GeoCalc Online: Using the New Point-to-Point Converter

Written by Jeff Hatzel

What is GeoCalc Online?

GeoCalc Online is Blue Marble Geographics’ online geodetic parameter repository. It contains all coordinate systems, transformations, and other definitions used by Blue Marble’s software. It is directly utilized by several Blue Marble software products: Geographic Calculator, the GeoCalc SDK, and Global Mapper. Users of these applications are able to query and update any supported definitions, as GeoCalc Online is kept current with the International Association of Oil and Gas Providers’ EPSG Geomatic Registry.

Users visiting GeoCalc Online have the ability to search the repository using the Filtered Search tool with advanced filtering options or by utilizing the Map Search tool, bringing all geodetic definitions to their fingertips. Logging into the site with a Blue Marble account will give access to a variety of actions, such as viewing or printing a definition’s parameters. For a limited time, signing in with an account tied to a Geographic Calculator order, will also provide full access to the brand new Point-to-Point Converter.  

Full mobile browser support now expands GeoCalc Online’s functionality even further. Users are not limited to running geodetic operations at their desks and can now work anywhere, searching the registry or logging in to run calculations in the field on the mobile device of their choice.

Point-to-Point Converter

Users of Geographic Calculator will find the Point-to-Point Converter similar to the popular Interactive Conversion Job found in the desktop software. The Point-to-Point Converter offers three operations: Convert, Forward, and Inverse. This blog explores the process of setting up a Convert operation in detail below. A Forward operation is used to compute a new coordinate that is a given distance and azimuth away from a starting coordinate. Similarly, an Inverse operation calculates the distance between two known coordinates on the same datum.

The Point-to-Point Calculator will have a familiar layout and functionality to Geographic Calculator’s Interactive Job.

When setting up a Convert operation, we’ll need to specify information regarding the source point and coordinate system, the target coordinate system, and the appropriate transformation between the two. GeoCalc Online provides users with a few different ways of completing this task. Those familiar with Geographic Calculator will find the Convert  setup familiar. The point is entered, given a name, and a picker is used to select the source coordinate system.

While the picker can be used to set the target coordinate system as well, there may be times when searching for a system is more appropriate. Navigating to the Search page of GeoCalc Online allows a search to be conducted based on a map location or by using the Filtered Search on the left for more detailed search options. 

In this example, EPSG Code 4326 was used as the search parameter for the Filtered Search. When viewing the search results, there are a variety of Actions that can be conducted; in this case, I chose Set As Converter Target. It’s worth noting that either the Source Point Coordinate System and/or the Target Point Coordinate System can be set via this method, or from the aforementioned picker. 

Viewing Actions associated with a search result allows users to directly set that coordinate system as the source or target in the Point-to-Point Calculator. Other Actions provide ways to view and share a given definition.

After navigating to the Point-to-Point Calculator, we’ll see the coordinate system that was previously set has been applied as the Target Point Coordinate System. Choosing “Select Transformation” will open the transformation picker. Finding and selecting a transformation involves a similar process to setting the Source Point Coordinate System. Once the operation is fully set, clicking “Calculate” will process the calculation, with alert messages displayed below. 

The banner across the bottom will alert users of any issues with their calculations. In this case, it was a success.

Without any need to install software, GeoCalc Online’s Point-to-Point Converter allows users to conduct basic operations right in the web app, expanding the reach of GeoCalc to users in the field.

To see GeoCalc Online in action, join us for a live webinar on November 18.  Register today to secure your spot and take a moment to peruse the website at  http://www.geocalconline.com/.    If you don’t have a Blue Marble account and would like to get a full trial of the Point-to-Point Calculator, please contact sales@bluemarblegeo.com.

Map Publishing in Global Mapper

Written by: David McKittrick

I have to admit that I am a vestige of a bygone generation, cartographically speaking of course. For me, the word ‘map’ still evokes memories of a bedroom wall adorned with National Geographic pull-outs or a tatty road atlas of Europe whose pages elicit fond memories of family road-trips. In my mind, a map is, first and foremost, a sheet of paper. 

Over the last few decades, the advent and rapid evolution of digital mapping technology have fundamentally changed how we perceive, represent, and share information about our world. Today, a map is much more likely to be rendered using an app on a phone or a window in a web browser. According to the prevailing consensus, paper maps are obsolete and inefficient, and have no practical use beyond esthetic or decorative appeal. It’s time to dispel this notion. 

Paper maps are inherently interoperable; they do not require a specific software or hardware configuration for viewing; they are effectively immune to power outages or connectivity issues; and they seldom require technical support. In short, they are arguably the most effective way to share geospatial data with a virtually unlimited audience.

Luckily for users of Global Mapper, this venerable software offers a plethora of tools for printing or publishing the results of any geospatial process; from simply printing the contents of the map view in 2D or 3D, to designing a professional-quality poster or atlas. In this article, we explore some of the map publishing capabilities of Global Mapper.

Any map design process must begin with the data. How should the features on the map be displayed? Is a supplementary base-map needed to provide context? Is it important to convey the spatial distribution of a particular characteristic of the data? Are labels necessary? When faced with these decisions, it is important to consider the audience. For whom is this map intended? A map is fundamentally a medium for communication, so it is essential that the map creator and viewer are speaking the same ‘language’. 

The simplest and most effective way to convey information in its geographic context is to apply a consistent visual pattern to the features on the map. Broadly described as thematic mapping, this pattern might reflect a numeric value, in which case the visual representation is best represented as an increased intensity of a particular color, or it may represent a recurring name or description, in which case the assigned colors can be random and distinct. 

In the example above, a vector polygon layer showing conserved lands in the state of Maine has been imported into Global Mapper and overlaid on a base map containing town and county borders. On the left, the map shows the generic appearance of the layer, while on the right, random colors have been applied to reflect the ownership of the land. A legend has been added to the on-screen display describing the meaning of the colors.

While Global Mapper offers the option of quickly printing this map or simply capturing the screen contents, there is a much more powerful Map Layout tool available.

 Accessed from the File toolbar or from the Tools menu, the initial dialog box of the Map Layout Editor offers three options that will define the overall appearance of the map: the size and orientation of the paper, the geographic extent of the map to be printed, and the scale of the printed map. Choosing the settings for two of these variables will automatically set the third. For instance, if a specific page size and extent are required, it is not possible to manually set a scale. 

In this dialog box, it is also possible to choose a previously saved template, from which all of the settings for a layout design will be automatically applied.

After confirming the overall layout parameters, the Map Layout Editor window will appear. This what-you-see-is-what-you-get interface offers numerous options for adding supplementary elements to enhance the design of the map prior to printing. Options include a scale bar, north arrow, map legend, text (for a heading or descriptive text), and images. 

In the example above, the Maine conserved lands layer has been loaded into the Map Layout Editor. The map has been centered and latitude/longitude tick marks have been placed around the neatline. Below the map, a title, scale bar, legend, and image of the State of Maine seal have been inserted.

The size, positioning, style, and other characteristics of these elements can be manually assigned, or they can be matched and aligned with other elements for a polished, professional look. 

The Map Layout Editor window is dockable so it can be positioned adjacent to the main Global Mapper map window allowing any adjustments to the display of the map itself, such as colors or feature labels, to be automatically reflected in the Layout Editor. 

After the element insertion and positioning processes are complete, the map is ready to be printed or to be exported as a geospatial PDF. These options are available from the File menu in the Map Layout Editor, from where it is also possible to save a template of the current layout, which can subsequently be applied to future printed maps.

The word ‘map’ is derived from the medieval Latin phrase, ‘Mappa Mundi’, which literally means ‘sheet of the world’. Today, however, a map is much more likely to be rendered in pixels than on parchment. Nonetheless, printed maps still play a pivotal role in sharing or communicating geospatial data, and for users of Global Mapper, the Map Layout tools provide the means to create the highest quality printed maps. 

If you missed the recent webinar on map publishing in Global Mapper, you can now watch the recording of the session. If you have any questions, please contact geohelp@bluemarblegeo.com.

Lighting Effects in Global Mapper

Written by Katrina Schweikert

Global Mapper® provides a variety of ways to apply sunlight or scene lighting to the map view, whether it is to create stunning visuals or to perform analysis based on sun angle. In this article, we explore some of the options for working with light across a variety of different types of data. 

Hillshading

Hillshading is an effect applied to terrain data in order to see the structure of the landscape. It uses shadows to show the terrain’s texture, such as slopes, hills, and valleys. This is also referred to as shaded relief because shadowing accentuates the relief of the terrain, even though the image, in reality, may be 2D. Hillshading works with terrain data in the 2D and 3D views and can also be applied to cartographic outputs like printed maps or digital images. 

Image of Lake Tahoe terrain with and without hillshading.

Hillshading is enabled by default when terrain data is loaded into Global Mapper and can be toggled on and off from the toolbar. The hillshading effect is visible in both the 2D and 3D views.  It may not necessarily be accurate for the location of the dataset because the default position of the sun for the hillshading is to the north-east. This sun angle creates a cartographic effect, in which most people will see mountains and hills extruded towards the viewer and valleys appearing indented. Moving the sun to another position will sometimes confuse the brain about the depth of certain parts of the terrain. Nonetheless, it is very useful for realistically modeling how the sun might hit the landscape. There are numerous sites on the internet that can provide the sun azimuth and altitude information for a specific location at a given date and time for modeling real-world conditions. 

The hillshade can also be applied to a custom terrain shader. In the below example a custom terrain shader was built replicating a palette similar to those used by Eduard Imhof in his famous shaded relief maps. 

Another option for working with hillshade is to apply the hillshade to an image or another raster layer overlaying the terrain. The quickest way to do this is to use the Texture Map option, however there are also several blending modes that combine an image layer with the underlying hillshaded terrain. 

Texture mapping applied to the NAIP imagery reveals that some of the topography is part of the lake bathymetry.

Additional Light Controls

The Dynamic Hillshading tool provides additional control over the lighting of the scene. Many of these settings also impact the lighting effect in the 3D view. Ambient lighting can be used to enhance the overall brightness of the terrain layer and how much sunlight touches the terrain.  Shadow darkness and highlight settings impact how black shadows and white highlights are rendered within the hillshading pattern. The Vertical Exaggeration feature amplifies the 3-dimensional nature of the landscape with the shaded relief by exaggerating the effect of lighting on the terrain. 

The light azimuth and altitude match real sun conditions to provide sun analysis. Shadows, Highlights, and ambient lighting are also adjusted to model this.

From the Dynamic Hillshading tool, it is also possible to add multiple light sources. With varied datasets such as terrain, 3D vectors, and 3D models combined into one scene, adding multiple light sources helps illuminate the various parts of the scene. 

Eye Dome Lighting

Eye Dome Lighting was added to Global Mapper with the release of version 22. This is a lighting effect that specifically applies to the 3D Viewer and is used to accentuate depth within the scene. Data in the middle ground of the scene that is three-dimensionally offset  from surrounding data is given a shadow outline. This provides the viewer with a better sense of features extruding from the ground.

With Eye Dome Lighting (EDL) enabled (top), it is easier to distinguish individual trees and powerlines from the rest of the 3D scene.

Within the 3D view configuration dialog box, the strength and radius of the Eye Dome Lighting effect can be adjusted. There are also several falloff options that define how the shadowing fades out across the radius. 

If you would like to explore this functionality in more detail, or familiarize yourself with any other new features in Global Mapper, request a two-week free trial today.  If you would like to speak with a representative about how the software can address your unique geospatial challenges, request a demo.

The New Spatial Operations Tool in Global Mapper v22

Written by Jeff Hatzel

One of the new additions featured in Global Mapper v22 is the ‘Spatial Operations’ tool. Part of the ‘Analysis Menu’, this tool allows users to conduct overlay operations based on loaded vector data. This tool further expands the application’s spatial analysis functionality, allowing users to identify regions where analyzed layers meet specific criteria.

The initial release of this tool includes the ‘Intersect’ operation. This operation analyzes two unique vector area feature layers. The result extracts new area features delineating where the source data overlaps.

One of the most common uses of intersect operations is suitability analysis, finding acceptable locations based on various input variables. Let’s look at a workflow highlighting how this tool may be used to find specific areas of interest.

Source Data:

In this example, we are working with two different source data layers. As you can see in the image below, one layer contains municipal information: roads (black lines) and the municipality boundaries (yellow areas). The green area features represent sensitive ecological regions.

The goal of this process is to analyze the source data to highlight all ecologically sensitive regions within one of the many municipalities. It’s possible that some of these regions extend beyond the boundary of the municipality, which would be beyond our area of interest. We can account for this in our analysis as well.

The ecological areas of interest (green) and municipality boundaries (yellow) are in two different source vector layers.

Setting Up the Spatial Operations Tool:

This tool currently functions on area features, so line features are not included as part of the analysis. In this scenario, we are only interested in one of the two municipalities so we do not need to run this analysis for both regions. Before opening the tool, I selected the municipality of interest using the ‘Digitizer’ tool. After opening the tool, I’m able to specify that I only want to work with my selected feature.

One of the municipality areas features selected, highlighted with a crosshatch pattern.

Located in the ‘Analysis Menu’, the Spatial Operations tool  has a few options that need to be set. Use the ‘Layer’ option to enter a name for the output layer. The ‘Intersection’ operation is currently the only one available within the tool. Next, choose which of the loaded layers you want to analyze using the ‘First Layer’ and ‘Second Layer’ options. When selecting the municipalities layer, enable the option ‘Only Selected Features’ to ensure that the analysis is only conducted within that region. The text box on the bottom of the tool’s window will provide a message once all of the settings are properly selected, and the tool is ready to run.

Naming the output layer and selecting which layers to analyze within the tool.

Results and Output:

Once this process completes, a new layer will be created. This new layer delineates the intersecting regions of the two source layers loaded into the tool, represented in red below. These regions highlight all the ecologically sensitive areas within the municipality. Since the criteria for this analysis required the intersection of both layers, the output layer may not necessarily cover the full extent of the source layer. For example, on the eastern and northern sides of the dataset, there are ecologically sensitive areas (green) that expand beyond the output regions (red). This is expected as there is no overlap with the municipality in that location.

This output data can be used for a variety of further analysis. These areas features can be used as the basis of selection of subsequent features, have attribute analysis performed on them, and be utilized in many other workflows.

If you would like to explore this functionality in more detail, or familiarize yourself with any other new features in Global Mapper, request a two-week free trial today.  If you would like to speak with a representative about how the software can address your unique geospatial challenges, request a demo!

The Ada Platform Creates Holographic Digital Twins of Your Global Mapper Data

Written by Keith Lay, Marketing Director at Clirio Technologies

Global Mapper® has revolutionized how engineers manage, analyze, and design with spatial and mapping data. Clirio Technology’s Ada Platform provides the next level of visualization for your sites and projects by creating a holographic digital twin of your data, straight out of the Global Mapper interface, viewable on a Microsoft HoloLens or iOS (iPhone or iPad) devices. The Ada Platform allows Global Mapper users to go beyond interpreting complex 3D data on a flat, 2D screen by bringing the data into the room around you, to view at any angle, up to a one-to-one scale.

Multiple users can view and collaborate on 3D spatial data, even at different locations.

Here is a look at the process of converting your Global Mapper projects into holograms using Ada’s one-button export function and cloud-based scene building tool.

Step 1: Export Your Global Mapper Project

Create your Global Mapper project using the workflow you are already familiar with to combine and georeference multiple data formats (such as GIS, lidar, photogrammetry, and subsurface), analyze, create, and edit your maps. With the Ada add-on module installed, use the one-button export function to quickly generate the files required to create holograms.

Using the one-button export add-on in Global Mapper (red circled area).

Step 2: Create Scenes from Your Data in the Ada Cloud

Next, add the files exported in the previous step, enter the information in the proper fields to describe the project, and click on the ‘Create Scene’ button. Ada uses the power of the Azure Cloud to process your data in minutes, converting it into a true three-dimensional hologram. With that speed comes state-of-the-art security that gives you the peace of mind over the safety of your data. 

Drag-and-drop your exported files into the Ada Cloud Scene creator.

Step 3: Build a Presentation

If your project requires multiple scenes to be shown, the Ada Cloud software has a built-in presentation tool that allows you to package together as many scenes as you require. Presentations are created by dragging items from the list of created scenes into the sequence you wish to view them. This allows you to group and show different sites, various views, or different data types relating to a project. Add some descriptive information into the fields and click the ‘Create Presentation’ button to make your completed presentations available to view on your HoloLens or iOS device. 

Easily combine Scenes to create Presentations.

Step 4: View and Share Your Holograms

The Ada Platform includes holographic viewers for both Microsoft’s HoloLens mixed reality headsets, as well as for iOS (iPad and iPhone) devices. With the HoloLens, you get a true holographic visualization of your data, represented as a persistent 3D object in your room. iOS devices use augmented reality to simulate the placement of your 3D data in your space through the screen of the device and provides for more ubiquitous access. Simply launch the viewer on your device, select your presentation from the list and place the map where you want it. This could be on a tabletop or could fill the room entirely as you require. Multiple users in the same space can view and discuss the 3D model, anchored to a common location. With our new Remote Collaboration feature, users can now view and discuss the holographic model from remote locations, all the while communicating spatially (with avatars and audio) through the system. This can dramatically reduce unnecessary travel and contact, while maintaining high-quality interaction with the data, and bring the site to the experts.

Launching the Ada Viewer and placing a holographic tabletop map

The Ada Platform is available now to add value to your Global Mapper workflow and create a true 3D representation of your data for engineering discussions, project reviews, client presentations, and stakeholder engagement. More information can be found at www.adaplatform.io 

A video showing the workflow outlined in this blog can be found here:  https://youtu.be/oxXfxtCT0EE 

If this blog piqued your interest and you’d like to find out more about Global Mapper and the Ada Platform, join us for a free webinar on Thursday, November 5th at 10:00 AM (EST). Register now to secure your spot!

If you’re not familiar with Global Mapper and the Lidar Modulerequest a two-week free trial today.

Top 5 Features of Global Mapper’s Lidar Module Version 22

Written by: Cíntia Miranda and David McKittrick

The Lidar Module®, an optional add-on to Global Mapper®, provides advanced point cloud processing tools, including Pixels to Points®, for photogrammetric point cloud creation using overlapping drone-captured images, automatic and manual point cloud classification, as well as feature extraction, hydro-flattening, and more.

The latest version of the Lidar Module includes several new tools, as well as improvements to many of the existing features and functions. This blog highlights the top five new features of version 22:

 

  • A new Terrain Paint tool 

 

Terrain Painting is a set of terrain editing tools that provide the ability to modify the elevation values of a gridded elevation dataset interactively. Using simple drawing tools, this innovative addition to the Lidar Module can be used to fill gaps in the terrain, raise or lower the existing elevation inside a defined area, or set a specific elevation height. Dynamically editing a terrain layer in this way is useful for site planning, modeling, and cleaning up or improving sensor derived elevation data. This tool works with all types of gridded elevation datasets, including DSMs and DTMs, bathymetric datasets, lidar derived terrain data, and more.

The ‘Fill Gaps’ operation is used to fill in missing areas of terrain.

The ‘Smooth Terrain – Average’ operation is used to create a cleaner terrain surface.

In this example, the ‘Set Terrain Height’ tool is used to create the simulated path of a road. The feathering effect creates a sloped transition into the surrounding terrain.

 

  • A new algorithm that improves building classification 

 

The Lidar Module includes a variety of automatic feature identification and point reclassification tools. The underlying algorithms analyze the point cloud’s geometric structure in a local context to look for patterns that match a prescribed format. The specific options include reclassification of points representing high vegetation or trees, powerlines, power poles, and buildings. For the version 22 release, the algorithm for identifying buildings in a point cloud has been updated to provide a more accurate reflection of human-made structures when working with point cloud data from any source.

The orange points have been automatically classified as building points.

 

  • Improved building extraction with better 3D shape simplification 

After a point cloud has been appropriately classified, individual vector features can be created, reflecting the object’s three-dimensional characteristics. For example, 3D line features can be automatically generated by connecting the dots for those points that were identified as powerline points. Perhaps one of the more useful applications for this feature extraction tool is for creating 3D polygons representing buildings. In version 22, several new settings and options have been added, and the vectorization algorithm has been significantly improved to provide more accurate building outlines. Individual surface planes are now created, allowing the building’s specific structure to be more precisely represented, and the simplification process has been updated, resulting in cleaner roof planes and sidewalls.

Complex building features extracted from a point cloud as 3D polygons.

 

  • A new option to generate a process summary report when using the Pixels to Points process 

 

The Pixels to Points tool is arguably one of the most powerful components of the Lidar Module. Using simple drone-collected images, this tool photogrammetrically analyzes and identifies recurring patterns of pixels in multiple images to create a 3D reconstruction of the environment. Version 22 of the Lidar Module includes several improvements to this function, most notably a new ‘Post Processing Report’ that concisely summarizes the pertinent information from the data generation process. This report includes a summary of input data, processing time, output data, quality assessment, as well as a visual representation of the individual output layers. The report is in HTML format and will automatically open in your default web browser from where it can be saved as a PDF file.

A section of the report generated after the Pixels to Points process has been completed.

 

  • Two new lidar draw modes

 

3D lidar or other point cloud data can be rendered to reflect various point attributes, such as elevation, return intensity, and point classification. This latest release introduces two new lidar draw modes:

Color by Source Layer — With this option, a unique color is applied to each loaded point cloud layer as a simple way to distinguish separate point cloud layers in the workspace clearly. A specific color can be selected for a layer in the Lidar Display for that layer.

Color by Scan Angle – In this mode, lidar points are colorized using the scan angle attribute, with values potentially ranging from -90 to 90 degrees. The actual color of the points is determined by the Shader Option chosen in the workspace.

If you’re not familiar with Global Mapper and the Lidar Module, request a two-week free trial today. If you would like to speak with a representative about how the software can address your unique geospatial challenges, request a demo!

Is Global Mapper right for you? Take a look at the application’s top 10 features

Written by: Cíntia Miranda

Global Mapper is a robust GIS application that combines a comprehensive array of spatial data processing tools with access to an unparalleled variety of data formats at a genuinely affordable price — license cost begins at $549, a fraction of the cost of competing applications.  The latest release includes Remote Desktop Protocol or RDP-enabled licensing for professionals working remotely — a very appropriate tool when many of us are working from home lately.

Developed for both GIS professionals and map enthusiasts, Global Mapper has virtually everything you need in GIS software such as complete interoperability with exceptional data support, powerful data processing in an intuitive interface, extensive raster and vector capabilities, state-of-the-art 3D visualization and analysis, simple installation and setup, and unlimited technical support.  

If you’re searching for a robust and affordable GIS application, here are the top ten features of Global Mapper:

1. Built-in online data access with extensive format support

Global Mapper offers a surprisingly extensive collection of free online data sources available for streaming or download as well as the ability to add in custom data sources of your choosing. Providing support for virtually every known spatial file format as well as direct access to common spatial databases, the application can read, write, and analyze virtually any spatial data.

2. Terrain analysis and 3D data processing

Global Mapper’s analysis functions include view shed and line-of-sight modeling, watershed delineation, volume measurement with cut and fill optimization, customized gridding and terrain creation, contour generation, and much more.  This is an extensive set of data processing tools for a truly affordable application.

3. Advanced point cloud and lidar processing capabilities

The Lidar Module is an optional add-on to Global Mapper that provides advanced point cloud processing tools, including pixels-to-points for photogrammetric point cloud creation from overlapping drone/UAV images, automatic point cloud classification, feature extraction, terrain hydroflattening, and much more. 

4. Data sharing and map publishing tools

When the time comes to share map data, Global Mapper offers numerous options including eye-catching page layout and printing tools, geospatial PDF creation, and direct web publishing to MangoMap, an affordable and easy-to-use online map service. Global Mapper also offers advanced page design and layout tools, including multi-page map book creation.

Multi-layered maps can be published to an online MangoMap account directly from Global Mapper v21.

5. Scripting and batch processing

Global Mapper users can automate most routine data processing functions using simple, text-based scripts or the built-in Batch Processing tool. The scripting language is simple and intuitive with a straightforward command and parameter structure mirroring many of the multi-step procedures that can be performed within the interface.

6. Advanced Image Processing

Global Mapper includes a powerful set of tools for processing imagery or raster layers. The image rectification tool allows any image to be positioned, scaled, aligned, and spatially distorted to create a geographically accurate raster layer. The powerful vector extraction tool can be used to create polygons from a range of colors in a raster layer. Image tiling, mosaicking, blending, cropping, feathering, and visual manipulation options provide the means to adjust the display and characteristics of any raster data layer.

7. Feature label creation and management

Professionals working in cartography say that the format and layout of a well-designed map always need some level of human input. Vector labels in Global Mapper can be assigned to their own layers, which makes formatting, moving, rotating, and deleting individual labels much easier. 

Label formatting in Global Mapper makes producing high-quality maps easier and faster. The screenshot above shows the repositioning of individual labels in a label layer.

8. Digitizing and Vector Editing Tools

When it comes to creating or modifying vector data, Global Mapper’s Digitizer provides a vast array of functions. From simple point, line, and polygon creation to COGO for manual geometric input, the Digitizer has all of the tools you need to create and manage vector layers. Specialized tools are also available for creating a custom grid, buffers, range rings, or virtually any geometric object. Supplementing these drawing tools are a large collection of attribute management and data visualization tools for creating thematic representations of vector data.

9. The ability to record a fly-through path using the fly-mode and walk-mode in the 3D Viewer 

Global Mapper not only is able to record fly-through videos, but it also allows users to “draw” a fly-through path by recording their movements in fly-mode and walk-mode in the 3D Viewer. Since the fly-through feature in Global Mapper is an easy way to create videos of 3D data and terrain, it’s commonly used for real estate and property management, planning drone or UAV flight paths, or simply creating a compelling presentation of your GIS data to stakeholders.

Global Mapper users can “draw” a fly-through path by recording their movements in fly-mode and walk-mode in the 3D Viewer.

10. A free mobile version

Global Mapper Mobile is a free app for iOS and Android devices that offers field viewing and data collection. It displays any supported data from the desktop software, streamlines data collection, and efficiently transfers data into the desktop software.  A professional-grade application is also available for purchase from the Apple App and Google Play stores.

There’s much more to Global Mapper! If this list piqued your interest and you’d like to find out if Global Mapper is the right GIS application for you, download a 14-day free trial and request a demo today!

Terrain Layer Support in Global Mapper Mobile v2.1

Written by Jeff Hatzel

One of the many new features in Global Mapper Mobile v2.1 is support for terrain layers, which introduces a variety of new functions and settings within the app. These new tools add to an already robust feature set that help to extend  the reach of your GIS. While much of this functionality is available in the free version of the app, some more advanced options are part of the optional Pro Module. 

Features available in the base version of the app:

Prior to the release of Global Mapper Mobile v2.1, a terrain layer exported from the desktop version Global Mapper was handled as a simple raster layer, without any elevation information.  The new functionality recognizes terrain layers and their respective elevation information and metadata.

All terrain layers will be rendered using the Atlas Shader, one of the default shaders in the desktop version of the application. Users can also control whether hill shading is enabled via a new setting found in the Configuration settings in the mobile app. 

Terrain data is displayed using the Atlas shader, with shading enabled by default (left). A setting found in Configuration allows users to disable hill shading if necessary (right).

Navigating to the Control Center within Global Mapper Mobile will feel familiar to users who work with the desktop software. The layer’s elevation range, units, and other related information are now available when viewing the metadata for a terrain layer. This provides a useful reference for users when in the field, providing situational awareness in relation to their data and surroundings.

Terrain layer metadata now shows relevant elevation information associated with the layer, including elevation range, units, and other pertinent information

The addition of terrain layer support to Global Mapper Mobile v2.1 also helps to expand location information by providing elevation information at a specific location. Enabling either Crosshair or GPS and Crosshair location mode will report the elevation values of the terrain at the crosshair location. This displays specific elevation information for a given location from a source other than the device’s location services.

The elevation value of a given location can be viewed when using a crosshair-based location option. As you pan and zoom on the map, the elevation value will update based on the loaded terrain layer.

Advanced options in the Pro Module:

Navigating to the new Shader Options section within Configuration provides Global Mapper Mobile Pro users more options to customize the terrain data. The Shader Name option allows access to any of the terrain shaders that are built into the desktop version of the software.

Users who need to simulate water level on their terrain data will find the Display Water Level settings beneficial to their workflows. Whether modeling water level rise or trying to understand what changes in water level will look like on the landscape, users can control when this is enabled, and at what elevation water is displayed.

Terrain layer support is just one of the many new features in Global Mapper v2.1. If you’re interested in exploring the app further, visit Global Mapper Mobile v2.1 for details. The app is also a free download from the Apple App Store and Google Play Store.

Working with Bathymetric Data

By: Katrina Schweikert

Global Mapper is well known for its file format support and terrain analysis capabilities. Perhaps what is less well known is the way the various data analysis tools in Global Mapper can be used to generate and analyze bathymetric data. 

Bathymetry is the study of topographic landforms below the water, such as on the ocean floor, the bottom of a lake, or even the bed of a river. Given that over 70% of the earth’s surface is covered with water, this branch of 3D analysis is extremely important in understanding the characteristics of the planet. What follows is an exploration of some of Global Mapper’s analysis and visualization techniques that are relevant to the bathymetric analysis. 

Great Barrier Reef Depth model obtained from Geoscience Australia

Bathymetric Data Support

Global Mapper provides support for over 300 file formats, and many of those include formats for bathymetric data, marine navigation, and remote sensing of subsurface data. Here are some examples: 

  • Marine Navigation and Nautical Charts (S-57 and S-63 with s-52 symbols, NOS/GEO, NV Verlag, PCX,  and others)
  • Sonar, Sidescan sonar and Bathymetric Sounding data (Lowrance Sonar, XTF, HTF, and others) 
  • Gridded Bathymetric Data (BAG, DBDBV, Hypack, IBCOA, GRD98, NITF, various other terrain formats such as netCDF, GeoTiff, ASCII grid)

Bathymetry in a DTM

Gridded bathymetric data provides various visualization and analysis options when loaded into Global Mapper.   The preformatted elevation shaders or a custom shader can be used to find the best color scheme to show depths of submarine landforms. Terrain Shaders can also reveal the slope steepness and slope direction of underwater topography. 

Displayed in the 3D viewer, gridded bathymetric data comes to life with draped imagery and charts, water level visualizations, and any other reference vector data. Quickly and easily generate elevation profiles, or a series of sequential cross-profiles using the Path Profile tool and Perpendicular Profiles setting. 

3D view of bathymetric data with path profile cutaway showing a shipwreck site in the Gulf of Mexico

Combining data from different surveys and fusing data from multiple sensors is as easy as loading in the datasets and ordering the layers. The analysis and visualization tools can automatically merge the various inputs to take data from the topmost layer or choose to view and compare the data from multiple surfaces simultaneously. There are also options for cropping, aligning, feathering, and comparing to create a more seamless integration between disparate datasets. 

Analyzing Bathymetry as a 3D Point Cloud

Global Mapper provides tools for converting existing sensor data such as sonar or soundings to a 3D point cloud; or for sampling existing gridded data to create an array of 3D points at the pixel centers. This enables the automated classification algorithms of the Lidar Module, which can be used to identify the seafloor and identify or remove other subsurface structures or topography. This powerful tool has been used for shipwreck detection and modeling, as well as identification of other subsurface features. 

Subsurface Contouring

Global Mapper includes an easy-to-use tool for generating precise depth contours and shorelines from gridded bathymetric data. The resulting line features can be edited and stylized in a variety of ways and combined with other datasets to create custom bathymetric charts. Alternatively, the areas enclosed by contours lines can be filled to create polygons that show the water extent at different depths or sea levels. 

Contour lines colored by elevation combined with other basemap data to create a custom chart

Measurement and Volume Calculation

Global Mapper provides various tools for calculating two- and three-dimensional measurements. In the 2D map view, the Path Profile window, and the 3D Viewer linear distances and areas are measured using a simple drawing function. Volume can be calculated from bathymetric data by either defining a height or by calculating numerous volumes across a range of water heights. Volume can also be measured by defining a plane or comparing the bathymetric data to a surface grid. This provides various options for water volume calculation. 

Flood Modeling

By combining bathymetric data with terrain data and using tools such as the watershed analysis and water level rise tool it is possible to discover flood extents, flow accumulation, and perform other hydrographic analysis. 

Employing the various terrain editing and terrain creation functions, Global Mapper can be used to create hydro-enforced DEMs or other modified surface models. These can be analyzed within Global Mapper or exported to various formats to support analysis in other applications. 

Temperature and other Measurements

The bathymetric analysis may also involve other gridded datasets such as surface temperature, salinity, gravimetric data, and various other measured values. These datasets can also be visualized, rendered in 3D, and contoured to provide additional insight into the dynamics of lakes, oceans, and other water bodies. 

The latest version of the Global Mapper and Lidar Module include several enhancements, many of which apply to bathymetric data analysis. If this blog piqued your interest and you’d like to find out if Global Mapper is the right application for you, download a 14-day free trial and request a demo today!

How Pixels to Points Works

By: Katrina Schweikert

The Pixels to Points tool in Global Mapper’s Lidar Module uses a process of Automated Aerial Triangulation to reconstruct the 3D scene present in overlapping images. This computationally intensive process may seem like magic, but it relies on basic concepts of vision and photogrammetry. Photogrammetry is the science of taking real-world measurements from photographs. Let’s pull back the curtain to reveal how this process works. 

What is Aerial Triangulation?

Based on photogrammetry techniques, the location, size, and shape of objects can be derived from photographs taken from different angles. By combining views from multiple images, the location of distinct parts of the image are triangulated in 3D space. This is similar to how depth perception works with two eyes; since the object in front of you is viewed from two slightly different angles, the brain can perceive how far away the object is.

Diagram of depth perception

In traditional photogrammetry with stereo-image pairs, the two angles of the image allow the photogrammetrist to measure objects in the image and determine their real world size. With automated techniques using many overlapping images, the entire 3-dimensional nature of the scene being photographed can be reconstructed. 

Photogrammetry measurement diagram

What are the steps in Automated Aerial Triangulation?

Automated Aerial Triangulation involves a number of steps to get from the original images to 3D point clouds, terrain models, textured 3D models, and orthoimages. The first step is to detect distinct features in each image, and then match those features across the adjacent images. The challenge is to automatically detect distinct features that may be at different scales and rotations in each of the images. 

Features detected in two images, with lines showing the matches found

After the features are tracked through the images, the initial reconstruction begins with a process called Structure from Motion (SfM). In the context of mapping technology, the structure of the 3D scene is revealed based on the motion of the camera. This process calculates the precise orientation of the cameras relative to each other and to the scene, and builds the basic surface structure of the scene. This is the point where the selected Analysis Method is applied. The Incremental Analysis Method starts with a set of the best matching photos, and incrementally adds the features from subsequent images into the scene to build the 3D reconstruction. This works well for drone-collected images collected over a large area in a grid pattern. The reconstruction will typically start somewhere near the center of the scene, and work outwards. The Global Method, by contrast, takes information from all of the images together and builds the scene all at once. This makes for a faster process, but it also requires a higher degree of overlap between adjacent images. This is recommended if the images are collected focusing on an object of interest, such as a building, especially when all of the images focus on that central area or object. The result of the Structure from Motion analysis is a sparse point cloud that builds the basic structure of the scene, and a set of precisely oriented cameras that show where and in what direction the images were taken relative to each other

Example of sparse point cloud with camera frustums

The final step of the Automated Aerial Triangulation process involves filling in additional details from each image that was calibrated as part of the scene. This process is called Multi-view Stereo. It involves calculating the depth of each part of the image (i.e. how far away it is from the camera), and then fusing those depth maps to keep the points that appear in multiple images. 

Depth map and confidence map based on overlap with other images

This process generates the final dense 3D point cloud. Based on the options selected, there may be further processing to convert the point cloud into a refined mesh surface (3D Model) that is photo-textured by projecting the images onto it. This option also produces the highest quality orthoimage, removing relief distortions based on the 3D mesh surface. 

What factors impact Automated Aerial Triangulation?

Lens Distortion

An important initial step in the Pixels to Points process is removing the lens distortion in the image. While the photograph may appear as a flat image capture of the target area to the untrained eye, most photographs contain some distortion, particularly towards the edge of the image, where you can see the effect of the curvature of the camera lens. Pixels to Points will remove distortion in the image based on the Camera Type setting. Most standard cameras need correction for the basic radial lens distortion in order to create an accurate 3D scene. The default camera type setting, ‘Pinhole Radial 3’, corrects for the radial lens distortion (using 3 factors). In some cases it might be beneficial to use the ‘Pinhole Brown 2’ camera model, which accounts for both radial distortion and tangential distortion, where the lens and sensor are not perfectly parallel. 

Image with distortion and processed undistorted imag

Some cameras have the ability to perform a calibration, which automatically removes distortion in the image. If the Pixels to Points tool detects from the image metadata that the images have been calibrated, it will switch to the ‘Pinhole’ camera model. If you know your images have already had the distortion removed either by the camera, or some other software, choose the ‘Pinhole’ camera model, which will not apply any additional distortion removal. The final two Camera Type options account for the more extreme distortion of Fisheye or Spherical lenses. Select these options if appropriate for your camera. 

Focal Length and Sensor Width

An important part of transferring the information in the image into a real world scale is knowing some basic camera and image information. The focal length and sensor width values allow for a basic calculation of how large objects are in the image, and thus how far away they are from the camera. What is calculated using these values is a ratio between a known real world size (the sensor width) and the pixel equivalent of that size in the image. This is a starting point for reconstructing the 3D scene. Focal Length information is typically stored in the image metadata. Global Mapper includes a database of sensor widths based on the camera model, however, you may be prompted for this value if your camera is not in the database. You can obtain this information from the device manufacturer. 

Image Position

The basic position of each camera is typically stored in the image metadata (EXIF tags). With a standard camera this location is derived from GPS, from which average horizontal accuracy is within a few meters. There are a few ways to improve the accuracy of the resulting data based on the desired accuracy, and decisions about cost vs. time spent. 

Height Correction

The GPS sensors contained in most cameras may have sufficient horizontal accuracy for some applications. However, the corresponding height values are usually less accurate and are based on an ellipsoidal height model. A basic height correction can be performed using the options for Relative Altitude. This will anchor the output heights based on the ground height where the drone took off (the height of the ground in the first image). You can enter a specific value, or Global Mapper can automatically derive the value from loaded terrain data or online references (USGS NED or SRTM). 

Ground Control Points

One way to correct the position of the output data is through the use of Ground Control Points. This is a set of surveyed points with known X,Y,Z locations that should be evenly distributed throughout the scene. The measured ground control point locations need to be visually identifiable throughout the corresponding images, so it’s common to use a set of crosshairs or targets placed on the ground throughout the collection area before the images are captured.

 

Ground Control Points can be loaded into the Pixels to Points tool and the corresponding locations identified in multiple input images. This will align the scene based on the control points taking precedence over the camera positions. This procedure is a more time-intensive option, but is streamlined through a process whereby the images containing each point are highlighted, It is also possible to use Ground Control Points after the output files have been generated. Global Mapper provides various tools for this, including 3D rectification and the Lidar QC tool, which can also provide accuracy assessment information. 

RTK and PPK Positioning

Hardware manufacturers provide options for improving the accuracy of the positional information by communicating with a reference base station in addition to satellites, and by performing additional corrections based on available information at the time of the image collection. This includes both Real-Time Kinematic and Post-Processing Kinematic options. With some systems, higher accuracy positioning information is written into image metadata, which can be used directly in the Pixels to Points tool. Other systems may save the higher accuracy positions in a text file, in which case you will want to load your images into the Pixels to Points tool and use the option to Load Image Positions from External File

 

Understanding the variables and data requirements for the Pixels to Points tool and other SfM processes will help you to collect images better suited for processing. In turn, this will create higher quality results for further geospatial analysis.

The latest version of the Global Mapper Lidar Module includes several enhancements, many of which apply to the Pixels to Points tool for generating point clouds and 3D meshes from drone-captured images. If this blog piqued your interest and you’d like to find out if the Lidar Module of Global Mapper is the right application for you, download a 14-day free trial and request a demo today!