BEST Products

In our designs, we strive for RAISES radiometers.
Reliable, Autonomous, Integrated, Simple, Easy to use, and Sturdy.

150 GHz Dual Polarization, Two Channel Radiometer


The 150 GHz radiometer has two channels in the atmospheric window between the 118 GHz oxygen absorption line and the 183 GHz water vapor absorption line. The channels’ center frequencies are at 150 and 165 GHz. Similar channels are used by various microwave instruments on operational satellites such as AMSU-B, SSM/T-2, SSMIS, and GMI, ATMS, respectively. The measurements of these channels are used mainly for cloud properties and precipitation retrievals.

A mechanical layout of the 150 GHz, dual polarization, two channel radiometer. All dimensions are in millimeters


Channel center frequency (GHz) Bandwidth (MHz) Radiometer sensitivity* (K)
150 3000 0.17
165 3000 0.17

*Radiometer sensitivity is evaluated for 10 ms integration time.


The radiometer antenna has 5° half power beamwidth. The Ortho-Mode Transducer (OMT) divides the incoming electromagnetic waves into two orthogonal linear polarization outputs. Observations in two polarizations are redundant to provide an advantage in data evaluation and analysis. The radiometer has two receivers, one per polarization, Receiver 1 and 2. Each of the receivers has two parts, a and b. The complete radiometer, as shown in Figure 1, consumes less than 1 W of power and its weight is about 100 grams.


183 GHz Dual Polarization, Five Channel Radiometer


The 183 GHz radiometer has five channels on the upper wing of the 183.31 GHz water vapor absorption line. The channels span ~182 to ~198 GHz, covering the absorption line center as well as the atmospheric window. This radiometer’s measurements can be used primarily for retrieval of vertical profile of humidity of the atmosphere and clouds ice parameters. Dual polarization provides redundancy in retrievals and can provide additional information about cloud particles.

All dimensions are in millimeters. The radiometer antenna has 5° half power beamwidth. The complete radiometer consumes less than 1 W of power and its weight is about 150 grams.

Channel center frequency (GHz) Bandwidth (MHz) Radiometer sensitivity* (K)
183.31 1900 0.27
185.21 1900 0.27
188.16 4000 0.19
192.16 4000 0.19
196.16 4000 0.19

*Radiometer sensitivity is evaluated for 10 ms integration time.


A mechanical layout of the 183 GHz, dual polarization radiometer. All dimensions are in millimeters.


The temperature weighting functions for a nadir looking radiometer located above the atmosphere (~20,000 m altitude) for various incident angles and background surfaces.

The temperature weighting functions, shown in Figure 3, indicate the sensitivity of the individual receiver’s channels to various levels of the atmosphere. Simulated observations are from 20km altitude and the nadir view corresponds to 0°. When a radiometer is pointed away from the nadir, the weighting functions’ peaks are sharper and peak higher in the atmosphere.

There is basically no difference in observations between the land and sea surface. This is because the channels are attenuated in the atmosphere and are not sensitive to surface below.

We are planning the development of a similar receiver operating between 90 and 119 GHz for atmospheric temperature profiling.


PRACO
Profiling Radiometer for Atmospheric and Cloud Observation


PRACO
PRACO
PRACO with ruler
PRACO with a ruler

PRACO Description:

PRACO is the world’s smallest microwave radiometer, yet it covers all of the important sounding bands in the microwave spectrum bellow 200 GHz. PRACO is very compact, lightweight and energy efficient radiometer designed for atmospheric observations from an aircraft. It covers four radiometric bands: 22-30 GHz, 51-59 GHz, 118 GHz and 183 GHz, totaling 22 channels. As its name suggests, it is designed mainly for thermodynamic profiling and cloud observation. Retrieved atmospheric variables are:

  • Temperature and water vapor profiles 
  • Integrated water vapor and integrated cloud liquid
  • Water and ice cloud particles discrimination
  • Mean cloud particle size estimate.

The 118 and 183 GHz radiometers have four channels each operating in both vertical and horizontal polarization allowing the discrimination between water and ice cloud particles. Due to the extra wide frequency range within one instrument, from 22 to ~194 GHz, mean cloud particle size can be determined too.


PRACO Operation:

The standard mode of operation for PRACO is a continuous elevation scan. The scanning portion is rotating constantly with speed of 2 rotation per second (or 120 rotations per minute), in a plane perpendicular to the aircraft line of flight. The leading edge of the aircraft wing is located above PRACO attachment plate. PRACO elevation scan samples the whole volume of the air, atmosphere, around the aircraft. Only the aircraft fuselage is blocking the radiometers from a 360° view. This mode of operation allows the radiometers to map completely the atmosphere around the aircraft. 

Each radiometer unit of PRACO is self sustained, thus it can operate in various configurations, depending on user needs. User can choose to use only one radiometer for a particular flight or experiment, or even fly three 51-59 GHz radiometers when needed.


PRACO Aircraft Installation:

PRACO is designed to be mounted under an aircraft wing and can be connected to the mechanical and electrical interface of a standard PMS probe. This means it can be flown on any aircraft where a standard in-situ atmospheric probe can be installed. It is much smaller and lighter than these probes usually are. It can be flown also on a small size UAV. Power and weight requirements also allow it to fly on Aerosonde’s Mark 4.7 and BAE System’s Manta. For electrical connection only a power (28 VDC nominal within an allowed range of 18-36 VDC) and an Ethernet connection is required. PRACO uses its own GPS receiver and antenna for location determination. Its Internal Inertial Measurement Unit (IMU) provides independent measurements of roll, pitch, and heading. These measurements are necessary for an instrument installed under a wing of an aircraft. PRACO must register its beam position accurately even when aircraft maneuvers and its wings flex.


PRACO Radiometers Specifications:

Pictures show the assembly of PRACO, without the instrument cone. The stationary part is attached to the aircraft. If mounted under a wing the leading edge of the wing extends up to the front end of the mounting plate. The mounting plate holds an SMA connector for the GPS antenna and a round military connector for power and Ethernet connection. Mechanical and electrical interfaces are compatible with a standard PMS (particle measurement probe; e.g., see the products of Droplet Measurement Technologies) probe connection.

Radiometer Channels (GHz) Bandwidth 3dB (MHz) Beamwidth (°) Polarization Wavelength (mm)
22-30 GHz 21.7351-22.7351 1000 15.5 V 13.5
  29.5-30.5 1000 11.5 V 10.0
51-59 GHz 51.25-52.75 1500 12 V 5.8
  53.25-54.75 1500 11 V 5.6
  55.25-56.75 1500 11 V 5.4
  57.25-58.75 1500 10 V 5.2
118 GHz 118.7503±0.1 90 4.7 V,H 2.5
  118.7503±0.325 315 4.7 V,H  
  118.7503±1.0 900 4.7 V,H  
  1138.7503±2.5 1800 4.7 V,H  
183.3101 GHz 183.3101±0.5 800 4.5 V,H 1.6
  183.3101±2 2000 4.5 V,H  
  183.31301±5.5 3000 4.5 V,H  
  183.3101±10 4000 4.5 V,H  

Overall PRACO Size:

CategoryValue
Length: 662 mm (26.05")
Diameter: 102 mm (4")
Weight: 5 kg (11 lbs)

PRACO Environmental Protection:

PRACO is sealed and each part of assembly uses rubber seals to hermetically close the instrument. Pressure equilibration with the ambient is allowed through a desiccant filter at the back of the instrument. The filter is easily accessible to users and can be checked after every flight. Internal humidity sensor indicates when the desiccant filter needs to be replaced.

PRACO Data Acquisition and Storage:

Each of the PRACO radiometers is a full radiometer capable of operating independently of each other. Each radiometer consists of an antenna, a microwave receiver, a video amplifier, an analog to digital converter, and a computer. They communicate with computers in the stationary part of PRACO via an Ethernet connection. The radiometers need only power and Ethernet to be able to work. A few logical signals used only for synchronization of digitization are distributed to each data acquisition computer within PRACO. This allows assembling PRACO in various configurations, depending on user needs.

The two computers within the stationary part collect radiometer and housekeeping data. The housekeeping data are encoder, IMU, GPS, ambient measurements, internal temperatures, humidity, pressure, etc. In addition, one of the computers supervises motion controller operations.

Network of PRACO computers can be accessed via the Ethernet connection through main connector. 

Ambient variables measurements:

CategoryValue
Pressure range: 1 to 110 kPa (10 to 1100 mbar)
Pressure accuracy: -0.2 to +0.3 kPa (-2 to +3 mbar)
Temperature: -40°C to +85°C (-2° to +3°C accuracy)
Humidity: -0 to 100% (±2% accuracy)

In order to increase reliability of measurements, of all ambient variables measurement are redundant. The pressure and humidity are measured by 6 calibrated sensors and temperature by 12 calibrated sensors.



22-30 GHz Radiometer:

CategoryValue
Length: 88 mm
Diameter: 102 mm
Weight: ~380 g

The 22 - 30 GHz complete radiometer is shown on the picture. It consists of lens horn antenna (15.5°, 11.5° beamwidth), waveguide transition, microwave receiver, video amplifier (interface board), analog to digital converter, and computer. 

PRACO 22-30 GHz front
PRACO 22-30 GHz front
PRACO 22-30 GHz back
PRACO 22-30 GHz back


51-59 GHz Radiometer:

CategoryValue
Length: 66 mm
Diameter: 102 mm
Weight: ~400 g

The 51-59 GHz radiometer is shown on the picture. It consists of lens horn antenna (12°-10° beamwidth), waveguide transition, microwave receiver, analog to digital converter, and computer. The video amplifier (interface board) is not shown.

PRACO 51-59 GHz front
PRACO 51-59 GHz front
PRACO 51-59 GHz back
PRACO 51-59 GHz back


118 GHz Radiometer:

CategoryValue
Length: 88 mm
Diameter: 102 mm
Weight: ~400 g

The 118 GHz radiometer design is completed, we are working on assembly and testing of the prototype.

PRACO 118 GHz
PRACO 118 GHz


183 GHz Radiometer:

CategoryValue
Length: 66mm
Diameter: 102mm
Weight: ~400g

The 183 GHz radiometer design is completed, we are working on assembly and testing of the prototype.

PRACO 183 GHz
PRACO 183 GHz

Atmospheric Window Microwave Radiometers


Microwave radiometers with channels in atmospheric windows, suitable for observation of surface parameters (ocean winds, snow properties, soil moisture, sea ice parameters) and also atmospheric phenomena such as rain, cloud particles.

10 GHz Microwave Polarimetric Radiometer

  • Direct detection receiver with low noise amplifier in front end.
  • Corrugated horn antenna
  • Beam width: 10 degrees
  • Center frequency: 10.65 GHz
  • Frequency band: 500 MHz
  • A ferrite polarizer is deployed in front end.
  • Receiving polarizations: 0 degree, +/- 45 degrees
  • Noise temperature: 300K
  • Temperature resolution: 0.03 K @ 1sec INT
  • Hermetic enclosure for the microwave unit.
  • Scanning variant is available upon request.

15 GHz Microwave Polarimetric Radiometer

  • Direct detection receiver with low noise amplifier.
  • Corrugated horn antenna
  • Beam width: 6.5 degrees
  • Center frequency: 15.0 GHz
  • Frequency band: 500 MHz
  • A ferrite polarizer is deployed in front end.
  • Receiving polarizations: 0 degree, +/- 45 degrees
  • Noise temperature: 400K
  • Temperature resolution: 0.03 K @ 1sec INT
  • Hermetic enclosure for the microwave unit.
  • Scanning variant is available upon request.

19 GHz Microwave Polarimetric Radiometer

  • Direct detection receiver with low noise amplifier.
  • Corrugated horn antenna
  • Beam width: 6.5 degrees
  • Center frequency: 89.0 GHz
  • Frequency band: 2000 MHz
  • A ferrite polarizer is deployed in front end.
  • Receiving polarizations: 0 degree, +/- 45 degrees
  • Noise temperature: 1000K
  • Temperature resolution: 0.03 K @ 1sec INT
  • Hermetic enclosure for the microwave unit.
  • Scanning variant is available upon request.

31 GHz Microwave Radiometer

31 GHz Microwave Radiometer
31 GHz Microwave Radiometer

The radiometer is a superheterodyne filter bank SSB receiver. A front end low noise amplifier is deployed. Channel center frequency, Fo, and frequency bandwidth are:

  • Lens-corrugated horn antenna with 9.5 degrees beam width.
  • Receiver noise temperature: 500 K
  • Temperature resolution: 0.02-0.045 K @ 1 sec integration time constant.
  • Radiometer consists of an internal reference load and noise source for periodic gain calibration.
Fo (GHz) 31.4 31.65 31.5
Band (MHz) 200 300 1000

The radiometer has been developed for installation in multi sensor scanning radiometric system Ground-based Scanning Radiometer (GSR). A stand alone scanning instrument with hermetic enclosure is available upon request.


37 GHz Microwave Polarimetric Radiometer

37 GHz Microwave Polarimetric Radiometer
37 GHz Microwave Polarimetric Radiometer
  • Center frequency: 37.0 GHz
  • IF Frequency band: 2000 MHz (DSB Mode)
  • A ferrite polarizer is deployed in front end.
  • Receiving polarizations: 0 degree, +/- 45 degrees
  • Noise temperature: 500K
  • Temperature resolution: 0.02 K @ 1sec INT
  • Beam width: 6.5 degrees
  • Hermetic enclosure for the microwave unit.
  • Scanning variant is available upon request.
  • Dimensions and weight:
    • Microwave unit - 600 x 180, 12.8 kg
    • Power supply - 340 x 320 x 130 mm, 7.5 kg
  • Scanning variant is available upon request.

The radiometer is ready to install on the Twin Otter aircraft. Supporting structure and fairing are available.

89 GHz Microwave Polarimetric Radiometer

89 GHz Microwave Polarimetric Radiometer
89 GHz Microwave Polarimetric Radiometer
  • Corrugated horn antenna
  • Beam width: 10 degrees
  • Center frequency: 89.0 GHz
  • IF Frequency band: 2000 MHz (DSB Mode)
  • A ferrite polarizer is deployed in front end.
  • Receiving polarizations: 0 degree, +/- 45 degrees
  • Noise temperature: 1000K
  • Temperature resolution: 0.03 K @ 1sec integration time constant.
  • Hermetic enclosure for the microwave unit.

89 GHz Microwave Dual Polarization Radiometer

  • Two channel radiometer with antenna orthomode coupler.
  • Lens-horn antenna.
  • Beam width: 3.5 degrees
  • Center frequency: 89.0 GHz
  • IF Frequency band: 2000 MHz (DSB Mode)
  • Noise temperature: 1000K
  • Temperature resolution: 0.03 K @ 1sec integration time constant.

The radiometer is developed for installation in multi sensor scanning radiometric system Ground-based Scanning Radiometer (GSR). A stand alone scanning instrument with hermetic enclosure is available upon request.

340 GHz Microwave Dual Polarization Radiometer

340 GHz Microwave Dual Polarization Radiometer
340 GHz Microwave Dual Polarization Radiometer
  • Two channel radiometer with grid polarization coupler.
  • Lens-horn antenna.
  • Beam width: 1.6 degrees
  • Center frequency: 340.0 GHz
  • IF Frequency band: 4500 MHz (DSB Mode)
  • Noise temperature: 3000K
  • Temperature resolution: 0.05 K @ 1sec integration time constant.

The radiometer is developed for installation in multi sensor scanning radiometric system Ground-based Scanning Radiometer (GSR). A stand alone scanning instrument with hermetic enclosure is available upon request.


80 & 89 GHz Filters for Direct Detection Radiometers


Download flyer 80 & 89 GHz Filters for Direct Detection Radiometers


One of the crucial components of a direct detection radiometer is a filter. The filter determines the operational band where the radiometer channel is sensitive to the observed scene. A filter should have low insertion loss and its bandwidth and frequency center have to be stable over the radiometer operational temperature range. The ease of manufacturing and its repeatability is also important for a filter, and eventually a radiometer and its cost. BEST has designed similar filters operating up to 200 GHz.


To prove our technological capabilities, we have designed, evaluated and tuned a couple of filters for 80 and 89 GHz. The filters are very small, their volume is approximately 10 mm3, thus very suitable for integration into a radiometer receiver. Figures 1 and 3 show a plot of the 80 and 89 GHz filter S21 and S11 parameters (gain and input return loss) respectively. Figures 2 and 4 show measured final bandwidth and insertion losses. Filter center frequencies vary only ±8 MHz over the operational temperature range from -40°C to +80°C.

Figure 1. Measured characteristics of an 80 GHz radiometer filter before and after tuning. The dotted line is a plot of the filter initial results and the full line show results after it was tuned for bandwidth and center frequency.

Figure 2. Measured bandwidth and insertion losses of the 80 GHz radiometer filter after tuning. The insertion losses are less than 1 dB and the bandwidth is from 79 to 81 GHz, as designed.

Figure 3. Measured characteristics of an 89 GHz radiometer filter before and after tuning. The dotted line is a plot of the filter initial results and the full line shows results after it was tuned for bandwidth and center frequency.

Figure 4. Measured bandwidth and insertion losses of the 89 GHz radiometer filter after tuning. The insertion losses are less than 1 dB and the bandwidth is from 88 to 90 GHz, as designed.


Data Acquisition Board for Environmental Measurements


Download flyer Data Acquisition Board for Environmental Measurements.

Several manufacturers offer small computer on module (COM) systems that find places in various consumer electronics applications. Such systems are, for example Gumstix, Toradex Colibri, Variscite and others. These COMs are focused on processing power, video graphics, audio processing, and offer various interfaces for cameras and screens, connectivity options and other functions that are not needed for environmental applications. We have designed a DAQ board specifically for radiometer data acquisition and control. The design goal was a data acquisition system that would be small, consume low power, and provide a number of analog to digital (A/D) input channels with very good resolution, with a multitude of digital inputs and outputs, data storage, Ethernet and other connectivity options.

The DAQ has 24 A/D with 18 bit resolution. Each channel can be sampled at 20 kS/s (kilosamples per second) and its input voltage range is between 0 and 3.3 V. The DAQ consumes about 1.6 W of power. It is, however, a conservative estimate assuming that the microprocessor is constantly writing to a μSD card with 200 mA current and all other board components are consuming their nominal power. The input voltage can be anywhere from 4.5 to 14 VDC. This input voltage is controlled by a switch on the DAQ and it is passed to the output connector. Thus it is available to power, for example, a radiometer receiver. The DAQ can be remotely powered up or down with a one-bit logical signal control. The board can communicate via Ethernet or a serial interface. Two synchronization signal GPIO (general purpose inputs/outputs) are available too. Operational temperature range is -40°C to +80°C.


Data Acquisition Board (DAQ) block diagram:

DAQ Board Block Diagram
Data Acquisition Board (DAQ) block diagram.

Data Acquisition Board (DAQ) layout:

DAQ Board Layout
DAQ board layout. The board size is 80 x 50 mm (for a comparison: a credit card size is 85 x 55 mm) and it is shown in an enlarged scale (2:1).

Microwave Radiometer Systems


Polarimetric Scanning Radiometer System (PSR)

Radiometer system developed for flights on traditional and unmanned aircrafts. PSR is able to provide passive microwave imaging of surface parameters such as ocean winds, snow, sea ice parameters, soil moisture. The instrument has three major parts:

  • Scanhead, a protective housing available to rotate according to programmed mode in any direction with the shortest azimuthal period of ~ 2.5 s. Scanhead houses the radiometers, computer, power supply and other electronics necessary for data sampling and Ethernet communication with other parts of instrument.
  • Positioner, mechanical assembly used to rotate the scanhead. Also includes two calibration targets, one ambient and one hot. Scanhead radiometers observe the targets in a programmed interval for external calibration. (note: all radiometers also have internal calibration).
  • Electronic boxes - two boxes with electronics to control the motion, interface to the airplane, record the data and communicate via Ethernet with other network computers.

To read more about the PSR, many of its successful mission and to check out the data observed please visit: http://cet.colorado.edu/instruments/psr/

PSR on NRL Pallet
PSR on NRL Pallet

Ground-based Scanning Radiometer (GSR)

For ground based observation - atmospheric profiling - another variation of the instrument was developed. It is called a Ground-based Scanning Radiometer and it is currently in operation on ARM site in Barrow, Alaska. This positioner also uses two calibration targets, one is cooled other is heated. Its unique method of scan and availability to observe almost complete horizon to horizon vertical scan while all the radiometers axes are aligned with natural Earth polarization are very unique features for ground based profiling radiometers. Members of the BEST have a patent pending for its design.

Three scanheads are operational and could be installed on either airborne positioners - PSR, or on the ground positioner - GSR:

  • PSR/A
  • PSR/C/X
  • PSR/S

To read more about the GSR please visit: http://cet.colorado.edu/instruments/gsr/

GSR in Barrow
GSR in Barrow

Marine Profiling Radiometer


BEST is developing a marine boundary layer profiler - the Marine Profiling Radiometer (MPR) - based on precision microwave scanning radiometry. The MPR instrument will continuously provide water vapor and temperature profiles and communicate the data in a user-specified format to a remote base terminal. The frequency of profile measurement is nominally one hour, but can be continuous depending on the amount of available power. A significant degree of environmental hardening, including use of use sealed components, has been incorporated into the design to permit long term operation in a marine environment on a buoy or ship. The hermetically sealed MPR is designed to operate through high seas, salt spray, and even after short term saltwater immersion. The overall power consumption is 120-200 Watts depending on weather and data measurement period.

Boundary layer temperature and moisture profiles obtained using the MPR in coastal areas are expected to be extremely valuable for nowcasting and forecasting maritime and coastal weather. Improvements in marine operations through use of MPR profiles are the result of adding this unique and presently unavailable information on the offshore boundary layer.

The mechanical design of the MPR is based on a suite of precision Dicke-switched profiling radiometers enclosed in an environmentally-hardened spinning scanhead. General specifications are:

  • Overall MPR size: ~60 cm by 60 cm (~23.5")
  • Overall MPR weight: less than ~50 kg
  • The scanhead drum encloses radiometers operating at several channels within microwave water vapor and oxygen absorption bands and window channels.
  • A optimized scan rate and diameter provide adequate temporal sampling of the atmosphere within the coherence time of radiometer drift noise, maximize the shedding of liquid moisture from the hydrophobic antenna surface, and minimize power requirements, weight, and cross-section.
  • The rotating design aligns the polarization basis of the instrument to that of the surface, thus improving surface calibration and yielding a precise radiometric signal and accurate boundary layer profile.

Please contact BEST for further information about MPR or a quotation to purchase.


Profiling Microwave Radiometers


Atmospheric temperature and humidity profiling radiometers. These radiometers are build for different water vapor and oxygen absorption lines, thus allowing sensing under various environmental conditions. For example, a radiometer build around the 183 GHz water vapor line is much more sensitive to water vapor than 22 GHz radiometer and thus very suitable for environment with low water vapor amounts, such as polar or high altitude locations.


Low cost 60 GHz Microwave Scanning Radiometer

Compact, low cost 60 GHz microwave scanning radiometer at oxygen absorption line for boundary layer air temperature profile measurements.

  • Center frequency: 60 GHz
  • IF Frequency band: 2GHz (DSB Mode)
  • Receiver noise temperature: 800 K
  • Radiometer temperature resolution: 0.03 K @ 1sec integration time
  • Corrugated horn antenna with low side lobes level < -30 dB
  • Antenna beam width: 6.5 degrees
  • Mirror spinning rate: 2 revolutions per second
  • Dimensions and weight:
    • Microwave unit with scanner: 700 x 120 x 180 mm, 9 kg
    • Power supply: 340 x 230 x 130 mm, 7.5 kg
  • Power consumption: 50 W
  • Power requirements: 120-220 V, 1 A, 50-60 Hz
  • Features:
    • Internal reference load and noise source for gain variation correction.
    • Thermo-electric coolers for temperature control.
    • Fast rotating mirror with hydrophobic self-cleaning Teflon protection (not shown in the picture)
    • Self-calibrating principle using air thermometer
    • Atmospheric altitude range 600m
    • Height resolution 30-90 m
    • Accuracy of temperature profile retrieval 0.3-0.7 K depending on type of profile.

The radiometer is ready to be installed on the wing tip of the Twin Otter aircraft. Supporting structure and fairing are available.

50-56 GHz Multichannel Atmospheric Temperature Profiler

This microwave radiometer has 11 frequency channels from 50.3 GHz to 56.325 GHz. The radiometer is a superheterodyne filter bank receiver with the mixer single side mode operation. A low noise amplifier is deployed in front end. The radiometer is developed for high altitude aircraft installation. Channel center frequencies, Fo and bandwidths are:

Fo (GH ) 50.30 51.76 52.825 53.29 53.84 54.4 54.95 55.52 56.025 56.215 56.325
Band (GHz) 180 400 300 360 190 220 300 180 250 50 50

  • Antenna beam width: 3.5 degree
  • Receiver noise temperature: 1000K
  • Brightness temperature resolution (for different channels): 0.07-0.2K @ 1sec integration time
  • Integration time constant: 1ms

Radiometer consists of an internal reference load and noise source for periodic gain calibration. The radiometer design is for installation into a PSR scanhead. It is installed in the PSR/S scanhead of the PSR system and it was flown on high altitude UAV Altair of General Atomics for the NOAA/NASA UAV demonstration mission. It i is developed for installation in multi sensor scanning radiometric system Ground-based Scanning Radiometer (GSR). A stand alone scanning instrument with hermetic enclosure is available upon request. For ground-based radiometer installation, the channel center frequencies and frequency bands could be recommended and realized as following:

Fo (GH ) 51.3 52.3 54.0 55.0 56.7 57.2 58.0
Band (GHz) 300 300 300 300 400 600 1000

118 GHz Oxygen Line Spectrometer

Double side band receiver with 9 frequency channels. The channel center frequency, Fo, and frequency bands are:

Fo=118.75 +/- (GHz) 0.08 0.2 0.4 0.7 1.1 1.5 2.1 3.0 5.0
Band (MHz) 20 100 200 400 400 400 400 1000 2000

  • Lens-corrugated horn antenna.
  • Antenna beamwidth: 3.5 degree
  • Receiver noise temperature: 1200K
  • Temperature resolution (for different channels): 0.04-0.4 @ 1 sec integration time
  • Internal reference load and noise source for periodic gain calibration.

The radiometer construction is developed for installation in multi sensor scanning radiometric system Ground-based Scanning Radiometer (GSR). A stand alone scanning instrument with hermetic enclosure is available upon request.

22 GHz Water Vapor Line Microwave Radiometer

Direct detection receiver with low noise amplifier in front end. The channel center frequencies, Fo, and frequency bands are:

Fo (GHz) 18.7 21.45 22.235 23.9
Band (MHz) 200 300 200 200
  • Beam width: 8.5 degrees
  • Receiver noise temperature: 300 K
  • Temperature resolution: 0.04 K @ 1sec integration time
  • Internal reference load and noise source for periodic gain calibration.
  • Dimensions:
    • 380 x 220 x 60 mm
    • antenna diameter: 180 mm
  • Weight: 5.5 kg

The radiometer construction is developed for installation in multi sensor scanning radiometric system Ground-based Scanning Radiometer (GSR). A stand alone scanning instrument with hermetic enclosure is available upon request.


183 GHz Water Vapor Line Spectrometer

Double side band receiver with 7 IF frequency channels.

  • Lens-horn antenna.
  • Antenna beam width: 1.7 degrees
  • Receiver noise temperature: 3000 K
  • Temperature resolution (for different channels): 0.05-0.2 K @ 1 sec integration time.
  • Gain calibration using mechanically switching mirror and the hot-cold target set.
Fo (GHz) 18.7 21.45 22.235 23.9
Band (MHz) 200 300 200 200

The radiometer construction is developed for installation in multi sensor scanning radiometric system Ground-based Scanning Radiometer (GSR).

380 GHz Water Vapor Line Spectrometer

5 frequency channel filter bank (GSR).

  • Lens-horn antenna.
  • Antenna beam width: 1.8 degrees
  • Receiver noise temperature: 3500 K
  • Temperature resolution (for different channels): 0.08-0.3 K @ 1 sec integration time.
  • Gain calibration using mechanically switching mirror and the hot-cold target set.
Fo = 380 +/-(GHz) 0.4 1.5 4.0 9.0 17.0
Band (MHz) 200 500 900 2000 2000

The radiometer construction is developed for installation in multi sensor scanning radiometric system Ground-based Scanning Radiometer (GSR). A stand alone scanning instrument with hermetic enclosure is available upon request.


Antennas and Microwave Components


Antennas

Horn antennas are very efficient antennas and thus a very popular choice for microwave radiometers. The following antennas can be designed to your specifications:

  • Corrugated horn antennas from 1 - 380 GHz
  • Single frequency lens-corrugated horn antennas from 6 to 380 GHz
  • Dual frequency lens-corrugated horn antennas at 6,10 GHz and 10,37 GHz
Horn Antennas
Horn Antennas

Mixers

Waveguide and MMIC design at:

  • 9-11 GHz
  • 14-16 GHz
  • 18-24 GHz
  • 22-32 GHz
  • 36-38 GHz
  • 50-56 GHz
  • 87-91 GHz
Mixers
Mixers

Local Oscillators


Gunn oscillators:

  • 30-100 GHz
  • 20-10 mW

Transistor local oscillators:

  • 1-60 GHz
  • 20-5 mW

Low Noise Amplifiers


Low noise amplifiers for remote sensing frequency bands:

  • 1.3-1.5 GHz
  • 5-7 GHz
  • 9-11 GHz
  • 14-16 GHz
  • 18-24 GHz
  • 22-32 GHz
  • 30-32 GHz
  • 36-38 GHz
  • 50-56 GHz
  • 87-91 GHz

Waveguide and coaxial inputs/outputs are available.

Low noise IF amplifiers:

  • 10-500 MHz
  • 0.1-3 GHz
  • 3-10 GHz
  • 1-12 GHz

Receiver Subassembly


We can designed integrated modules to your specifications:

  • mixer + IF amplifier
  • mixer + local oscillator + IF amplifier
  • IF power divider + filters + detectors + video amplifies