Talk Description to Me
Talk Description to Me
Episode 50 - Satellite Imagery
If you go way way up, and look way way down, what you see can be surprising. In this episode, Christine and JJ describe satellite images and discuss the intriguing perspective they provide. From ecology to archeology to a view of ourselves, the big picture has an awful lot to offer!
To explore Google Timelapse, as discussed in this episode, visit: g.co/Timelapse
Talk description to me with Christine Malec and JJ Hunt.
Christine Malec:Hi, I'm Christine Malec.
JJ Hunt:And I'm JJ Hunt. This is talk description to Me where the visuals of current events and the world around us get hashtag in description rich conversations.
Christine Malec:Before we get going today, we want to announce our very first clubhouse event very exciting. On May 20, we will be having special guest experts, Kim Arcand from the Chandra X ray observatory. So our clubhouse events are going to be a combination of guest experts and professional description. So they're going to provide some really amazing opportunities for learning. And we're hoping to have one each month. And so if you are on the clubhouse, please follow us at talk description to me and look for our event describing the invisible universe. That's may 28 at 7pm Eastern. Today, we're going to talk about satellite imagery and all sorts of imagery from above. And this takes so many fascinating forms. And, JJ, maybe it's helpful to start by talking about why these kinds of images are so powerful and so useful.
JJ Hunt:Yeah, I mean, there's so many different kinds of applications now for satellite imagery. It's really quite staggering. You know, satellite imagery is used in meteorology, oceanography, fishing, agriculture, in you know, conservation, forestry and landscaping in geology and cartography in archaeology, regional planning, education, intelligence and warfare, it's used all over the place, and the satellite with the longer satellites are in space. The more images we have, the more can be done with them. And some of these images some satellite images have played pretty major roles in history and kind of an even key to our understanding of self right like, think of the the famous photo called the blue marble. This was taken on December 7 1972, from 29,000 kilometers above the earth on the Apollo 17 mission. This is a clean and crisp image of the earth, it's a perfect looking sphere, against the black backdrop, and the earth has swirls of white clouds covering dark blue oceans and, and brownish landforms. The sun for this picture was behind the astronauts. So in this image the earth is in is in full light, it makes it particularly clear and bright. And this picture of the Earth was was revolutionary to people there had been pictures from space of Earth before and other Apollo missions. But this one was so vivid, so clear, it has become one of the most widely distributed photos ever taken in the history of photography. And then think about like, so the US Secretary of State Colin Powell, infamously used satellite images and images from spy planes as proof that Iraq was hiding weapons of mass destruction. This was in his 2003 presentation to the United Nations. Those images were were really grainy in 2003. The images from satellites were quite grainy, these ones were black and white. And what they showed were roads and rooftops, deserts and farm fields. Those are all identifiable but the details were not overly clear, just based on the visuals alone, so interpretations were added directly onto the images. So in these gray grainy images presented by Powell, buildings, labeled munitions bunkers are circled in yellow and are part of the active chemical munitions bunkers. Those are outlined in in more aggressive red squares. And then in close ups, buildings and vehicles are identified by yellow text boxes with speech bubble tales, and they identified objects such as missile storage containers, and warhead canisters. Now, almost all of that was incorrect. But it was an incredible demonstration of the power of an annotated image presented by an authority figure. So these satellites Images. I mean, they do everything from track a global warming and give us a sense of self, but also can be instrumental in the launching of wars and satellite images are really quite key to our understanding of self.
Christine Malec:On April 15, Google Earth launched something that's really exciting. And it's actually something I've wondered about before. And it's a basically a time lapse tool for satellite imagery. Can you tell us about that?
JJ Hunt:Yeah. So this time lapse, Google Timelapse allows users to view changes to the earth through a series of satellite images taken between I think it's 1984 and 2020. So Google has an incredible amount of data - of imagery - that's been accumulated in that time. And if you go to the time lapse website, which is g.co, slash timelapse, we'll be sure to put a link in our in our show notes. And you can go to the website, and you type in your location that you're interested in. And so I was trying to think when I when I went onto the website, I wanted to go to a place I wanted to see a time lapse of a place that I knew that but it was kind of remote, maybe it's a little off the beaten track. My brother and sister in law live on Koh Tao, this is an island off the east coast of Thailand. And, and I know that island reasonably well, I know there's been some changes there. So I typed in Koh Tao, into the website. And what happens is, you get swept there, it's like you're flying. So visually, you scan over, you soar over the earth, the Earth turns you zip over oceans and continents, until you arrive at your destination. And then the image, basically, you get parked above whatever it is that you've typed. In this case, it was an island, but it could be a city, it could be a mountain range, if it's in their system, you will zip right there and just kind of Park above it high in the air and look down. So Koh Tao is, is a is a small little Green Island. It's changed dramatically in the last 20 years, it went from like a small backpackers diving island to a major tourist destination. So what happens is the time lapse automatically plays kind of like a jerky stop action film. And over the course of these images, this little green island in the Gulf of Thailand, starts to get a few brown patches in this in this lush green Island. These are clearings these are towns being developed. And then those brown patches spread. And they are surrounded by very fine brown lines, these are roads. And then those roads spread and grow until they connect these little dots are connected by the little brown dots that have spread and grown are connected to these roads that are all spreading and growing. And then finally, you get to where Koh Tao is today, which is still a lush green Island. But it's got some fairly major developments connected by roads. And all of that is visible from space in these images. Not all of these satellite images in the Google time lapse website are perfect. Some of the images are grainy, or maybe a little digitized. Sometimes there's cloud movement over, you know, in some locations, but they're certainly clear enough to be useful. What Google has done is they've released a series of more processed cleaner, fully produced time lapse videos. So there are, I think 300 videos from locations around the world. All of them are about 40 seconds long. And they begin with little fanfare, you can find them on YouTube, or you can find them through Google. And they begin with very little fanfare, you just kind of turn on you zip over the earth in that same way that I described before. You then hover over a location with a little bit of movement. And you watch the images play in sequence again, like a stop action movie. There are also there's a series of curated movies, like three, three minute long videos, one's called our cities, one's our forest, and one is our oceans. These are pretty highly produced. They have soundtracks, they've On screen text and messaging, very clean, beautiful images. So they've they've processed the images more so that they're more cinematic, they're more cinematic than like you're using a just a straightforward mapping tool. And the thing is, in almost every case, in these movies, humans are clearly colonizing and the planet is reacting. Almost everything that you look at whether it's cities growing and a you know, you know, taking up the land around them, forests being cut down or oceans ocean levels rising and you know, ice sheets melting all of that is clear through these time lapse. So for example, in the cities video, you go to Dubai. You start in Dubai, you're kind of hovering over Dubai. And the on screen text tells you that it's 1984. And at this point, the city has a population of 325,000. It's a coastal city, that's really nothing more than a strip, a very fine strip of development at the edge of a sandy desert. And then the time lapse begins and it starts zipping by year by year by year image by image by image. And by 2001, the city has grown to almost 2 million people. And that strip of development has expanded quite significantly. And then really abruptly, in only a few quick photos, these strange landforms just pop up in the water. And these are the famous artificial islands that have been created off of Dubai. Some of them are shaped like palm leaves with like encircled palm leaves. And other of these false islands are clustered in a fabricated archipelago. And in this time lapse video, they just seem to appear out of nowhere, they just pop up these landforms. And the on screen text tells you that by the year 2020, the population has grown to over 3 million, so a tenfold increase in 35 years. It's just, it's quite staggering. The visuals of these are really staggering.
Christine Malec:I feel like it watching them, you know that there's life involved. It's humans and forests. But I have the sense that watching it, it would be as though you were watching some distinct life form. Am I making any sense there?
JJ Hunt:Yeah, the way the way the spread works, there is a there is an intention to it, to the way it moves. And it's slightly different in different places. Like in the in the "Our forest" video, for example, they take you from forest one forest to another that starts green and lush, and then gets turns brown over time, because the the deforestation, and it's different in different places. So some of the landscapes are, you know, there's mountain landscapes, coastal landscapes, there's deep, deep forest. And in some cases, I think it was in the mountains of Oregon, the forests are cut down patch by patch. So what you get are these Boom, boom, boom, boom, boom, these patches of brown that pop up all over the place until what was a Green Mountain, green mountain ranges, are now really heavily populated with brown patches. And then in some cases it's more of a spread, right? In some cases there's almost a line that keeps moving, an encroachment of clear cutting that just goes further and further and further and further. And so I'm not sure which one looks more intentional or more parasitic, almost. But there are different ways this spread, or this kind of popping up that it's like gobbled up here gobbled up, they're gobbled up here.
Christine Malec:It's allowing us to look at the recent past. But one of the things that's always really intrigued me about satellite imagery is its use in archaeology. And I've read some fascinating articles about things archaeologists have been able to identify that you just cannot see from the ground. But once you get high above the ground, some things become really obvious. And they become huge archaeological discoveries. What did you find in the realm of archaeology?
JJ Hunt:I'm totally with you. I'm fascinated by this. So satellite archaeology is kind of archaeological imaging that's not entirely dissimilar to the ground penetrating radar that can be used at surface level. Archaeologists can use radar to find out what's underground. But you can only do that, you know, a few meters at a time when you're on the earth, what archaeologists do is use high resolution satellites that have thermal and infrared capabilities. And the infrared light from the satellites can penetrate the earth surface to about a meters depth. And the resulting images are then processed. And what these identify are anomalies in the soil, vegetation, and geology. And these these anomalies will suggest earlier human activity. And because you're not doing this meter square meter by square meter on the ground, you can really do this like almost square kilometer at a time, you can get a ton of information, and therefore, you have greater context, right? So I've got a pair of images here that I dug up that were captured using this technology, one of the images is raw, and then one is is processed. The raw image that was that was pulled up is this. It's pale and it's blurry and it's pixelated, so it's an image of muted greens. There's a little bit of pinkish yellow mix. in there, and right near the center of this image are some darker lines, they're faint. But there they are reasonably clear. It's it's the fact that that the lines are kind of straight. That makes them distinct in this otherwise very, very blurry image. But the processed version of this image is totally different. So it looks more like a kind of a poor resolution photo of a forest canopy taken from above. And so it's basically it looks like it's packed, the whole image is packed with tufts of greenery. But right in the middle is this series of dark, straight lines, that they're kind of arranged like an architect's floor plans. If you're going to buy a new condo or something and you and it hasn't been built yet, you get the architect's plans. And what you see are all of the walls on the the exterior and thinner walls on the interior. That's what these series of straight lines looks like in the processed image. It's representing a break, these lines represent a break in the underground soil structure, likely the remnants of walls. So with this image in hand, archaeologists can dig with confidence knowing that there's something significant underfoot, even if the topography of the land doesn't show any visible signs of that. There's another technology that's used in archaeology called LIDAR. LIDAR is used to very similar effect. But but with LIDAR, it's these are images taken from a plane or this is using planes that fly over a point of interest. Instead of just taking images, they actually shoot laser pulses at the ground. And these laser pulses are then used to create the the information is brought back. And they can create digital 3D maps of the terrain based on what the lasers hit. And this can work, you can zap right through the forest canopy, you can zap right through the vegetation. And what you're taking images of are just solid materials that are above the surface, and also under the soil surface. So let's say you're walking through the forest around Angkor Wat in Cambodia, and you come across a mound of earth or like a mound of some kind of plant material vegetation, you might notice it, but you might not right, it might just you might just register as part of the landscape. But when you have LIDAR imagery, that mound becomes really clear. And it's it's also clear, because of the context, the context of that mound, how it relates or is connected to other underground shapes and structures, that becomes really clear. Again, because you're taking images from so much higher up, you're getting a much broader understanding of the area, these images are quite different. Because they're visualizations of the data, they're not really photographs. So what they end up looking like are very bright, outrageously colorful 3d images, kind of like they look like they're almost from video games. So instead of being shown just a perfect bird's eye view, looking straight down, as you will often get in a satellite image. These images are often presented at a slight angle that highlights the three dimensionality that is that you're capable of producing with this LIDAR. I've got a couple of different images here. One image is neon yellows, and a little bit of orange, and there's some kind of green tints to it. This is a picture of Tikal an ancient Mayan city in Guatemala, then this image, this you know, produced image, it looks kind of like a tactile replica that you would find in a museum, but it doesn't have any trees, there's no vegetation that is, you know, weeded out as this as it were, by the by the LIDAR. And it's as if you're looking at one of these museum replicas, through yellow tinted sunglasses. I've got another image also of Tikal, and this one looks like it's been taken through night vision goggles. Here, they're the different heights. So the different stratas have been digitally assigned different colors. Most of the land is neon blue, an underground structures are very dark blue. But then platforms and low walls, those are turquoise, and pyramids are yellow, and even orange, so the different heights get different colors. So if a foundation that's buried a foot underground that will register in this image as dark blue, and might have a turquoise outline, if the fragments of the outside walls still remain. And if a structure is buried under a mound that might register as yellow. So from ground level, this will just look like a rain forest with mounds of Earth surrounding a few pyramids or temples that have been exposed and excavated. And if you were to take a look at this using a traditional satellite, you would probably not see anything but a forest canopy surrounding the already exposed pyramids. But by using infrared satellites and LIDAR imagery, the structures beneath the vegetation, and even in the top layers of the soil and Earth, they become clear and visible. It's amazing.
Christine Malec:That is so awesome. That's like ghostly. Did you see any of roads? Ancient roadbeds?
JJ Hunt:Yeah, I have seen a couple of those there are. When Oh, when I was in Mexico, recently, a few of these ancient Mayan cities were connected by hundreds of kilometers of roads, just, I mean, incredibly long roads. And, and parts of those roads have been excavated. And what they found was that the roads are actually the surface of the roads were built with crushed shells, so that they would glow in the moonlight. So you could actually travel these roads at night, but just off of the lights reflecting off the full moon, quite amazing. So you'll get sections of these roads that have been excavated, they've been found. But then if you use this technology, the LIDAR technology or other archaeological satellite tech, you can see how they connect from, you know, one ancient city to another, which might be you know, 100 kilometers away. It's remarkable.
Christine Malec:That is so ghostly and cool. I love the overlap of archaeology and satellite technology, that is just so awesome! When Chris Hadfield was commander of the International Space Station, he was tweeting a lot of photos, and I was following him at the time. Because he was very good at telling you what was in the photo. And before we dive into this, I just want to say that my professional ambition is to interview Chris Hadfield. So if anyone knows him, I'm just putting that out into the world that if you can get me past his people, I really want to interview Chris Hadfield. But that's just a side note. As a side. Yeah, just a side note, is his photo descriptions were quite beautiful. And he's not describing them for blind people. Although I will add that he did tweet one at one point and said, I've become aware that I have several blind and visually impaired followers. So I'm going to start sending out more multisensory material, which he did, because that's the kind of great guy he is, but even his own photo descriptions were compelling to me as a blind person. And so when JJ and I were talking about this episode, I dug up I had curated for for another presentation, I had kept a bunch of texts of his tweets, because just the photo descriptions themselves were so useful. And so I asked JJ, if he would have a look back and see if any of these were, were worth describing. And we both felt that that some of them were so JJ, what did you find?
JJ Hunt:Tons of these photos, and you had a good long list that you sent me, and I really could have described any of them and be quite happy because they are amazing photos. Often photos that come from astronauts, they're somewhat scientific, and they're somewhat artful. But I mean, your Astro hunk, really did elevate the art form! He really did.
Christine Malec:Tee hee hee.
JJ Hunt:He took some beautiful images. So I've got a couple here. Let's start with this one of the Egyptian Israel border. This is a really interesting image. So when I was a kid, I actually thought that the lines that were drawn on the maps were real, I thought those were tangible, physical borders.
Christine Malec:Me too!
JJ Hunt:You too?! I guess it's not because it makes intellectual sense but because of the visual representations of borders on maps is so ubiquitous, I just presumed it to be reality.
Christine Malec:For sure.
JJ Hunt:In fact, they're very, very, very rarely, you know unless the border is a river or something like that, borders are generally invisible, if especially from space. But Chris Hadfield took a picture of this one this, the border between Egypt and Israel is actually visible from the International Space Station. So let's start with a bit of the geography because that'll help with the description. The image that he presented features a section of the curved shoreline of the Mediterranean Sea. Some might remember that description from our episode of the ship stuck in the Suez Canal. And the border between Egypt and Israel runs more or less north south. Egypt is on the west side. So that would be the left side of North is is pointing up is generally the case in depictions in Israel and the Gaza Strip there on the East or the right side. So in in commander Hatfields photo, the curve shoreline is at the top of the image. So it forms kind of like a bowl of dark blue water. And the shoreline itself is quite clear. And even so it's not it's not super rough, it's not very nobly it's a very clear shoreline. And right in the center is where the border line begins. In this orientation, it cuts down and to the left. So it's kind of aiming for like seven o'clock on a clock face. Now there is an actual fence along the border. But that fence is in no way visible from the space station, it's just far too narrow to be visible from space, the border is clear, because of the different landscape and human activity on either side, that's what makes the line look like a line because of what's going on on either side. So at the water's edge, on the Egyptian side, is a patchwork of rectangular green and brown farm fields. It looks like they were made with like tiny flicks of a very fine brush, right, this little patchwork of, you know, farm fields. And then on the east side, right along the water, that's the Gaza side is there's the Gaza side of the city of Rafah. This is a split city, but a lot of it is on the the Gaza side. And from the distance, it looks like a steel blue cloud like this color of steel blue. And that's because of the amount of concrete construction in the city. So on one side, you have farmer's fields. On the other side, you have this concrete blue color, and then you move further inland, so in the image a little bit down. And then there are farm fields on both the Egyptian and Israeli sides of the border. But in Egypt, these fields are over grazed, and they're not very well irrigated. So they actually look really quite Sandy. They're very, they're quite sandy brown. But in Israel, these fields are more irrigated, and so therefore, they are more green. So as you move inland, you get Egypt with brownfields and Israel with green and so that creates the line the separation if you more further inland soak again further toward the down toward the bottom of the image. The border line continues, because on the Egyptian side, the grazing of livestock and the trampling by humans has exposed the light colored sand, which is kind of like the color of milky tea. But the land is more undisturbed on the Israeli side. So the darker soil, that's a top the sand dunes is still intact. So they've got this defacto line in the sand because there's a bit of texture that looks almost like stippled, you know, light gray paint on top of the Milky tea on one side. And on the other side, it's just this milky tea color. All of that is, is is packed in to one image taken from the space station.
Christine Malec:Yeah, he liked to look at lands the interaction between landscape and human human activity. What other ones did you find?
JJ Hunt:There's another one tha's it's quite striking. Again, his idea of human activity and landscape, there's a photo that he dubbed the polka dot desert. o here is a sandy desert again the color of milky tea. And the e are a few discernible idges a little bit of texture t the desert. So there's like a C shaped Ridge where the sa d on the inside of the Seas a l ttle bit darker. The Ridge it elf has like a crumb like t xture. And at the upper left, here are some darker spots it almost looks speckled. I' not actually sure what that is But the really notable feat re in this photograph i the series of perfect blue circles, dotting the desert. nd in his caption, Commander Ha field identifies these as Cen erpoint irrigation farms. So Ce terpoint irrigation farms are fa m fields that are irrigated by sprinkler systems that move in a circular pattern around a cen a central point. So the resul is perfectly round fields and i satellite images of lush farm ng land. So you'll see this acr ss the United States and i Canada. In those lush farming a eas, satellite images are look ike grids filled with circles i shades of green. Outside of th circles, you're going to h ve paler green and inside the ci cles, it's going to be darker reen, because that's what's getting the irrigation. B t in this image, it's really ntriguing because those the ci cles are kind of blue. I'm no sure why they're blue if it's just the amount of water that's being used, but they're surr unded by sandy desert. So t e circles are perfect circ es surrounded by desert and t ey're in really quite a quir y configuration. It's almost ike someone was making a hea t shape with Braille dots So they made the bumps at the Top using these dots, and th n they started going down t e right side and then they go bored and stopped. That's the s ape of these dots. And some of he blues are quite dark and opa ue. But some of them are rea ly quite faint and they're, the're transparent almost so yo can see the sand quality bene th them. Really quite striki g. Very, very artful, beau iful image.
Christine Malec:And you would never see this perspective except from above. I could do this all day. Okay, what else have you got?
JJ Hunt:Okay, I got one more. This is the Australian outback Okay, so this image I ho estly I hardly know what I'm lo king at here, The landsca e fills the frame so there ar no clear points of referenc. There's nothing that's r ally discernible. I, I genuine y don't even know what I'm loo ing at here. So I'm just going t describe it as a piece of art. In his description Hadfield sa s Jackson Pollock would have be n would have been further in pired by seeing the outback fr m orbit. And it's true. This lo ks like a like a Jackson Po lock painting with streaks of co ors and dots on a canvas. It's r ally wild. So what we have i an image in terracotta reds, and kind of cloudy oce n blues. And it resembles a close up of a bowling ball, elieve it or not. It looks like marble cave wall with dripp ng mineral streaks. If this was vertical image, I would descr be the terracotta color as almo t dripping down into the patc es of blue. And I genuinely d n't really know what it I can't even imagine what this looks lik from ground level. It is su h an amazing, dripping meld ng of colors and the blues wi h the cloudy patches and the s reaking. It's really mesm rizing purely as a piece of art It's beautiful. It's a lovely image.
Christine Malec:If we have any Australian listeners who have insights about what that's about, please, please email us or let us know somehow. We love making this podcast. If you love hearing it, perhaps you'll consider supporting its creation and development by becoming a patron. We've set up a Patreon page to help cover the costs of putting the show together. You can contribute as a listener or as a sponsor to help ensure that accessible and entertaining journalism continues to reach our community. Visit patreon.com slash talk description to me that's pa t ar e o n.com slash talk description to me have feedback or suggestions of what you'd like to hear about here's how to get in touch with us. Our email address is talk descriptio to me@gmail.com. Our Faceboo page is called talk descriptio to me. Our website is ta k description to me.com and y u can follow us on Twitter at ta k descriptio