Mexicana de Aviación The headquarters of the company were in the Mexicana de Aviación Tower in Colonia del Valle, Benito Juárez, Mexico City. In addition to domestic services, Mexicana operated flights to various international destinations in North America, Central America, the Caribbean, South America and Europe (until August 31). Their primary hub was Mexico City's Benito Juarez International Airport, with secondary hubs at Cancún International Airport, and Guadalajara's Don Miguel Hidalgo y Costilla International Airport. Mexicana's main competitors were Aeroméxico (although the two companies "codeshared" on several routes), and low-cost carriers such as Volaris and Interjet. Mexicana was North America's oldest airline and
S transform S transform S transform as a time–frequency distribution was developed in 1994 for analyzing geophysics data. In this way, the "S" transform is a generalization of the short-time Fourier transform (STFT), extending the continuous wavelet transform and overcoming some of its disadvantages. For one, modulation sinusoids are fixed with respect to the time axis; this localizes the scalable Gaussian window dilations and translations in "S" transform. Moreover, the "S" transform doesn't have a cross-term problem and yields a better signal clarity than Gabor transform. However, the "S" transform has its own disadvantages: the clarity is worse than Wigner distribution function