A compact, multifrequency radar built by a team at NASA’s Jet Propulsion Laboratory will make it easier to collect information about dynamic cloud systems. Called CloudCube, this new instrument simultaneously probes the atmosphere with three radar signals, spanning 36 to 240 GHz, for optimized sensitivity to a wide range of water droplet and ice particle sizes.
由美国宇航局喷气推进实验室的一个团队建造的紧凑型多频雷达将使收集有关动态云系统的信息变得更加容易。这款新仪器名为 CloudCube，可同时利用三个雷达信号（频率范围为 36 至 240 GHz）探测大气，以优化对各种水滴和冰颗粒尺寸的灵敏度。
Built with funding from NASA’s Earth Science Technology Office Instrument Incubator Program , CloudCube transmits and receives Ka-, W-, and G-band signals, making it the first compact radar system capable of simultaneously probing meteorological targets at wavelengths spanning approximately one to ten millimeters. Researchers will be able to combine information from the three signals to learn more about the initiation and evolution of precipitation, as well as cloud microphysics and radiative properties.
CloudCube 是在 NASA 地球科学技术办公室仪器孵化器计划的资助下建造的，可发射和接收 Ka、W 和 G 波段信号，使其成为第一个能够以大约 1 到 10 毫米的波长同时探测气象目标的紧凑型雷达系统。研究人员将能够结合来自三个信号的信息，以了解有关降水的起始和演化以及云微物理和辐射特性的更多信息。
“We’re making a low-power, low-mass instrument to facilitate new cost-efficient missions for atmospheric observations. Building a multi-frequency radar, especially at G-band, is very novel,” said Raquel Rodriguez Monje, a systems engineer at JPL and principal investigator for CloudCube.
JPL 系统工程师兼 CloudCube 首席研究员 Raquel Rodriguez Monje 表示：“我们正在制造一种低功耗、低质量的仪器，以促进新的经济高效的大气观测任务。构建多频雷达，尤其是 G 波段雷达，是非常新颖的。”
Each of CloudCube’s three signals observes a different element of cloud physics. Ka-band radar signals are ideal for collecting precipitation profiles; W-band radar signals are preferred for measuring cloud particles that give rise to precipitation; and G-band radar signals, which have never been collected from a space-based instrument, are ideal for measuring ice and liquid water content inside very light clouds (a paper describing this measurement can be found here ).
CloudCube 的三个信号中的每一个都观察到云物理的不同元素。 Ka波段雷达信号非常适合收集降水剖面； W 波段雷达信号更适合测量产生降水的云粒子； G 波段雷达信号从未从天基仪器中收集过，非常适合测量极轻云内的冰和液态水含量（可以在此处找到描述此测量的论文）。
Probing the atmosphere simultaneously with three signals allows researchers to collect data on all these cloud features at once, which is valuable for improving weather forecasts and especially climate modeling. CloudCube leverages innovations in millimeter-wave hardware to pack three radar modules–one for each signal–within a single compact system.
通过三个信号同时探测大气，研究人员可以同时收集所有这些云特征的数据，这对于改进天气预报，尤其是气候建模非常有价值。 CloudCube 利用毫米波硬件的创新将三个雷达模块（每个信号一个）封装在一个紧凑的系统中。
One CloudCube innovation concerns the specialized components required to transmit G-band power from a compact, low-power instrument. The detection of cloud signals requires high transmit power, which CloudCube achieves by combining the outputs of multiple high-efficiency frequency-multiplication devices that allow the instrument to generate hundreds of milliWatts at 240 GHz. Another innovation of CloudCube is that it was designed to use as few radio frequency components as possible to reduce its mass and power consumption, which could lower the cost of future Earth-observing orbital instruments.
CloudCube 的一项创新涉及从紧凑型低功耗仪器传输 G 波段功率所需的专用组件。云信号的检测需要高发射功率，CloudCube 通过组合多个高效倍频设备的输出来实现这一目标，使仪器能够在 240 GHz 下产生数百毫瓦的功率。 CloudCube的另一项创新是，它被设计为使用尽可能少的射频元件，以减少其质量和功耗，这可以降低未来地球观测轨道仪器的成本。
Flying an instrument equipped with G-band radar in space will be a new capability and will allow researchers to achieve greater spatial resolution and sensitivity in the study of cloud microphysical processes.
在太空飞行配备 G 波段雷达的仪器将是一项新功能，将使研究人员在云微物理过程的研究中获得更高的空间分辨率和灵敏度。
“Basically, we’re weighing clouds using these combinations of frequencies in a way that we couldn’t do before we had the G-band,” said Matt Lebsock, a researcher at JPL and co-investigator for CloudCube.
JPL 研究员兼 CloudCube 联合研究员马特·莱布索克 (Matt Lebsock) 表示：“基本上，我们使用这些频率组合来衡量云的重量，这是我们拥有 G 频段之前无法做到的。”
The instrument has been tested in the field. A ground-based prototype of CloudCube’s G-band channel operated continuously for 11 months during the Department of Energy’s Cloud and Precipitation Experiment at Kennaook (CAPE-K) campaign. CloudCube also participated in the Eastern Pacific Cloud Aerosol Precipitation Experiment, a ground campaign sponsored by the Department of Energy. A paper describing the results of that experiment can be found here.
该仪器已经过现场测试。 CloudCube G 波段通道的地面原型在能源部肯纳库克云与降水实验 (CAPE-K) 活动期间连续运行了 11 个月。 CloudCube 还参加了东太平洋云气溶胶降水实验，这是一项由能源部赞助的地面活动。可以在此处找到描述该实验结果的论文。
Most recently, CloudCube successfully operated all three frequency bands from NASA’s Gulfstream III aircraft and collected its first airborne observations of snowfall as part of the North American Upstream Feature-Resolving and Tropopause Uncertainty Reconnaissance Experiment campaign —a NASA-funded campaign designed to improve forecasts of high-impact winter weather. The CloudCube team is currently calibrating and processing the data for public release.
最近，CloudCube 成功操作了 NASA 湾流 III 飞机的所有三个频段，并收集了首次机载降雪观测数据，作为北美上游特征解析和对流层顶不确定性侦察实验活动的一部分，这项活动由 NASA 资助，旨在改善对高影响冬季天气的预测。 CloudCube团队目前正在校准和处理数据以供公开发布。
For additional details, see the entry for this project on NASA TechPort.
有关更多详细信息，请参阅 NASA TechPort 上该项目的条目。
Project Lead: Dr. Raquel Rodriguez Monje, NASA’s Jet Propulsion Laboratory
项目负责人：Raquel Rodriguez Monje 博士，美国宇航局喷气推进实验室
Sponsoring Organization : NASA’s Earth Science Technology Office Instrument Incubation Program
赞助机构：NASA 地球科学技术办公室仪器孵化计划