PPK vs. GCP Drone Surveying
Drone technology is improving rapidly, with new models and technologies being developed at an unprecedented rate. You might feel inundated with so many different options. One choice you’ll need to make for your drone surveying/drone inspection needs is whether to use GCP drone surveying or PPK drone surveying. Here at Extreme Aerial Productions, we’ve done the groundwork for presenting you with the pros and cons of each, and why you might want to use one over the other.
What is GCP?
GCPs refer to strategically placed points on the ground of a survey location. During data processing, reproduced maps are calibrated with these points, enabling the drone to get incredible accuracy. They can be marked and measured with rover and base or you can use moveable smart GCP’s, which are dropped around the survey area in a careful distribution. Using smart GCP’s is still somewhat time-consuming, but at least saves you from having to paint the points for visibility and shoot them with a rover.
GCP Pros and Cons
Pros: You’ll have survey-grade accuracy down to the sub-centimeter level. GCP’s are great for mapping out areas that demand a very high level of accuracy, such as land title surveys. GCP is still the most reliable way to collect data.
Cons: Setting up GCP surveying takes a considerable amount of legwork. Expect to spend up to an entire day to set it up on a large site. In cases of uneven landscapes or personal safety concerns, GCP’s are not a good choice. You will also have to set up GCP’s every time, versus just having to buy a PPK drone once.
*Call or email EAP now to learn how GCP can help your business.
What is PPK?
Post-Processing Kinematic (PPK) workflow is a GPS correction technology that uses drones to provide corrections to location data post-flight, after the data has been captured and uploaded. Here’s how it works: a drone will input coordinates, based on the on-board GPS unit, to each image. Meanwhile, a base station also records its own locational data. Post-flight, these two sets of data will use a photo timestamp to be matched up. The on-board GPS data is then updated with accurate geotags. PPK is often talked about in conjunction with Real Time Kinematic (RTK), another GPS correction technology that provides real-time corrections to location data while the drone is in-flight.
Did you know?
Drones that use RTK or PPK to process data don’t have different hardware sets. They just use different workflows to process the data.
PPK Pros and Cons
Pros: Mapping with an RTK/PPK drone is especially helpful in cases of dense vegetation or difficult landscapes, where setting up GCP’s would be challenging.
Cons: The data isn’t quite as pinpoint reliable as GCP, and there is a high price point of initial investment.
*Contact us to learn how PPK can help you with your drone surveys.
What We Use
At EAP, we use advanced PPK drone technology for our aerial topos and drone inspections to produce detailed, interactive maps of vast tracts of land. When creating aerial topos of land tracts as large as 1000 acres (or more), we use one of our fixed-wing aircrafts. We can produce aerial topos to 1/10th of a foot or better. But we also always use GCP for ground truthing the models, to ensure the most accurate results possible.
*Interested in how GCP or PPK can help with your drone needs? Get a quote today!