Two Examples of Drone Based Survey Data
F.A.S.T. owner Dave Dagostino gets into the details.
I have been in this survey game for a while now—20-plus years. As time has passed, the advancements in technology have been amazing and have made us so much more productive. Surveyors can produce 1,000 times the amount of data in half of the time it used to take to collect and process it. The way we charge for these advancements in relation to the old days is a hotly debated topic for another day. For now, we will stick to the technology and its benefits.
I started out reading Vernier on a theodolite and dragging around a 100- or 200-foot steel tape. Then we got a top-mounted EDM that looked like a small microwave on top of our theodolite, but we still chained everything under 100 feet anyway and wrote it all down in the field book. Next came the total station and data collectors.
Man, we were cooking now and production went through the roof. We could accomplish so much more in a day without hand calculations and writing down every angle and distance. Then came GPS—days of traversing for miles were reduced to two hours, then one hour, then eight minutes to now three-minute observations to get centimeter-accurate positions on the face of the Earth. All of these advancements have been extremely expensive when they first came on the scene but have now become another common tool in the survey rig we could not imagine doing without.
The Latest Advances in Survey Technology has moved the industry.
The latest advances have been in the areas of laser scanning, LIDAR, mobile mapping and Unmanned Aerial Systems (UAS) or drones. These latest technologies have allowed us to capture exponentially more data, on the order of 10,000 times what was previously possible. This allows us to deliver incredibly dense and rich three-dimensional data sets that document every change in topography, building or other structure. As we move forward into a three-dimensional design world, our clients—the architects, engineers, and designers—are going to expect this kind of rich 3-D data, and if you are not able to provide it, you will quickly become obsolete. Here are two examples of how this technology has been utilized at FAST to improve turnaround times and the quality of the data surveyors produce.
1. The 2 week, 35 acre Alta Survey
The first project was an ALTA Survey. The property was a sports arena covering approximately 35 acres and having about 1,400 parking spaces. This survey did not include topographic elevations but did include all improvements, including parking stripes as well as the boundary and title work of course.
A traditional survey of total station traversing, GPS and locations for this property was estimated to require the following:
|Field Crew||80 Hours|
|Survey Tech||40 Hours|
Traditionally my client was basically looking at a minimum of three weeks to get this project completed and delivered. Of course, the client had a short due diligence period on a multi-million-dollar deal and needed the survey faster than that—the usual in the survey world. This is where FAST’s ability to fly our drone and do the mapping from the combination of the generated orthophoto and point cloud saved the day.
Using the drone based system allowed us to complete the project on the following schedule:
|Traditional Survey Crew||12 Hours|
|Drone Crew & Processing||6 Hours|
|Survey Tech||40 Hours|
Florida Aerial Survey Technologies was able to deliver our preliminary survey to the client in less than two weeks, allowing our client ample time to review and have the final draft for closing. An added bonus was the ability to provide an orthophoto as a background on the survey that was collected on the day of the survey date. This allowed for a more comprehensive view of the project over straight CAD line work. The client was thrilled with the timeliness and service provided and more than happy to pay the cost of the survey based on an estimate of almost double the time, vastly increasing the margins we were able to generate.
“We were able to deliver our preliminary survey to the client in less than two weeks “
2. The topographic survey with 37,000 times the data
The second example I would like to share involves straight topographic data and volume calculations. We received a call from a client asking us to provide monthly monitoring of a material pile that needed to be rationed over an extended period of time. This stockpile of material is quite large in the spring and is gradually used over the course of the summer and winter. The client needed to monitor his company’s use to ensure the material would last until the spring.
The material pile covers approximately 20 acres and is, at times, over 50 feet tall. The material is very loose where it slopes, so climbing is very difficult and can be quite dangerous. Before the client was estimating the volume by putting an RTK GPS receiver on a front-end loader, driving it around on the pile to collect data. They tried to supplement as best as possible on foot. As you can imagine the results were less than stellar.
FAST proposed to set permanent ground-control point targets around the pile and collect photos using our drone. Utilizing state-of-the-art software, we then processed those photos into point clouds to obtain our volume calculations and provide our results. The difference in the two methods was amazing.
|Number of Data Points||1,500 points|
|Time to Collect Data||6 Hours|
|Time to Process & Deliver||4 Hours|
Drone Survey and Mapping:
|Number of Data Points||56 Million points|
|Time to Collect Data||20 Minutes|
|Time to Process & Deliver||3 Hours|
Again the use of a drone allowed us to deliver the data much faster—same day instead of days. Even more beneficial was the quality of the data and the accuracy of our calculations. We ran our calculations using two different software suites and both volumes came out within 1% of each other. The comparison to the traditional survey that had been done the day before showed their volume was off by more than 25% from the true volume. This was due to the limitations in the ability to collect comprehensive data to calculate the volumes. Using drone data with the increased data density allows us to take into account very small changes in the surface of the pile increasing overall accuracy.
“The comparison to the traditional survey that had been done the day before showed their volume was off by more than 25% from the true volume. This was due to the limitations in the ability to collect comprehensive data to calculate the volumes.”
As these two examples show, drone systems have revolutionized the way surveys are done—the same way GPS did previously. If you are not using a licensed drone surveying and mapping firm, you are falling behind. As we move forward, clients are going to come to expect the more. More comprehensive 3-D data, more services like drone surveying and aerial laser scanning, and more rapid turnarounds.
Point clouds will become common deliverables and old ways of using a few thousand points and interpolation will no longer be acceptable. The benefits to surveyors are quicker turnaround times and fewer man-hours needed. This, assuming pricing holds similar to current methods, will significantly increase the margins we are able to generate. It’s a win-win for both sides—the client gets better data faster and surveyors can increase their margins.
About the author
About FAST: Florida Aerial Survey Technologies (FAST) is a full-service aerial-mapping firm offering both photogrammetric and LIDAR-based drone surveying and mapping services. We also offer consulting services to firms looking for guidance on developing in-house drone and UAS programs. Founded in 2018, FAST brings over 30 years of survey experience and 10 years of UAS and private pilot experience to its clients.