European Data Format

European Data Format (EDF) is a standard file format designed for exchange and storage of medical time series. Being an open and non-proprietary format, EDF(+) is commonly used to archive, exchange and analyse data from commercial devices in a format that is independent of the acquisition system. In this way, the data can be retrieved and analyzed by independent software. EDF(+) software (browsers, checkers, ...) and example files are freely available.

EDF was published in 1992 and stores multichannel data, allowing different sample rates for each signal. Internally it includes a header and one or more data records. The header contains some general information (patient identification, start time...) and technical specs of each signal (calibration, sampling rate, filtering, ...), coded as ASCII characters. The data records contain samples as little-endian 16-bit integers. EDF is a popular format for polysomnography (PSG) recordings.

EDF+ was published in 2003 and is largely compatible to EDF: all existing EDF viewers also show EDF+ signals. But EDF+ files also allow coding discontinuous recordings as well as annotations, stimuli and events in UTF-8 format. EDF+ has applications in PSG, electroencephalography (EEG), electrocardiography (ECG), electromyography (EMG), and Sleep scoring. EDF+ can also be used for nerve conduction studies, evoked potentials and other data acquisition studies.

Lockheed Martin F-22 Raptor

The Lockheed Martin F-22 Raptor is a fifth-generation single-seat, twin-engine, all-weather stealth tactical fighter aircraft developed for the United States Air Force (USAF). The result of the USAF's Advanced Tactical Fighter program, the aircraft was designed primarily as an air superiority fighter, but has additional capabilities including ground attack, electronic warfare, and signals intelligence roles.Lockheed Martin is the prime contractor and was responsible for the majority of the airframe, weapon systems, and final assembly of the F-22, while program partner Boeing provided the wings, aft fuselage, avionics integration, and training systems.

The aircraft was variously designated F-22 and F/A-22 prior to formally entering service in December 2005 as the F-22A. After a protracted development and despite operational issues, the USAF considers the F-22 a critical component of its tactical air power, and states that the aircraft is unmatched by any known or projected fighter. The Raptor's combination of stealth, aerodynamic performance, and situational awareness gives the aircraft unprecedented air combat capabilities.