What is below my plane right now?
SkyDot names what is below your window as you pass it: the nearest city, the country, or the sea. It reads a gazetteer stored on your phone, so both halves stay local. The position comes from GPS satellites and the place names from data bundled in the app.
By Jahanzaib Akhter, developer of SkyDot
Looking down, not up
This page is about the view from a seat on the aircraft: which town, country or sea is under the window. If you are on the ground wondering which plane just passed overhead, that is the opposite question and needs a live tracker such as Flightradar24, which SkyDot is not.
The gazetteer is on the device
Naming a place from a coordinate normally means asking a geocoding server, which is unavailable at altitude. SkyDot ships the lookup table instead, so the answer is computed on your phone in the time it takes to read the GPS fix.
The table holds every town and city with a population above 5,000, drawn from GeoNames, and every airport with scheduled service, drawn from OurAirports. It is part of the app itself, so it works even if you never downloaded a map pack.
- Towns and cities
- 69,305
- Airports
- 4,045
How it decides what to name
Over land, SkyDot finds the nearest town in the table and shows it with the country and continent, so a line reads like a place and a region rather than a bare coordinate. Small villages are not in the table, so in thinly populated country the name can be a town some distance away. That is still the most useful answer to "where is this?"
Over water, once no town is within about 220 km, it names the sea or ocean instead and tells you how far the nearest city is: "Over the Arabian Sea · 420 km from Mumbai". Thirteen seas are recognised, along with the Atlantic, Pacific, Indian, Arctic and Southern Oceans.
What it tells you
The nearest named place and the country you are over, with your coordinates and the accuracy of the current fix. The same line sits on the live map, so you can glance at it without opening anything.
Every country you pass over is also recorded, which is what fills in the world map and the countries count in your travel log.
What it does not name
It is a gazetteer, not a landmark guide. Mountains, lakes, rivers and national parks are not labelled, and there is no camera view that identifies what you can see out of the window. If geology and points of interest are what you want, Flyover Country is built around exactly that.
What SkyDot gives you is the dependable part: which town, which country, which sea, updated every few seconds for the whole flight with the radios off.
Getting a good reading from your seat
The name is only as good as the GPS fix behind it. A window seat gets a fix within a minute or two. From an aisle seat, hold the phone towards a window until the accuracy figure drops. Phones are typically accurate to around five metres under open sky; through a cabin window the figure is larger, but still far smaller than the distance between two towns.
Questions
How can an app know what I am flying over with no signal?
Two local pieces: GPS gives the coordinate without any network, and a gazetteer bundled in the app converts that coordinate to a place name. Neither step needs a connection.
Does it identify landmarks and mountains?
No. It names the nearest town or city, the country and continent, and seas and oceans. It is a gazetteer lookup rather than a landmark or terrain database.
Does it work over the ocean?
Yes. GPS coverage is global, and far from land SkyDot names the sea or ocean and shows the distance to the nearest city. Mid-ocean is where the difference from a connected tracker is most obvious.
Can I see what I am flying over without an app?
Sometimes. A seatback moving map shows it if your aircraft has one, and Google Maps shows your blue dot over an offline area you downloaded before the flight. Neither names the country or sea for you as you cross it.
How accurate is the place name?
The position is accurate to a few tens of metres from a window seat, so the country and the nearest listed town are reliable. In remote areas the nearest town with more than 5,000 people can be some distance away, and SkyDot still shows it.
Sources
- GeoNames: the cities5000 place-name dataset
- OurAirports: open airport data
- GPS.gov: GPS accuracy, including the 4.9 m smartphone figure
Flyover Country, Flightradar24 and Google Maps are trademarks of their respective owners. SkyDot is not affiliated with, endorsed by or sponsored by any of them.