Abstract: A method of aligning two images of the same scene by matching features in a first image to features in a second image is disclosed. The method comprises identifying edges of objects in the first image using two different processes. The edges identified using both processes are compared and combined into one image representing confirmed edges which are readily identified in other images of the same scene. A template is then formed from the confirmed edges which is matched to a subregion of the second image.

Abstract: Home entertainment equipment control apparatus for limiting user access and limiting operation time. In various embodiments, the apparatus may limit the allowed operation time for one user or several specified users. In a more sophisticated embodiment, the apparatus is programmable to control the time periods during which home entertainment equipment may be used, as well as the total time for which the equipment may be used and time period durations of use by specified individual users.

Abstract: In a packet based communication network 10, a key management center 20 is used to distribute cryptographic keys for either a switched virtual circuit or a permanent virtual circuit. The disclosed methods allow the key management center 20 to communicate directly with the data encryption/decryption devices (DE's) 14 even though they operate in a transparent mode (rather than a store and forward mode). This is accomplished by balancing link counters with calls to fictitious addresses and/or use of interrupt packets transferred between the DTE 12 and the DE 14. In permanent virtual circuits, the MAC of the last packet transmitted under the old cryptographic key is exchanged to synchronize the key change.

Abstract: An improved security system is disclosed which uses an IC card to enchance the security functions involving component authentication, user verification, user authorization and access control, protection of message secrecy and integrity, management of cryptographic keys, and auditablity. Both the security method and the apparatus for embodying these functions across a total system or network using a common cryptographic architecture are disclosed. Authorization to perform there functions in the various security component device nodes in the network can be distributed to the various nodes at which they will be executed in order to personalize the use of the components.

Abstract: A guard for an active antenna array is formed from first and second subarrays of the elements of the antenna, the first and second subarrays each being quadrant symmetric and having respective center phases which are 90 degrees apart. This arrangement greatly reduces nulls in the resultant guard pattern.

Abstract: A lock control method for on-board terminal equipment of a mobile telecommunications network surely inhibits persons other than the user or an authorized person person from unlocking the equipment with the intention of originating a call thereon. When a unauthorized person enters a lock code resembling a set first lock code, or unlock code, by chance after a great number of lock codes, the first lock code is replaced with a second lock code. Hence, the unauthorized person cannot unlock the equipment despite that the entered code may coincide with the first lock code. While the unauthorized person may further enter other different lock codes, the second lock code serving as the unlock code will be replaced with the first lock code as the entered code approaches the second lock code.

Abstract: A video system includes a central facility and a terminal. Means are provided for transmitting to the terminal a video program including a series of television fields including a first field containing both a random digital code encrypted according to a code encryption key and program identification data, and a second field containing an unintelligible video signal previously transformed from an intelligible video signal according to the random digital code. The terminal includes means for sending the program identification data to the central facility. The central facility includes a data base for storing and retrieving at least one code encryption key corresponding to the program identification data and means for sending the code encryption key from the central facility to the terminal.

Abstract: A video recording medium storing a video program includes a series of television fields including a first field containing both a random digital code encrypted according to a code encryption key and program identification data, and a second field containing an unintelligible video signal previously transformed from an intelligible video signal according to the random digital code.

Abstract: Television picture transmission stage in which besides means for transmitting at least one picture characteristic extension video signal via at least one transmission path, means for scrambling at least a part of said extension signal or signals, and receiving stage comprising corresponding receiving and descrambling means. These stages are particularly intended for a television picture transmission system in which one or more video signals for extending the aspect ratio of the picture and the video signals for extending the horizontal and vertical definition of the said pictures are transmitted and transferred superposed on the conventional video signals which correspond to the original pictures, said extension signals having been submitted before transmission to a cyclic permutation from a cut point defined for each line with the aid of a pseudorandom sequence generator.

Abstract: A sensor provides remote angular orientation sensing. A rotational signal transmitted to a rotatable input shaft mounted in an encoder body causes the shaft to rotate. Light signals are transmitted through a digital code wheel mounted to the shaft. As the code wheel and shaft rotate, the light signals passing through the code wheel are superimposed with light pulses corresponding to incremental and directional changes of angular position of the code wheel with respect to the encoder body. The light signals are propagated through an optical fiber to a remote combination digital and analog circuit which converts them into a digital representation of the angular position of the code wheel.

Abstract: A precision satellite tracking system incorporating a novel smoothing processor. The satellite tracking system estimates an angle between an antenna boresight and a desired line of sight to a moving satellite. The smoothing processor receives a sequence of pointing error measurements and using a Taylor series mathematical model of the satellite motion, the processor utilizes the sequence of measurements to generate the coefficients of the Taylor series model. The processor then executes a sequential, discounted least mean square algorithm to estimate the satellite's angular position, velocity, and acceleration as a function of time. Based on these estimates, the processor determines incremental adjustments to azimuth and elevation pointing angles of the antenna to maintain the center of an antenna beam on the moving satellite. The information is used in a program track mode to continually update the pointing of the antenna beam during the measurement process.

Abstract: A roadside beacon system in which a plurality of roadside antennas transmit data to vehicles passing closely adjacent. The transmitting antennas are mounted high above the sides of the roads and have a gain pattern directed obliquely downward. The mobile antennas on the cars have gain patterns directed upwardly.

Abstract: A digital cordless telephone system which comprises a primary station (PS) controlled by a system controller (14 or 15) and a plurality of secondary stations (SS) capable of communicating with the primary station by way of a time division duplex radio link, the primary and/or secondary station having means to generate a beacon signal which is receivable by a secondary station outside the range of normal speech communication and the beacon signal comprising a low bit rate signal which is transmitted at a power comparable to the digitized speech signal. In one embodiment the beacon signal is recovered using a narrowband filter and a demodulator. In another embodiment direct sequence spread spectrum techniques are used to send the beacon signal and a correlator/matching circuit is used to recover the low bit rate data representative of the beacon signal.

Abstract: Disclosed is a password security method in a man-machine system for keeping the secrecy of a password during a setting process of the system. To keep not only the secret of the password but also the presence of the password from unauthorized users, the method comprises a prompt displaying step for prompting to enter an equipment name and not prompting to enter the password; a password discriminating step to discriminate whether or not a correct password is entered; a step for entering a normal mode when the correct password is not detected; and step for entering a password mode when the correct password is detected.

Abstract: The presence of random noise, interference, multipath, and imperfect frequency response in terrestrial broadcasting channels, and of pervasive low-level reflections in cable systems, degrades the quality of television reception. These effects tend to reduce the difference in quality between that of NTSC and that of various advanced television systems, as actually delivered to the home via such channels. Several methods are disclosed for dealing with these effects, and thus to preserve the improved quality made possible by currently proposed EDTV and HDTV systems. Automatic channel equalization is used for first-order correction of multipath and frequency distortion. A scrambling method is described that transforms all remaining degradations to additive random noise, which, for a given noise power, is of minimum visibility. Random noise, whether additive or produced by scrambling of other defects, is suppressed by adaptive modulation.

Abstract: A correlation processing device using a surface acoustic wave convolver, is disclosed, in which there are disposed gate sections in the in- and output stages of the convolver and these gates are controlled synchronously to reduce the self convolution in the convolver.

Abstract: A spread spectrum receiver using a convolver controls the level of a reference signal applied to the convolver in response to comparison of a true correlation output and other correlation output of the convolver or, alternatively, in response to the level of received input signal.

Abstract: An airborne surveillance platform utilizes a low aspect ratio delta-shaped aircraft having a radar-transparent hull. The antenna is located within, and stationary relative to, the hull. The antenna comprises planar or linear phased arrays arranged to scan in a continuous 360 degree pattern in all azimuthal directions or in a continuous 180 degree pattern in all forward azimuthal directions. Planar phased arrays can be arranged to scan in a continuous pattern in the range from zenith to nadir or in portions of that range. In the case of forward direction scanning, the antenna arrays are located immediately inside the radar-transparent leading edges of the aircraft hull, thereby allowing a large cargo space within the hull between the antenna arrays. Access to the cargo space is provided through an opening in the trailing edge.

Abstract: A method and apparatus for protecting software used in an electronic system. An electronic key is associated with the software, which is at least partially unreadable unless modified. The electronic system using the software to be protected receives the electronic key, and reads the software to determine that the electronic key and software are associated. The system then modifies the software to render it readable and identifies the software with the electronic system by storing an identifier of the system with the software. Finally, the system modifies the electronic key to render it useless.

Abstract: An item bearing an indicia which verifies a status of the item and a method and apparatus for applying such indicia. The indicia represents an encrypted message and has the form of a number n base N number system represented by characters selected from an unambiguous machine-readable character set having n characters. The characters consist of connected graphs drawn on a predetermined grid and meeting certain selected requirements. A set of descripters is selected, including a number of type 1 and type 3 points in a character and a subset of characters is selected from the set of all possible characters meeting the requirements so that each character is unambiguously described in terms of the selected descripters. In one embodiment disclosed the item is a mail piece and the status is the payment of postage.