XDD-938 Expendable Digital RadiosondeGeneral Description The XDR-938 Expendable Digital Radiosonde represents the state-of-the-art for making precise upper air observations using high resolution Global Positioning System technology. The XDR is unique in that it is capable of radiosonde and dropsonde sounding modes, providing vertical profiles of pressure, temperature, humidity and 3D winds. It can be released manually, deployed in the Model ARL-9000 launcher, or released via UAV. The XDR-938 features a precision calibrated, radiation-shielded thermistor and solid state micro-machined (MEMS) humidity sensor, providing exceptional calibration and stability. Pressure is derived via GPS altitude, while wind data a 12 satellite GPS engine. An optional pressure sensor is available to support hurricane work. Digital RF data telemetry in the 403 MHz meteorology band communicates to a METHUB or AIRHUB Receiver. A web browser displays sounding data via a conventional Skew-T graph, or as text data reports. Features
Applications
Principle of Operation A radiosonde is an electronic met sensor package released into the atmosphere, typically attached to a balloon filled with helium. In dropsonde mode, it is deployed from aircraft (via ECM chaff dispensers) or UAV. During ascent (or descent for dropsondes), it telemeters PTU meteorological data and winds data in real time once a second. For radiosonde soundings, a METHUB Meteorological Data Receiver, located on the ground records the data. The AIRHUB supports either radiosondes or dropsondes from aircraft or UAV. The XDR allows you to migrate to automated upper air flight operations, using the same hardware/software. XDR-938 Expendable Digital Radiosonde Unlike older radiosondes that used water-activated batteries, the XDR-938 uses commonly-available lithium dry cell battery technology. The battery is activated by a slip-fit fiber optic cable. Prior to release, the fiber optic cable latches the battery on and real time data telemetry commences until the end of the flight. (A manual jumper allows battery deactivation if necessary.) Each second a Manchester-encoded data packet is sent via frequency shift keying (FSK). Met sensor calibration coefficients are sent once a minute, eliminating the overhead of paper tapes, and a cyclical redundancy check is appended to each packet to ensure RF link integrity. During flight, received upper air data are displayed in real time via a web server, allowing sharing of data via TCP/IP networking. Data are stored in a database, and can be exported in a variety of formats or as ASCII. The XDR is compatible with both the ARL-9000 auto launcher and AIRHUB for UAV hurricane work. When used with the ARL launcher, the roof is opened and the helium gas line is cut, whereupon the sonde is lifted up and away. When used with UAV, soundings initiate on pressure drop.
Automated XDR Deployment Methods
Specifications
Temperature vs. ADC resolution of Tambient |
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XDD-938 Expendable Digital Radiosonde
The Model XDD-938 Expendable Digital Radiosonde conducts precise upper air observations using GPS wind finding technology. It is the first system capable of both radiosonde and dropsonde sounding modes, providing vertical profiles of 3D pressure, temperature, humidity and winds. It can either be released manually or used in the Model ARL-9000 launcher, which includes an integrated METHUB ground station.
MFR-7 Multifilter Rotating Shadowband Radiometer
The Model MFR-7 Multifilter Rotating Shadowband Radiometer measures total, diffuse, and direct irradiance at six wavelengths (415, 500, 615, 673, 870, and 940 nm, each 10 nm FWHM) in the visible/NIR, and includes one unfiltered broad-band silicon pyranometer. Thermally stabilized, environmentally sealed state-of-the-art interference filters provide excellent long term calibration stability.
TSI-880 Full-Color Total Sky Imager System
The Model TSI-880 Total Sky Imager is an automatic, full-color sky imager system that provides real-time display of daytime sky conditions. Traditionally, human observers reported sky conditions, resulting in considerable discrepancies from subjective observations. The TSI-880, a self-contained system which automatically processes images, replaces the need for these human observers under all weather conditions.
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Who We Are
We design and manufacture quality meteorological instruments for scientists committed to accurate and precise environmental measurements
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Our Mission
To engineer the most durable and precise meteorological and environmental sensors on the market
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Our Vision
A world where scientists and government agencies work together to solve the meteorological and environmental problems of our generation
