Laser communication and ranging experiments were successfully conducted from the satellite laser ranging (SLR) station at NASA Goddard Space Flight Center (GSFC) to the Lunar Reconnaissance Orbiter (LRO) in lunar orbit. The experiments used 4096-ary pulse position modulation (PPM) for the laser pulses during one-way LRO Laser Ranging (LR) operations. Reed-Solomon forward error correction codes ...

The rapid development of various kinds of aerospace application systems requires the appropriate high-accuracy time and frequency standard. In order to establish suitable time and frequency standard in aerospace, based on the establishment of aerospace satellite visual model, we simulate the satellite visual time of 3-layer satellite constellation, including GEO satellite(Geostationary Earth Or...

Autonomous position determination in the Globalstar satellite communication system is discussed. ( ) The two-way communication between a user terminal on the earth’s surface and a single low earth orbit LEO satellite makes it possible to derive range and range-rate and determine the user terminal position instantly. Expected accuracy is presented, and a simple direct solution is given. INTRODUC...

To enable global scale quantum key distribution (QKD), satellite based systems are the most promising approach. So far, free-space QKD has already been demonstrated on communication channels with attenuation comparable to satellite downlinks, and classical laser communications with satellites and aircrafts is heavily explored. Here, combining both these challenges, we demonstrate an aircraft to...

introduction: acne scar is formed after severe episodes of acne in teen and earlyadult years. several treatment options have been used for depressed acne scars suchas punch grafting, punch excision carbon dioxide (co2) laser etc. moreover, studiesshow that laser skin resurfacing such as co2 fractional can effectively treat depressedacne scars. we investigated the efficacy of fractional co2 lase...

In the laser cutting process some well-known parameters, e.g. laser power and cutting speed, play major roles in the performance of the process. Each parameter or a combination of parameters can affect the material removal volume and cutting volume efficiency. The purpose of this research is to study the effect of power and maximum cutting speed on the material removal rate (MRR) and cutting vo...

It is known that partially (spatial) coherent beams can reduce the effects of scintillation in a free space optical link. However, practical implementations of this type of beam are still under investigation. In this work we apply a wave optics model to analyze the propagation through turbulence of a coherent beam and a particular version of a pseudo-partially coherent beam. The beam we study i...