of writing (Nov. 2015) two versions of the program are accessible from two locations:
Newer: The Line Tools Ribbon Tab in the Processing Manager (newer functionality using in-house developed format QGF).
Original: The icon in the lower panel of the QINSy Console (older functionality using the Terramodel Toolbox - PRO format).
All point, line and route data was originally stored in a *.PRO file, which is the native format for Terramodel. This is still the case when starting the utility directly from the Console. When creating line files in the Processing Manager, data is stored in the newer QPS developed format (*.QGF file).
During the transition period away from PRO to QGF any existing *.PRO files are automatically converted to equivalent *.QGF files, meaning both files co-exist side by side. A *.QGF file is automatically updated when changes are made in a *PRO file.
Creating line files from the Processing Manager offers the advantage of background geographical information, e.g. ENCs, DXF, Geotiff, KML. Being much older, the original program does not provide this contextual benefit.
This Howto concentrates on using the Line Tools in the Processing Manager. However, both share almost identical functionality so that this Help is easily adaptable to the older program. Note that the older program has its own help pages too.
Currently (Nov. 2016) the original LDM is still needed to generate DTM links.
Tools in the online Navigation Display provide interaction with Line Database files - please refer to Online Help pages.
Before any points, lines and/or polylines can be created, a Line Database File must exist.
In the Processing Manager:
Open the File tab. Click on New. Click on Line File.
Enter a file name. Click on Save.
The new Line File is stored under the current project in the folder \LineData (unless a specific common files folder is set in the Console - Settings - Folders).
The new line file is listed in the Project Explorer window. A SURVEYLINES layer is automatically created. This name may be changed and additional layers generated. Clicking on the line file name in the Explorer window, and then the Edit tab opens the Line Tools ribbon. Press the Edit tab under the Line Tools tab to activate the Line Planning tools:
The Line Tools tab only becomes active when a Line Database (listed under Line and CAD / GIS Files) is selected in Project Explorer window.
To organize points, lines and routes used, perhaps, for different purposes, it is useful to add layers to the single layer created in the new *.QGF file.
Click on to open the Edit Layers dialog.
Click on and then edit the name of the layer added. Add other layers as necessary.
Set colors, pen widths and line style. Primitive Count refers to the number of elements in each layer.
In the Explorer window make sure the focus is on the correct line database and layer on which the objects are to be added.
Click on the button. The cursor changes to indicate that a point can be selected in the Plan View area:
For a Point, click once with the left mouse button, then click the right mouse button to end the drawing mode. To create a point with a radius, hold down the CTRL button.
For a Line, click two points with the left mouse button, then click the right mouse button to end the drawing mode.
For a Polyline (route), click multiple points with the left mouse button, then click the right mouse button to end the drawing mode.
For an Area click the vertex points of the area with the left mouse button, then click the right mouse button to end the drawing mode. Make sure to click on or near the first point to create a closed boundary. In the plan view the figure then fills with a default grey color. The Shift button can also be used when closing the area boundary. This will automatically invoke the extra options for defining an area.
In each case the Add New Object dialog opens.
Point: Enter a name, and define attributes - color, radius 1, radius 2 and icon. Line: Enter a name, and define attributes - color, width and style. Polyline: Enter a name, and define attributes - color, width and style.
In the case of an area, check the 'Make it an area' tick box to actually create an area.
The dialog then changes. If not activated, the boundary of the area is stored as a polyline and it cannot be filled with a color.
Modify object and icon properties as necessary.
Avoidance objects: To define an entire area make sure the last polyline point is identical to the first (i.e. is a closed polygon). Then it is automatically recognized as an area. Note that only a 2D check is carried out on areas.
3D Checks are carried out only on polylines that are NOT closed; of course the height should be filled in properly in the Line Database Manager.
In dredging work, the deepest point of the dredge head model is used to calculate the clearance between dredge head and avoidance object.
Wing lines are simply lines generated parallel to a single baseline or polyline. Creating wing lines requires that a line or polyline be defined first. Before generating any wing lines, make sure to select the layer on which they must be stored.
Single Line
Click on the pertinent line in the Plan View.
'Wing lines' (and 'Cross lines') commands become active.
Click on to open the Wing Lines Settings window.
Enter values and make selections to generate wing lines on the port and starboard side of the initial line selection.
Press OK to start the creation of the wing lines.
Click on and select Lines to view the results of the wing line generation.
Cross lines are simply lines generated at an angle to a single baseline or polyline. Creating cross lines requires that a line or polyline be defined first. Before generating any cross lines, make sure to select the layer on which they must be stored.
Single Line/Polyline
Single line and polyline operations are identical; single line is illustrated.
Click on the single survey line in the plan view.
The 'Cross lines' (and 'Wing lines') commands become active.
Click on which opens the Cross Lines Settings window:
Enter values and make selections to generate cross lines at intervals along the initial line selection.
The naming convention for the cross lines:
#S: Sequence number #N: Name of along line #K: Station number (KP) #M: Station number (MP) #U: Station and offset (USA)
All other text can be added optionally.
Entering an angle rotates cross line bearings so they are no longer perpendicular. This image shows the settings and result when generating wing lines for the entire polyline/route:
Press OK to start the creation of the cross lines.
Click on and select Lines to view the results of the cross line generation.
Double click on the Line Tools ribbon tab to activate the Line Tools
Click on Import to initiate the Import Wizard
Supported File Formats
On the first page of the wizard, select the data file format type.
The contents of remaining wizard pages depends on the data format chosen. The following formats are supported:
Supported formats
DXF (Text) File
AutoCAD DXF File. Notice that two dimensionally defined lines are imported as pline objects. To convert them to routes after importing use the 'Edit Other Objects' option.
DXF versions 2.5 through 2014 are supported.
DXF (Binary) File
AutoCAD DXF File. Notice that two dimensional defined lines are imported as pline objects. To convert them to routes after importing use the 'Edit Other Objects' option. DXF versions 2.5 through 2014 are supported.
DWG File
AutoCAD DWG File. Notice that two dimensional defined lines are imported as polyline objects. To convert them to routes after importing use the 'Edit Other Objects' option. DWG versions 2.5 through 2014 are supported.
ASCII (X/Y/Z) File
File contains grid co-ordinates (easting, northing, height or x,y and z). Fields can be in fixed columns, or comma, tab or space separated. If none of the predefined import layouts work, you can create a new import layout - see next section.
ASCII (Lat/Lon) File
File contains geo co-ordinates (latitude, longitude, height). The user is asked for geodetic parameters to convert from geo to grid. These parameters are retrieved from a template database (*.db).
KML
KML is a file format used to display geographic data in an Earth browser such as Google Earth, Google Maps, and Google Maps for Mobile. KML uses a tag-based structure with nested elements and attributes and is based on the XML standard. All tags are case-sensitive and must appear exactly as they are listed in the KML Reference. The Reference indicates which tags are optional. Within a given element, tags must appear in the order shown in the Reference.
The two import routines are very similar. The differences are:
ASCII XYZ - Select Easting/Northing/Height field types. ASCII (Lat/Long): Select Latitude/Longitude/Height field types.
Geographical coordinates are converted to grid coordinates during the import so you must make sure to have the correct template database active.
Select ASCII Files.
Add the ASCII file(s) to be imported.
Click Next.
ASCII XYZ: Two predefined layouts are available, E,N,H (Comma delimited) and E N H (Tab delimited). ASCII Lat/Long: Two predefined layouts are available, Lat,Long,Ht (Comma delimited) and Lat Long Ht (Tab delimited).
If data in the ASCII file has a different layout, there is an option to create a new user defined import layout. Select 'New Format' from the drop down list or click on . This opens the Layout Editor:
Click the 'New' button.
Provide a name for the new layout and the delimiter used.
In case the ASCII file contains header information, define the row on which the coordinates start.
Click on the 'Add' button in order to define the fields of data in the ASCII file being imported.
Select the first field type. Repeat until all fields are defined.
To test decoding of the ASCII data, copy and paste a line from the file into the Example text box provided.
Click 'Test' and check decoded sentence.
Clicking OK returns you to page 2 of the import wizard where you select the 'Primitive Type', enter a 'Layer Name' and check/change the 'Skip Rows' number. Click 'Finish' and the imported points/lines/polylines are shown as a layer in the plan view.
Additional ASCII files may be added to this line file if necessary.
Coordinates and attributes are shown in a data grid like this:
In the Processing Manager, Data Grids are often used for showing properties of multiple items located in such places as the Points, Lines, Polylines and Areas Editor and the PM Project Explorer.
The Data Grids offer many opportunities for customization such as filtering, sorting and grouping. Most of these options are found by right clicking on the column headers to open the contextual menu.
All functions are fairly self explanatory except, perhaps, for the following:
Points, Lines, Polylines and Areas - Attributes 1 and 2
Custom numeric attributes. Change the attribute names by right clicking on the column header selecting Set attribute names.
Attribute 1 options -
T.M.D. (True Measured Depth, used in VSP surveys)
Velocity
SD (horizontal)
Weight (horizontal)
Attribute 2 options -
T.V.D. (True Vertical Depth, used in VSP surveys)
Velocity
SD (height)
Weight (height)
For example a Weights column can be created or a column with Standard Deviation values. The custom attributes can be used in the Data Fusion to calculate a weighted mean or least squares approach.
Use this option to calculate the mean of the points selected in the Points data grid list.
The calculation options are:
Mean - Calculates the new position based on the average positions of the selected points.
Weighted mean - Calculates the weighted mean of the selected points. Points with zero weight are excluded. The weights can be entered in the attribute columns in the Points Editor.
Least square approach - Calculates the new position using a least squares approach. All selected points must have proper Sd values, which can be entered in the attribute columns in the Points Editor.
Use this option to create interpolated lines between the two or more lines selected from the list in the Edit Lines window.
For example, two lines are defined:
Before adding interpolated lines make sure the correct layer is selected:
In the Edit Lines data grid select both lines.
Click on the Interpolate button which opens the Interpolation Settings window.
Interpolate Lines Settings
Name
Enter a name manually and combine with it one of the possible predefined settings:
#S - Step number
#N1 and #N2 - Name of the adjacent line
#I - Interpolated number found in the line name
Color
Select in which color the interpolated lines will be displayed in the Plan View.
Maximum line spacing
Enter the maximum distance between the interpolated lines.
Maximum angle
Normally lines can be inserted between two adjacent lines when these two lines are more or less parallel.
Maximum angle is used to see if the two lines are more or less parallel: within the criteria of this angle. So if lines are exactly parallel, then this maximum angle can be 0°.
Two attempts are made to see if the lines are pointing in the same direction:
When the given two lines are not pointing in the same direction (+/- max angle), then one line will be reversed, and a second check is done to see if they are now pointing in the same direction (+/- max angle).
If this is still not true, then no additional lines will be inserted.
Rule of thumb to produce new lines between two lines is to use an angle larger than the angle between the two lines. Use the line bearings in the Bearings column to calculate this angle.
Press OK to start the interpolation. The new lines are displayed in the Plan View when OK is pressed in the Edit Lines dialog.
Interpolation is also possible between 3 or more lines:
The line simplification is used to reduce the number of segments in a polyline without losing too many details.
Polylines - KP Calculations
This function either extrapolates KP values between the selected control points, or it calculates values between entered KP values.
In this example:
...the following settings were used to compute KP values:
Automatic KP value calculation
begin cp/end cp
Use the up/down arrows to select control points for the selected polyline. KPs are calculated between the two cp points selected - Example #1 below.
start KP value/end KP value
Enter a value manually or use the up/down arrows to select a value. End KP only active when Extrapolate is disabled. Useful if resurveying part of a polyline/route beginning partway along the route - Example #2 below.
Extrapolate
If activated, then the end KP value is calculated automatically. If not activated, then the KPs are fitted between the entered start and end KP values - Example #3 below.
Start calculation
Press to start calculating KPs along the polyline.
For lines, polylines and areas, clicking once on the line changes the color to grey. Clicking again changes the line color back and adds edit points at each vertex. Hover over one of the edit points, click and drag.
Clicking once on the route changes the color to grey. Clicking again changes the route color back and adds edit points at each vertex. Hover over one of the vertices, click and drag. Release mouse button when vertex is appropriately placed. While the focus is still on the route line edit points remain at each vertex for further moving. Click anywhere in the panel and the route reverts to grey. Removing the focus from the route changes the line color back to its original.
Export data to one or more of the following formats:
Actions - Clipping Lines
By way of an example, a survey to be performed in an area with an irregular coastline and an island:
Clip Outside
Make sure the correct layer is selected, i.e. the layer on which the lines to be cut are resident.
Select the larger polygon and click on .
For the lines that cut the polygon, the pieces of lines that fall outside are cut. Any lines that do not cut the polygon are unaffected and should be removed by hand.
