Radiometer Pool
Contact Persons
Dr. Daniel Schläpfer |
Keywords
Bidirectional Effects, Goniometry, Spectral Radiometry, BRDF, Laboratory
Abstract
The Radiometer Pool contains of different instruments for measuring the radiance, irradiance and transmittance. There are also two Sun Photometers (Reagan Solar Radiometer and YES MFR-7), which are used for atmospheric and solar irradiance measurements. The instruments are:
- RTS-3ZC Integrating Sphere
- ASD FieldSpec-3
- ASD FieldSpec Pro FR
- GER 1500
- GER 3700
- Reagan Solar Radiometer
- YES MFR-7
Instruments
RTS-3ZC Integrating Sphere
Parameter | Description |
Manufacturer | Analytical Spectral Devices Inc., Boulder (CO) USA |
Spectroradiometer characteristics | refer to used instrument * |
Interior diameter | 7.62 cm |
Interior material | Zenith diffuse reflectance PTFE |
Sphere geometry | 13°/D specular excluded reflectance |
Measured quantities | Specular included reflectance, Specular excluded reflectance, Transmittance |
Illumination source | Collimated tungsten light source with adjustable baffle; 10W, 6V |
Size, Weight | approx. 10 x 10 x 10cm, 1.5 kg |
Ports | 6 ports to accept supplied accessories (sample holders, light source, fiber optic adapter, light trap, port plugs) |
Reference standards | 2 nominal 99% Zenith reference standards (calibrated, uncalibrated) |
Battery Life / Voltage | 3 h / 12 V * |
Digitization | 16 Bit * |
Wavelength Accuracy / Repeatability | ±1 nm / ±0.1 nm * |
Spectrum Averaging | Yes, user defined * |
Dark Current Correction | Based on user defined measurement setup |
Operating Environment | 10 - 90 % Rel. Humidity, -10° to 50° C * |
* ASD FieldSpec-3
Purpose:
The RTS-3ZC integrating sphere collects optical radiation which has been reflected from or transmitted through a sample for the purpose of measuring reflectance or transmittance. The sphere is designed for use with an ASD FieldSpec spectroradiometer. The RTS-3ZC integrating sphere features a 13º/D geometry to allow near normal incidence at 13º and diffuse collection via the instrument’s fiber optic bundle. The interior of the integrating sphere is made of Zenith diffuse polymer material, a solid, machined form of PTFE. Zenith® is a highly reflective (>95%) and lambertian reflector over the broad spectral range of 350–2500 nm, which provides maximum efficiency and optical performance. A specially designed collimated tungsten light source, included with the sphere, delivers close to solar irradiance levels at the sample.
ASD FieldSpec-3
Parameter | Description |
Manufacturer | Analytical Spectral Devices Inc., Boulder (CO) USA |
Spectral Range | 350 - 2500 nm |
Channels | continuous |
Linear Arrays | (1) 512 Si, 350-1000nm |
Bandwidth | 1.4 nm (350 - 1050nm) |
Scan Time | 100 ms |
Field of View | Dependent on fore-optic |
Size, Weight | 35 x 29 x 13 cm / 5.2 kg |
Battery Life / Voltage | 3 h / 12 V |
Digitization | 16 Bit |
Wavelength Accuracy / Repeatability | ±1 nm / ±0.1 nm |
Spectrum Averaging | Yes, user defined |
Dark Current Correction | Automatic, based on user defined measurement prior to data take |
Operating Environment | 10 - 90 % Rel. Humidity, -10° to 50° C |
Control unit | Wireless remote control up to 150 feet away |
Purpose:
Field spectrometry is the quantitative measurement of radiance, irradiance or transmittance in the field. Portable, battery powered spectroradiometer, such as the ASD FieldSpec-3, are typically used to make these measurements. The instrument is equipped with a silicon photodiode array and two fast scanning thermoelectrically cooled spectrometers capable of data collection from 350 - 2500nm. One of the primary uses is the collection of field data for analysis of remotely sensed images of the earth's surface. The ASD FieldSpec-3 is operated using a wireless remote control reaching up to 150 feet. Two such instruments of the same type are positioned on the zenith arc of the goniometer system (dual-view FIGOS) in order to perform dual-view spectrodirectional measurements.
ASD FieldSpec Pro Fr
Parameter | Description |
Manufacturer | Analytical Spectral Devices Inc., Boulder (CO) USA |
Spectral Range | 350 - 2500 nm |
Channels | continuous |
Linear Arrays | (1) 512 Si, 350-1000nm |
Bandwidth | 1.4 nm (350 - 1050nm) |
Scan Time | 100 ms |
Field of View | Dependent on fore-optic |
Size, Weight | 35 x 29 x 13 cm / 7.2 kg |
Battery Life / Voltage | 3 h / 12 V |
Digitization | 16 Bit |
Wavelength Accuracy / Repeatability | ± 1 nm / ± 0.1 nm |
Spectrum Averaging | Yes, user defined |
Dark Current Correction | Automatic, based on user defined measurement prior to data take |
Operating Environment | 10 - 90 % Rel. Humidity, -10° to 50° C |
Purpose:
Field spectrometry is the quantitative measurement of radiance, irradiance or transmittance in the field. Portable, battery powered spectroradiometer, such as the ASD FieldSpec Pro Fr, are typically used to make these measurements. Whereas "Fr" means Full Range devices, which is employing a silicon photodiode array and two fast scanning thermoelectrically cooled spectrometers capable of data collection from 350 - 2500nm. One of the primary uses is the collection of field data for analysis of remotely sensed images of the earth's surface.
GER 1500
Parameter | Description |
Manufacturer | Spectra Vista Corp.(NY) USA, Serial number: 2036 & 2037 |
Spectral Range | 350 - 1050 nm |
Channels | 512 |
Linear Arrays | (1) 512 Si |
Bandwidth | 1.5 nm |
Scan Time | ≥ 5 ms |
Field of View | Dependent on fore-optic |
Size, Weight | 83 x 152 x 197 mm, 1.8 kg |
Battery Life / Voltage | 4 h / 6 V |
Digitization | 16 Bit |
Wavelength Accuracy / Repeatability | ± 1 nm/ ± 0.1 nm |
Spectrum Averaging | Selectable |
Dark Current Correction | Automatic |
Operating Environment | 10 - 90 % Rel. Humidity, -10° to 50° C |
Purpose:
The GER 1500 is supplied in a sturdy, weather-tight field case, with batteries, battery charger and cables. System components can also be easily carried in a backpack. Generated data are displayed on screen in real-time for immediate interpretation and evaluation. Data is stored in ASCII format for transfer to other software programs. Additionally, the GER 1500 spectroradiometer can be operated with the sub-notebook computer which provides real-time display and hard disk t ransfer. By using the two different modes of operation, the operator can confirm the data integrity while maximizing collection efficiency.
GER 3700
Parameter | Description |
Manufacturer | Spectra Vista Corp. (NY) USA |
Spectral Range | 300-2500 nm |
Channels | 704 |
Linear Arrays | (1) 512 Si |
Bandwidth | 1.5 nm (300-1050 nm) |
Scan Time | ≥ 50 ms |
Field of View | Dependent on fore-optic |
Size, Weight | 28.6 x 30.5 x 11.4 cm, 6.4 kg |
Battery Life / Voltage | 4 h / 12 V (6.8 Ah) |
Digitization | 16 Bit |
Wavelength Accuracy / Repeatability | ± 1 nm /± 0.1 nm |
Spectrum Averaging | Selectable |
Dark Current Correction | Automatic |
Operating Environment | 10 - 90 % Rel. Humidity, -10° to 50° C |
Purpose:
The GER 3700 is a single FOV spectroradiometer operating in the visible, near and short-wavelength-infrared. The optical head can be mounted on a variety of platforms. The major use is a tripod for field reflectance measurements and on the FIGOS / LAGOS. On the tripod as well as on the FIGOS /LAGOS a laptop computer controlling the instrument and the batteries are kept in a specially desinged holder.(Rest analog "GER 1500, Purpose")
Reagan Solar Radiometer
Parameter | Description |
Manufacturer | University of Arizona, Tucson (Az) USA |
Spectral Range | 382 - 1033 nm |
Channels | 10, parallel coalligned FOV tube |
Bandwidth | 10 nm |
Scan Time | n.a. |
Field of View | 3.2° |
Size, Weight (only Head) | 28.3 cm x 21.6 cm x 16.5 cm, 7.7 kg |
Battery Life / Voltage | 24 h / 12 V |
Digitization | 16 Bit |
Automatic sun tracking | YES, ± 17° tracking capability |
Data logger | 2 - 3 days of data acquisition |
Operating Environment | Temperature stability at 43° ± 0.5° C by heater control |
Purpose:
The Reagan sun-photometer is a sun-looking ground based instrument for atmospheric measurements. In Remote Sensing applications it is mainly used for atmospheric measurements in order to improve atmospheric correction algorithms. It therefore is used as atmospheric ground truthing instrument in field campaigns. It's continous monitoring of the state of the atmosphere allows furthermore conclusions on atmospheric stability and daily developments of aerosol contents. Cross calibration with other instruments will help to evaluate their performance.
VES MFR-7
Parameter | Description |
Manufacturer | Yankee Environmental Systems Inc, Turners Falls (MA) USA |
Spectral Range | 415 - 940 nm |
Channels | 415, 500, 615, 673, 870, and 940 nm plus a Si-based broadband channel |
Bandwidth | 10 nm FWHM |
Sampling Rate | Up to 4 samples / min |
Size, Weight | 38 x 29 x 20 cm, ?? kg |
Power Requirement | 115 /230 Vac, 50 / 60 Hz, 50 Watts (max) or |
Digitization | 13 Bit ?? |
Cosine Response | Better than 5 % for 0-80° zenith angle |
Spectrum Averaging | ?? |
Dark Current Correction | ?? |
Operating Environment | - 30° to 50° C |
Purpose:
The Multi-Filter Rotating Shadowband Radiometer (MFR-7) is a field instrument that simultaneously measures global, diffuse, and direct normal components of spectral solar irradiance. The MFR-7 uses independent interference filter-photodiode combinations, mounted in a temperature-controlled enclosure, to detect spectral irradiance at six wavelengths and in one broadband channel. The choice of wavelengths allows the reconstruction of the incident solar spectral irradiance and the determination of optical depths of water vapor, aerosols, and ozone. The MFR-7 consists of two basic components: a Detector Assembly and an Electronics Enclosure.