Project OASIS: The Design of a Signal Detector for the Search for Extraterrestrial Intelligence

An 8 million channel spectrum analyzer (MCSA) was designed the meet to meet the needs of a SETI program. The MCSA puts out a very large data base at very high rates. The development of a device which follows the MCSA, is presented

Measuring temperature - dependent propagating disturbances in coronal fan loops using multiple SDO/AIA channels and surfing transform technique

A set of co-aligned high resolution images from the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO) is used to investigate propagating disturbances (PDs) in warm fan loops at the periphery of a non-flaring active region NOAA AR 11082. To measure PD speeds at multiple coronal temperatures, a new data analysis methodology is proposed enabling quantitative description of subvisual coronal motions with low signal-to-noise ratios of the order of 0.1 %. The technique operates with a set of one-dimensional "surfing" signals extracted from position-time plots of several AIA channels through a modified version of Radon transform. The signals are used to evaluate a two-dimensional power spectral density distribution in the frequency - velocity space which exhibits a resonance in the presence of quasi-periodic PDs. By applying this analysis to the same fan loop structures observed in several AIA channels, we found that the traveling velocity of PDs increases with the temperature of the coronal plasma following the square root dependence predicted for the slow mode magneto-acoustic wave which seems to be the dominating wave mode in the studied loop structures. This result extends recent observations by Kiddie et al. (Solar Phys., 2012) to a more general class of fan loop systems not associated with sunspots and demonstrating consistent slow mode activity in up to four AIA channels.Comment: 23 pages, 8 figures, 2 table

Design of a digital compression technique for shuttle television

The determination of the performance and hardware complexity of data compression algorithms applicable to color television signals, were studied to assess the feasibility of digital compression techniques for shuttle communications applications. For return link communications, it is shown that a nonadaptive two dimensional DPCM technique compresses the bandwidth of field-sequential color TV to about 13 MBPS and requires less than 60 watts of secondary power. For forward link communications, a facsimile coding technique is recommended which provides high resolution slow scan television on a 144 KBPS channel. The onboard decoder requires about 19 watts of secondary power

Application of advanced on-board processing concepts to future satellite communications systems: Bibliography

Abstracts are presented of a literature survey of reports concerning the application of signal processing concepts. Approximately 300 references are included

Oceanographic and underwater acoustics research conducted during the period 1 May 1961-31 October 1961

Research during this six month period was performed during cruises of the CHAIN to the Romanche Trench, to the Puerto Rico Trench, and to the Mediterranean Sea, and during a cruise of the BEAR to the Gulf of Maine. New instrumentation aboard the CHAIN included the 12, 000 joule Boomer and a 25, 000 joule Sparker for continuous Seismic reflection profiles and other research in hydroacoustics. A semiautomatic data recording system for shipboard use was in.stalled and operated by IBM and, to facilitate launching and retrieving deep gear, a closed circuit television system was used . Also the navigational system, GEON, was installed and tested. Prior to the cruises of the summer and fall redesign and refinement of the instrumentation and equipment entailed overhaul of the thermistor chain and contouring temperature recorder, modification of the heat probe for thermal gradient measurements to lessen lowering time, and improvement of the inverted echo-sounding equipment. Research at sea included collecting samples of rock and sediment and photographing the ocean floor in support of research into the structure and dynamics of the Romanche and Puerto Rico Trenches and the Mid-Atlantic Ridge , observing internal waves in the North Atlantic studying water circulation in the Mediterranean, the dynamics of flow through the Strait of Gibraltar (concentrating this year on internal waves there), observing the behavior and measuring the sound scattering properties of deep scattering layers in the Mediterranean, measuring heat flow from the inner Earth across the Mid-Atlantic Ridge and in the western Mediterranean, and studying the relationship between sound transmission and the physical properties of the water and sea floor in the eastern Mediterranean. At Woods Hole various analysis programs progressed. Several of these used programs of digital computing which have been prepared lately at Woods Hole. The precision time source for remote control reported earlier was improved and tested ashore. A tape recording system for Scuba divers was devised and tested satisfactorily in thirty feet of water.Undersea Warfare Branch Office of Naval Research Contracts Nonr-1367(00)NR 261-102 and Nonr-2129(00)NR 261-10

A preliminary experiment definition for video landmark acquisition and tracking

Six scientific objectives/experiments were derived which consisted of agriculture/forestry/range resources, land use, geology/mineral resources, water resources, marine resources and environmental surveys. Computer calculations were then made of the spectral radiance signature of each of 25 candidate targets as seen by a satellite sensor system. An imaging system capable of recognizing, acquiring and tracking specific generic type surface features was defined. A preliminary experiment definition and design of a video Landmark Acquisition and Tracking system is given. This device will search a 10-mile swath while orbiting the earth, looking for land/water interfaces such as coastlines and rivers

Oceanographic and underwater acoustics research : conducted during the period 1 November 1960 - 30 April 1961

Digital computing techniques have been used in special computing applications in underwater acoustics at WHOI for many years, but recently we have commenced intensive application of digital data handling and computing facilities to a variety of computing, data storage, and data handling problems. Progress in these applications is described under Acoustic Instrumentation below. Some bathymetric studies carried out recently under another contract have shown that even very narrow-beam, single-beam echo sounders simply cannot provide reliable depth sounding information where the topography is complex. In this work we have been experimenting with the inverted echo sounder, discussed below, originally developed to measure depth of the sound velocimeter. The inverted echo sounder is lowered to a position within a few feet of the bottom. The total acoustic travel time from surface to bottom may be read as the sum of the travel times from the instrument to the bottom and surface . True depth is then computed in the usual way with appropriate s cnmd velocity data. In its present form the inverted echo sounder is suitable for mapping ~mall areas~ a few square miles, provided there is a suitable means of positioning the instrument. We have experimented with radio-acoustic navigation, and intend to experiment with vertical triangulation from the suspending ship as well. Steady demands for new, modified, and improved instrumentation have been responded to in echo sounding, seismic profiling, and spectrum analysis, as detailed below.Undersea Warfare Branch Office of Naval Research Under Contracts Nonr-1367(00)NR261-102 and Nonr-2129(00)NR261-10

Tight error bounds for asynchronous multicarrier CDMA and their application

Upper and lower bounds on the average bit error rate for binary phase-shift keying (BPSK), asynchronous multicarrier (MC)-CDMA communications using coherent detection are derived. The bounds can be made very tight by adjusting a parameter in the computation and this is demonstrated by numerical examples. Based on the derived bounds it is shown by numerical examples that the performance of asynchronous MCCDMA using Zadoff - Chu sequences is better than that using Walsh codes.published_or_final_versio