I met Sean “Skeeter” Sherman at the 2025 SUN ’n FUN Aerospace Expo at his Skeeter Enterprises display where he introduced me to his Stadia line of portable radar altimeters.
The Stadia ($615) uses Light Detection and Ranging (LIDAR) to measure the height above ground level, accurate to two inches when below 130 feet AGL. The Stadia Neptune ($1,170) uses radar instead of lidar and is accurate to eight inches below 300 feet AGL, but works when over water.
Since both units are portable, neither require FAA paperwork. Either unit can be mounted to a tie-down ring or wing strut. Both units are controlled via an iOS or Android app connected via Bluetooth.
After the show, Sean and I hopped on a video chat so I could learn a bit more of his background and some additional details of the Stadia and Stadia Neptune radar altimeters.
Following is a lightly edited version of our conversation.
Ben Sclair: It is always fun to chat with a fellow University of North Dakota alum. But you mentioned a stint in the U.S. Air Force after college. Tell me about that.
Sean Sherman: I did four years in the Air Force research labs as a developmental engineer. And I worked on a few things. I worked on some artificial intelligence. I worked on the engineering side of special operations and then a couple of other little programs. But the one that’s related to this conversation was a lidar ranging device for special operations. Long story short, I gave my dad a high level briefing on what I was working on. And with his flying background, that’s where the idea for Stadia came from.
Ben: Interesting. Thanks Dad. When did you come to market with Stadia?
Sean: 2021. I sold a handful at the beginning of 2021. And then at Oshkosh 2021 I debuted it to the public and that’s when it really took off.
Ben: And then Neptune a couple years later, I would assume?
Sean: I started development in 2022. And then came out with the first commercial model in 2024.
Ben: Neptune was a response to market feedback, right?
Sean: Yes, from the floatplane pilots. But I’d been thinking about it for a while —pretty much as soon as the initial lidar version came out. My dad did a lot of testing with it in Alaska. We realized pretty quick that the LIDAR works really good in a lot of circumstances, because it’s just so precise and so lightweight, but it doesn’t do well over water. The physics of it. The water just absorbs all the infrared energy and so you can’t get a good return. And so I realized pretty quick that radar was the answer.
Ben: The two units look nearly the same. What are the differences?
Sean: I made them as identical as possible, so it makes my manufacturing process easier. (Sherman 3D prints the shell at his home office.) Their weight differs by just a few ounces. The radar is kind like a big credit card versus the LIDAR’s optical sensor. And so the radar just needed a slightly different profile shape as a result. The Neptune requires a bit more material, even though the radar itself is technically lighter and physically less volume. It takes up a little bit more space though, because it does have to be small and flat. And if you already have a Stadia, and you want to swap it out with the Neptune, it’s really simple to do.
Ben: Then what is the same between the Stadia and Stadia Neptune?
Sean: The mounts are identical. The mounting options are a tie-down ring mount or a strut mount. The strut-based mount includes a rubber block that is strapped to the strut and weighs two to two-and-one-half pounds. And the tie-down ring, built by MyPilotPro, weighs less than a pound. I think it’s like 12 ounces or something. The software that powers the app is identical. You can literally just swap out a Stadia for a Neptune and you’re good to go. You won’t even know the difference except that it works better over water.
Ben: What’s the accuracy of the Stadia and the Stadia Neptune?
Sean: Stadia is good for plus or minus two inches of accuracy. The Neptune is good for plus or minus eight inches. And I always tell people your typical 737 radar altimeter is good for plus or minus five to eight feet.
Ben: Both the Stadia and Stadia Neptune connect to the same app. How does that process work?
Sean: The first pairing between the app and the unit requires a few extra steps. After mounting the device a user must then calibrate it. But after that, the app remembers the device and all the calibration settings. So as soon as you open the Stadia app, it automatically connects and you’re good to go.
Ben: Does the app re-calibrate for each use?
Sean: You can, but you don’t need to. The distance from the mount to the ground doesn’t change. But in the app there is a calibrate button. And so as soon as you get it mounted and it’s paired, you can press calibrate and it recalibrates itself. I mean, it’s literally one press of a button and you’re done.
Ben: Does the app work in the background?
Sean: Yes. I tell pilots, before you start your descent open the Stadia app real quick just to make sure everything’s still connected and working. Pilots set their own altitudes alerts before flight. You generally don’t care when you’re 100 feet or more above the runway. You care about the last couple of feet and you don’t want buzzers and voices going off when you’re talking to the tower. But when you’re landing, that’s the most important thing. Most pilots probably set it to 10 or 15 feet and then have it talk them down all the way to that last foot.
Ben: Describe battery management. You have an active and standby battery setting, right?
Sean: Yes. Standby mode kills power to the lidar or the radar. On standby mode, the unit will last 12 or 13 hours. I suggest pilots get it all calibrated and then put it in standby mode to save a little bit of battery. It’s going to save probably three or four hours of battery life. But even in full active mode the Stadia battery will last eight hours, which is a lot longer than the typical fuel tank. But you can still get a few hours extra out of it in standby mode. As I mentioned before, when you are leaving cruise and before the workload increases, flip your device to the Stadia app, double check that everything is still connected and set it to active mode. Then switch back to your primary EFB and you’re done.
Ben: What are the battery recharging options?
Sean: A micro USB port on the back.
Ben: For those who go further afield, backcountry on land or water, I suppose solar charging is optional.
Sean: Yeah. My dad, when he’s flying around, he’ll do exactly that. But he’s had times when he didn’t have his solar charger and because the battery lasts so long he will go weeks without charging it. In reality, his flights are just an hour or two, and if it’s on standby and he only uses it for a couple of the landings, he can be out in the bush for weeks at a time and not need to recharge it.
Ben: So when you are done, the unit is powered off.
Sean: Right. Flip the power switch and the unit is fully off.
Sean’s Air Force callsign was Skeeter, thus the company name, Skeeter Enterprises.
For more information: SkeeterEnterprises.com
