We receive great questions from our customers and prospective clients, some with regard to the types of tools and methods we employ for data acquisition (both in the field and external sources) and the creation of maps. We all live in a fast paced world of technology where the tools and methods for data collection and mapping are constantly changing, and keeping pace with them can be quite daunting. Here at Geographic Techniques, as our name implies, we are diligently on the lookout for new or improved tools that continue to move us forward with maintaining the accuracy and consistency that our clients expect. This blog briefly discusses the main applications and equipment we use to make great maps in the hope to answer those questions some folks may have.
Tools for the office
Our mapping software is GIS, which stands for "Geographical Information System." The GIS platform is an extremely powerful mapping application that combines geographic objects, data bases, and analysis tools to help us visualize complex spatial relationships shown through quality maps and graphics. Two major GIS mapping applications we employ are QGIS and Global Mapper(TM). Other applications (e.g., video and image processing software, and cloud computing solutions) are also used for pre- and post-processing of field data, GIS data, drone acquired imagery, LiDAR derived point clouds, and raster imagery. Not any one program ever does it all for us, but a suite of products generally gets the job done.
Above, the making of a map using QGIS.
Equipment for the field
Many of our mapping projects require us to conduct field observations and assessments. Besides "boots on the ground" surveys that involve eyeballs, compasses, and notepads, our high
accuracy GPS (Global Positioning System) is used extensively to aid in mapping features, recreational trails, setting up study plots, setting ground control points (GCP's) for aerial mapping missions, and more. Generally, sub-meter GPS accuracy works fine for most applications. When higher locational accuracy is desired, we link to a local CORS (Continuously Operating Reference Station) network via an internet connection, which offers sub-foot level measurements. For aerial mapping projects requiring greater positional accuracy, we use the combination of GPS and CORS to register GCP targets. The GCP's can then be used to match and spatially adjust the aerial photographs to their proper geographic location.
Another tool we have on hand is a high precision laser rangefinder. Using a built-in laser, the rangefinder measures distances and angles to the nearest half-foot, with a range of a half-mile or so. The rangefinder is especially useful for land measurements in difficult terrain. Utilizing both the rangefinder with GPS measurements, we can get very close to survey quality accuracy.
After we received our FAA commercial UAV (Unmanned Aerial Vehicle, or drone) license In the Spring of 2017, we began flying drones for field mapping projects. Flying commercially requires us to abide by strict regulation of airspace. We often need to apply for a waiver that will allow us to fly in restricted airspace, a process that can take weeks to months to obtain. (That process is expected to shorten up dramatically within the next couple of months.) But, once we have the proper FAA authorization we are good to go.
Our drones are equipped with a GPS unit and a 1-inch 20-megapixel high-resolution camera that provides remarkably detailed aerial photos of property and land features. It allows us to derive orthoimagery (NADIR), elevation models, plant health indices (especially for agriculture), point clouds, 3-D models, and assist in property inspections for insurance and real estate purposes. In 1-hour we can map up to 100 acres, and have a map to you within a couple of days. We are also search, rescue, and recovery mission ready for aerial reconnaissance assistance or aerial image interpretation. For us, drones are a game changer and have significantly enhanced the scope of our local mapping capabilities.
To go along with our field equipment, we have several associated mapping applications specifically designed to manage the piece of equipment and/or the data they collect. For example, the GPS apps show us the location (latitude, longitude) and elevation for points of interest, and help to track our movements through space and time. Another GPS app shows us the accuracy and error calculations while connected to the CORS network. The rangefinder app shows us distance, height, angles, and off set measurements to far away objects. Drone apps help us plan, see, and fly before, during, and after mapping missions, and allows us to control the drone either manually or autonomously. What is cool is that all of these apps run on either smartphones or tablets, making it very convenient for field work.
Please feel free to contact us for more information. We are ready to do some mapping for you!