{'fraction_non_alphanumeric': 0.015234375, 'fraction_numerical': 0.009765625, 'mean_word_length': 5.185990338164252, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Virtual Field Test for cognitive-dynamic spectrum access radios and spectrum usage inventory

Summary form only given. A RF spectrum survey was conducted during a Navy exercise in the summer of 2013 to characterize the electromagnetic environment of a military surface ship and the associated emissions of complementary ships present during the exercise. The spectrum survey system consists of receiver antennas, a real-time spectrum analyzer, computer and associated instrumentation. The spectrum range from 20 MHz-6000 MHz and from 9390 MHz-9430 MHz were surveyed and captured in 40 MHz bandwidth blocks. For each 40 MHz block, the I/Q data of the spectrum was saved in the .mat format compatible with MATLAB®; a screenshot of each collected spectrum band was also saved. The I/Q data represents the environment, however, it cannot be used in that format for a spectrum usage inventory. The I/Q data is post-processed to provide a spectrum utilization profile for a particular frequency band. MATLAB® scripts were created to generate a matrix of integer values to represent multiple granularity levels of the absolute power in the spectrum represented by the collected data. The dimensions of the matrix can be scaled to provide a time or frequency resolution and power granularity level supporting the analysis needs. A total of 138 GB of data were collected in three days on board the ship. During the exercise, other research groups performed collections at different shore and shipboard locations. Comparative analysis of the data sets with associated position information tagging provides a basis for understanding of the propagation characteristics in the marine environment. The resulting data sets are shared with the US Department of Defense community through incorporation into the DoD Wireless Networking Library, a resource sponsored by the Assistant Secretary of Defense for Research and Engineering. The collected data set can also be manipulated to create specific testing scenarios. The resulting scenarios have been used to regenerate the spectral environment with an arbitrary waveform generator that is a component of the Virtual Field Test Testbed. Regeneration of the synthesized spectral environment scenarios is used in the research and development of cognitive or dynamic spectrum access radios, as well as legacy radios to understand the performance of the radios under relevant spectral conditions. The collection, processing, regeneration and application of the spectrum environment in the Virtual Field Test Testbed are described.