Estimating Property Modifications in Global Mapper

Connecting to the US NAIP high-resolution imagery.
Connecting to the US NAIP high-resolution imagery.

 

I recently purchased a house in Hallowell, Maine, where the Blue Marble Geographics office is located. Hallowell is a teeny tiny city with lots of historic homes that sit on a rather large hill overlooking the Kennebec River. One aspect of my historic fixer-upper property that needs some work is the drainage. I have decided to explore drainage solutions by estimating property modifications using Global Mapper and publicly available data.

Finding Data in Global Mapper

The first step is finding the right data. So, to start with, I use the search tool in Global Mapper to create a point feature at my address. I also change the projection to something that works for the area, such as the State Plane projection for Maine. Next, with the online data tool, I easily connect to the US NAIP high-resolution imagery.

The State of Maine GIS site, MEGIS, has a number of other helpful layers that can be added. Vector data can be downloaded as shapefiles using a web browser and can be loaded into Global Mapper by simply dragging the files into the software. Like a lot of states, Maine’s GIS site also offers web services that can be added to the list of online sources in the software. For my project, I need the outline of my individual property, so, I first download the property parcels layer for the entire city and drag the downloaded zip file onto the map to import it. I use the Digitizer to select my property and then use CTRL+C and CTRL+V to copy it to a new layer.

Using the Digitizer tool
I use the Digitizer to select my property and then use CTRL+C and CTRL+V to copy it to a new layer.

What I really need for this analysis is some high-resolution terrain data, and luckily my property is close enough to the coast to be included in the NOAA coastal LiDAR data. I use the online data source tool again to search the Digital Coast for data that matches my current map bounds.

Cleaning up LiDAR Data in Global Mapper

A quick look at the LiDAR data confirms that it contains preexisting point classifications, including a lot of points marked as noise that look fine to me.

Raw LiDAR Data
Cleaning up and improving the classification of LiDAR points with the Automatic Classification tool.

My first task is to clean up and then improve the classification with the Automatic Classification tools. Using the Path Profile tool, which renders a lateral view of the point cloud data, I can clean the data up even more with some manual editing, since it is such a small area that I am interested in.

Classified LiDAR Data
Note the edges of the property boundary in blue on the profile window. There are some trees on both sides.

Applying Colors to a Point Cloud in Global Mapper

The Maine GIS site also provides 4-band ortho-imagery that was collected in a similar time frame to the publicly available LiDAR data. From that imagery, I apply the RGB color values to my point cloud using the Apply Color tool, which improves the point cloud analysis capability and creates an interesting visual perspective of the data. The imagery is leaf-off, so it does not match up perfectly with the point cloud, but it adds some detail that can help with identification and analysis.

View From the House in LiDAR Data
Looking down at the Kennebec River from my property with 3D colorized LiDAR points.
CIR
False color infrared (IR) display of the points highlights the coniferous vegetation and other late autumn greenery in red.
House Profile in False Color IR
Profile of the false color IR with the house in the middle.

Estimating Property Modifications with Global Mapper

After creating a terrain surface from the classified and filtered LiDAR data, I estimate the modifications that are needed to improve the drainage around the base of the house.

Using the new Breakline and Hydro-flattening tools, I create a flattened foundation by applying a height to the buildings in the terrain modeling process. Next, using the Watershed tool, I see the current drainage problem.

Drainage area that flows through the house and garage
Drainage area that flows through the house and garage shown in pink.

By using the digitizer tool and calculating the elevations, I create a line for a back drainage that would allow water to flow from start to finish. Then using buffering and site planning tools, I create a modified terrain surface that will calculate the necessary terrain modification.

I create a line for a back drainage that would allow water to flow off of the property.

Finally, I measure the volume of soil to be removed, and calculate the benching and terracing for the back retaining wall.

Site Plan Volume
Measuring the volume of soil to be removed for the drainage plan.

After the modification, the drainage from the back of the house to the road is much better. I am also glad to have some warning of just how much dirt removal a plan like this will involve.

Cross sectional path profile view of property
A cross sectional path profile view shows the new drainage line compared to the original terrain and classified LiDAR data.

 

Modified Drainage Watershed
Flow modeling shows how the terrain modification improves the flow of water around the back of the house.

 

I am still considering options for creating a small pond, ending with a tile drain, and many other possibilities. But thanks to freely available data and some quick calculating and visualization with Global Mapper, I have a much better sense of the scope of this project and what the final results might look like.


Katrina Schweikert
Katrina Schweikert


Katrina Schweikert is an Application Specialist at Blue Marble Geographics. She provides technical support, training, and software documentation. Katrina has over five years of professional experience in GIS, a GIS certificate from University of Wisconsin-Madison, and a degree in Geography from Middlebury College. She is happy to be working in technology back in her home state, as well as meeting GIS users across the globe.

DroneMapper: Using Global Mapper for UAV Data Processing

Once the GRID generation is completed you have a bare earth DTM which can be exported as a GeoTIFF or any other elevation format via Global Mapper.

DroneMapper is one of the success stories in the fledgling field of UAV data collection and processing. After several decades of experience working in the aerospace industry, CEO Pierre Stoermer was quick to recognize the potential for drones as a viable low-cost alternative to manned aircraft for this purpose. Serving customers in a wide variety of industries and business sectors, including agriculture and mining, Stoermer recognized the importance of efficient data management and processing, both for their internal processes and for the value added products that the company delivers to their customers. This lead Stoermer to Global Mapper for UAV data processing.

CHALLENGES

Like most small businesses, one of the main challenges faced by DroneMapper was finding tools that provide the right level of functionality but that fit within the company’s inevitable budgetary constraints. As with any business expenditure, investing in technology must bring some degree of assurance that there will be a return on this investment. Traditional GIS applications are notoriously complex and cumbersome, requiring an inordinate amount of time and a high degree of training and expertise to effectively operate, which significantly impacts the overall cost of any project.

Without a dedicated GIS technician at DroneMapper, the operation and maintenance of the GIS data processing workflow is the responsibility of the current staff. The selected software must therefore be easy to learn and easy to apply.

DroneMapper has an expanding client and customer base, whose needs and requirements necessitate an efficient data processing platform that can generate deliverables in a wide variety of formats and with varying specifications.

A 3D view of piles in Global Mapper that were measured to give the viewer perception of their relative sizes.

SOLUTIONS

Unlike most companies who, when faced with a technology decision, evaluate multiple software alternatives, DroneMapper found Global Mapper first and has stuck with it. The range of functionality in tandem with the unparalleled format support were enough to convince them that Global Mapper was an ideal solution for their needs.

A visualization of what has been filtered from an initial point cloud and digital elevation model.

This versatile, fully functional GIS application has been steadily gaining an eager and dedicated worldwide following among geospatial professionals. Recent development work has focused on the visualization and analysis of 3D data, especially LiDAR and other point cloud formats. According to Stoermer, “Global Mapper provides an outstanding set of tools for efficiently assisting us and our client base in an affordable manner”.

GLOBAL MAPPER FOR DATA PROCESSING

Global Mapper is at the core of most of DroneMapper’s data processing workflows. The company employs the software’s intuitive 2D and 3D visualization tools to provide initial quality control of ortho-rectified imagery and DEMs.

Further along the production line, Global Mapper is the go-to application for filtering point cloud data to create accurate, bare-earth Digital Terrain Models. These DTMs allow the company to generate customized contour lines that can be exported in shapefile or virtually any other vector format. Global Mapper’s powerful cut and fill analysis capability and volumetric calculation tools are used to precisely measure volumes, providing DroneMapper’s clients in a variety of industries with site-specific intelligence that is essential for efficient project management.

Employing Global Mapper’s powerful raster calculation functionality, DroneMapper is able to quickly and accurately analyze vegetation patterns by generating NDVI grids. This provides an invaluable service to clients in the agriculture and forestry industries.

BENEFITS

DroneMapper’s decision to settle on Global Mapper for its spatial data management allows the company to perform both internal data processing as well as customer services on one powerful and easy-to-use platform. The application’s SDK will also provide an opportunity for future custom development projects and will allow DroneMapper to adapt Global Mapper to more specifically meet their needs.

ABOUT GLOBAL MAPPER

Global Mapper is an affordable and easy-to-use GIS application that offers access to an unparalleled variety of spatial datasets and provides just the right level of functionality to satisfy both experienced GIS professionals and beginning users. Equally well suited as a standalone spatial data management tool and as an integral component of an enterprise-wide GIS, Global Mapper is a must-have for anyone who deals with maps or spatial data. The supplementary LiDAR Module provides a powerful set of tools for managing point cloud datasets, including automatic point classification and feature extraction.

ABOUT BLUE MARBLE GEOGRAPHICS

Trusted by thousands of GIS professionals around the world, Blue Marble Geographics is a leading developer of software products and services for geospatial data conversion and GIS.  Pioneering work in geomatics and spatial data conversion quickly established this Maine-based company as a key player in the GIS software field.  Today’s professionals turn to Blue Marble for Global Mapper, a low-cost, easy-to-use yet powerful GIS software tool. Blue Marble is known for coordinate conversion and file format expertise and is the developer of The Geographic Calculator, GeoCalc SDK, Global Mapper, LiDAR Module for Global Mapper, and the Global Mapper SDK.