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Image Analysis: How to Interpret Satellite Photos in 5 Easy Steps

We’ve all had this problem: You’re looking to buy a property and wonder if it really comes with that full-sized submarine in the front yard. At the same time, you’ve had your eyes on that airfield in the middle of nowhere and want to confirm its inventory of fighter jets. God knows, the real estate business is not immune to empty promises. Those euphemistic property descriptions and glossy pictures can be deceiving. So, which one is worth your time and investment? You may be surprised what a five-step satellite image analysis can tell you about a property.

Admittedly, you may be looking at less bizarre real estate, such as your future suburban family home. In any case, chances are you’ve checked out Google Earth for a more unbiased impression. It’s a good idea to assume the best in people, namely that your agent is honest about the upsides and downsides of your future house. Exercising your own due diligence is an even better idea.

It helps if you have a specific question you’re trying to answer: How unobstructed is this beach view really? Is that carport as roomy as the photos suggest? Or the all too familiar: Is the front yard submarine just a fake?

Satellite Image Analysis in Five Steps

This imagery analysis primer will give us the tools to critically assess our aerial or satellite images by using a set of five criteria to structure our thinking. We‘ll go beyond mere guesswork to enable us to justify what we’re saying about the properties, why we’re saying it and what it all means.

Let’s take a critical look at the two properties mentioned in the very beginning. For the sake of the argument, we’re doing it based on two assumptions: First, we’ve verified the authenticity of the images, meaning they have not been manipulated. Second, we’re unable to just google our properties to find out what’s going on. Think of it as a puzzle waiting to be solved. So, what about that submarine and those fighter jets?

1. Size

Our first criterion in the analysis of satellite images is size. Unfortunately, our images don’t have a scale. But when it comes to determining the size of an object, we can look at it in relation to other structures whose size we can estimate. Buildings are a good starting point, but they come in many shapes and sizes so they may not be a reliable indicator. Roads, footpaths or even the road surface markings can give us a good indication, too, since their sizes may be much more standardised.

Image Analysis

While we can take all objects into account, what seems easiest, for now, is taking the size of a car as a point of reference. There are heaps parked on the side of the road. We could go through the hassle of identifying the specific makes and models to determine their exact lengths, but for our purposes, the average car length of 4.5 metres will suffice. If we compare the cars to the supposed sub, that gets us an estimated vessel length of around 75 metres and a diameter of around 5 metres in the middle section. While the length sounds reasonable, the diameter is a bit odd. The sub is quite narrow in relation to its length. That‘s okay for now, we’re only getting started. Let’s park this conclusion along with the yet unknown height of our object.

Let’s check out the potential fighter jets next.

Image Analysis

Our airfield image is a bit blurrier and lacks contrast. In terms of size, our alleged planes are all very similar. If we compare them to the scope of the airfield’s ramp, the taxiway and the other structures, they indeed strike us as jet-sized. They’re certainly not as large as an Airbus A380 or as small as your uncle’s high-end model plane. The jets may be around 15 metres in length and 10 metres in width. They would certainly fit into the aircraft hangars that are spread across the airfield. In other words, the proportions match. That’s good news and confirms our agent’s claims.

2. Shape

Submarine Closeup

Shape is the second point to consider in satellite image analysis. As you’d expect, our potential submarine is a long cigar-shaped structure, narrower on one end and wider on the other. At the wider part, there are attached objects that stand out. They appear to be fins. Also, at the same end, a bulky structure protrudes. It’s also worth noting what we can’t see, namely anything that looks remotely like a propeller. Regardless, in terms of shape, there’s still not much that speaks against a genuine submersible.

Jet CLoseup

Moving on to our jets, we can come to the same conclusion. While two positions seem empty, the other objects are neatly parked next to each other. There are five of those objects, definitely the shape of a jet. They feature a pointy front, a tail and swept wings that indicate that this object has aerodynamics that make it capable of flying at supersonic speed. Brilliant, just what we’re after.

3. Texture

Our next criterion in satellite image analysis is texture, which refers to the characteristics of the object’s surface. For example, is it rough or smooth, matt or glossy, fine or coarse? For instance, the bushes that surround the house have a rather rough and irregular texture while the bitumen appears smoother and more even. Our supposed sub has a rather even, matt, dark greyish surface. So, as far as we can tell, it’s not made of corrugated sheet metal; with the exception of the middle section, where objects seem to stand out making the surface appear rougher. The same goes for the bulkhead mentioned earlier and a few spots that could potentially be the sub’s hatches.

Examining our airfield, the alleged jets have a similarly smooth, matt, greyish surface. At the same time, the fuselage, or body, of the plane breaks the even surface between the wings. It’s a lighter grey and to the very least suggests that the object is not a single monolithic one. Even though it’s difficult to tell given the image quality. I’m still in favour of giving our agent the benefit of a doubt.

4. Surroundings

Image Analysis

The fourth point to consider in satellite image analysis is the surrounding area. I’m not going to lie, it’s more than unusual for our submarine. Typically, U-Boats are found near, in, or underwater. The area of our property, however, looks quite rural or suburban. To be fair, this isn’t evidence that the submersible is fake. In the same way, finding it floating in the ocean wouldn’t make it real per se. Luckily, we’re not looking to take the sub for a spin anyway. We’re only interested in owning one so our kids can have a little submarine adventure in earshot of our house. Regardless, let’s put a pin in here and move on.

Image Analysis

Back to our jets, we’re equally pleased. The surroundings match our expectations. As pointed out above, we have a ramp, taxiway, and hangars. The planes are in their natural habitat. We wanted an airfield with jets and it looks like this is what we’d get. Just like the agent said. Good bloke.

5. Shadow

Our final satellite image analysis criterion is shadow. Shadows can help us determine the height of an object, but can also assist with determining its shape.

Submarine Closeup

Regarding our submarine property, the shadows reveal that the uneven structure in the middle of the vessel is actually a tower with objects on top; possibly antennas, a periscope and other sensors. Generally, these are the kind of fittings you’d want to find on a genuine submarine.

If we compare the shadows cast by the building to the one of the tower, the latter seems to be even taller than the building next to it, which is probably a single storey house. The tower’s shadow further confirms our supposition that we’re looking at an actual underwater craft.

Now there’s one caveat. The overall hull, on the other hand, seems flatter than we’d expect from a full-sized U-Boat. There’s hardly any shadow, which means it’s definitely not sitting on the grass in its full size. On the other hand, submarines don’t have kickstands as they’re usually submerged underwater. There doesn’t seem to be any structure to support it. So, it may be buried in the ground. This would also explain the relatively small diameter of the visible parts we flagged earlier. It’s entirely possible we’d be purchasing only a quarter of a sub. It may be a dealbreaker, but not necessarily so.

Jet Closeup

Let’s take one last look at our jets. Here we run into a more serious problem. There aren’t any shadows that would allow us to estimate the height of our jets. Sure, the property manager may also be an excavation enthusiast who prefers to bury his most valuable assets to avoid theft. But that wouldn’t explain why there’s not even a shadow of the fuselage, vertical stabilizer or rudder. You might say, the reason there’s no shadow could be that the sun is at its zenith. Though, that wouldn’t explain the sizable shadows cast by the other structures on the airfield. The more logical explanation is: Our jet fighters are flat as a pancake. I think we have collected enough evidence to make a decision.

Satellite Image Analysis Conclusions

It’s time to wrap it up in our final analysis. What does it all mean?

Starting with our supposed jets, it seems that our dream of owning an airfield with a fighter squadron has ended abruptly. It is extremely likely that the aircraft are mere silhouettes painted on the ground. It’s a decent fake that passed four out of our five tests. But it looks like the real estate agent is trying to fool us. Granted, he could still claim those jets he was talking about are hidden in the hangars. But let’s face it: Thanks to our newly acquired critical thinking skills in satellite image analysis, we know enough to walk away from this shifty deal. And if my son asks why he doesn’t get to fly a jet for his 2nd birthday, I’ll be able to explain to him exactly how I’ve come to that conclusion. I’m sure he’ll understand.

The front yard submarine on the other hand looks like a potentially sweet deal. It has passed all evaluation criteria. We‘ve run into a few uncertainties such as the whereabouts of the sub‘s hull, but none are fundamentally unexplainable. The U-Boat may still be just a well-propped façade, but at this point, there’s only one way to find out whether it’s worth our investment. Let’s travel to Holbrook, Australia and see for ourselves.

Image Analysis
HMAS Otway (S 59), Holbrook Submarine Museum, NSW, Australia

Closing Thoughts

The five-step satellite image analysis is an easy way to evaluate any satellite image of your choice. All you need is internet access and a clearly defined problem to solve. The set of five simple criteria – size, shape, texture, surroundings and shadow – will guide you through the analysis. They’ll help you mitigate cognitive biases, avoid misapplying mental shortcuts and intuitive traps. In turn, this will vastly improve your reasoning and decision-making.

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