Abstract: A focal plane array (FPA) including a layered composite structure having several layers of materials with differing thermal expansion coefficients (TECs) and thicknesses to stabilize and maintain FPA performance during thermal cycling and excursions. An optical substrate is coupled to a multiplexer through a network of indium bumps. The typical TEC mismatch of the layered materials is offset by particularly selecting the types of materials used and the thicknesses of the individual layers of the FPA. Consequently, undesirable deflections and distortion of the multiplexer and the indium bumps are minimized, thereby substantially improving FPA reliability.

Abstract: The inventive laser radar uses a multiple frequency processing technique for the purpose of extracting relative range information from a received signal by transmitting and receiving two frequencies that are derived from a reference signal source modulated by two modulators that are driven by a different frequency, the reference frequency source also serving as a local oscillator.

Abstract: A process for forming composite hollow crown stiffened skins and panels in which a first layer or skin is placed on a forming surface of a female mold and, after forming a plurality of U-shaped stiffener elements in the first skin, a second skin is placed over the first skin, whereupon the resulting assembly is prepared for autoclave curing. The stiffener elements are formed by pressing the first skin into U-shaped depressions in the female mold surface and inserting a hollow, expandable rubber mandrel into each of the depressions on top of the first skin. Valve stems in the mandrels enable maintaining the pressure inside at atmospheric pressure. The mandrels are maintained in their "pressurized" state during subsequent formation and autoclave curing steps.

Abstract: The present invention is a thrust reversing apparatus for diverting purely rearwardly directed air flowing through an engine nacelle to combined rearward-and-radially-outward flow, and then to a combination of various radially outward angles and forward flow, where in the latter states thrust reversal is effected. The apparatus includes parallel inner and outer air flow blocking members driven by actuators which are coupled to the blocking members for effecting synchronous movement. The inner member includes a first door having fixed vanes and a solid second door pivotably coupled to the first door. The inner member has a closed position in which the two doors are collinear, and various open positions in which the two doors are pivoted relative to one another. The outer member comprises an array of pivotable, parallel vanes, and has a closed position in which the vanes tightly overlap, and various open positions in which the vanes are pivoted out of contact with each other through various amounts of rotation.

Abstract: A method of fabricating a rocket engine combustion chamber comprising assembling a liner having cooling channels, a plurality of throat support sections, and a structural jacket having inlet and outlet manifolds. Then heating the assembly in a pressurized furnace to bond the assembled parts to each other.

Abstract: A radar digital IF (intermediate-frequency) signal is to be complex demodulated, then processed through a two-channel real lowpass filter, prior to Doppler correction, clutter filtering, and other usual processing steps. A particularly efficient form of lowpass filtering for such applications is the so-called CIC (cascaded integrator/comb) filter. The first stage of such a filter is always an integrator. A conventional mechanization would therefore feature a conventional complex demodulator followed by an accumulator on each of the two demodulator outputs, followed by more processing. This invention more efficiently mechanizes this function by replacing the usual pair of multipliers and pair of accumulators (or integrators) with a single two-delay (54, 58) accumulator having an add/subtract control (48) on the input adder (42), and a pair of multiplexer switches (62, 66).

Abstract: The tool comprises the first step of providing a first software component, serving as a timing element, for receiving global synchronization commands as input and issuing global simulation scheduler task dispatch commands as output. A second software component is provided, serving as a global simulation scheduler, for receiving the global simulation scheduler task dispatch commands as input, synchronizing discrete event model and continuous model task dispatch as a function of simulation time, and issuing local simulation scheduler task dispatch commands as output. At least a single third software component is provided, serving as a local simulation scheduler, for receiving the local simulation scheduler task dispatch commands as input and issuing local simulation task execution commands as output. The combination of these steps provides a processing environment wherein the local simulation task execution commands invoke user supplied simulation application tasks in a time synchronized manner.

Abstract: A stir friction welding tool with a variable length pin relative to the shank of the tool is disclosed. The pin is moveable from a totally retracted position relative to the shank such that the shank may engage a workpiece without the pin engaging the workpiece. The pin then may be slowly extended into the work piece. The stir friction welding tool may also have a variable diameter shank to provide a variable volume cavity. Then as the pin is extended further into the workpiece the variable width shank can expand to increase the circumference of the shoulder and the volume of the cavity in the shank such that the pin length to cavity volume are within a range to insure a good surface material flow and a high weld quality using the stir friction welding process.

Abstract: The axially stiff link provides a rigid connection linking two shaft segments (1, 2) of a shaft such that it can bend and or twist yet remain rigid with no slop for high tolerance positioning applications. The link is composed of two rolling elements (4) attached to the shaft segments (1, 2) having a rolling line contact (10) with each other. The rolling elements (4) are held together and preloaded by a ring spring (6) which encircles a portion of the rolling element extending transversely from the shaft segment and engages it by rolling line contact (8). The rolling elements may be solid plain curved portions of the shaft ends, a cylindrical bar, cylindrical bar pairs, or conical pairs to provide for torsional as well as axial bending in the link. Closely spaced perpendicularly disposed axial links provide for 2 axis bending of the shaft.

Abstract: A turbopump assembly comprises first pump section housing, a second pump section housing, and a common rotatable shaft positioned within said housings which further define First and second pump sections. The housings and rotatable shaft also define internal manifolds selectably positioned in the first pump section and second pump section whereby said first pump section, second pump, and internal manifolds form an integrated turbine and dual pump configuration.

Abstract: The sacrificial tube shock attenuation device services as a deformable energy absorbing system designed to be employed between a bumper receiving a potentially destructive force and a payload which is to be protected from the force. The device is composed of a tube assembly running through and aligning apertures of a maul, or series of mauls, which is (are) attached to the bumper and the apertures of a pair of stators, or multiple pairs of stators, that each maul is situated between. The stators are attached to the payload. When overloaded the maul(s) moves relative to the stators causing a misalignment of their respective apertures resulting in deformation of the tube assembly. A simple tube assembly may be comprised of a single tube. A more complex tube assembly may be comprised of multiple tubes within tubes depending on the anticipated overload. In a multi-tube assembly the inner tubes receive the load consecutively as the misalignment of the apertures of the maul and stators progresses.

Abstract: In the construction of cylindrical tanks having end domes wherein the domes are attached by stir friction welding, a wagon wheel is placed inside the tank at the interface of the tank cylinder and the dome such that it provides backup support for the pressure exerted by the stir friction welding tool and strengthens the weld area and the tank by being welded into the tank by the stir friction welding process.

Abstract: The identifiable bullet includes a jacket having sidewalls and a rear base; a bullet core contained within the jacket, the bullet core comprising a rear end; and, an identification member positioned between the rear base and the rear end. The invention provides an inexpensive method to add identification members to bullets that will remain legible following cartridge discharge, bullet impact and post firing environments.

Abstract: A process invention for protecting alpha-2 and gamma titanium aluminide alloy specimens subjected to high temperature oxidation comprises providing an ion beam having an energy range from about 100 keV to about 170 keV. The ion beam incorporates an elemental species capable of promoting alumina formation. The ion beam is exposed to the specimen so as to implant a dose in a range from about 2.times.10.sup.16 to about 8.times.lO.sup.17 ions/cm.sup.2 for a sufficient time period to form a surface alloy of the elemental species and titanium aluminide near the surface of the specimen.

Abstract: This invention provides a means of achieving the close control of iodine flow rate, temperature of the resulting combined gaseous mixture of iodine in diluent gas, as well as the rapid start and stop response time needed for full-scale laser operation. It comprises an iodine charge stored as a solid and is heated to converted the iodine to a liquid, a means to heat the iodine under pressure to extend the liquid temperature range of iodine, an atomizer for complete vaporization of the iodine, a helium iodine mixer to provide heat for iodine vaporization purporting iodine to helium proportion mass ratio and provides for complete mixing and a flow control system which controls the low iodine flow rates accurately.

Abstract: The blade flash signature in a radar return is enhanced and used to detect and classify helicopter targets. The radar return of a target is fast Fourier transformed 34, and the frequencies corresponding to DC and the body of the target are filtered out 38. The filtered signal is inverse transformed 44, moving averaged 52, and auto-correlated 54. Auto-correlation 54 may take place in the frequency domain. If there are significant peaks in the auto-correlation output (other than at zero time delay), then a helicopter is present. The time delay between peaks is the period of the blade. The height of the peak indicates whether it is the main blade or the tail blade which has been detected, and allows a signal indicating both periods to be output. The main blade period and the ratio of the period to that of the tail blade can be compared with a data base to classify the helicopter.

Abstract: A system and process for enhancing the surface of a material for cleaning, material removal or preparation for adhesive bonding or etching. An environment is provided which includes a skin region in which charged particles may be generated. An exposure region is spaced from the skin region. A material may be positioned in the exposure region which contains neutral, chemically active particles generated by the charged particles. When the material to be altered is positioned in the exposure region, a desired surface of the material chemically reacts with the neutral, chemically active particles so as to alter the surface as desired for cleaning, material removal or as preparation for adhesive bonding or etching.

Abstract: A wireless apparatus and communication system for remotely determining the unique identification of individual remote devices, among a plurality of remote devices, and to simultaneously determine the location of each individual remote device, associated with its unique identification number. This invention further provides a wireless signaling response capability for the purpose of relaying generic digital data from a remote device to a host system.

Abstract: A radar lens 14 is made from a conventional Fresnel lens 10, but replaces the conventional curved surface 32 with a stepped approximation thereto 22, 24, 26, preferably of three steps. The thickness of the stepped lens 14, at each step, is a half-wavelength or a multiple half-wavelength of the radar operating frequency in the medium of the lens 14. The half-wavelength or multiple half-wavelength separation of the steps 22, 24, 26 causes reflections from the front 16 and rear 18 surfaces to cancel, thereby minimizing the (undesirable) standing wave between the lens 14 and the feed horn or feed horns 46, 48, 50. This avoids the necessity of reducing the standing wave by presenting the curved or stepped side 18 forward. The planar side 16 of the lens 14 (unlike the stepped side 18) doesn't need to be protected from road debris. The lens 14 can therefore be molded as an integral unit of a radome, desirable in the automotive setting.

Abstract: Sparse sampling of an analog signal is desirable because it allows a large number of analog signals to be monitored using a minimum of electronics. The analog signals may be multiplexed and the multiplexed signal applied to a single analog-to-digital converter (ADC) driving a single digital processor. However, such sparse sampling undesirably lengthens the time it takes to get an accurate measurement of the signal. This delay is minimized by Hilbert transforming the digitized signal 16 to produce an in-phase signal I and a quadrature-phase signal Q, and by measuring I.sup.2 +Q.sup.2. I.sup.2 +Q.sup.2 is the square of the amplitude of the input signal. The input signal 12 is sampled at about four times the signal's frequency. DC bias is eliminated in a two-delay delay-subtracter dc blocker 18B. The de-blocked signal 20 is applied to a two-delay Hilbert transformer 22. Only five samples are required to accurately measure the amplitude of the input signal 12.