Orbital imaging is one of the most popular categories in the new space industry, but there’s more to it than meets the eye. Pixxel has raised $25 million to launch a constellation of satellites that will provide hyperspectral images of the Earth: a wide swath of the electromagnetic spectrum that can reveal all kinds of details invisible to conventional cameras.
In fact, the ability to see many miles below the surface of the Earth opens up all sorts of possibilities. But just like in the lab you need more than a standard digital camera, so it is with orbital imaging.
An additional device that you can find in the laboratory is the spectrometer, which records what frequencies are absorbed or reflected, and what part of the object or substance is irradiated. Everything has a different spectral signature, making it possible to distinguish even closely related materials, such as two kinds of the same mineral.
Hyperspectral imaging is a camera-like process, and performing it from space allows you to find the spectral response of an entire area in a single image. NASA and other agencies are doing this for planetary observation purposes, and now Pixxel is building on their work to launch a constellation of satellites that will provide hyperspectral coverage on demand.
Founder and CEO Awais Ahmed said that, as with other emerging aerospace industries, the company has been helped by a combination of shrinking technology and frequent low-cost launches. He bluntly admitted that NASA worked so that Pixxel could work, but they don’t just reuse taxpayer funded technology. You can think of the EO-1 mission and the Hyperion hyperspectral dataset as early market research.
“Hyperion about 30 meters [per pixel] In any resolution, which is great for scientific purposes. But you need to go down about five meters or so, otherwise it doesn’t matter what we do,” Ahmed explained.
The Pixxel constellation, although it won’t have exactly six satellites when it launches later this year, will be able to provide five-foot resolution over most of the Earth every 48 hours. There is already a test satellite sending image samples, and the second generation bird will be launched next month. Production versions are larger and have more tools to improve the quality and quantity of photos taken.
Ahmed said the company already has dozens of customers queuing up for the data they will eventually provide, if not for the images already taken from the test satellites. These companies are primarily active in the agriculture, mining, oil and gas industries, where regular large land surveys are vital to ongoing operations.
This is where 5m resolution comes in handy because there are features that are there at small scales that are lost or averaged at large scales. If you’re mapping a continent, a resolution of 100 feet is an exaggeration, but if you’re checking the shores of a lake for harmful chemicals or checking to see if an area is drying out, you can achieve the best possible accuracy.
Hyperspectral images show even more, as visible light is exposed to emissions such as methane or has the same color for two very different materials. If there is dark discoloration around the edge of the lake, is it algae, a shelf below the surface, or industrial wastewater? It’s hard to tell when it’s “blue” and “dark blue”. But hyperspectral images cover much of the spectrum, producing a rich image that is difficult for humans to intuitively understand. In the same way that birds and bees can see ultraviolet and it changes their perception of the world, it’s hard for us to imagine what the world would look like if we could see at wavelengths of 1900 nanometers.
As a simple example showing scale here, this NASA map shows the spectral features of three minerals with wavelengths ranging from 0 to 3000 nanometers; The part that is visible to human vision, I marked in blue:
As you can see, there is still a lot of work on the table.
“We have hundreds of colors to play with. It helps you see if a particular nutrient in the soil is oversaturated or undersaturated? Each of them shows up as a tiny change in this smooth spectrum in hyperspectral images. But in RGB it is invisible,” says Ahmed.
Pixel sensors collect several hundred “slices” of the spectrum, while conventional cameras capture only three: red, blue and green. The planet’s satellites have a few extra useful segments called multispectral images, but when you combine tens or hundreds of segments, you get a more complex and representative picture. In the chart above, more segments means the curve is more accurate and is likely to be more accurate.
Although there are other companies involved in hyperspectral orbital imaging, none of them have launched a working satellite that is currently returning data, nor have they reached the 5-meter resolution and range of spectrum slices that Pixcel makes. So while there is likely to be competition in this space, that amount is likely to rise.
“The quality of our data is the best, and the bonus is that we do it very cheaply,” says Ahmed. “We are fully funded by Constellation First.”
The $25 million Series A was led by Radical Ventures with Jordan Noone, Seraphim Space Investment Trust plc, Lightspeed Partners, Bloom Ventures and Sparta LLC.
The money will, of course, be used to build and launch satellites, but Pixxel is also working on a software platform so that customers don’t have to build hyperspectral analysis stacks from scratch. They cannot reuse what they have—in fact, such data has never been available before. So Pixxel is building “a common platform with built-in models and analytics,” Ahmed said. However, it is not yet ready for public display.
The Pixel is due to enter service in the first or second quarter of 2023 due to general space uncertainty.