Monsoon cloud observations using a low power vertical looking Ka Band Cloud radar

In radar meteorology, greater interest is dedicated to weather radars and precipitation analyses. However, cloud radars provide us with detailed information on cloud particles from which the precipitation consists of. Motivated by research on the cloud particles, a vertical Ka-band cloud radar (35 GHz) was installed at the Milešovka observatory in Central Europe and was operationally measuring since June 2018. This study presents algorithms that we use to retrieve vertical air velocity (Vair) and hydrometeors. The algorithm calculating Vair is based on small-particle tracers, which considers the terminal velocity of small particles negligible and, thereby, Vair corresponds to the velocity of the small particles. The algorithm classifying hydrometeors consists of calculating the terminal velocity of hydrometeors and the vertical temperature profile. It identifies six hydrometeor types (cloud droplets, ice, and four precipitating particles: rain, graupel, snow, and hail) based on the calculated terminal velocity of hydrometeors, temperature, Vair, and Linear Depolarization Ratio. The results of both the Vair and the distribution of hydrometeors were found to be realistic for a thunderstorm associated with significant lightning activity on 1 June 2018.

Download Full-text

An ultra-low power InAs/AlSb HEMT Ka-band low-noise amplifier

IEEE Microwave and Wireless Components Letters ◽

10.1109/lmwc.2004.827132 ◽

2004 ◽

Vol 14 (4) ◽

pp. 156-158 ◽

Cited By ~ 59

Author(s):

J.B. Hacker ◽

J. Bergman ◽

G. Nagy ◽

G. Sullivan ◽

C. Kadow ◽

...

Keyword(s):

Low Power ◽

Low Noise ◽

Low Noise Amplifier ◽

Ultra Low Power ◽

Ka Band ◽

Noise Amplifier

Download Full-text

Low Power Ku- and Ka-Band SiGe HBT Low-Noise Amplifiers

2020 Austrochip Workshop on Microelectronics (Austrochip) ◽

10.1109/austrochip51129.2020.9232993 ◽

2020 ◽

Author(s):

Syed Sharfuddin Ahmed ◽

Hermann Schumacher

Keyword(s):

Low Power ◽

Low Noise ◽

Low Noise Amplifiers ◽

Ka Band ◽

Sige Hbt

Download Full-text

Low-Cost Ka-Band Cloud Radar System for Distributed Measurements within the Atmospheric Boundary Layer

Remote Sensing ◽

10.3390/rs12233965 ◽

2020 ◽

Vol 12 (23) ◽

pp. 3965

Author(s):

Roberto Aguirre ◽

Felipe Toledo ◽

Rafael Rodríguez ◽

Roberto Rondanelli ◽

Nicolas Reyes ◽

...

Keyword(s):

Continuous Wave ◽

Low Cost ◽

Medium Size ◽

Physical Parameters ◽

Mountain Range ◽

Ka Band ◽

Range Resolution ◽

Cloud Radar ◽

Marine Stratus ◽

Application Fields

Radars are used to retrieve physical parameters related to clouds and fog. With these measurements, models can be developed for several application fields such as climate, agriculture, aviation, energy, and astronomy. In Chile, coastal fog and low marine stratus intersect the coastal topography, forming a thick fog essential to sustain coastal ecosystems. This phenomenon motivates the development of cloud radars to boost scientific research. In this article, we present the design of a Ka-band cloud radar and the experiments that prove its operation. The radar uses a frequency-modulated continuous-wave with a carrier frequency of 38 GHz. By using a drone and a commercial Lidar, we were able to verify that the radar can measure reflectivities in the order of −60 dBZ at 500 m of distance, with a range resolution of 20 m. The lower needed range coverage imposed by our case of study enabled a significant reduction of the instrument cost compared to existent alternatives. The portability and low-cost of the designed instrument enable its implementation in a distributed manner along the coastal mountain range, as well as its use in medium-size aerial vehicles or balloons to study higher layers. The main features, limitations, and possible improvements to the current instrument are discussed.

Download Full-text