Bessel may refer to: Bessel beam Bessel ellipsoid Bessel function in mathematics Bessel's inequality in mathematics Bessel's correction in statistics. Bessel filter, a linear filter often used in audio crossover systems Bessel Fjord, NE Greenland Bessel Fjord, NW Greenland Bessel (crater), a small lunar crater Bessel transform, also known as Fourier-Bessel transform or Hankel transform Bessel window, in signal processing Besselian date, see Epoch (astronomy)#Besselian years , a German merchant ship in service 1928–45, latterly for the Kriegsmarine People Friedrich Wilhelm Bessel (1784–1846), German mathematician, astronomer, and systematizer of the Bessel functions Bessel Kok (born 1941), Dutch businessman and chess organiser See also Bessell