Search Results
The search returned 1,237 publication(s) on its.ntia.gov.
The feasibility of angle diversity reception over a 404 km obstacle-diffraction link in southern Europe was investigated during the summer of 1969. The primary objective of the measurement program was to determine the effectiveness of an experiment...
Comparisons are made between all the past measurements of Minuteman launch control type receivers, and these measurements are compared with the theoretical performance for receivers of this type acting in atmospheric noise. Comparisons are made for b...
This study presents one-way error correcting techniques for IGOSS (Integrated Global Ocean Station System) channels. Emphasis is on applicable HF radio experiments and alternative simple implementations. The "most promising" 1/2 rate code for IGOSS i...
1. The F2-region ionospheric response to individual internal gravity waves is calculated as a function of the azimuth of wave propagation. The physical basis for the great anisotropy of the ionospheric response is discussed. 2. We present computer ...
This report summarizes and presents in mathematical, graphical, and tabular form the fundamental characteristics of basic analog and digital modulation processes used in the Air Traffic Control (ATC) communication system. Single channel modes of ...
This report describes a study by the Institute for Telecommunication Sciences (ITS), to plan a moderate expansion of the National Crime Information Center communication system. Improvements discussed are transmission of data at higher rates than curr...
Use of a decibel plot for the Bessel function makes it a simple task to obtain the single tone peak deviation of FM radio systems. The procedure offers ways to calibrate deviation meters, supplement the carrier disappearance technique, and check the...
Swept frequency (CHIRP) modulation is analyzed as to its suitability for use in the Integrated Global Ocean Station System (IGOSS), a system for the collection of synoptic data from ocean platforms (buoys and/ or ships) using high frequency (HF) radi...
This report proposes and compares convolutional codes with the (15,5) BCH code. Word-error probabilities are computed for each of the codes with the convolutional codes performing at least an order of magnitude better than the (15,5) BCH code. The co...
This paper describes instrumentation for recording digitally the relative phase and amplitude of MF and HF radio signals backscattered from ocean waves. Eight stepped frequencies, two spaced receiving antennas, and four different ranges are used. T...
Predictions of tropospheric transmission loss over irregular terrain using the computer methods described by Longley and Rice (1968) are compared with measurements, to determine their limits of applicability and define the boundary conditions for the...
Rain gauge data measured at the sub-common volume points when converted to an equivalent radar reflectivity and plotted in terms of a cumulative distribution correlates well with the similar cumulative distributions for the bistatic reflectivity for ...
This report reviews the techniques for calculating position with the Loran navigation system, including the use of phase correction factors computed for ground wave propagation over a smooth spherical earth. If the earth is rough or inhomogeneous, th...
A computer program. for calculating ground wave propagation in an ionized atmosphere is documented and listed. The conductivity of the atmosphere can vary in an arbitrary way with altitude. The notion of continuous stratification of the profile has b...
An operational one -way error correcting system is described that employs an interleaved block code with one -third rate and minimum distance decoding. For each decoded output character, the receiver also provides the minimum distance count. All timi...
It is shown that the optimum receiver for coded binary noncoherent Frequency Shift Keying (FSK) depends on the Joint probability distribution of mark and space channel phases. Ideal Gaussian noise, steady signal, and perfect timing are assumed throu...
The Institute for Telecommunication Sciences with the aid of the U. S. Bureau of the Census has undertaken a study of the distribution of the population within 10, 20, 30, 40, 50, 60, and 70 miles of 1120 selected television market centers within th...
Intensive radio and meteorological measurements were conducted on two beyond-the-horizon links during January, February, and March of 1970 to investigate the possible causes of severe fading and to determine corrective action for existing paths in th...
A description of the development and details of a range estimation computer program is presented. The program was tested with about 1700 range estimates with known sources. While the median range estimate errors generally fell in the 5-10 percent ran...
This report provides summary functional statements for the major laboratories comprising the ESSA Research Laboratories, or ERL; an organization chart, with program areas, leadership, and location; a summary list of scientific and technical publicat...