This is a guest post from Keith Perry, founder of Hudson Valley Drones. Keith is an instructor in the free course, “Solar + Drones: Site Surveying and 3D Mapping Around Trees“.
Before we go into this in more detail, it’s important to remember that your drone is going to serve as a tool throughout the surveying process and should be viewed as such. Similar to the way in which a person wouldn’t just walk into Home Depot, buy a saw, and call themselves a carpenter, we shouldn’t expect to just buy a drone and become a professional drone surveyor without conducting the appropriate research to find the right drone and getting some practice to become familiar with the equipment after purchasing it.
I’m going to break down our hardware considerations into four categories: flight platform, camera quality, obstacle avoidance and remote controller capabilities. Today, we’re going to focus mainly on DJI’s product offerings, but there are other options out there that could be a good option for you.
Flight platform refers to the software being used to conduct your flight operation. Often people decide on a flight platform after already selecting a drone, but we advocate for taking this into consideration in the early stages of the hardware selection process because it is important that the drone that you select be compatible with the software that you want to use to fly the drone.
All drones offer a native flight platform– DJI Go, DJI Go 4, or the more recent DJI Fly. You’ll use these apps for manual flight modes and assisted flight modes like PoI like David explained a few moments ago.
Other applications like DroneDeploy, Pix4D, DJI GSP and others provide different types of autonomous flight plans. Each has their own niche features so it’s important to ensure that the drone that you select is going to be compatible with the flight platform that you’ll need to use to get your desired result.
Selecting the drone with a camera that meets your required specifications is also incredibly important. A drone at its simplest is nothing more than a flying camera, so it’s important to take the camera into consideration. Certain platforms like the Matrice and Inspire series offer interchangeable payloads, but consumer and prosumer models like the Phantom Series, Mavic Series, and Air series offer a camera that is not modular so you’re stuck with whichever one you purchase.
Resolution is important– generally the higher the better. Most platforms today offer a sensor with no less than 12MP so while it’s important to pay attention to, it’s not typically a factor on newer platforms.
The type of shutter on the camera is also very important. A mechanical shutter will generally produce a more crisp and accurate image versus an electronic shutter, although in certain cases the difference is negligible.
Other considerations could include field of view, which defines how wide a camera can see, and the dynamic range which defines the range of colors that a camera can see under a given set of conditions.
Obstacle avoidance has been showing up more and more on drones and generally speaking, most drones come with obstacle avoidance to some degree or another.
Here you’ll see an example of the Mavic 2 series aircraft and it’s six degrees of obstacle avoidance– front, rear, top, bottom, and each side. It’s beneficial to have these sensors as they provide protection for your aircraft while operating in point of interest mode or in other intelligent flight modes.
It’s important to be aware of the type of obstacle avoidance your platform has and operate in a way that accounts for this. As we saw on the last slide, the Mavic 2 Pro has six direction obstacle avoidance which means that an obstacle from virtually any angle can be detected. The Phantom 4 Pro has a similar capability with 5 directions, but lacks a top obstacle sensor which could be risky if you’re taking off in an area with a lot of trees or changing altitude during a PoI maneuver.
An older platform like the Mavic Pro has front and bottom obstacle avoidance, but lacks lateral, rear and upward, meaning that you’ll be completely on your own when orbiting.
A quick final note on obstacle avoidance: it should be viewed as, and used as, another tool in your arsenal. Nothing beats old fashioned situational awareness and keeping good VLOS on the drone.
Smart Controller vs. Standard Controller
Next we’re going to talk about what to think about when selecting a remote controller.
For most platforms, DJI offers an option between a standard remote and a smart remote. A standard remote typically requires use of a smart-device as a screen such as a phone or tablet. A smart controller has a built in display.
A standard remote is beneficial in that it comes at a lower upfront cost and is packaged with the basic package of most aircraft. You’ll need to use a third-party device as a display, but this allows for the use of third party apps like Dronedeploy or Pix4D.
A disadvantage is that it can often be challenging to see the display of the third party device on a bright, sunny day.
A smart remote is a more recent addition and provides a built-in display which alleviates the need to use a phone or tablet. While it comes at a larger upfront cost, it’s unparalleled in viewability on a bright day.
A disadvantage is the lack of compatibility with third-party apps, so generally speaking you’re stuck with using proprietary DJI flight platforms.
We’re also going to touch on some helpful accessories here and our recommendations as they related to that.
The first and most important addition to your drone kit will be additional batteries. We’d recommend to have at least three total, but you might need more depending on your workload and project specifics.
A close second to the batteries would be a hard-sided carrying case. This serves two purposes– first and most obviously, to protect your investment from damage while bouncing around in your vehicle or being carried on a jobsite. A letter thought of benefit of the hard case, though, is that it looks significantly more professional while onsite as opposed to a soft sided case or (even worse) the original box you bought the drone in.
Other accessories would include a car charger, spare propellers, a charging hub for multiple batteries, propeller guards, and spare SD cards.