Ultraviolet and Visible Wavelength Profiling Radiometers

Compact Optical Profiling Systems (C-OPS)

BSIs newest, high-performance freefall aquatic profiler, the C-OPS, is a radiometer system for determining apparent optical properties in shallow-water aquatic systems. It consists of two radiometers: one measuring in-water upwelling radiance, and the other either downward irradiance or upward irradiance. Both radiometers are equipped with up to 19 wavebands and are mounted in a free-fall backplane that can be optimized for either slow descent rates for work in very shallow waters, or faster descent rates for observations in the deeper systems up to 125 m.

• Complete, integrated system for measuring radiometric variables in optically complex waters; ideal for aquatic profiling in shallow water
• Submersible instruments are optimized for measuring vertical profiles of radiance and irradiance at depth; surface reference optimized for use in air
• Rapid sampling (15 Hz); slow, freefall descent; adjustable buoyancy; it is hand deployed; and has a 125 m maximum depth
• Very wide dynamic range (10+ decades); based on microradiometer technology (the system does not saturate at natural light levels even when the radiance aperture is pointed directly at the solar disk)
• Up to 19 discrete microradiometer wavebands radiance and irradiance; covering the UV-B 305 to 865 nm in the SWIR spectral range
• Radiance Field-of-view: 7° half-angle in water (compliant with SeaWiFS specification)
• Irradiance cosine departure of less than 2% from 0–65° and less than 10% from 65–85°
• Accessories include above-water reference irradiance sensors to measure incident irradiance, the “BioSHADE” shadowband assembly for making diffuse measurements, and the “BioGPS” for providing position and time.

XTRA Reflectance Radiometers (XRR)

XRL being deployed in Mission Bay, CABiospherical Instruments Inc (BSI) has released the newest member of the Expandable Technology for Radiometric Applications (XTRA) class of high performance field instruments called the XTRA Reflectance Radiometers (XRR). The XRR is an economically priced multiwavelength radiometer for determining apparent optical properties in aquatic systems. Belonging to the instrument class that also includes the Compact Optical Profiling system (C-OPS), among other microradiometer-based instruments, the XRR is designed to fill the niche that was occupied by the PRR-600 and PRR-2600 as well as the PRR-800; they are very similar in shape to the PRR-600/PRR-2600 instruments, but are smaller in diameter, weigh less, and have greatly improved performance.

 The distinguishing features of XRR radiometers are: 

• Single housing, integrated system for measuring radiometric variables in optically complex waters; ideal for aquatic profiling in shallow water
• Submersible instruments are optimized for measuring vertical profiles of radiance and irradiance at depth; surface reference optimized for use in air
• Rapid sampling (15 Hz); slow, freefall descent; adjustable buoyancy; it is hand deployed; and has a 125 m maximum depth
• Very wide dynamic range (10+ decades); based on microradiometer technology (the system does not saturate at natural light levels even when the radiance aperture is pointed directly at the solar disk)
• Up to 10 discrete microradiometer wavebands radiance and irradiance; covering the UV-B 305 to 865 nm in the SWIR spectral range
• Radiance Field-of-view: 7° half-angle in water (compliant with SeaWiFS specification)
• Irradiance cosine departure of less than 2% from 0–65° and less than 10% from 65–85°
• Shares all accessories (except C-PrOPS) that are available for C-OPS radiometers.

XRRs are available in two measurement geometries: XRL and XRE. The XRL, the most common configuration, features 10 optical-filter microradiometer >wavebands (selected from 29 different optical filter wavelengths) of in-water downward  irradiance (E_d) and 10 wavebands of in-water upwelling radiance (L_u). The XRE nominally uses 10 wavebands of downward irradiance (E_d) and 10 wavebands of upward irradiance (E_u). XRRs also take advantage of a new free-fall flotation collar called the “X-SLOWS,” which affords excellent near-surface sampling in an instrument with a traditional "rocket-shaped" design.  XRRs use the same microradiometer detector technology as C-OPS, and thus has the same outstanding radiometric performance specifications as C-OPS. Microradiometers also mean that the XRR can use all of  the same software, surface solar reference, and all of the C-OPS cables and accessories such as the BioSHADE and BioGPS.  

4 Channel Profiling Radiometers for UV and Visible

Biospherical Instruments’ BIC family of radiometers are scaled-down version of our widely used PUV/GUV and PRR instrument systems. The standard BIC measures downwelling (cosine) irradiance in three monochromatic wavebands, as well as PAR (400–700 nm). Wavelengths are available ranging from 305 nm in the UV-B, to 875 nm in the near infrared. BIC photodetectors share a common Teflon collector for maximum accuracy over time. BICs are available in submersible and surface reference versions. A submersible BIC fitted with optional temperature and pressure transducers may be combined with a matching surface reference BIC to provide accurate vertical profiles of irradiance down to 100 m. Compact and lightweight, the BIC features a wide dynamic-range (>5 decades) and is suitable for a variety of aquatic research applications. The BIC connects to either a PC workstation or laptop computer (not included) for all data-acquisition duties. Windows-based LoggerLight software is included.

BIR deployed from a small boat

• Measures cosine irradiance in four user-selected UV wavelengths (305, 313, 320, 340, 380, or 395 nm) or 3 wavebands and PAR (400–700 nm)
•  Serial output affords direct connection with a computer or PC-based datalogger
• Suitable for both aquatic profiling and remote field measurements
• Optional sensors for water temperature and depth
• Windows-based data-acquisition software
• 5 decades of dynamic range; up to 2 Hz sampling speed
• Compact design is battery-powered and ideal for hand deployment from a small craft and other vessels