摘要 :
Over the past 20 years, NASA Goddard has successfully developed space-based lidar for remote sensing studies of the Earth and planets. The lidar in all missions to date have used diode pumped Nd:YAG laser transmitters. Recently we...
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Over the past 20 years, NASA Goddard has successfully developed space-based lidar for remote sensing studies of the Earth and planets. The lidar in all missions to date have used diode pumped Nd:YAG laser transmitters. Recently we have been concentrating work on developing integrated path differential absorption (IPDA) lidar to measure greenhouse gases, with the goal of measurements from space. Due to the absorption spectrum of CO2 a fiber-based master oscillator power amplifier (MOPA) laser with a tunable seed source is an attractive laser choice. Fiber-based lasers offer a number of potential advantages for space, but since they are relatively new, challenges exist in developing them. In order to reduce risks for new missions using fiber-based lasers, we developed a 30- month plan to mature the technology of a candidate laser transmitter for space-based CO2 measurements to TRL-6. This work is also intended to reduce development time and costs and increase confidence in future mission success.
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摘要 :
The Directorate of Land Requirements (DLR) is engaged in an acquisition process that will deliver a new Canadian Ranger Rifle (CRR) capability to the Canadian Forces (CF). The aim of this project was to assist the DLR in assessing...
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The Directorate of Land Requirements (DLR) is engaged in an acquisition process that will deliver a new Canadian Ranger Rifle (CRR) capability to the Canadian Forces (CF). The aim of this project was to assist the DLR in assessing the draft operational requirements and better define the overall CF requirement for a new CRR. Eight half-day workshops were held with 135 Canadian Ranger (CR) personnel from four of the five Canadian Ranger Patrol Groups (CRPG). The workshops were broken down into five modules: background information, weapon use inventory, performance requirements, basic technical requirements, and detailed technical requirements. The in-service Lee Enfield No 4 Mark 1* rifle is generally considered a durable, reliable, and accurate weapon but is faulted for its weight, age and availability of parts, and magazine. Protection from predators, hunting/survival tool, and a symbol of Canadian sovereignty/CR were the most important roles of the CRR. Reliability, accuracy, and durability in extreme environments were most important performance criteria. The basic and detailed technical requirements modules collected CR preferences on specific characteristics and features wanted in the new CRR. Results suggest the new CRR should be a bolt action of .308 Winchester / 7.62mm calibre that is shorter and weighs less than the current Lee Enfield. Further technical requirements are presented and discussed. Overall, the results from these workshops indicate that the CR require a reliable, durable, and accurate rifle, with updated features that is lighter than the current Lee Enfield.
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