Headwall Photonics Blog

Hyperspec SWIR Gets UAV Wings!

Posted by Christopher Van Veen on Thu, Sep 14, 2017

Remote sensing with hyperspectral sensors is  a combination of several elements: an imaging spectrometer and a fast data processing system to acquire and analyze spectral and spatial data. For remote sensing missions such as crop disease or invasive species detection, the spectral range of most interest is the visible-near-infrared (VNIR) from 400-1000nm.

Geologic exploration requires a different spectral region as spectral signatures of interest are evident in the shortwave-infrared (SWIR) range of 900-2500nm. Each type of mineral has its own unique spectral signature reflecting its chemical composition. Since certain minerals reflect light slightly differently, it's important to have many contiguous spectral bands.  

Given the sensor requirements for generating SWIR hyperspectral data, spectral imaging sensor systems require efficient consideration of size, weight, and power requirements for deployment on UAVs. Headwall has worked strategically to 'lightweight' its Hyperspec sensors for field deployment. One of the main design aspects is that Headwall uses an 'all-reflective' approach which allows for a very small instrument size and form factor. The Hyperspec sensors are smaller and lighter but also more robust in airborne situations, particularly for UAV deployment. 

DJI-with-SWIR-small.jpg

Headwall's Micro-Hyperspec SWIR is being successfully deployed on the multi-rotor UAVs with excellent stability and imaging results. What's more, the entire payload also includes a high-performance GPS/IMU and Headwall's HyperCore data-fusion hub that synthesizes the data streams coming from complementary instruments. For example, LiDAR can also be integrated to the payload and handled by HyperCore.  

There are several aspects of Headwall’s spectral imaging sensor design that are advantageous for geological research. “When you’re using a UAV, flight time is crucial,” said Peter Clemens, Director of Engineering at Headwall. “Efficiently capturing wide swaths of valuable image data on each flight is therefore a huge advantage.” Headwall has built ortho-rectification into its Hyperspec spectral software allowing users to generate highly accurate geospatial data. “We give our customers the technology to identify not only what they see within the scene but a precise location as to where it is on the ground,” continued Clemens. Headwall has developed solution bundles that package both hardware and software systems necessary so that customers can quickly acquire spectral data but also efficiently process this data and view spectral maps.

Tags: hyperspectral imaging, Airborne, Remote Sensing, geology

The Eyes Have It...But Not Always

Posted by Christopher Van Veen on Thu, Apr 13, 2017

Humans have a marvelous ability to see and identify objects within what is called the visible range of the electromagnetic spectrum. That starts at roughly 380 nanometers and goes up to around 700 nanometers or so.

But there are things that researchers and scientists might wish to 'see' that fall below (ultraviolet) or above (infrared) this 'visible' portion of the spectrum. If you were a bumblebee, you could see into the UV range; a rattlesnake, you could see into the infrared range. Obviously (and thankfully) we're neither, but to see into these other ranges we need help. And why would we care about anything our eyes cannot see? Well, to take just precision agriculture as a key example, there are vegetative indices (VI's) that depend on seeing into the infrared ranges where the spectral signatures of chlorophyll fluorescence are detectable. Chlorophyll fluorescence is predictive of crop stress and vigor, so being able to see and quantify its effects can tell crop scientists much more than their own eyes can. 

DJI-MATRICE-600.jpg

Since we aren't bumblebees or snakes, we need tools to see into the nether regions of the spectral range. Hyperspectral and multispectral sensors do the work our eyes can't, and they do it very well. They collect, in the case of hyperspectral, a full spectrum of image data for every pixel within the field of view. Dozens of vegetative indices exist, with each using spectral data to discern answers to questions: Are there diseases on my crops I cannot see? Is my soil nutrient-rich? Are there invasive species I need to worry about? In the end, scientists concern themselves with finding answers to these and other questions rather than poring over complicated hyperspectral data cubes. In layman terms, you go to Home Depot not to buy a drill; you go there to buy a hole.

Hyperspectral and multispectral differ with respect to the amount of image data being collected. Hyperspectral is to multispectral what hundreds of bands are to a handful. With multispectral, you also may have gaps between the rather wide bands and what you want to detect with the sensor might not register. But hyperspectral represents hundreds of narrow and contiguous spectral bands, so if a certain spectral signature is there you'll see it. There are places for both multispectral and hyperspectral; if you know the spectral signature of the vegetative indices of interest and you're sure the multispectral sensor can capture it, you're all set. But much more common is the case where scientists do not exactly know where along the electromagnetic spectrum a key VI exists. Is it somewhere between 400 and 1000 nanometers (nm), which we call the visible-near-infrared VNIR range? Or is it in further up, between 900-2500nm (the shortwave-infrared SWIR range)? Indeed, missions may change over the course of the instrument's life, which means that scientists would opt for a combined VNIR-SWIR sensor capturing image data from 400 nm all the way up to 2500 nm.

Hyperspectral and multispectral imaging sensors are often 'line-scan' instruments, basically meaning they capture image data a slice at a time. The composition of all these slices (or frames) is a hyperspectral data cube, which can be several gigabytes in size. Post-processing software is very good at unscrambling this complex cube of data into meaningful answers, but just as important is aircraft stability. Since UAVs are quickly becoming the 'go-to' platform for crop scientists and others, making sure the craft is stable in the air is fundamental to making sure the data is orthorectified. In other words, not a casualty of a wobbling UAV. Fortunately, stabilized gimbals are outstanding nowadays, having the immediate ability to keep the sensor in its desired position no matter what the craft does.

Obviously, a UAV-based remote sensing system is a function of optics, electrics, and aerodynamics. Integration is an overlooked task, because many users assume that they can buy a UAV and a sensor and bolt the two together. Unfortunately, experience shows that such a piecemeal a-la-carte endeavor is likely to fail. Battery life comes into play, balance rears its head, and understanding the relationship between frame rate and ground speed can flummox anyone. Fortunately, though, companies like Headwall Photonics exist to manage this integration process. They understand a thing or two because they've seen a thing or two. They can recommend the right kind of UAV, take size/weight/power (SWaP) into consideration, integrate spectral sensors with other instruments such as LiDAR, and deliver turnkey, flight-ready packages that even bumblebees and snakes would have to admire. 

Tags: hyperspectral imaging, Airborne, Remote Sensing, Nano-Hyperspec

Hyperspectral Takes Old Maps Into New Territory

Posted by Christopher Van Veen on Thu, Mar 26, 2015

Late in 2014, Headwall sponsored a successful event at London’s Natural History Museum. The purpose of the gathering was to introduce curators and preservationists to the advantages and capabilities of hyperspectral imaging. Professionals in this field understand that the treasures under their control...paintings, documents, and artifacts...need to be preserved using the most advanced techniques available. Preservation largely means having an excellent understanding of the chemical composition of the underlying materials used to create the treasures. And what the eye cannot see, hyperspectral imaging can.

The Bodleian Library (Oxford, UK) has been an acknowledged pioneer with respect to the use of spectral imaging technology. While newer than other imaging techniques, hyperspectral is relatively affordable and provides a wealth of image data that experts can pore through. With this data, the overall body of knowledge is exponentially increased on treasures having enormous historical prestige and significance. The identification of specific materials, inks, pigments, and substrates can help determine when (and perhaps even where) a document or artifact was created. Everything a hyperspectral sensor sees can be categorized with respect to its chemical signature, or ‘fingerprint.’ The color ‘Yellow’ resonates a certain way to the eye, but spectral imaging can discern the chemical composition of a particular ‘Yellow’ and match it to known spectral libraries. The results are clearly beneficial to the Bodleian, which is why the Library has taken great measure to partner with Headwall Photonics to implement systems geared specifically to what they'd like to see and learn.

BodleianTwo prized maps at The Bodleian...the 17th-Century Selden Map of China, and the medieval Gough Map of Britain...recently underwent precise analysis using Headwall’s hyperspectral sensor. The Gough Map in particular represents a mystery to Bodleian experts: when was it created, by whom, and why. By illuminating the map with non-invasive, non-destructive ‘cold’ lighting, the near infrared and shortwave infrared sensors collect a digital map of inks and materials. It even highlights features that were deliberately masked and others that simply faded or flaked away over time.

The Bodleian’s David Howell, an early advocate of spectral/chemical imaging and who helped spearhead Headwall’s Natural History Museum event, has been extremely pleased at the results seen thus far. In an interview with the BBC, Howell said that he was “blown away by the data that’s already coming out.” He noted that the technology first and foremost does not put the treasures at risk. The imaging illumination is non-destructive and the treasures themselves do not need to be removed from their climate-controlled premises.

Howell concluded with a plug for the promise of hyperspectral imaging technology: “Our biggest problem now is there’s just so much data to sort through to fully explore what we’ve uncovered!”

To read the BBC article on this exciting venture, click here.

Tags: hyperspectral imaging, artifacts, antiquities, Artwork, artwork preservation

Nano-Hyperspec...in the air and on the ground

Posted by Christopher Van Veen on Fri, Feb 06, 2015

Next week during Photonics West we’ll be demonstrating our very newest hyperspectral sensor: Nano-Hyperspec. We gave it that name because it’s small...exceptionally small. Think of a Rubik's Cube and you've got it. The market said it needed a robust, aberration-corrected hyperspectral sensor purpose-built for small, hand-launched UAVs. One perfect example is the X6 from the Aibotix division of Leica-Geosystems, a company with whom Headwall signed an agreement in late 2014. “There’s a confluence within the remote sensing marketplace,” said Headwall CEO David Bannon. “The attractiveness of affordable, easy to launch UAVs runs headlong into the need for perfectly matched sensor instruments that they can carry.” In conceiving Nano-Hyperspec, Headwall consolidated and integrated as much as possible to yield a small, performance-packed unit that even the smallest UAVs could easily carry.

“Ordinarily, a hyperspectral sensor talks to a separate computer in order to transfer large amounts of image data quickly,” noted Bannon. “But small UAVs don’t have the payload capacity to carry a separate data-processing unit and the cables they require.” So the first order of business was to put the data processing and storage technology into the sensor itself, which frees up space for other accessories. For proper image-data collection from a UAV, the hyperspectral sensor needs to work along with a GPS. Nano-Hyperspec was designed so that the GPS can attach directly to the housing, further saving weight and space. “Integrating these normally disparate pieces into an integrated whole is what the market continually tells us it needs,” noted Bannon. “All of this not only makes for a lightweight sensor package, but also allows for the addition of technology such as LiDAR, which itself is collecting valuable data for scientists to use.”

Nano Leica logoNano-Hyperspec focuses on the Visible and Near-Infrared spectral range (often referred to as ‘VNIR’) of 400-1000nm. “Much of what needs to be seen from a UAV is taken at slow speeds and low altitudes,” said Bannon. This can be precision agriculture, environmental monitoring, minerals and geology, or any of a number of other uses. But to a large degree, what becomes visible to a hyperspectral sensor between 400 and 1000nm can include the presence of disease conditions on a tree canopy where it otherwise might be invisible from below. “Entire economies depend on agriculture,” said Bannon. “If a low-flying UAV with our specially-tuned hyperspectral sensor can ‘see’ an invasive disease, our technology becomes vital rather than simply desired.”

One of the hallmarks of all Headwall sensor designs is aberration-correction. In simple terms, this means making sure that the sensor sees as crisply and clearly off to the edges of its field of view is as it does straight beneath the line of flight. The holographic diffraction grating embedded within each sensor is designed to make this so, by eliminating unwanted artifacts such as ‘keystone’ and ‘smile’ that are more pronounced off to the edges of the field of view. “In practical terms, it means that the sensor has a very wide field of view that is accurately represented,” said Bannon. A wider view means a more efficient flight path. In short, the UAV can cover more ground because it can accurately ‘see’ more ground. This is particularly crucial because UAVs are battery-powered; the objective is to maximize useful work in the limited time aloft. A wide view of the ground at exceptionally high spatial and spectral resolution allows this to be so.

holographic gratingsIt has been said that people buy holes, not drills. They basically have a problem that needs an answer. How they get their hole or derive their answer is an exercise in technology, economics, and speed. “We have a technical solution that is affordably priced,” said Bannon. The partnership with Leica-Geosystems helps. “Time-to-deploy is an exercise in economics and lost opportunity because real value can be derived the sooner the UAV/hyperspectral package is airborne and collecting useful data.”

Not lost on the remote-sensing community is this: many applications involve taking image data from the ground rather than from a UAV. Nano-Hyperspec is easily attached to a tripod and a rotational stage so that the necessary movement (which ordinarily would come from a UAV) instead happens from a ‘stationary’ platform. These deployments are sometimes called ‘point-and-stare’ or ‘pan-and-tilt,’ and it represents a means of accomplishing movement-based hyperspectral imaging on the ground.

Headwall's booth at Photonics West (Moscone Convention Center, San Francisco) is 2506. Hope to see you there!

Tags: hyperspectral imaging, Headwall Photonics, Remote Sensing, UAS, UAV, Leica-Geosystems

Headwall Delivers Micro-Hyperspec® Sensors to Columbia University

Posted by Christopher Van Veen on Thu, Oct 09, 2014

High-performance imaging sensors on small, commercial UAS will assess ocean and sea ice variability in Arctic zones

FITCHBURG, MA - OCTOBER 9, 2014: Headwall Photonics has delivered two high-performance hyperspectral imaging sensors to Columbia University as part of its Air-Sea-Ice Physics and Biogeochemistry Experiment (ASIPBEX). ASIPBEX is part of a larger international collaborative investigation of Climate Cryosphere Interaction with colleagues from Spain, Germany and Norway. This crucial remote-sensing project will use a high-endurance unmanned aircraft system (UAS) to investigate climatological changes present in the Arctic Ocean around Svalbard, Norway. The instrument payload comprises two Micro-Hyperpsec sensors; one will cover the Visible-Near-Infrared (VNIR) range of 400-1000nm while the other will cover the Near-Infrared (NIR) range of 900-1700nm. Together, the sensors will be crucial in detecting indicators of sea ice physics, solar warming and global carbon cycles.

 

UAS and Micro-Hyperspec"We chose the Headwall sensors for several reasons," stated Christopher Zappa, a Lamont Research Professor at Columbia's Lamont-Doherty Earth Observatory. "The very high resolution allows us to collect and process vast amounts of spectral and spatial data upon which our research and analysis depend." The wide field of view of the Headwall sensor combined with aberration-corrected optics also contributes to overall flight-path efficiency. The UAS allows scientists to measure in places that typically are impossible to get to using ships or manned aircraft. This opens up the possibility for transformative understanding of the climate system. "Since we're using a UAS, we depend on 'seeing' as much of the ocean surface as possible, minimizing any aberrations or unwanted artifacts along the edges of the field of view," noted Prof. Zappa. The combination of Micro-Hyperspec and Headwall's advanced Hyperspec III airborne software allows for the successful collection, classification, and interpretation of the spectral data collected during each flight.

 

This particular deployment for the ASIPBEX project is fundamental to Headwall's strategy of advancing the science of remote sensing aboard small, commercial unmanned aircraft systems. "Hyperspectral represents a crucial payload for any manned or unmanned deployment," noted Headwall CEO David Bannon. "But significantly notable is that the UAS has become a 'go-to' platform. This means not only smaller and lighter sensors, but also integrated solutions that factor in everything from LiDAR and data-management to post-processing tasks such as ortho-rectification that our software can handle." Because the Micro-Hyperspec sensor uses high efficiency diffraction gratings in a concentric, optical design, imaging performance and signal-to-noise are both maximized. The patented optical design provides a package that is rugged and robust for airborne use in harsh environments such as the Arctic ocean.

 

The Observatory for Air-Sea Interaction Studies (OASIS) 

Led by Professor Christopher Zappa, the Observatory for Air-Sea Interaction Studies (OASIS) conducts research in a variety of fields focused on the oceanic and atmospheric boundary layers. These include wave dynamics and wave breaking, air-sea CO2 gas exchange, non-satellite remote sensing and boundary-layer processes. Affiliated with the Lamont-Doherty Earth Observatory (LDEO) and Columbia University, OASIS is involved in joint projects with the Polar Geophysics Group of LDEO, Yale University, the University of Heidelberg, the University of Connecticut, and the University of New South Wales and participated in various large multi-institution projects such as CBLAST-Low, GasEx, VOCALs, RaDyO, DYNAMO.  

The group develops and deploys instruments including infrared, multispectral, and polarimetric cameras on different fixed and mobile platforms such as ships, aircrafts, buoys. The study areas range from laboratory wind-wave tanks, Biosphere2, to local rivers and estuaries, to shelf seas and polynyas, to open ocean from the poles to the equator.


For information contact:

Professor Christopher J. Zappa, Lamont Research Professor 

Lamont-Doherty Earth Observatory 

[email protected]

Tags: hyperspectral imaging, Airborne, Remote Sensing, Micro Hyperspec, UAS

UAVs and Hyperspectral Imaging Unite

Posted by Christopher Van Veen on Tue, Mar 25, 2014

One of the things we’re seeing at Headwall is the proliferation of airborne applications. Multispectral suffers a bit with respect to hyperspectral (a handful of bands versus hundreds), which is why hyperspectral is winning the day.

UAV choicesOne reason is instrument affordability. Multi-million-dollar hyperspectral sensor programs might have flown (literally and figuratively) in the military world, but not in precision agriculture or with universities. Budgets are smaller, and that money has to be spread among not only the sensor but the UAV and everything in between. This is where small, entrepreneurial companies like Headwall shine, because everything in between can mean LiDAR, GPS/IMU technology, application software, data processing, and so much more. We understand hyperspectral imaging better than anyone, and our focus has always been to better that technology while driving costs lower. This is the essence of commercial-off-the-shelf (COTS), where highly specialized military instrumentation finds a home all across industry and academia. With respect to Headwall, COTS implementation means smaller, lighter and more affordable sensors that are easier to use yet just as optically precise as their multimillion-dollar military counterparts.

Second, you cannot go a day without seeing stories about UAVs. Fixed-wing designs like those from AGX and PrecisionHawk are crowding the skies along with multi-rotor helicopters like Infinite JIB and AIBOTIX. These are much more than hobbyist playthings and are perfect for scientific reasearch duties. They have excellent range and payload-carrying characteristics, and they are stable aloft.  From mineral exploration and agriculture to petroleum and pollution control, UAVs are everywhere it seems. And everyone takes notice when household names like Facebook, Google and Amazon decide that the UAV is going to be instrumental to their future success. Much of this might sound fanciful and far-off, but it is happening now. Court challenges are being won, and while care needs to be taken on how regulations are drafted and enforced, no one doubts that the UAV is not only here to stay but will become commonplace.

Obviously, UAVs simply take up airspace unless they are doing good work. And largely, we seem to hear about bad things happening when mention of UAVs (and drones) is made. But stop and consider for a moment how a famine-stricken area can be made crop-fertile thanks to hyperspectral data that a UAV-mounted sensor can collect. A scientist will know about disease conditions with enough time to prevent damage by skimming the treetops and looking for anomalies that become ‘visible’ through hyperspectral imaging. A farmer will know where to plant and harvest…and where not to. Crop stress will be seen long before it becomes a worry, and the amount of wholesome and nourishing food planted in areas once thought impossible will blossom. In short, small and light UAVs are affordable for the people who need to use them. They can be flown in areas that vehicles and humans cannot yet reach, providing a window of research never available to scientists before.

As we see the proliferation of UAVs capable of carrying sensor payloads, it is important to understand how everything goes together. Here, Headwall is taking a leading role. Many mistakenly believe that slapping a sensor onto an octo-copter is all they need to do. But making sure everything works the way it should aboard a flying, unmanned vehicle is another challenge altogether. How much ground do you need to cover, and do you have enough battery power to do it? How much hyperspectral data do you need to collect, and do you have the computing and storage horsepower to make that happen? What are you looking for, and what spectral ranges are those things in? How do you ortho-rectify the data during post-processing? And how do you use the science of ground-truth as it relates to airborne hyperspectral imaging? This last consideration is hugely important, because the collaboration of airborne hyperspectral and ground-truth delivers the best possible accumulation of data. Headwall and ASD have even authored a 12-page whitepaper on the relationship between airborne hyperspectral data and ground-truth techniques.

Tags: hyperspectral imaging, Airborne, Remote Sensing, UAV, precision agriculture

Headwall's Field-of-View Calculator

Posted by Christopher Van Veen on Mon, Mar 17, 2014

When it comes to hyperspectral imaging, it isn’t always about the hardware. Before users even get to the stage of specifying a sensor instrument, they need to ask a few questions:

  • What do I want to look at?
  • How am I deploying the sensor?
  • What is the spectral range of what I’m looking at?
  • How far from the object will I be?

The answers to these questions will lead to an informed decision about the kind of sensor that’s best, the kind of lens it will need, and how small and light the sensor needs to be.  At Headwall, we’re helping customers sort through these questions and considerations every day. We make on-line tools available that make instrument specification easy. With the answers to a few simple questions, the overall application-specific design of a hyperspectral instrument is well within reach. This means quicker time-to-deploy for customers who have challenging scientific questions that need answers.

One of Headwall’s newest tools is the Field-of-View (FOV) calculator. This tool collects a few important user-defined parameters to arrive at several what-if scenarios. The first parameter is distance from lens to object. In an airborne application, the distance would likely be measured in meters. For lab-based or in-line deployment, it might only be centimeters.  The second parameter is the wavelength, which can be UV-VIS (380-825nm) all the way up to SWIR (950-2500 nm). Knowing the spectral signature of the item of interest will point you in the correct direction.

FOV resized 600

The calculator will take this information and combine it with choice of sensor and lens to arrive at useful data for the customer. In this case, we see that for the parameters and options chosen we are given the number of spatial and spectral channels (1004 and 335 respectively). We’re also given the linear and angular FOV, the instantaneous FOV, and the spectral resolution. In an airborne application, the linear FOV can be thought of as the flight swath. The wider the better, because the aircraft or UAV will be able to collect full hyperspectral information with fewer passes over the ground.

Output

Spectral libraries are common starting points for defining where to look along the spectral range. The spectral signature for everything from plants and crops to minerals and petroleum is known or catalogued.  While everything has its own signature, the real strength of hyperspectral imaging is to discriminate and classify. So while the sensor can actually ‘see’ everything, it is tuned to look for things that may resonate at 900 nm or 1900 nm for example. A disease condition on a fruit tree may be impossible to detect by any visible means, but it will resonate quite clearly when seen with a hyperspectral sensor.

Customers come to Headwall regularly with certain ‘needs.’ A crop scientist may want to analyze the soil from an airborne UAV. Another may want to adopt hyperspectral imaging along a high-speed food processing line to see and remove foreign matter. A third may be a museum preservationist interested in understanding the artwork and artifacts under their care. But in all cases, the first question is: What do you want to see?

 

Tags: hyperspectral imaging, Headwall Photonics, Airborne, Sensors

Hyperspectral Sensors for UAV Applications

Posted by Christopher Van Veen on Wed, Feb 19, 2014

The scientific research community is beginning to understand and embrace hyperspectral imaging as a useful tool for a few primary reasons. First, sensors are more affordable than ever. Originally conceived as multi-million-dollar ISR platforms for defense applications, hyperspectral imagers have been successfully ‘commercialized’ over the past few years. Scientists typically embracing RGB or multispectral technology before can now acquire hyperspectral sensors at affordable price points.

Hyperspectral sensors of the ‘pushbroom’ type produced by Headwall require motion to occur. That is, either the sensor flies above the field of view, or the field of view moves beneath the sensor. For UAV applications, Headwall’s small and lightweight Micro-Hyperspec is the platform of choice. Available in the VNIR (380-1000nm), NIR (900-1700nm), and SWIR (950-2500nm) spectral ranges, the sensor is truly ‘SWaP-friendly.’

Spectral range is often where the decision-making starts. The chemical fingerprint—or spectral signature—of anything within the field of view will lead the user in one direction or another. For example, a certain disease condition on a tree canopy may become ‘visible’ within the SWIR spectral range (950-2500nm). Similarly, a certain mineral deposit may become ‘visible’ in the VNIR range (380-1000nm). One approach to ensuring the spectral ‘fidelity’ of images collected by the sensor makes use of ‘diffractive optics’ comprising aberration-corrected holographic gratings. This ‘Aberration-corrected concentric’ design is shown below.

concentric imager

There are several advantages to this ‘reflective’ approach. First, the design is simple, temperature insensitive, and uses no moving parts. This assures robustness and reliability in airborne situations. Second, diffraction gratings can be made very small so that the instruments themselves can be small and light; in other words, capable of fitting the new class of lightweight, hand-launched UAVs. Third, the design optimizes technical characteristics that are most important: low distortion for high spatial and spectral resolution; high throughput for high signal-to-noise; and a tall slit for a wide field-of-view. Because the design is an all-reflective one, chromatic dispersion is eliminated and excellent focus is assured across the entire spectral range.

Many within the environmental research community and across ‘precision agriculture’ prefer to use UAVs as their primary airborne platform. They are more affordable than fixed-wing aircraft and easy to launch. But as UAVs get smaller and lighter, so must the payloads they carry. And integrating the sensor into the airframe along with other necessities such as LiDAR, power management/data collection hardware, and cabling can be a daunting task (Figure 3). Orthorectification of the collected data is another key requirement, which is the means by which the hyperspectral data cube is ‘managed’ into useful information that has been ‘corrected’ for any airborne anomalies. In other words, the collected hyperspectral data needs to be ‘true’ to what’s actually within the field of view.

 Micro Hyperspec

Acquiring a UAV and a hyperspectral sensor won’t assure compatible performance, and a high level of ‘integration work’ is needed. The UAV community and the hyperspectral sensor community are both challenged with pulling everything together. Recognizing this, Headwall Photonics is taking an industry-leading position as a supplier of fully integrated airborne solutions comprising the UAV, the sensor, the power and data management solution, cabling, and application software. The result is that users are flying sooner and collecting better hyperspectral data than ever before.

Type of UAV is very often one of the first decisions a scientist will need to make. Fixed-wing and multi-rotor are the two general categories, with numerous styles and designs within each. In-flight stability and flight-time duration are both paramount concerns, and this is where payload restrictions will often point toward one or the other. Multi-rotor UAVs launch and land vertically, so this type will be favored in situations where space is tight. Conversely, a fixed-wing UAV requires suitable space to launch and land but can provide longer flight duration and carry a heavier payload. The wide field-of-view characteristic of the concentric imager allows a UAV to ‘see’ more ground along its flight path.

Integrated airborne package

Two other key areas managed through Headwall’s integrative process are data management and application software. While a separate subsystem is used to control the sensor operation and store the hyperspectral data, the direction is clearly toward on-board integration of these capabilities. Flash storage and solid-state drives will soon make it possible for the sensor to ‘contain’ all the related functionality that now needs to be contained in a separate module. This will clearly lighten the overall payload, reduce battery consumption, and boost airborne flight time.

Headwall’s Hyperspec III software represents a complete, modularized approach to the management of hyperspectral data. Orthorectification is one such module within the software suite that removes the unwanted effects airborne behavior. The resultant orthorectified images have a constant scale wherein features are represented in their 'true' positions. This allows for the accurate direct measurement of distances, angles, and areas. Other aspects of the software suite can be used to control GPS/IMU devices, control multiple sensors simultaneously, and save polygons (A Google-map-enabled tool that allows the user to define geographic coordinates).

 

 

Tags: hyperspectral imaging, hyperspectral, Airborne, Remote Sensing, Micro Hyperspec, agriculture, diffraction gratings, precision agriculture

Headwall Remote Sensing Capabilities Seen “Down Under”

Posted by David Bannon on Wed, Jul 31, 2013

melbourneThis past week, Headwall remote sensing team finished a productive week Down Under at the International Geoscience and Remote Sensing Symposium (IGARSS) in Melbourne, Australia.  The conference, organized by the IEEE, comprises a ‘Who’s Who’ across the global remote sensing community. But curiously absent were representatives from the United States, probably reflecting the topic du jour: sequestration. Imagine holding a geo-spatial and remote sensing conference and no one from NASA was able to attend?

From an international perspective, we observed tremendous interest from customers looking to gain spectral capability for their manned aircraft and also surprising interest from organizations looking to buy “all-inclusive” UAV configurations that include the Micro-Hyperspec imaging spectrometer, a GPS/INS unit, a lightweight IGARSS 2013 Boothembedded processor, and an suite of application software. This complete airborne package was a big hit at IGARSS because while users have good grasp on the benefits of airborne hyperspectral, they need help making it work in particular application.  Two very nice UAVs on display at IGARSS created a lot of buzz in the Headwall booth. Although Headwall doesn’t make the UAV platform, we make them do some pretty amazing things within the realm of hyperspectral remote sensing. That message came through loud and clear, as our stand at IGARSS was phenomenally busy from the start right through the end.

A bit further up in altitude were visitors interested in hyperspectral remote sensing from space. A major point of interest throughout the conference was a demonstrated need for cost effective, space-qualified hyperspectral sensor payloads.  With most of the world’s planned remote sensing missions being delayed for budget reasons, VNIR (380-1000nm) and SWIR (900-2500nm) space-qualified imagers are hot commodities. This is an area that Headwall Great Ocean Roaddeveloped over the last five years with its own space-qualified sensor payloads.  There was also strong focus from attendees on how satellite collaboration could be established among the world’s most notable remote sensing programs.  Japan’s ALOS-3 (2016 launch?), European ENMAP (2017 launch?), and NASA HYSPIRI mission (2023 launch?) represent three of several.

Even with all the activity at IGARSS, Headwall’s remote sensing team led by Kevin Didona, Principal Engineer at Headwall, also took some hyperspectral scans of rock wall formations at some very scenic places along the Great Ocean Road on the South Coast of Australia.

As Headwall has developed extensive experience in the application of hyperspectral sensors specifically designed for UAVs, please drop us a line or give is a call if we can provide some information to meet the objectives of your remote sensing research.

Email us at [email protected]

Visit us at www.HeadwallPhotonics.com

Or call us at Tel: +1 978 353 4003


Tags: hyperspectral imaging, hyperspectral, Headwall Photonics, Airborne, Remote Sensing, Sensors, Micro Hyperspec, UAS, SWIR, Sensing, VNIR, Satellites, UAV

Hyperspectral and Remote Sensing the focus at EARSeL!

Posted by Christopher Van Veen on Wed, Apr 03, 2013

Headwall's exhibition schedule kicks into high gear this month. First up is our appearance at the 8th Imaging Spectrometry Workshop, sponsored by The European Association of Remote Sensing Laboratories (EARSeL). This event gives visitors the opportunity to understand how hyperspectral imaging can be a valuable scientific tool for the research community. Precision agriculture, mining & minerals, petroleum pipeline surveillance, and disaster mitigation are just a few application areas and more are uncovered all the time as the technology becomes more affordable and easier to use.

EARSeL blog photoHeadwall is seeing a meteoric rise in the use of small and light UAVs for remote sensing activities. SkyJib (from Droidworx) and the Mk II by Winehawk Labs are two such examples, and you’ll see both at EARSeL. The more nimble these hand-launched airframes get, the smaller and lighter the sensors themselves need to be. Headwall’s collaborative engineering approach gives customers a fast path to success with lightweight solutions that also include integrated application software and a GPS/INS. The beauty of Headwall’s Micro Hyperspec sensor is that it is purpose-engineered for flight. Besides being rugged, it also provides outstanding spatial and spectral resolution in the NIR (900nm-1700nm) and VNIR (380nm-1000nm) ranges while also having a very wide field of view. A wide field-of-view means a more efficient the flight path. In other words, the UAVs can cover more territory by collecting precise spectral detail not only directly below but also off to the sides.

While small, hand-launched UAVs are perfect for a wide range of scientific exploration activities, fixed-wing aircraft ranging from the Cessna to the Twin Otter are also used as a platform for hyperspectral sensors. Headwall’s High-Efficiency Hyperspec sensor covers the NIR (900nm - 1700nm) and SWIR   (950nm - 2500nm) spectral ranges. Aberration-corrected and completely athermalized, it provides the highest optical performance and diffraction efficiency of greater than 90%. We’ll be showing this at EARSeL also.

Later in April…beginning on the 3oth actually…Headwall will be at the Defense, Security + Sensing show in Baltimore. We’ll be in Booth 1830 at the Baltimore Convention Center for DSS, which is quickly becoming the go-to show for all things related to surveillance and reconnaissance. While the interest here is largely airborne, visitors also want to know about ground-based and hand-held hyperspectral sensors. Headwall’s flagship hand-held sensor is Hyperspec RECON, which won the R&D100 Award in 2012. This portable instrument covers the VNIR (380nm-1000 nm) spectral range and can render a 6-inch sq. hyperspectral scene at a distance of over a kilometer. Best of all, it’s easy to use and can be ‘tuned’ by loading spectral libraries via an integrated SD slot. Hyperspec RECON represents a very flexible reconnaissance platform that can also be used in a stationary manner (mounted to a mast or a vehicle, for example).

While Hyperspec RECON and its handheld ingenuity is a groundbreaking achievement, many applications need instruments that can either point-and-stare’ or ‘pan-and-tilt.’ Headwall has sensors for both types of deployment that exhibit the very same aberration-corrected concentric imaging performance as their airborne counterparts. Since hyperspectral imaging depends on movement to occur, the instruments are motorized and fully engineered for the tasks they are challenged with.

Headwall will be at several exhibitions and conferences throughout 2013 aside from the two described here. These events will serve as excellent venues as we come out with new products and enhanced versions of existing ones.

 


 

Tags: hyperspectral imaging, hyperspectral, Headwall Photonics, Airborne, DSS, Remote Sensing, Sensors, Micro Hyperspec, Sensing, UAV, ALAVA Ingenieros