Expendable Bathythermograph Expendable Sound Velocimeter (XBT/XSV) Expendable Profi ling Systems Expendable Bathythermograph Expendable Sound Velocimeter (XBT/XSV) A standard XBT/XSV system consists of XBT and XSV are an expendable probe, a data processing/ available in air-launched recording system, and a launcher. An electrical connection between the and sub-launched probe and the processor/ recorder is confi gurations. made when the canister containing the probe is placed within the launcher and the launcher breech door is closed. Expendable Bathythermograph Following launch, wire dereels from the (XBT) probe as it descends vertically through Temperature profi les and computed the water. Simultaneously, wire dereels sound velocity data obtained by the from a spool within the probe canister, XBT are used by ASW operators to compensating for any movement of the identify the impact of temperature on ship and allowing the probe to freefall sonar propagation and acoustic range from the sea surface unaffected by ship prediction. The XBT also provides Lockheed Martin motion or sea state. a quick and inexpensive means expendable The XBT/XSV system uses a sea water of collecting temperature data for profi ling systems ground. As soon as an electrode within oceanographic and geophysical studies. offer a fast, the nose of the expendable probe makes The XBT contains a precision accurate, cost- contact with the water, the circuit is thermistor located in the nose of the effective means complete andtemperature or sound probe. Changes in water temperature are velocity data can be telemetered to the recorded by changes in the resistance of of collecting ship-board data processing equipment. the thermistor as the XBT falls through environmental data Data are recorded and displayed in the water. The XBT is capable of without restricting real time as the probe falls. The nose temperature accuracies of +0.1°C. ship operation. of each expendable probe is precision The XBT has proved to be reliable in weighted and the unit spin-stabilized over 30 years of use. During this time, to assure a predictable rate of descent. Lockheed Martin has developed several From this rate of descent, probe depth variations of the standard probe to meet is determined to an accuracy of +2%. the requirements of a wide range of When the probe reaches its rated applications. depth (a function of ship speed and the quantity of wire contained within the shipboard spool) the profi le is completed and the system is ready for another launch.

Launchers LM-2A LM-3A Hand-Held Launchers are Deck-Mounted Provides portability, allows more fl exibility in selecting The LM-2A is easily available in three launcher position and reduces installed on the deck of any models. Each is interference with other equip- vessel compatible with ll ment. XBTs, XSVs and shipboard data processing systems. Expendable Bathythermograph (XBT) Expendable Sound Velocimeter (XSV) Lockheed Martin also offers an XSV for the direct measurement of sound velocity. The XSV obtains accurate sound velocity profi les for the support of ASW operations, mine countermeasure operations and oceanographic research. The XSV measures the speed of sound in water using a sing around sound velocity sensor. The XSV obtains real time sound velocity data accurate to +0.25 meters/second at depths up to 2000 meters. The XSV can signifi cantly increase the accuracy of sonar propagation and acoustic range predictions, improve the accuracy of acoustic positioning systems and provide data for the study Expendable Sound Velocimeter (XSV) of acoustic propagation in the world’s oceans. The XSV is most useful in such areas as Arctic, Mediterranean and coastal waters where high salinity variability may cause computed sound velocity data, based upon temperature profi les and assumed salinity data, to be inaccurate.

XBT provides a quick and inexpensive means of collecting temperature data . . .

XSV obtains accurate sound velocity profi les . . .

The XBT is capable of temperature LM-4 Thru-Hull accuracies of +0.1°C. The standard auncher for all military vessels. Employs the same basic assembly as the LM-2A, however, the LM-4A is installed below deck for The XSV obtains real time sound improved safety and increased convenience under heavy velocity data accurate to +0.25 weather conditions. meters/second at depths up to 2000 meters. Lockheed Martin Mission Systems and Training 300 M. Street, SE Washington, D.C. 20003 www.lockheedmartin.com/mst/product_contacts Copyright ©2013 Lockheed Martin Corporation All rights reserved PIRA #MAR200909001

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