Service & Repair
SVC stands behind all of its instruments and accessories. These Legacy Products are no longer in production, but are fully supported for calibration and repair based on component availability. Contact us for support questions and more information.
- GER3700 – NOT SERVICEABLE
- GER2600 – NOT SERVICEABLE
All remote sensing sensors receive electromagnetic radiation. The sensor then converts the radiation into an electronic signal. However, an electronic signal is meaningless unless it is related to a physical unit. Simply speaking, calibration of a remote sensing sensor is the procedure to establish the conversion parameter that translates output of the sensor to a measurable physical unit.
For example, the output reading of a spectroradiometer has the units of radiance at a specifically measured wavelength. The spectroradiometer must be properly calibrated in radiance, irradiance, and wavelength .
In the case of an airborne imaging spectrometer, the sensor measures not only the radiance but also the spatial aspects of the image. Calibration requires characterization of the spatial resolving and positioning capability of the instrument. Other calibrations may be required due to specific optical system used. (e.g. whisk broom scanning, push broom scanning, single-facet scanning, or multi-facet scanning optics, etc.)
Spectra Vista Corporation maintains a fully equipped optical laboratory for complete calibration and characterization of all Spectra Vista or GER produced sensors.
All field spectrometers are calibrated to their published specification. Equipment most often used in this calibration include: fully automated monochrometer, spectral line source (e.g. Argon, Mercury, Krypton, etc.), narrow band filters and other known band targets.
Proprietary software is used to generate calibration parameters from all calibration measurements.
All field portable spectrometers are calibrated by NIST traceable, automated integrating sphere calibration standard (Optronic Laboratories, Inc., OL Series 462).
Field of View calibrations
The optical field of view for a field portable spectrometer determines what is being measured. All field spectrometers are calibrated to give a clearly defined field of view.
On-site training courses are available for new users in field spectroscopy and light measurement. The interactive courses aim to give a greater understanding of spectral light measurements, instrumentation and accessories, best practice in field spectroscopy and reflectance data analysis. The modules below list the topics covered in the course. The content and duration of the training course can be tailored to suit your experience level, area of interest and extent of a practical field trial.
Primer Part 1 – Introduction, Instrument Communication & Operation
- Introduction to reflectance measurements, field spectroscopy and spectral image cubes
- SVC application installation, laptop and PDA communication and control
- Laser alignment, field of view plots, built-in target camera
- Reflectance panels
- Optional accessories – Fiber optic light guides, LC-RP reflectance probe, DC-RT sphere, irradiance integrating sphere, WEDI interface & detectors
Primer Part 2 – Spectral Reflectance Measurements
- Laboratory testing
- Spectroradiometer & reflectance panel care and calibration
- Data records & log sheets
- SVC iSeries configurations – PDA, Laptop & Stand Alone modes
- Data processing
- Data download
Radiometry & Calibration
- Jargon, Irradiance, Radiance, Exitance, Diffuse & Spectral
- Reflectance via radiometry & via reference panel
- Brief introduction to BRDF & BRF
- Calibration – spectroradiometer wavelength, radiance and irradiance
- Calibration – diffuse reflectance panels
- Measurement uncertainties
- Getting to Know Your Spectroradiometer
- Monochromators & spectrometers
- Diffraction gratings & detector arrays
- Spectral resolution, sampling & bandwidth
- Alternative optical layouts
- Field of view
- Cosine correction & Lambertian reflectance panels
Introduction to Field Spectroscopy
- What is field spectroscopy and what can it be used for?
- Multi-spectral & hyper-spectral
- Measurement geometries
- Examples in field spectroscopy
- Ground targets & vicarious sites
- Introduction to atmospheric correction of multiband and hyper-spectral images
- Minimum ½ day depending on travel time
- Research aims
- Survey, sampling design – point, plot & transact
- Preparation – personnel, planning & equipment
- Replication & pseudo-replication
- Ambient lighting conditions, weather, atmosphere and seasonal restrictions
- Field measurements with tripod (or monopod) – FOV & alignment
- Field measurements – stand alone
Spectral Libraries in ENVI:
- Creating and importing spectral data & libraries in ENVI
- Resampling spectral libraries
- Use in spectral matching algorithms
- Use in spectral linear unmixing algorithms