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.
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.
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.
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.
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!
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!
Billy Noble, Applications Specialist at Blue Marble Geographics, answers questions that come into the technical support inbox. In this video, Billy demonstrates how to find the coordinates of a point in a loaded point cloud in LAS format using Global Mapper.
Interim releases of Global Mapper typically offer the Blue Marble development staff an opportunity to fine-tune some of the functionality that was introduced in the most recent major release. While the upcoming version 20.1 release includes its fair share of performance improvements and code tweaks, it also offers a surprising collection of new tools covering everything from the Digitizer to scripting. With the release just a few weeks away and the final edits being applied to the underlying code, we take a sneak peek at some of the more significant additions.
Path Profile Zooming
The importance of Global Mapper’s Path Profile tool has grown immensely since the introduction of the LiDAR Module. While it is most commonly used to render a cutaway view of a terrain layer, it also displays a cross-sectional view of points in a point cloud and can used to edit or delete selected points. New in version 20.1 is the option to zoom in the profile view – a function that ensures that even the most densely-spaced points can now be individually identified and selected.
Continuing the theme of improvements to the Path Profile tool, a new option has been added to more clearly define the individual surfaces when rendering profile lines for multiple layers. A legend, which can be placed anywhere within the Path Profile window, shows each line style along with the corresponding surface layer. This is particularly useful when visualizing and analyzing multiple layers representing change over time.
Global Mapper’s projection management is universally acknowledged for its simplicity. Load any layer and the inherent projection parameters associated with the layer define the display projection. Each successive layer is then automatically reprojected on the fly to adhere to this system. No questions asked. Change the display projection and each exported layer will ultimately include these new projection parameters. In Global Mapper 20.1, an even simpler approach to projection management can be enabled with the assignment of a universal default projection. With this new configuration setting, a specified projection will be automatically applied when creating or importing any new layer.
Vector Gap Closing
When creating abutting polygons, Global Mapper’s snapping functionality helps ensure that the features’ shared vertices are a perfect match, without overlap or gaps. When importing external files, however, such precise geometric integrity is not always the case. A new Digitizer tool available in version 20.1 can be used to automatically correct these errors. The “Close Gaps Between Adjacent Features …” function allows a maximum distance threshold to be established allowing the boundary lines to be perfectly matched.
LiDAR Proximity Selection
A common use case in point cloud or LiDAR analysis is the detection of encroachment, and a new point selection option in the LiDAR Module provides this functionality to Global Mapper users. The “Select LiDAR by Distance” tool can be used to specify a particular point type (such as powerline), a distance threshold, and a target point type (such as high vegetation). In this case, running the search will highlight vegetation points that are encroaching within a defined distance of powerlines. This tool can be applied in many other workflows and includes the option to detect points within the proximity of 3D line features instead of points.
So, there might be a chance that you haven’t actually heard of this event. That’s ok! I’m writing this to convince you that, whether you are a Blue Marble software user or not, you should know about this conference.
Here are the five reasons why you should join us at the Blue Marble User Conference next year:
1. I’m there! … and Global Mapper architects, developers, and experts are too
Yes, I’m there running around taking pictures and recording video (and eating the food), but what’s more valuable to you are the software developers and resellers who are there to hear your questions and requests.
This particular Blue Marble User Conference was especially valuable because the Global Mapper guru Mike Childs and our international resellers were there. After the day’s presentations and software demonstrations were over, Mike answered questions and heard software suggestions from attendees while our product manager jotted down the ideas.
It’s a part of Blue Marble’s core values to welcome and encourage users to be part of the development process. That user-to-developer communication is usually in the form of emails, but at a Blue Marble conference, users can communicate directly with the experts and know their ideas will make it to a discussion in our development meetings.
2. You will be inspired by presentations from distinguished GIS professionals
Did you know that scientists know more about the surfaces of Mars and the moon than they do of the Earth’s ocean floor – aka 75% of the world’s surface? I didn’t.
At this Blue Marble User Conference, Larry Mayer, Director of the School of Marine Science and Ocean Engineering and Director of the Center for Coastal and Ocean Mapping at the University of New Hampshire (phew! Long title!), delivered a presentation on the advancements in sonar and visualization technology for exploring the sea floor. He explained how the technology has helped in the discovery of 3,000-meter high mountains in the Arctic, D-day wrecks, the behavior of whales, and the history of climate through the impact of ice on the sea floor. He touted that investing in more ocean research would help us, people of the world, gain a better understanding of our planet.
Our second keynote speaker and CEO of Aerial Filmworks, Ron Chapple took attendees from exploring the deep with Larry to examining the Earth from above. Ron talked about the challenges that came with producing the Pulitzer Prize-winning documentary “The Wall”, which analyzes the impact of the proposed wall along the border between the U.S. and Mexico. His role in the project was to shoot aerial footage, over which he highlighted the location of the 2,000-mile long border using Global Mapper.
I was surprised to learn how difficult it was for the team of “The Wall” to accurately represent the curvy U.S.-Mexico border in the video.
My point is that BMUC includes amazing presentations by distinguished GIS professionals that give insight into projects that are relevant to the industry today.
3. You will leave smarter and gain Global Mapper “Tips and Tricks”
In between presentations at this year’s BMUC, Senior Applications Specialist David McKittrick took a few minutes to share some “tips and tricks” on how to use Global Mapper. The tips ranged from how to use the multiview display, smooth contours, view data in Google Earth, and create a terrain cutaway.
David also presented on the recent release of Global Mapper 20 and the LiDAR Module, which offers streamlined map layout tools, the ability to create a point cloud from a 3D mesh, a new eyedropper tool for selecting features, dramatically faster loading speeds for working with vector files, and a lot more.
All of these demonstrations were followed by an opportunity for attendees to ask questions that would help them apply these techniques to their own projects.
4. You will eat with other GIS professionals and have a chance to win a prize
Throughout the day, drinks and snacks were available, and at noon we provided lunch. During lunch, we challenged our attendees to participate in a Where in the World Geo-Challenge, in which they were asked to guess the names of geographic features in a slideshow.
At this year’s BMUC, we came prepared with a tiebreaker question, since we expected that a room full of GIS professionals would easily be able to guess all of the features correctly. The winner of the challenge went home with a gift card to the Blue Marble Emporium.
5. You will spend only $25 to attend
So why wouldn’t you attend BMUC if it’s only $25 for a day full of GIS presentations, networking, and lunch?!
They had me at “lunch”, so … I’m not sure why you wouldn’t register.
Stay tuned for future Blue Marble User Conferences
All jokes aside, BMUC truly has a lot to offer GIS professionals, even if you aren’t a user of Blue Marble software. From the insights of our keynote speakers, to the latest software developments and one-on-one interactions with our experts, BMUC is a great opportunity to connect with Blue Marble staff, have a direct impact on the software you use, and to network with members of the GIS community.
Chelsea Ellis is Graphics and Content Coordinator at Blue Marble Geographics. Her responsibilities range from creating the new button graphics for the redesigned interface of Global Mapper 18 to editing promotional videos; from designing print marketing material to scheduling social media posts. Prior to joining the Blue Marble team, Ellis worked in graphic design at Maine newspapers, and as a freelance photographer.
Did you catch Global Mapper on television over the summer? In an episode of the Travel Channel show, “Expedition Unknown,” the production crew visited Guatemala in search of Mayan Ruins. A team from LiDARUSA, longtime Global Mapper users, were also involved in the project, collecting LiDAR data for the Mirador Basin Project. Using a combination of drones and helicopters, the data was collected and processed, revealing an uncharted Mayan causeway. As you will see in the footage below, Global Mapper was used to classify bare earth and to view the model that was generated.
No need to worry about this brief cameo going to our heads, the “As Seen On TV” people won’t let us use their logo.
If you are like most people, it’s unlikely that you take the time to read the plethora of dialog boxes that appear when installing software but if you did, you might actually learn some interesting details about the application. In the case of Global Mapper, one of the windows that beckons for your attention is the “What’s New…” list. While we understand the eagerness of most users to repeatedly click the Next button and finish the installation process so they can “play” with their new toy, it might be worth pausing on this one for just a moment.
Blue Marble’s development process requires each new tool, functional upgrade, bug fix, and performance improvement to be meticulously documented and archived. What you are presented within the “What’s New …” list is an abbreviated version of this archive. In a sense, the list offers a summary report of what the development staff has been working on over the preceding weeks and months. It can make for some interesting reading.
For the soon-to-be-released Global Mapper version 20, there are more than 200 individual changes that have been noted. Given the dynamic nature of the development process, this number will likely increase by the actual date of release.
For those of you who do not have the time or the wherewithal to peruse the entire list, what follows, in no particular order, is a summary of five of the most significant new features that you will find in Global Mapper 20.
1) Improvements to the Map Layout function
One of the surprising findings from last year’s Global Mapper user survey was the importance of map printing. For years, the prevailing opinion has been that printed maps would eventually bite the proverbial dust, but this has not been the case. Global Mapper’s Map Layout functionality was completely redesigned a couple of years ago and it has been undergoing continual improvements ever since. For this release we have introduced a new tool for creating a map book or atlas from selected features; a new option to filter the legend by layer; and a custom macro function that allows you to create title blocks with name, company, etc. Suffice to say, if your workflow requires the printing of maps, Global Mapper 20 has all the tools you need.
2) Support for Windows Tablets with improved touchscreen functionality
While Global Mapper has always been supported on Windows-based touchscreen devices, certain actions and UI procedures have been difficult. In version 20, there have been significant improvements that allow a wider range of actions to be controlled with your fingers. Pinching to zoom the map is now supported as well as swiping with two fingers to pan the map in both the 2D and 3D views. Previous enhancements to support touchscreen interaction include, touching the screen to activate contextual menus and tapping on the screen with any of the digitizing tools enabled to place points or vertices.
3) Ability to create a point cloud or flattened orthoimage from a 3D mesh or model
Creating a point cloud, similar in structure to LiDAR data, from an existing 3D model or mesh may seem like an inverted procedure. It is the reverse of what would be considered a normal workflow. It does, however, open up a number of interesting 3D analysis workflows, in which the source data is an existing 3D mesh. For instance, the point cloud created from the model can be readily classified, edited, and filtered using Global Mapper’s LiDAR processing tools, and points representing ground can be used to create a DTM. Version 20 of Global Mapper not only offers this new point cloud creation tool but it also offers the option to create a flattened orthoimage derived from the colors in the mesh.
4) Speed improvements when loading large vector files
Citing any type of performance improvement as a new version highlight is often perceived as subjective and difficult to quantify or validate. In the case of Global Mapper 20, the improved speed when working with larger vector files is tangible. During our internal testing, the load time for a specific large shapefile was measured at just over four minutes in version 19 of Global Mapper. In version 20, on the same multi-core machine, the load time was shaved to 2.5 seconds. That’s almost 100 times faster. Improvements have also been made to the rendering of large vector files in the 3D View.
5) Eyedropper tool for accurate color selection
Perhaps not a major functional upgrade, however, when considered in the context of one of the author’s favorite Global Mapper tools, it is a godsend. The tool in question is a feature informally referred to as “Raster Vectorization” or, to give its proper name, “Create Area Features from Equal Values”. The premise is simple: By identifying a specific color in an image, you can create polygons that enclose the extent of the pixels of that color or you can expand the tolerance to accommodate similar colors. Previously, fine-tuning the color selection involved manually entering the required RGB values. In version 20, there now is a color picker option, with which you simply click the section of the raster image that you want to extract. This color picker is also available when choosing a transparent color for a raster layer.
And a couple of bonus highlights for LiDAR Module users:
Tool for creating a 3D model or mesh from selected LiDAR points
The underlying technology that enables the creation of an orthoimage was incorporated into Global Mapper within the Pixels to Points tool, introduced in the LiDAR Module in version 19. As a byproduct of the photogrammetric 3D point cloud generation process, there is also an option to generate a flattened raster representation of the area in question. Previously, the only way to create either of these data outputs was from drone images. With version 20 of the LiDAR Module, there is now an option to create a mesh or orthoimage from selected points in an existing LiDAR file or point cloud.
Option to spatially thin a point cloud
The LiDAR Module offers an extensive array of point cloud filtering and editing tools. Among the options are: deleting selected points, geographically cropping a point cloud, removal of noise points, manual or automatic reclassification of points, and horizontal or vertical shifting of the point cloud layer. Added to this list in version 20 is a new function to spatially thin a LiDAR layer. This tool allows the user to specify a target resolution for the point cloud which eliminates redundancy, reduces file size, and improves performance.
Version 20 Coming in Mid September
Global Mapper 20 is scheduled for release in the second half of September 2018. Check your inbox or visit bluemarblegeo.com to find out when it is available for download. As always, you can activate a free two-week trial and if you have time, check out the full What’s New list to see what improvements have been made to your favorite Global Mapper tools.
Product News, User Stories, Events, and a Chance to Win a Copy of Global Mapper Every Month
For many, summer is a time for relaxing, for taking your foot off the gas, for being lazy. Not at Blue Marble. We are busy preparing for the next major release of Global Mapper in just over a month, planning our hectic autumn travel schedule, and making the final preparations for our 25th anniversary user conference here in Maine. In this edition of Blue Marble Monthly we formally invite you to join us at BMUC. We also hear from Sam Knight about becoming a licensed drone pilot; we discuss the differences between LiDAR and PhoDAR; and we challenge your geographic prowess in the Where in the World Geo-Challenge.
We hereby cordially invite you to Blue Marble’s home state for our User Conference (BMUC), as we continue to celebrate our 25th birthday. Not only will you have a chance to meet other users and learn about the latest software developments, but you’ll also hear from some interesting presenters including Ron Chapple who will be speaking about his work in the Pulitzer Prize-winning project, “The Wall”.
Ready for the kids to go back to school? Sorry, we can’t help you with that, but we recently sent our own Sam Knight back to school to learn what it takes to become a licensed drone operator. As we continue to develop tools for the UAV industry, it is essential that we have the first-hand knowledge of what is required. For Sam, this was a journey into unknown territory.
Blue Marble’s development process has always relied on direct input from users and now you have a chance to be part of that process. Sign up as a beta tester today and we’ll let you know when a beta version of either Global Mapper or Geographic Calculator is available for you to put through its paces.
The Pixels to Points tool has caused quite a stir in the UAV industry. Creating a high-density 3D point cloud from a drone would have been unheard of just a few years ago. While the data may look and feel like traditional LiDAR, there are significant differences between the two formats. In a recent blog post, we outlined some pros and cons of each.
In the latest Global Mapper case study, we hear from Michael Frings, General Manager of MFBI Technologies about how the LiDAR Module’s point cloud processing tools played a critical role in planning autobahn truck stops in Germany.
“The fact that the LiDAR Module is so powerful, giving us the ability to handle large point clouds, was the killer argument for us to go with Global Mapper.” – Michael Frings
Simply stated, Global Mapper gives you more functionality for less money. Need proof? Take a look at this short video highlighting some of the terrain processing tools that are available out of the box in Global Mapper. No extensions required.
The geographic sleuths were once again hard at work in July. Most of you were able to identify all five locations in the Where in the World Geo-Challenge. The randomly selected winner of a copy of Global Mapper is Roy Mayo, a land surveyor from Mackay, Mackay, and Peters. If you are one of the handful whose response to the capital city question was, “Haven’t a clue” or words to that effect, check out the correct answers here then click the link below to see if you can do any better in August’s challenge.
The Blue Marble training team will be hitting the road again in October with the next three-day Global Mapper class scheduled for Houston. Typically our Houston classes fill up fast so be sure to sign up as soon as possible to reserve your spot.
“Without a doubt, one of the most informative and enjoyable technical training classes I have ever taken.” – Recent Global Mapper trainee
The development of a wind energy project, big or small, is a complex process that considers several factors. From measuring the actual wind resources in an area to researching potential zoning and ordinance conflicts, it’s not a project that’s easily simplified. But in the beginning stages of planning, whether you’re considering bringing wind energy to your own property or to a larger community, creating a rough visualization of a wind project can be relatively easy.
In this blog entry, we explain the online resources and tools available through Global Mapper that can help estimate resources and terrain modifications, and create a visualization of the preliminary plans of a wind project. We’ll do this by simulating a simplified planning process for a wind farm to arrive at a 3D visualization.
Importing & Analyzing Online Data in Global Mapper
In the planning of an actual wind project, we would want to know the annual average wind energy potential of our property, any legal limitations, and so much more information before even beginning plans for development. But for this simple simulation, our purpose is to introduce how relevant data can be accessed, analyzed, and visualized in Global Mapper.
One online source that we are using is the National Renewable Energy Lab, which is a federally owned and contractor-operated facility that provides data and maps for energy-focused purposes. The data set we are downloading shows the wind energy potential of areas across the state of Maine on a relative scale ranging from values of 0 to 7, with 7 representing the greatest potential.
Running a Simple Query to Target Specific Attribute Values
If we determine the required value for our wind farm plans, we can build a query that targets those specific areas that match our requirement. For instance, if we wanted to find areas that are greater than or equal to the value of 6, we can run a simple query to find those areas within this data set. We can also use the Info tool to explore the wind energy potential of properties within an area.
Applying Color to Visualize Patterns in Data
Another way we can visualize the distribution and range of values in this data set is by applying a color scheme. As we can see, this visualization makes it easy to target those areas of maximum wind potential. If we wanted, we can add a legend to our map to further illustrate what values the colors actually represent. But in this instance, we are interested in visualizing which areas have the highest potential.
We can bring in some additional data to add more context, such as county outlines and town boundaries within the state. If we were looking to develop wind energy in a particular geographic location, for instance in a particular town, we have the background data that shows those boundaries. We can also pull in road data to see the road access to areas being considered for development.
For our simulation, we are choosing an area based on this very quick visualization of the NREL data we imported into Global Mapper.
Accessing Free Terrain and Land Cover Data Through Global Mapper’s Online Data Service
With our area of interest chose, we can find more relevant data through Global Mapper’s free online data service. For our simulation, we are choosing to use a specific area of a 10-meter National Elevation Data (NED) data set that we streamed into the application and exported to a local Global Mapper grid file.
We streamed the data through the online data service, which has a wide range of data options categorized geographically as well as by data type and theme. In this instance, we are interested in terrain data to give us visual context and also a functional base for some of the modification processes we will run later.
We are also interested in land cover data, which will help us visualize the roughness of the terrain. We can find a raster representation of our area under the land cover section in the online data options.
Generating a Roughness Grid from Land Cover Data
Areas with less friction, or surface roughness, are better suited for wind energy production. From our land cover data, we can generate a grid to visualize areas where roughness could reduce energy potential.
To create this roughness grid, we can open locally saved land cover data that we had previously exported from the online data service. Either by right clicking the land cover layer or from our analysis menu, Global Mapper gives us the option to generate a roughness grid and to choose a shader with which to render the grid. For this visualization, we prepared a custom shader beforehand that illustrates the range of roughness through the gradients of a single color – lighter tints representing less roughness, darker shades representing greater roughness.
This visualization allows us to see open areas such as fields or bodies of water that may provide ideal conditions for a wind farm.
Finding Ridge Lines & Isolating a Single Ridge
Another ideal location for a wind farm is on a ridge. We can find a ridge line or high point within the focus area by using the Find Ridge Lines tool, which is a function that works similarly to a watershed analysis, but in reverse. Instead of looking for areas where drainage would accumulate, the tool finds the highest points on our terrain.
After choosing specific parameters, such as the width threshold of the lines, we can see a variety of ridge lines appear in the area visible on our screen. These lines are actually segmented, so in order to isolate a ridge we want, we can combine the segments of that ridge into a single line by selecting the desired segments and using the Combine Features tool.
Plotting Points Along a Ridge to Represent Wind Turbines
With our new ridge line selected, we can generate point features to represent our wind turbines along the ridge by using the Create New Points from Selected Lines tool. We can specify that we want ten vertices to represent ten wind turbines evenly spaced along the ridge, and discard vertices that may have already been part of our original ridge line. Once these parameters are set up, we can see that the ten vertices have been generated that represent the wind turbines in our simulation.
We can then edit these inherently generic point features and choose a Feature. For this simulation, we prepared a custom feature type called Wind Turbine which has a 3D visual representation of a wind turbine assigned to it. This 3D model is actually pre-configured in Global Mapper. We can also edit the attributes of these, but for this simulation, we are only assigning our customized feature type.
Once these points have been edited, we can view them in the 3D Viewer and see the 30-meter height attribute of the 3D models we prepared in advance, and the even spacing between each model along our ridgeline.
Creating Buffers Around Wind Turbine Locations
After we have placed our wind turbines, we can then generate a buffer around each point in preparation for creating flattened areas, or site pads, in the terrain. With our points selected, we can click the Buffer tool in our toolbar. In this simulation, we are choosing to have buffer areas with a 10-meter radius around each of our wind turbines. Once the buffer areas are defined and generated, we see the concentric ring that represents the physical area that will be flattened around each point in the terrain-modification process.
Generating an Elevation Grid from LiDAR Data
In order to generate a more accurate terrain model for our simulation, we can import pre-cropped LiDAR data that was originally streamed from the U.S. Geological Survey through Global Mapper’s online data service. This higher quality elevation data allows us to create more precise modifications and visualization than the lower-resolution terrain data we had originally imported.
To create an elevation grid from this LiDAR point cloud, we can simply click the Elevation Grid button with our LiDAR data layer selected. In this simulation, we are choosing to grid only ground points. Once the new grid has been generated, we can open the Elevation Options to feather, or blend, the edges of our higher quality grid into the lower-resolution terrain data.
Calculating Cut and Fill Values & Creating Pad Sites
With our buffers selected, we can use the Flatten Site Plan tool to flatten those buffer areas of the LiDAR-based elevation grid. The tool calculates the volume of material that must be shifted in order to achieve a flattened site – giving a cut volume and a fill volume. Not only does Global Mapper give these helpful calculations, it also modifies the elevation grid so we can visualize what the cut and fill alterations would look like.
Viewing the Visual Impact of a Project with the View Shed Tool
With one of our wind turbine points selected, we can click the View Shed tool to see the extent at which our wind turbine is visible in the distance. We can base our analysis on the height of our selected wind turbine and on the height of an average person — 2 meters or so. Global Mapper calculates the areas at which our wind turbine will be visible to an average person, and displays these areas in red. This analysis allows us to see the visual impact of our wind farm in the area of development.
Creating a Fly-through of a Wind Energy Project
After setting up our wind turbines and modifying our terrain surface, we can create a 3D fly-through to further visualize the project. We can do this by drawing a line for our flight path using the Digitizer tool. With this line selected, we can set up the specifications of our fly through by using the Create Fly-through tool.
Once we’ve established the height, bank angle, and duration of our flight, we can preview it in the 3D Viewer. If we’re happy with this fly-through, we can also save it from the 3D Viewer. If we aren’t happy with it, we can go back and edit the flight or segments of the flight line again.
Creating a fly-through is a great way to present a project, particularly one like a wind energy project that may need to be proposed to government officials or multiple stakeholders.
Global Mapper: A Robust Tool for Any Development Project
While this simulation involves some behind-the-scenes preparation, such as the creation of a custom point feature type and the cropping of LiDAR data, it’s still a prime example of how simple data visualization and terrain modification can be in Global Mapper. It can be easy, not only in the context of a potential wind energy project, but for any development plan that requires quick access to terrain data and robust digitizing tools.
When we have a new product release like the version 19 of the LiDAR Module that comes with the Pixels to Points™ tool, it’s always exciting to see that feature in action for the first time outside of the Blue Marble office. Our South and Central American reseller Laurent Martin from EngeSat was quick to try the new Pixels to Points tool for himself using drone data collected by his peer Fabricio Pondian.
The new Pixels to Points tool uses the principles of photogrammetry, generating high-density point clouds from overlapping images. It’s a functionality that makes the LiDAR Module a must-have addition to the already powerful Global Mapper, especially for UAV experts.
Below, screenshots captured by Laurent illustrate the simple step-by-step process of creating a point cloud using the Pixels to Points tool and some basic point cloud editing using other LiDAR Module tools.
1. Loading drone images into the LiDAR Module
2. Calculating the point cloud from loaded images
3. Viewing the generated point cloud
4. Classifying the point cloud
5. Creating an elevation grid and contours from the point cloud
A quick and easy process
In just a few steps, Laurent was able to create a high-density point cloud from 192 images, reclassify the points, and create a Digital Terrain Model. It’s a prime example of how easy version 19 of the LiDAR Module and the new Pixels to Points tool are to use. Check out EngeSat’s full article on the release of LiDAR Module.
Over the past few months, the Blue Marble team has taken on the challenge of collecting drone imagery of our property for testing exciting new features coming soon to Global Mapper. As we began to step into the fairly new commercial UAV field, we realized that there are few assumptions we can make. First of all, there is a learning curve that comes with simply flying a drone to take pictures or collect imagery. There are also a number of legal hurdles, safety concerns, and practical challenges to consider. We needed guidance as we began this initiative, from which we learned a few important lessons.
Drone Flight Concerns and Considerations
Though it appears to be a relatively simple technical challenge, flying a drone has legal and safety considerations that were readily apparent to us but may not be common knowledge. Our first concern was that the Blue Marble headquarters are only about a mile and half, as the crow (or should I say UAV) flies, from the Augusta State Airport. Small planes fly overhead frequently and quite low at times. We were not sure if our building was located near banned airspace. Our second concern was that our property abuts the Hall-Dale elementary school playground. A location that is full of children three or four times a day during business hours. What if we crashed in the school yard while children were at recess? What a PR nightmare.
These concerns about the airport and school property were enough to stall us from simply buying or building a drone, and prompted us to seek guidance. Fortunately for us, the University of Maine at Augusta offers an unmanned aerial vehicle training course taught by certified pilots. A quick call to one of the faculty members for more information resulted in the gentlemen visiting our offices to conduct some test flights and to share a bit of their knowledge with us. We learned a great deal even from our first test.
Setting Up the Drone for Flight
Certified pilots Dan Leclair and Greg Gilda joined us at our office on a beautiful, clear and wind-free day in early October. They confirmed that we could fly over our property with some stipulations, despite our location near a commercial airport. As a precaution, the gentlemen brought with them a hand-held radio to monitor pilot communication in the area as we set up our flight path. They also reassured us that there was little chance of the drone flying off of our property during school recess, since the drone would be programmed and flown on autopilot. Dan and Greg shared a litany of information about how the drones now have homing devices, automatically avoid collisions with structures, and fly on a pre-programmed flight pattern. If, for some reason, it did fly over school property, we could manually fly it back. We also learned that the drone must stay within our view to remain in compliance with Federal Aviation Administration (FAA) regulation, which was no problem. We weren’t flying a large area anyway.
As we chose and programmed the drone flight path with a laptop, the pilots focused on a very common issue for us GIS folks — proper elevation above ground. Since we are located in the descent path of planes landing at the airport, we needed to keep the drone relatively low to avoid any potential, and of course unwanted, collisions with an aircraft. We decided that we would fly at 100 feet above ground on a path that was 1,793 feet long and would take about 3 minutes.
The software the pilots used had some short comings in that the user had to manually select points for the back-and-forth flight path we wanted. As a software guy, this seemed tedious. I would rather draw a quick polygon or box around my area of interest and have that converted to a flight pattern. Perhaps that could be a new feature for Global Mapper Mobile in the future? In this case, our area of interest was our building, so it did not take long to manually designate the flight pattern by selecting waypoints for the drone to fly back and forth. We also set up the drone camera for the light conditions, and programmed it to capture an image every two seconds during the flight. One practical lesson we learned was that a good staging area for the laptop is preferable on a sunny day. We used the back of an SUV for the shade, so we could see the laptop screen and comfortably program the software.
After a bit of work we were ready to fly.
Flying the Drone and Collecting Data
We set the drone on a circular landing pad made of nylon near the back of our property. Greg attached the rotor blades, very carefully I might add. The blades attach rather easily to the quad copter by snapping into place. Dan explained that this step was done before turning the drone on, saying something to the effect of “you don’t want to lose a finger”.
Once the UAV was ready to fly we all stepped back. Dan launched it into the air with the touch of a button or two, and the drone began its pre-programmed flight path. For those experienced pilots, you might notice that we did not discuss ground control. More on that in a later blog entry, I suppose, but these early tests were not including that. The flight went seamlessly and Dan only took over manual control as he brought the drone in for a landing — a personal preference of his.
Everything seemed to progress well but we quickly learned that the drone ended up capturing only video (see below) and not still photography. A few more attempts later, we sadly learned that we would not be able to collect still imagery that day. Apparently there was some incompatibility with the flight planning software and the drone. Not to fear, they agreed to return another day after a software update to collect the imagery. So perhaps the most important lesson of the day was that, despite the best laid plans of mice and men, things do not always go as planned with drone data collection. If you’re interested in learning some more about the foils and follies of drone data collection visit this handy resource: http://knowbeforeyoufly.org/
We’ll have more to share with you on this process and, of course, what we are doing with the data soon.
Patrick Cunningham is the President of Blue Marble Geographics. He has two decades of experience in software development, marketing, sales, consulting, and project management. Under his leadership, Blue Marble has become the world leader in coordinate conversion software (the Geographic Calculator) and low cost GIS software with the 2011 acquisition of Global Mapper. Cunningham is Chair of the Maine GIS Users Group, a state appointed member of the Maine Geolibrary Board, a member of the NEURISA board, a GISP and holds a masters in sociology from the University of New Hampshire.