Link to HySpex Overview Page
Contact (HyperSpectral)
Hyperspectral Products
Hyperspectral Cameras
The HySpex(TM) line of hyperspectral cameras are a result of the knowledge
and experience accumulated through more than a decade (starting in
1995) of research activities in the field of imaging spectroscopy at
NEO.
The spectrometer design is flexible, and the specifications and performance can be tailored to the user's requirements and needs. Four different versions of the spectrometer are currently available with the following main specifications:
|
Module |
VNIR-640 |
VNIR-1600 |
SWIR-320i |
SWIR-320m |
|
Detector |
Si CCD
640*480 |
Si CCD 1600*1200 |
InGaAs
320*256 |
MCT (HgCdTe)
320*256 |
|
Spectral range |
0.4-1µm |
0.4-1µm |
1-1.7µm |
1.3-2.5µm |
|
Spatial pixels |
640 |
1600 |
320 |
320 |
|
FOV across track |
18.4°
|
17°
|
14°
|
14°
|
|
Pixel FOV across track/ along track |
~0.5mrad/ 0.5mrad |
~0.185mrad/ 0.37mrad |
0.75mrad/ 0.75mrad |
~0.75mrad/
0.75mrad |
|
Spectral sampling |
5nm/10nm |
3.7nm |
5nm |
5nm |
|
# spectral bands |
128/64 |
160 |
160 |
256 |
|
Digitization |
12bit |
12bit |
12bit |
14bit |
|
Frame rate to HD |
500/850fps |
120fps |
350fps |
100fps |
Due to continuous development, the specifications are subject to changes.
The HySpex camera is a line imager, meaning that all spectra across a
spatial line in the image are recorded simultaneously. Some form of
scanning, depending on the application, is used to record sequential
lines, building up a hyperspectral image with two spatial
dimensions. The scanning can be done by either camera movement
(e.g. aircraft) or movement of the scene (e.g. conveyer belt).
All the HySpex cameras perform very well in terms of the
characteristics commonly used to describe the quality of hyperspectral
line imagers:
- Spatial resolution
- Spectral resolution
- Spectral keystone
- Smile effect
- Alignment of sensor, slit and dispersive element
- Responsivity
- Stray light
- Second order suppression
- Sensor characteristics
- Radiometric accuracy
All the spectrometer modules are based on the same general
architecture, with lenses and gratings separately optimized for the
different modules.
The fore-optics and collimating optics is based on a special
configuration of two aspherical mirrors. This unique design avoids
introduction of spherical and chromatic aberrations before the
grating, and at the same time minimizes stray light. The transmission
grating is polarization independent and has been chosen among a large
selection tested gratings. The lens system for final focus is
optimized for minimization and equalization of the point spread
function across the FOV and spectral range. Additionally, spectral
keystone and smile effects are only a small fraction of a pixel. The
optical performance is nearly diffraction limited, as can be seen on
the figure. A detailed tolerance analysis has been performed, ensuring
that the tolerances of the optical and mechanical parts are specified
sufficiently tight in order to make sure that the real performance is
close to the simulated performance. The spectrometer modules are
extremely rugged with no moving parts.
A detailed experimental characterization is performed for each camera
to verify that the performance is according to the specifications. The
results of this characterization are documented in a detailed test
report which follows each instrument. The end user thus has full
access to all relevant performance characteristics.
All the cameras are also spectrally and radiometrically
calibrated. The basic output of the systems is thus a radiance
spectrum in W/(m^2 nm sr) for each pixel in the image.
Dedicated image processing algorithms can be implemented to provide an
output tailored for a specific application (anomaly detection images,
thematic maps, etc), possibly in real time for e.g. on-line
applications.
Airborne systems
NEO can supply airborne hyperspectral camera systems based on all the
above mentioned standard hyperspectral cameras, either separately or
in combination. A delivery of an airborne system can include a
navigation system (IMU and GPS) to allow direct georeferencing of the
images based on continuous logging of the position and attitude data
for the camera. Software for post processing of the navigational data
can be included. The systems can also be designed to interface with
the customers existing navigational hardware.
This picture shows the Piper aircrafrt used for airborne HySpex
operations in Norway in 2005-2006.
This picture shows the HySpex system (VNIR and SWIR)
mounted in the airplane.
Ground based systems
All the HySpex hyperspectral scanners can be easily operated on a
rotation stage or a translation stage using a laptop computer, making
them ideal for acquiring hyperspectral images of static scenes, either
in the field or in a laboratory setting. Control of
rotation/translation scanning is implemented in the camera software
ensuring that the camera movement is automatically synchronized with
the camera frame rate.
This picture shows the HySpex VNIR-1600 camera integrated with a
linear translation stage.
This picture shows the HySpex VNIR-1600 camera integrated with a
rotation stage.
Industrial systems
Due to their extremely high speeds, the HySpex cameras are well suited
for a wide variety of industrial applications such as material
inspection or quality control (see applications). In a typical
industrial application, the camera is mounted above a conveyer belt
using the belt motion for scanning. By training/calibrating the
hyperspectral inspection system for a specific application, an online
process can be continuously monitored and controlled based on the
detailed spectral information in each pixel. Due to advances in image
processing algorithms and hardware, it is now possible to do online
hyperspectral quality control in real time. For this type of
applications, we can either supply just the hyperspectral camera
itself (in the cases where the end user is capable of implementing it
in the process) or we can team up with the end user to develop
customized solutions solving a specific problem. Possible customers
include manufacturers of industrial sorting/processing machines as
well as end users in industry.
Custom Developments
If your application requirements cannot be met by the standard HySpex
configurations, you are welcome to contact us to discuss your
specifications. The HySpex design can be readily modified to suit your
application. To ensure that the end user gets what he/she really
wants, NEO can assist by acquiring a test/demo data set for your
application to provide a starting point for a trade-off analysis which
could lead to the definition of a unique set of specifications for
your specific application. So do not hesitate to contact us even if
our standard configurations do not match your application
requirements.
Hyperspectral Services
In addition to our of standard line of high performance hyperspectral
cameras, NEO can also provide the following services in the field of
hyperspectral imaging:
- Custom developments of hyperspectralcameras/systems
- Acquisition of hyperspectral lab or field data (in
our lab at the customer's location)
- Acquisition of airborne hyperspectral data
- Processing (e.g. geocoding) of airborne hyperspectral data
- General image processing
- Calibration services
- Participation in R&D projects
Please contact us to discuss your needs or requirements for
hyperspectral instruments or services.
Applications of Hyperspectral Imaging
Hyperspectral imaging can be an extremely powerful tool in a wide
variety of applications, due to the ability of producing scientific
quality spectroscopic data with high spatial resolution at high
speeds. Some of the main application areas are listed below. NEO's
HySpex series of hyperspectral cameras can be employed in all of these
application areas and many more.
Airborne remote sensing
Airborne hyperspectral data is useful in a wide variety of
applications where it is of interest to classify or identify
properties of objects on the ground with high precision and
resolution. Such applications include:
- Defense and security: Military target detection/identification, surveillance, search and rescue.
- Forestry: Forest mapping/classification, forest health monitoring
- Agriculture: Precision farming, growth monitoring, yield prediction, governmental monitoring
- Geology: Mineral mapping, environmental impact around mine areas
- Environmental monitoring: Algae blooming, oil spill detection, land and sea monitoring
- Government: Land use monitoring, urban planning/management
This figure shows a vegetation (grass) radiance spectrum. ("ASI"
is the former name of the HySpex range of hyper spectral cameras. )
This picture shows airborne HySpex data from a precision farming
application. [Planteforsk]
Industrial
Due to the extremely high speeds achievable with the HySpex camera
series, these systems can be used in many industrial/machine vision
applications for online process control, quality control,
classification and sorting (sizing, uniformity, colour, foreign object
detection, subsurface composition). Examples of product/application
areas where hyperspectral data can provide valuable information are:
- Food industry
- Paper industry
- Color printing
- Textile industry
- Mineral sorting
- Pharmaceuticals
- Waste/recycling
- Chemical processes
- Chemometrics
- NIR-spectroscopy
This picture shows the HySpex VNIR-640 system mounted in a set-up for
detection of parasites in fish filet, a food quality
application. [Fiskeriforskning]
This picture illustrates food quality sorting on an apple based on
HySpex data. (Left: RGB image. Right: Principal Components Analysis
classification image.)
Ground based field scanning
By mounting the hyperspectral camera on a rotation stage which is
synchronized with the camera and operating it from a laptop, the
system is easily deployable for field measurements in all the above
mentioned application fields. This provides the opportunity to acquire
hyperspectral images of objects (e.g. plant leaves or rock samples) in
the field with very high spatial resolution. Security and surveillance
is another typical applications for this kind of systems.
Geological application: HySpex field measurements of rocks and cliffs,
image shows artificial RGB image with red channel at 730nm (red parts
are mainly plants containing chlorophyll).
HySpex camera mounted on a tripod (left).
Laboratory:Biology/Chemistry/Medical
Hyperspectral imaging can also be employed in many typical laboratory
applications, where a single point spectrometer is not sufficient and
spatial information is required. Some of these application areas are
listed below.
- Tissue sample analysis
- Blood analysis
- Chemical samples
- Diagnostics (e.g. skin diseases, cancer)
- Skin characterization
- Cosmetics
- Fluorescence imaging spectroscopy
This image shows the bilirubin levels in bruised skin after 66
hours (left) and 180 hours (right) based on analysis of HySpex data.
[Lise L. Randeberg, NTNU]
Survey of coastal areas (Airborne)
The below image illustrates the use of HySpex cameras for
survey of coastal areas. Image from Normandie, France.
Courtesy Actimar, France, www.actimar.fr
For more information see the following link:
Airborne hyperspectral survey over the coastal zone of Normandie (Actimar, France)
Geology, mineralogy
Hyperspectral cameras can be used for resource mapping, geological
surveys, sorting within the mining industry, and generally within
mineralogy etc.
The figure below shows the kaolinite spectrum acquired with our
HySpex SWIR camera. The characteristic kaolinite spectrum is
clearly visible.
Reflectance spectrum of kaolinite acquired with the HySpex
SWIR-320m camera. The spectrum is shown from around 1300 nm to
2500 nm.
Other applications
Below is a list of applications which do not belong in any of the categories above. Many more potential applications are foreseeable in the future.
- Forensics
- Counterfeit detection
- Art work scanning
- Colour measurements
- Print control
These pictures illustrate how it is possible to detect a plastic plant
among real plants using HySpex data. Top: Image shown with "normal"
colours (RGB). Middle: Using the IR information which is displayed in
red (red channel chosen above chlorophyll red edge at ~700nm). Bottom:
Classification image where the real plants are green, the fake plant
is red and the pottery is blue. As can be seen, a plastic plant can
easily be detected among real plants using a HySpex camera even though
the plastic plants visually look identical to the human eye.
Link to HySpex Overview Page
Contact (HyperSpectral)
HySpex is a Trade Mark of Norsk Elektro Optikk AS.