Abstract: A towed vehicle for positioning a towed device about a submarine, comprising: (a) a housing having a wing for providing lift when said housing is towed through water; (b) means coupled between said submarine and said housing for towing said housing; and (c) means coupled to said housing for varying the relative positions between the center of buoyancy and the center of gravity of said housing to dispose said wing in a given position.

Abstract: A traveling wave, linearized, modulator device includes: an optical waveguide disposed on a substrate and consisting of an input-output portion, a terminal portion and a plurality of arms disposed between and connected to the other portions. A first arm has an optical characteristic that varies responsive to supplying of an electric field thereto. A reflector (e.g., mirror) located at the distal end of the terminal portion of the optical waveguide causes light entering the input-output portion and propagating through the waveguide to be reflected back through the waveguide so as to exit through the input-output portion. A traveling wave electrode structure disposed on the substrate terminates in an open circuit substantially at the distal end of the terminal portion of the waveguide. The electrode structure includes an electrode disposed on the first arm so as to supply an electric field to that arm responsive to an electrical voltage being supplied to the electrode.

Abstract: Circuit for stabilizing the spectral extent of a varying signal containing harmonically related frequency components and having particular utility in the spectral analysis of radar return for the purpose of target identification. The variable signal is written into a storage device at a fixed rate and read out with a variable time compression which is controlled by a discriminator circuit that is connected through a filter to receive one of the harmonic frequency components of the storage device output signal. Also included is signal conversion for digital storage with analog input and output signals.

Abstract: A signal processing apparatus for providing concurrent electrical frequency measurements of multiple, time-coincident signal inputs. In one embodiment of the present invention, an input signal is received that contains a plurality of individual signals independent of each other in frequency, phase, and electrical amplitude. A power splitter splits the input signal into two separate input signals. A delay line introduces a time delay to one of the two separate input signals. Two Bragg cells within a channelized optical phase measurement (COPM) device modulates two optical carrier signals with the delayed and non-delayed input signals, respectively, separating the modulated delayed and non-delayed input signals into multiple time-concurrent frequency channel signals. Upon exiting the Bragg cells, the two optical beams interfere spatially to develop an interference pattern along the phase and frequency channel number axes of a photodetector array.

Abstract: A multi-mode gain fiber is provided which affords substantial improvements in the maximum pulse energy, peak power handling capabilities, average output power, and/or pumping efficiency of fiber amplifier and laser sources while maintaining good beam quality (comparable to that of a conventional single-mode fiber source). These benefits are realized by coiling the multimode gain fiber to induce significant bend loss for all but the lowest-order mode(s).

Abstract: Circuitry and technique for improving the analysis of a signal, such as radar return, by eliminating the effects of frequency variations of the carrier and thereby stabilizing the modulation spectrum. This is accomplished by tracking the carrier frequency and using it as a reference signal for translating the carrier frequency in the radar return to zero frequency.

Abstract: A system is disclosed for computing least cost paths under hard constraints such as turn angle constraints. In an explicit embodiment, a transformation is performed on a graph representation of an optimization problem to generate a transformed graph incorporating the hard constraint in the edges of the transformed graph. Unconstrained optimization is then performed on the transformed graph using an implementation of Dijkstra's algorithm. The structure of the transformed graph lends itself to searching for an optimal solution using data structures of the vertices of the original graph. In an implicit embodiment, the searching is performed using the data structures but without explicitly generating the transformed graph. The enhanced performance of the invention is sufficient to allow for dynamic re-routing of vehicles in uncertain or changing environments.

Abstract: An improvement in the present radar/IFF equipment used by the military whereby the transponding equipment, when used in crypto-secure Mode 4, is enabled to reply with its unique coded identification number (Mode 2 reply) after it has made its Mode 4 reply. This is accomplished by adding an AND gate and a delay means to the present equipment. The AND gate is connected to couple the Mode 4 three-pulse interrogation to the delay means if it is received at the same time the I/P activate switch is in its operating position. The delayed three-pulse interrogation signal is coupled to the encoder and activates a Mode 2 reply. The ground equipment is also modified to enable it to faithfully reproduce the entire video output of its interrogator section.

Abstract: A method for characterizing degree of phase fluctuation of a signal and a signal processor for accomplishing such characterization, is described, in which a time series of complex data vectors are received, initial spectral processing is accomplished, an estimate of the excess phase rotation is made, and a quantity WSC equal to WSC = [ 1 M ⁢ ∑ i = 3 N ⁢ B ⁡ [ C ⁢   ⁢ Φ i ] L ] is calculated.