Deep space FM system, a concept

Deep space frequency modulation system permits transmission of data where the signal deviation is greater than 1/2 the predetection bandwidth. It provides satisfactory performance at great distances or with low signal levels

Method and apparatus for decoding compatible convolutional codes

This invention relates to learning decoders for decoding compatible convolutional codes. The decoder decodes signals which have been encoded by a convolutional coder and allows performance near the theoretical limit of performance for coded data systems. The decoder includes a sub-bit shift register wherein the received sub-bits are entered after regeneration and shifted in synchronization with a clock signal recovered from the received sub-bit stream. The received sub-bits are processed by a sub-bit decision circuit, entered into a sub-bit shift register, decoded by a decision circuit, entered into a data shift register, and updated to reduce data errors. The bit decision circuit utilizes stored sub-bits and stored data bits to determine subsequent data-bits. Data errors are reduced by using at least one up-date circuit

Random digital encryption secure communication system

The design of a secure communication system is described. A product code, formed from two pseudorandom sequences of digital bits, is used to encipher or scramble data prior to transmission. The two pseudorandom sequences are periodically changed at intervals before they have had time to repeat. One of the two sequences is transmitted continuously with the scrambled data for synchronization. In the receiver portion of the system, the incoming signal is compared with one of two locally generated pseudorandom sequences until correspondence between the sequences is obtained. At this time, the two locally generated sequences are formed into a product code which deciphers the data from the incoming signal. Provision is made to ensure synchronization of the transmitting and receiving portions of the system

Phased array antenna control

Several new and useful improvements in steering and control of phased array antennas having a small number of elements, typically on the order of 5 to 17 elements are provided. Among the improvements are increasing the number of beam steering positions, reducing the possibility of phase transients in signals received or transmitted with the antennas, and increasing control and testing capacity with respect to the antennas

Improved convolutional coding

Convolutional coding, used to upgrade digital data transmission under adverse signal conditions, has been improved by a method which ensures data transitions, permitting bit synchronizer operation at lower signal levels. Method also increases decoding ability by removing ambiguous condition

An improved learning decoder

Learning decoder was developed which operates at system data rate without limiting data rate. Decoder is much simpler than those in existence, operates near Shannon's channel capacity, and automatically recovers operation after loss of signal

Design document for shuttle task 501. Shuttle carrier aircraft transceiver console (SED 36115353-301)

The flight data for the space shuttle orbiter (SSO) is transmitted via S band to a transceiver in the shuttle carrier aircraft (SCA) for relay to the ground during the mated portion of the approach and landing test (ALT). The transceiver is mounted in the SCA transceiver console for shuttle task 501 testing. This document defines the requirements for the SCA transceiver console, the design description, test plan for the console prior to installating the spacecraft equipment in the console, and the test plan for acceptance tests

Simplified antenna controller system operation manual

A simplified controller system for a seven element phase array antenna is described, and information necessary for operation of the system is given

The effect of war on art: the work of Mark Rothko

My goal for this thesis was to adequately illustrate the effect war can have on art and artists. I chose to single out one particular artist who lived and worked during a time of war and explore his life and work. My choice of artist was not random: I chose an individual who was particularly concerned about his external environment, and was active in the political and social issues of the time. My subject is Mark Rothko, a Russian-Jewish artist who immigrated from Russia as a boy and spent his life in the hotspot of artistic inspiration, New York City. Rothko was sensitive to socio-political matters and his involvement with politics affected his work. In order to fully comprehend the artist and his creations, I did a thorough investigation into the artist’s life; studying his influences, exploring his philosophies, and examining his works. It is difficult to trace the evolution of the style and themes Rothko employed at certain stages in his life because the artist rarely dated his paintings. Only years later, when he made an inventory of his work, did he date them, but without records and entirely relying on his memory. Even so, I was able to assess his work and came to the conclusion that Rothko was heavily influenced by the war going on around him, as well as the aftermath of the First World War and the instability of the Great Depression. From this research, I can deduce that Mark Rothko was a product of his war-torn environment, of which his work was a true reflection