Leica Infinity: Feature Coding
What is feature coding?
When surveyors collect field data, they document the position and details of required features. Everything can be considered a feature: a building, a fence, a road, a bench, or even a tree. When measurements are made, the surveyor records the details of the features by entering codes and attributes, which are stored with the measured point.
The codes categorise and identify the feature, describing what it is in the field; for example, a single point can be coded to represent a tree or gully and few points can be coded to represent a road or fence. A special code property called linework is used to join the points with a line to create a linear feature like a building or wall.
Attributes are linked to a code and are used to describe the feature and give additional details. For example, if your coded feature was a wall, the attributes you use might include its material type, height or width.
Using feature coding saves time and increases productivity both in the field and the office by having features described and for visualizing the data in the software. This is helping with QC of collection of features and help the data processing step before sending data to CAD or GIS solutions.
The typical feature coding workflow in Infinity
Working with feature coding requires some data preparation and processing in the office before and after measuring in the field. The typical workflow is:
Pre-defining a library of codes and features style – first the user must create the Code table which is managing the list of codes, attributes and styling information used to assign to measured data. The table is applied to data imported or created in a project.
Creating a codelist – from the Code table the user can export a codelist to use in with the field software Captivate, Viva, System1200, iCON and Zeno
Creating a codelist – from the Code table the user can export a codelist to use in with the field software Captivate, Viva, System1200, iCON and Zeno
Data collection – the codelist is transferred to the field software and it should be used to define features with the measurements in the field job.
Office data processing – the collected data is imported into an Infinity project with the coded features. The code table applies automatically the correct style to the imported field data.
This workflow describes all the steps for efficient field collection. Using feature coding makes verifying the job easier in the office. To support individual customer’s visual styles, a user can create several different Code tables using the same library of codes but apply different feature definitions and styles.
Using Code tables in Infinity
How using Code tables in Infinity supports the whole process of feature coding?
Using a Code table to create a codelist
Creating a codelist before doing the fieldwork is not mandatory but doing it within the field software can be time consuming and awkward with limited functionality. The best practice is to predefine a list of codes that is suitable for the type of work. The same codelist should be used by all field crews.
When creating a code, the user defines the type of the code and a style for the linear features. Infinity supports all types of codes including points, lines, areas and free codes used by the existing System 1200 and Leica Viva users.
There are two methods for feature coding, thematical codes which are assigned to points, lines and areas or by free codes. Free codes differ from thematic codes as they are purely time-related information and are recorded in-between measurements in the field. A timestamp is recorded with each free code allowing a chronological order of export points and free codes to be used for third party mapping software.
For each code, the user can enter one or more attributes and define if they shall be automatically prompted to enter it. An attribute can be defined in many ways, for example, as a simple text field, a choice list, a range to choose from or a default value.
The user does not necessarily need to create a codelist from scratch as they can use existing data to automatically populate a new library of codes. This can be done by importing an existing codelist, a Leica DBX job, FlexLine CLS file, ESRI geodatabase or HeXML file.
The benefits of using a code table in Infinity are as follows:
- Quick and efficient way to create a library of codes
- Easy way to re-organize, update or join lists of codes
- The same codes can be exported to different instruments types or formats
- A Code table can be easily shared between users
VIDEO 1: Watch the video to learn how to create a code table.
Using a Code table to style features
When creating a drawing in CAD software, an operator uses geometry objects to represent features. For example, a certain CAD block represents a tree or a signpost or a special line style is used to distinguish between road and a kerb. The operator also defines similar styles for related features, and groups them on the same layers allowing fast modifications to be made to the whole group of features.
Infinity automatically applies the required coding style during the data import. This means the user can view the data in a format that is already styled very closely to the finished deliverable straight after import.
How can the Code table be set up to provide the styling? The user can import a pre-defined CAD file with all the required layers, blocks and line styles. The layers and blocks can be extracted from a DXF/DWG file. The layers can be used so that the coded features are grouped together using the same style.
A block can be used to represent a feature by a simple geometry object. This includes 2D or 3D features. By assigning the block to the code, the code attributes can be used to scale the block to represent the feature in its true relative size. For example, the attributes can be used to scale a tree block, so that the canopy size is drawn correctly.
The line styles can be imported from the .LIN files, this way a line can be represented as a pattern of dashes, dots, text or symbols.
Watch the videos to learn how to use blocks, layers and custom line styles
VIDEO 2: How to use blocks and layers
VIDEO 3: How to use custom line styles
Feature processing in Infinity
Feature processing in Infinity is a straight forward task. User just needs to create a project, attach a Code table and import the data. In the 3D view, the points are automatically plotted with the blocks, the lines use the defined style and the features belong to the assigned layers.
Once a Code table is attached to the project, the entire content, including the code and style information, is included in the project. This means that if the project is transferred to another user, there is no need to provide additional files. If the position of the data in the project needs to be updated due to any processing tasks like GNSS or TPS processing, the features will be updated automatically without the need of further re-processing.
If a user needs to edit codes within a project, this can also be done using the Project Code Manager where one can find the same editing capabilities that are available in the Code Manager, such as being able to edit layers, blocks and line styles. However, any edits made in the Project Code Manager will only apply to the current project and automatically update the data in the project.
In the Project Code Manager, the user also sees any new codes that have been created in the field. The new codes can be easily merged into the Code Table’s codes and styles.
Infinity offers a range of tools allowing a user to correct any data issues. Problems can be due to incorrect coding, typing mistakes or obstacles while observing features. A few examples would be when a code was not assigned to a point or a wrong attribute was entered, or an incorrect point was measured.
The feature editing menu contains options to Join, Break, Delete, Split or Curve line features. Missing features can be easily added by creating new points, lines and assigning codes.
Thematic features can be easily exported to CAD software. Before an export, the user can define in the Layer Manager which survey and thematic layers must be sent to CAD. The export settings can be saved to a template file for future references. Afterwards the data and features can be exported by selecting *.dwg or *.dxf format type.
Author
Monika Bodziak
Product Engineer, Leica Infinity
Leica Infinity
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