We are often asked the question “What makes a complete True View mapping kit?” This is an excellent question that requires a bit of a glance at best practices for drone mapping.
For this article, we will consider only the True View 3D Imaging Systems (3DIS). These systems comprise:
The level of the POS and laser scanner will depend on what you have selected for your primary mapping needs. This was the subject of a prior True View Bulletin.
We have found a variety of perhaps 10 different drone models that meet the above requirements. For general purpose use, we recommend the DJI M600 Pro. It is reliable, inexpensive and has landing gear that fold up out of the way of the sensor. A M600 Pro equipped with a True View 410 3DIS and a Drone Rescue Systems parachute is shown in Figure 1. You will need to add a tablet for attachment to the drone controller. We use one of the inexpensive versions of iPad.
You will want a battery strategy that allows you to operate continuously in the field. With the M600 Pro, we have found this is possible with three full sets of batteries and two hex chargers (the M600 uses a set of 6 batteries). We use a portable generator driving the battery chargers. We have two sets on charge at all times. The batteries will achieve a state sufficient for re-flight after 1 hour of charging. For the M600, we recommend the higher capacity TB-48 batteries. With this arrangement, you can fly back-to-back missions all day long.
The most accurate (and economical) mode for reference positioning for the True View systems is a local multi-frequency GNSS base station that can record a static observation file. An entire kit of static base station, tripod and pole is around $3,500 so this is an inexpensive option.
While it is certainly possible to collect great data with no ground truth whatsoever, any professional drone mapping provider will want to provide an accuracy report as part of the customer deliverable. If you are mapping sites that are not frequently revisited, you will need some way to measure ground check points (GCP). While there are a lot of ways to do this, I recommend a decent Real Time Kinematic (RTK) base/rover kit. You can use the base from the RTK kit for positioning the drone so no need for the above mentioned static base if you employ an RTK setup. If you are a surveyor who is adding on drone technology, you already have this gear. If you are new to the field, we can supply a full RTK setup for about $18,000.
Finally, you will want a good laptop for processing data. I recommend at least an i7 processor, 32 GB of RAM, at least 2 TB of solid state storage (SSD) and a high quality Nvidia graphic engine. All software necessary to generate 3D colorized point clouds and extract analytic information is included with the True View sensor. If you intend to do photogrammetric processing (Structure from Motion, SfM) in addition to colorized LIDAR, you will want to add software such as Agisoft Metashape or Pix4D.
Of course, it is convenient to have rugged carrying cases for the above gear, especially the drone. All of our True View systems include a ruggedized carrying case so that is not a worry.
Of course, you will also want a set of best operating practices. These are provided by GeoCue in various forms ranging from included system training to technical support.
When you work with us on selecting your sensor, we will discuss your goals, operational scenarios, project types and so forth. We will help you in selecting the kit you need that will best meet your return on investment scenarios.