ASD Field Spectrometer

Description

The Analytical Spectral Devices FieldSpec Pro (Full Range) is a high performance single-beam field spectroradiometer measuring over the visible to short-wave infrared wavelength range. The instrument is very rapid scanning, acquiring single spectra in milliseconds via its fibre-optic input. The spectrometer unit is controlled by a sub- notebook computer, and can be fitted with a range of field- stops, sighting devices, pistol grips and fibre-optic extension cables to enhance the functionality of the instrument for a wide range of remote sensing studies.

Principle of Measurement and Specification

At less than 8 kg, FieldSpec FR is a truly portable field spectroradiometer. With a 0.35-2.5 µm spectral range and 10 nm spectral resolution, you get the data you need to analyze remotely sensed images collected by both present and future sensors. Its speed of 10 spectra per second provides versatility not available in other instruments. Configure FieldSpec to rapidly collect many spectra or select the scan averaging mode and collect fewer, high signal-to-noise, spectra. Choose from a variety of available fore-optics to customize FieldSpec to your application. The FieldSpec translates measurements into instant feedback: continuous real-time display on the notebook computer's LCD screen. The FieldSpec's intuitive graphical interface allows you to easily configure and control the instrument to make the measurements you need. Also available are UV/VNIR (350-1050 nm) and SWIR (1000 to 2500 nm) versions of the FieldSpec, and Dual Spectrometer UV/VNIR for oceanographic applications. Call us to discuss your application. And experiment with ideas, not equipment.

The FieldSpec portable spectroradiometer for solar reflectance, radiance and irradiance measurements is available in six different models: FieldSpec UV/VNIR (350 - 1050 nm), FieldSpec NIR (1000 - 2500 nm), FieldSpec FR (350 - 2500 nm), FieldSpec UV/VNIR/CCD (350 - 1030 nm), FieldSpec Dual UV/VNIR (350 - 1050 nm), and the FieldSpec OS (300 - 1100 nm). All of these FieldSpec models come complete with the following standard features:

Fiber optic cable input, 1.2 meters in length with 25° full angle cone of acceptance field-of-view.
Built-in sub notebook computer with AC/DC adapter-charger, battery, hard disk drive, and floppy disk drive.
Spectrometer Computer Interface: Bi-Directional Parallel Port.
Spectrometer battery pack with pack battery belt and harness.
User interface software with pull-down menus and easy-to-use screens.
Software for data acquisition and storage of Raw DN, reflectance, radiance and irradiance measurements. Real-time calculations of reflectance.*
Real-time display of Raw DN or reflectance spectra.*
Real-time spectrum averaging for up to 31,800 spectra for increased signal-to-noise.
Post processing file structure for radiance and irradiance calculations and display.**
16 bit encoding. 12 bit for CCD units.
Offset correction with built-in shutter and automatic offset subtraction.
Automatic time stamp in spectral file headers and automatic spectral file extension assignments.
Pistol grip that can be mounted on a tripod.
Users manual 1 year limited warranty

* Except FieldSpec Dual units, which feature post processing calculation and display of reflectance.
**Optional ASD laboratory radiometric calibrations or user radiometric calibrations required.

The FieldSpec FR spectroradiometer combines three spectrometers to cover the entire solar reflected portion of the spectrum, 350 to 2500 nm. A photo diode array spectrometer is used to cover the 350 to 1000 nm spectral range (UV/VNIR), while two fast scanning spectrometers provide coverage for the wavelength range from 1000 to 2500 nm (SWIR 1 and 2). The UV/VNIR detector is a 512 element low dark current NMOS photo diode array operated at ambient temperature. Single element InGaAs detectors, thermoelectrically cooled, are used in the two SWIR spectrometers. All three spectrometers utilize concave holographic grating as the wavelength dispersing elements.

The light input to the FieldSpec FR's spectrometers is through a fiber optic bundle, 1.2 meters in length. While the use of longer fiber optic cables is possible, the performance will be degraded at wavelengths beyond 2200 nm. The optical fibers carrying the light to the spectrometers are packaged as a single bundle exterior to the instrument. Once inside the instrument, the fibers are separated into three bundles which then deliver the collected light to each of the three spectrometers. The common probe end has a 25° field-of-view and may be fed through the included tripod mountable pistol grip. Optional fore optics attach to the pistol grip. Optional fore optics include: cosine receptor for irradiance measurements, and field of view fore optics for reflectance and radiance measurements.

The instrument is controlled, and data displayed and stored using a sub-notebook computer integral to the instrument. Spectra from each spectrometer are joined by software and electronics forming continuous spectra from 350 - 2500 nm. Rechargeable NiCad batteries for portable operation are contained in a waist belt.