Abstract: An augmentation information adjustment unit (102) reduces an amount of information in augmentation information by combining: update cycle adjustment processing (1021) to set an update cycle of the augmentation information to be an integer multiple of a predetermined update cycle; geographic interval error value adjustment processing (1022) to reduce the number of geographic interval error values by selecting from among a plurality of the geographic interval error values each of which is an error at every predetermined geographic interval out of a plurality of error values, a geographic interval error value at every geographic interval that is an integer multiple of the predetermined geographic interval; and bit count adjustment processing (1023) to reduce a bit count of the error value for each error value.

Abstract: An augmentation information adjustment unit (102) reduces an amount of information in augmentation information by combining: update cycle adjustment processing (1021) to set an update cycle of the augmentation information to be an integer multiple of a predetermined update cycle; geographic interval error value adjustment processing (1022) to reduce the number of geographic interval error values by selecting from among a plurality of the geographic interval error values each of which is an error at every predetermined geographic interval out of a plurality of error values, a geographic interval error value at every geographic interval that is an integer multiple of the predetermined geographic interval; and bit count adjustment processing (1023) to reduce a bit count of the error value for each error value.

Abstract: The root end is attached to the rotor head for rotationally driving. The central portion has aerodynamic characteristics depending on the leading and trailing edges and which extend linearly from the root end in parallel to each other, and the chord dimension therebetween. A planform shape of the blade tip portion is defined by the first leading edge which extends forwardly as the distance from the outboard end of the leading edge of the central portion outwardly increases, the second leading edge and the side edge which are rearwardly swept as the distance from the outboard end of the first leading edge toward outboard side outwardly increases, the first trailing edge which is curved forwardly as the distance from an outboard end of the trailing edge of the central portion outwardly increases, and the second trailing edge which is swept rearwardly as the distance from the outboard end point of the first trailing edge outwardly increases.

Abstract: A low-noise level landing apparatus for helicopters comprises a helicopter position calculator for calculating the position of the helicopter, a data input device, an air data sensor for measuring an airspeed and a descending angle, a rotor tachometer for detecting a rotor rotational speed, a memory and a fuel gauge for calculating the weight of the helicopter, a rotor rotational speed controller for controlling the rotor rotational speed, a BVI noise generating area database device for storing noise levels in accordance with parameters of descending speed, airspeed, descending angle, rotor rotational speed and weight of the helicopter. A computer selects a flight route, an airspeed, a descending angle and a rotor rotational speed wherein noise is reduced, by setting a plurality of flight routes on the basis of the helicopter position and landing point and by referring to the noise generating area database device. Low-noise level landing is then carried out by pilot manual control or automatic flight control.

Abstract: A main rotor torque compensation apparatus for a helicopter having a main rotor and a tail rotor includes vertical tails that are supported at a variable angle of attack. An actuator adjusts the angle of attack such that the main rotor torque is compensated by the torque of the tails together with the torque of the tail rotor.

Abstract: A stabilizing method of a synthetic aperture radar and a position determining method by the radar. At least three repeaters are arranged in mutually different positions on the ground or the sea and a radio frequency signal having a predetermined frequency is transmitted from the radar mounted on a radar platform such as an aircraft to the repeaters. Each repeater frequency-modulates and amplifies the received signal to return the signal to the radar. The radar receives the signal returned from each repeater. The radar calculates a distance between the radar platform and each repeater on the basis of a time required for the transmitting and the receiving and phase information of the received signal. When the position of each repeater is known, by using the positions of the repeaters and the calculated distances, the position of the radar platform can be calculated. On the basis of the obtained position of the radar platform, a reference signal for phase compensation is generated.