Satellite images are of enormous importance in military contexts. A battery of mathematical and image-processing techniques allows us to extract information that can play a critical role in tactical planning and operations. The information in an image may not be immediately evident. For example, an overhead image gives no direct information about the height of … Continue reading Image Processing Emerges from the Shadows
Tag: Trigonometry
Al Biruni and the Size of the Earth
Abu Rayhan al-Biruni (AD 973--1048) The 11th century Persian mathematician Abu Rayhan al-Biruni used simple trigonometric results to estimate the radius and circumference of the Earth. His estimate has been quoted as 6,340 km, which is within 1% of the mean radius of 6,371 km. While al-Biruni's method was brilliant and, for its era, spectacular, … Continue reading Al Biruni and the Size of the Earth
Elliptic Trigonometry: Fun with “sun”, “cun” and “dun”
Introduction The circular functions arise from ratios of lengths in a circle. In a similar manner, the elliptic functions can be defined by means of ratios of lengths in an ellipse. Many of the key properties of the elliptic functions follow from simple geometric properties of the ellipse. Originally, Carl Gustav Jacobi defined the elliptic … Continue reading Elliptic Trigonometry: Fun with “sun”, “cun” and “dun”
ThatsMaths 