Got a Drone? Now What? — Using Global Mapper with Your UAV

Let’s start with a question. How many of you currently own a Segway? Unless you moonlight as a mall cop or run an urban tour company, you probably decided not to jump on that gyroscopically-controlled bandwagon. If the hype that surrounded the release of this ‘revolutionary technology’ was to be believed, we would long since have abandoned our cars, redesigned our cities, and be living much more fulfilling lives. Alas, the reality has fallen a little short.

The emergence and proliferation of Unmanned Aerial Vehicles (UAVs) or Drones, on the other hand, while not accompanied by a cacophony of hyped-up fanfare, promises to have a much more profound impact on our lives. If current speculation is to be believed, within a few short years, the skies overhead will be swarming with delivery drones, traffic monitoring drones, and even people-moving drones.

For those of us in the mapping industry, this eye-in-the-sky technology effectively addresses one of the perennial challenges that we face: where do we get data, and more specifically, where do we get current data? Traditionally, we have depended on often inadequate and outdated public geospatial data archives or expensive commercial sources. With the advent of readily accessible UAV technology, on-demand data is within anyone’s reach.

The rapid growth of UAV ownership has resulted in an interesting dilemma for some would-be pilots. Having purchased the hardware and collected some data, many are often unclear as to what exactly they can do with it? Over the last couple of years, I have attended several UAV-focused tradeshows and a question that I am often asked is, ‘What can I do with Global Mapper?’ The answer: many things.

Initial Flight Planning

Among the freely available online data services in Global Mapper are high-resolution aerial imagery, Digital Elevation Models (DEMs), aviation charts, and topographic maps.

Before hitting the launch button, it is a good idea to virtually reconnoiter the project area. What possible obstructions are in the vicinity, what are the terrain characteristics, are there any nearby buildings or other facilities that might have overflight restrictions, what is the coverage area? These questions and more can be answered by loading the relevant data into Global Mapper and conducting some rudimentary pre-flight analysis. Among the freely available online data services are high-resolution aerial imagery, Digital Elevation Models (DEMs), aviation charts, and topographic maps. Global Mapper’s drawing tools can be used to delineate the extent of the project site to determine coverage area and to draft an initial flight plan to optimize the data capture process. All of this data can be transferred to an iOS or Android device running Global Mapper Mobile to allow field checking of the flight plan parameters.

Geotagged Image Viewing

Images can be loaded into Global Mapper as picture points creating a geographic photo album. Derived from the coordinate values embedded in the image files, the location at which each photo was taken is represented by a camera icon in the map view.

One of the most basic functions of a UAV is taking photographs and as we will discuss below, with sufficient overlap, these images can be processed into a 3D representation of the local area. Before proceeding with this more advanced functionality, the images themselves can be loaded into Global Mapper as picture points creating a geographic photo album. Derived from the coordinate values embedded in the image files, the location at which each photo was taken is represented by a camera icon in the map view. Using Global Mapper’s Feature Info tool, each photo is displayed using the computer’s default image viewer. Viewed in the 3D Viewer, the camera icons will appear above the terrain or ground providing a precise representation of the drone’s altitude when each image was captured.

3D Reconstruction

The functionality of the Pixels to Points tool transforms simple drone-collected image files into a dataset that can be used for countless 3D analysis procedures.

Incorporated into the optional LiDAR Module, beginning with the version 19 release of Global Mapper, the Pixels to Points tool is used to analyze an array of overlapping images to create a 3D representation of the environment. This powerful component identifies recurring patterns of pixels within multiple photographs and employs the basic principles of photogrammetry to determine the three-dimensional structure of the corresponding surfaces. While the underlying technology is extremely complex, as is typical in Global Mapper, the user’s experience is very straightforward. Simply load the images, apply the necessary settings for the camera system, add ground control points if available, click the Run button, and wait while it creates a high-density point cloud and, if required, a 3D model or mesh. The functionality of the Pixels to Points tool transforms simple drone-collected image files into a dataset that can be used for countless 3D analysis procedures.

Orthoimage Creation

A byproduct of the aforementioned point cloud generation process is the option to create an orthoimage. Defined as a raster layer in which each pixel’s coordinates are geographically correct, the orthoimage is generated by gridding the RGB values in the point cloud. Given its inherent accuracy, this 2D imagery layer can be used for precise measurements or as a base layer for digitizing or drawing operations.

DTM creation and Terrain Analysis

Global Mapper can generate a Digital Terrain Model (DTM) from point cloud data.

As mentioned previously, the Pixels to Points-generated point cloud represents the raw material for numerous analysis procedures in Global Mapper. As with any unprocessed dataset, some QA, cleanup, and processing will be required before embarking on any meaningful workflow. Fortunately, the software offers a plethora of editing and filtering options, including noise point removal, spatial cropping, ground point identification, and automatic reclassification. After isolating the points representing bare earth, the gridding tool is employed to create a Digital Terrain Model (DTM), a 3D raster layer that depicts the ground surface. In turn, this terrain layer can be used to create custom contour lines, to calculate volume, to delineate a watershed, to conduct line-of-site analysis, and, if overlaid on a previously created DTM, to identify and measure change over time.

Video Playback

Aside from capturing still images, most UAVs are equipped with the necessary hardware to record video. Beyond simple recreational use, this functionality is useful for building or asset inspection, strategic reconnaissance, forestry inspection, and in countless other situations where a remote perspective is needed. Global Mapper includes an embedded video player that will play this recording while displaying the corresponding position of the UAV in the map window. The determination of position is derived from the per-vertex time stamp recorded in the track file recorded during the flight. After loading this file as a line feature, and associating it with the corresponding video file, the playback is initiated from the Digitizer’s right-click menu.

LiDAR Processing

The Global Mapper LiDAR Module offers a set of tools for identifying, reclassifying, and extracting these features as vector objects.

Not too long ago, it was generally accepted that, due of the size and weight of the required equipment, LiDAR collection could only be carried out using a manned aircraft. This simple fact contributed to the high cost and logistical challenges of the LiDAR collection process. Today, miniaturization of the LiDAR apparatus has reached the point where it is within the payload capacity of many larger drones. Given the limited range of the aircraft, drone-collected LiDAR is only viable for small, localized projects however it does allow frequent re-flying of a project site and is thus ideally suited for change detection. Global Mapper, along with the accompanying LiDAR Module, offers a wide range of tools for processing LiDAR data. As previously mentioned, points can be filtered and edited before creating a surface model for terrain analysis. Compared to photogrammetrically created point cloud data, LiDAR provides a more complete three-dimensional representation of non-ground features such as buildings, powerlines, and trees. The LiDAR Module offers a set of tools for identifying, reclassifying, and extracting these features as vector objects.

Fundamentally, UAVs and maps have much in common. Both are intended to provide a remote, detached perspective of an area of interest and allow us to see spatial distribution and patterns in our data that would not otherwise be detectable. It is understandable, therefore, that one of the primary functions of a drone is to provide data that can be used for creating maps and other spatial datasets. Global Mapper is ideally suited for this type of workflow and it provides an extensive list of tools that can be used by drone operators.


A thirty-year veteran in the field of GIS and mapping, and a lifelong geographer, David McKittrick is currently Outreach and Training Manager at Blue Marble Geographics. A graduate of the University of Ulster in Northern Ireland, McKittrick’s experience encompasses many aspects of the geospatial industry, including cartographic production, data management, marketing and sales, as well as software training and implementation services. McKittrick has designed and delivered hundreds of GIS training classes, seminars, and presentations and has authored dozens of articles and papers for numerous business and trade publications.

 

How to Compare Point Clouds Using Global Mapper v21.1

Written by: Mackenzie Mills,  Application Specialist

In many areas of GIS,  change detection can be a powerful analysis tool. Comparing datasets through time can add another dimension to your work as you can visualize and measure how a study area changes. This type of analysis is becoming particularly important as drone mapping and collection of first-hand data are more common. Change detection analysis can also be very useful when looking for natural change in an area, like the impact of a natural disaster or new vegetation growth year to year; or a man-made change, like the progress of construction in an area or deforestation; or change made to the data by previous edits.

In the release of Global Mapper version 21.1, the Compare Clouds tool was introduced to detect change points between overlapping lidar or point cloud layers. Previously in Global Mapper, change detection was only available using the Combine/Compare Terrain Grid tool, which creates a new elevation layer based on the difference in the per-pixel Z-values of the overlapping layers using the subtraction setting.  The output of the new Compare Clouds tool is a layer containing the points that have changed between the input point clouds. 

To use the Compare Cloud tool, start by loading the point clouds you would like to compare into Global Mapper. Select the Compare Could tool from the Lidar Tools toolbar. 

Compare Lidar Point Clouds
Compare Lidar Point Clouds

In the Point Cloud(s) to Compare Against box, select the starting or original point cloud. This is typically the first or earlier pass over an area. The cloud(s) selected in the Point Cloud(s) to Find Changes In box will be compared to the “Point Cloud(s) to Compare Against when the tool is run.

This new tool works to compare point clouds by having the user input a distance to use for comparison. This Minimum Distance Between Point Clouds value allows for a looser or tighter comparison of the clouds. This setting is important when comparing point clouds because they are made up of individual points and not interpolated like a terrain grid. It is unlikely that the point clouds you are looking to compare will contain points in the exact locations, so a threshold (specified in point spacings, meters, or feet) is required for comparison. Any points from the Find Changes In point cloud that do not have a corresponding point in the Compare Against cloud will be considered changes in the area.

When the process runs, those points in the second layer that have been found to have shifted beyond the designated threshold when compared to the original layer will be marked as having changed. After running this process, you will find a new layer added to the workspace containing only the points that have changed.

Points detected to be changed using the Compare Cloud tool in Global Mapper
Points detected to be changed using the Compare Cloud tool in Global Mapper

In the image above, you see an area of rocks where some have been removed between point cloud one and point cloud two, after running the Compare Cloud tool we see the selected (red) areas are the points detected to be changed.

After identifying change in an area using the Compare Clouds tool, you may wish to classify the points detected as changed or delete them to reconcile multiple datasets. Alternatively, you may want to generate gridded layers to show the changed areas and layer these changed grids over the original or use the Compare Against layer.

This powerful new tool speeds up the process of change detection on 3D data by directly comparing two point clouds to find points with significant change. This change detection functionality can be applied in a wide variety of industries including agriculture, forestry, and engineering. Take a look at the latest release of Global Mapper and the Lidar Module to bring this streamlined workflow into your own data analysis.

How to use Global Mapper’s Raster Reclassify tool

Written by Jeff Hatzel, Senior Application Specialist

With the release of Global Mapper v21.1 comes the addition of an exciting new tool, Raster Reclassify. The development of this tool, like so many in Global Mapper®, was heavily driven by requests from our users. The initial release of this tool allows users to modify the pixel values of a palette image. A common use case for this might be to adjust the classes with a landcover file to create a new layer with a simplified set of classes. Let’s look at a more advanced workflow: using Raster Reclassify to adjust the values of an image created from classified lidar.

Hint: If you’d like to learn about this tool in detail, review the Raster Reclassify Knowledge Base page!

Using Lidar Classification Codes to Make a Raster Layer:

If you’re familiar with the Create Elevation Grid tool in Global Mapper, you know that this tool allows you to create a terrain layer based on the elevations within the source point cloud. You may also know that when working with lidar data, this tool allows you to create a grid-based on a variety of lidar attributes and properties, for example, classifications.

Classified lidar data
Classified lidar data (left) was gridded based on its classification code to make an output raster (right).

This resulting file represents multiple lidar classes from the source point cloud. The classes follow the same color scheme used to display lidar by classification. However, it’s possible we may only have an interest in a specific set of classes or an individual class, buildings for example. We’ll address that with Raster Reclassify.

Hint: Take a look at the different Grid Type options in the Create Elevation Grid tool.

Raster Reclassify to Highlight Classes of Interest:

The Raster Reclassify tool (part of the Analysis Menu) allows you to adjust the values of the source layer. In this situation, we want to focus on buildings. We’re going to merge all non-building classes: ground, low, medium, and high vegetation, bridges, powerlines, and water. Buildings will be retained as a unique class.

Raster Reclassify
Raster Reclassify allows you to load the source palette from a reference file. You can choose which classes you want to reclassify, adjusting their description, color, etc.

This tool creates a new output layer within the current Global Mapper workspace. As you can see below, that layer will now only show the newly created classes you outline in the Raster Classification Rules section of the Raster Reclassify tool.

Source file comparison
The source file (left) compared to the reclassified layer (right). The reclassified layer now only shows two classes, based on the rules set in the Raster Reclassify tool.

Hint: Want to display different layers side-by-side in the same workspace as we’ve done in some of the above images? Check out Multiple 2D Map Views!

What’s Next?

Products created by Raster Reclassify can be used in a variety of applications. Some may be final deliverables for reclassified landcover datasets, used to make or adjust clutter grid files, or any other number of possibilities.

How will you use the Raster Reclassify tool?

Keep an eye out in the future for new functionality in this tool, including the ability to reclassify terrain data and non-palette imagery!

How to move your Single User Global Mapper® license in a few easy steps

The day has come, you received a computer upgrade at work or you finally splurged on a new laptop. The excitement and joy of finally having a faster computer with better graphics and a new operating system can quickly be diminished by the laborious task of transferring files and software to the new machine. This blog aims to alleviate some of that headache by walking you through Global Mapper’s single-user license transfer workflow. 

The first thing to do is to check the version number of your installation of Global Mapper. If you have version 20 or 21 you will be able to download the installation files directly from the Blue Marble website to your new machine. If you have version 19 or older you will need to move the installation files manually to the new computer. You’ll also want to ensure your Maintenance and Support (M&S) is still active. If you have questions or concerns about moving your license or the status of your M&S, please contact authorize@bluemarblegeo.com before moving your license.

Once you have checked your version of Global Mapper, navigate to the Help menu at the top of the screen, click “License Manager”, and the window below will open:

Blue Marble License Manager
Blue Marble License Manager

Select “Release” next to the license you would like to remove. A prompt will appear to confirm that you want to move forward. Click the “Yes” button. After the removal process is complete, you should receive a message containing the removal code for your license. This code will also be copied to your computer’s clipboard. To complete the removal, send the removal code to authorize@bluemarblegeo.com for confirmation that your license is no longer active. After the Blue Marble licensing team verifies this information, you will be able to move your license to the new machine.

It is possible that you may not receive a prompt upon removal, but do not worry, you can access it from the C: drive. On most computers, the file can be found in the following folder location: C:\ProgramData\GlobalMapper\GlobalMapper[your version number]. The ProgramData folder is hidden by default in Windows. If you can’t navigate to that directory,  you can view hidden files and folders with the instructions below.

Navigate to the search bar next to the Windows “Start” button and type “hidden files”. This will bring you to the “For Developers” prompt.

For developers window prompt
For developers window prompt

Under the heading “File Explorer”, click the “Show settings” next to “Change settings” to show hidden and system”. The Folder Options window will open, review the options and select “Show hidden files, folders, and drives”, then click the OK button. Please note these instructions are for Windows 10, for instructions on how to access “Hidden Files” in other versions of Windows please visit the Microsoft support page.

Windows File Explorer OptionsCintia Miranda | Projections
Windows File Explorer Options

Once this step is completed, you will be able to locate the Program Data folder on your C: drive. Please attach a copy of your GlobalMapper.lic_removed file in an email to authorize@bluemarblegeo.com.

Global Mapper license location on C Drive
Global Mapper license location on C Drive

The Licensing Team will then verify your license removal and you will be able to move your license to the new machine. Before beginning the licensing process, please remove your computer from all external hardware, including docking stations. Finally, follow the detailed steps to set up and obtain the license in Part I of Global Mapper’s Knowledge Base.

Remember, if you have any questions or run into any problems moving your license, our Licensing Team is available Monday – Friday 8 am – 5 pm Eastern Standard time. They can be reached by phone at 207-622-4622 ex 1146 and by email at authorize@bluemarblegeo.com

Chelsea E | Projections
Rachael Landry is a Blue Marble Geographics Marketing Assistant and an unofficial licensing guru.

Get access to Blackbeard online oil and gas data from Global Mapper 21.1

On February 19, 2020, Blue Marble Geographics® released version 21.1 of Global Mapper®. The release included many new software features, including subscription-based access to Blackbeard Data — an online data service for accessing pipeline, well, and lease information.

Blackbeard Data is primarily known for providing information to assist institutional professionals and independent investors in the acquisition of mineral assets, specifically buying oil and gas royalties.  Blackbeard Data maintains the world’s largest database of oil and gas royalty owners and the world’s largest database of oil and gas comparables built from oil auction histories, which is invaluable to many users of Global Mapper in the energy sector.

Version 21.1 of Global Mapper introduces BlackBeard Data as part of its extensive online data portal. This subscription-based service is available through an intuitive interface, enabling users to seamlessly transfer and analyze oil and gas data from Blackbeard Data to Global Mapper, saving time and effort.

Users of Global Mapper can now access Blackbeard data by following these five easy steps:

  1. Press the Connect to Online Data button in the File toolbar or File Menu
  2. Navigate to PREMIUM CONTENT > Blackbeard Oil and Gas Data
    Select a sub-layer of interest
  3. Enter your API key or visit  https://blackbearddata.com/data-products/global-mapper

    Blackbeard Data Dialogue Box - Global Mapper V21.1Blackbeard Data Dialogue Box on Global Mapper V21.1
  4. Specify the desired data bounds, then press connect.
  5. Use the Info tool to get info about WMS or WMTS layers, or open the Attribute Editor to view attributes for the vector WFS layers.

    Blackbeard Data Screen View in Global Mapper V21.1Blackbeard Data Screen View in Global Mapper V21.1

Upgrade now to version 21.1 of Global Mapper to have direct access to Blackbeard Data (with a premium subscription) — the world’s largest database of oil and gas. For more information on how to acquire version 21.1 of Global Mapper visit globalmapper.com. For more information on how to acquire Blackbeard Data premium subscription visit blackbearddata.com.