Looking for planetary moons in the spectra of distant Jupiters

More than 100 nearby stars are known to have at least one Jupiter-sized planet. Whether any of these giant gaseous planets has moons is unknown, but here we suggest a possible way of detecting Earth-sized moons with future technology. The planned Terrestrial Planet Finder observatory, for example, will be able to detect objects comparable in size to Earth. Such Earth-sized objects might orbit their stars either as isolated planets or as moons to giant planets. Moons of Jovian-sized planets near the habitable zones of main-sequence stars should be noticeably brighter than their host planets in the near-infrared (1-4 microm) if their atmospheres contain methane, water, and water vapor, because of efficient absorption of starlight by these atmospheric components. By taking advantage of this spectral contrast, future space observatories will be able to discern which extrasolar giant planets have Earth-like moons capable of supporting life.     

Decisions, endings, and new beginnings

The Washington Watch column examines NASA shuttle developments, airline pilot age issues, development of a personnel recovery vehicle, and includes an obituary for retired Air Force General Bernard Schriever, remembered as an air and space pioneer. The discussion of NASA shuttle developments reports on the space shuttle flight schedule and NASA's ability to deliver hardware to the International Space Station, funding levels and equipment development schedules related to President Bush's mandate to visit Mars, a report on the space program by the American Academy of Arts and Sciences, and top-level management changes at NASA. The discussion of airline pilot age issues examines efforts to change mandatory retirement requirements. The discussion of personnel recovery vehicles reports on development of an aircraft designed to rescue survivors during combat search and rescue missions.     

Renewal, reform, and return to flight

The Washington Watch column discusses budget issues on Capitol Hill relating to aerospace issues, including the shuttle's delayed return to flight and Michael Griffin becoming the new NASA administrator; the Transportation Security Administration becoming downsized; and new personnel at the Pentagon.     

Caution, contention, and consolidation

The Washington Watch column provides an overview of NASA's cautious approach to the launch of Space Shuttle Discovery STS-114, contention between the Air Force and administration about production of the F/A-22 Raptor aircraft, and consolidation among U.S. airline companies.     

利用基于卡尔曼的平均位移估值器进行多目标探测

本文研究了利用由卡尔曼平均位移估值器所获得的位移估值中的异常物来探测前视红外（ＦＬＩＲ）场景中的多目标（获得回波）问题。由目标产生的初始位移估值与（多个被测目标）回波相关联，从而获得目标新的位置估值。为实现多目标跟踪，此过程对场景中的所有目标均可重复。本文还考查了位移估值期望值与迭代次数的函数关系以及位移误差协方差矩阵和卡尔曼增益矩阵与迭代次数的函数关系。