Global mapping of attenuation at ku- and ka-band

Chandrasekar, V.; Fukatsu, Hiroko; Mubarak, K.

doi:10.1109/tgrs.2003.815973

Cited by 20 publications

(7 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Note that these GPM CORRA products are not fully decoupled from actual GNSS RO measurements, as the retrieval algorithm uses information from models to apply certain corrections (e.g. path attenuation in Chandrasekar et al , 2003). Since GNSS RO are assimilated into global weather models, indirect RO information may be embedded in the GPM products being used in this exercise.…”

Section: Generation Of Reference Probability Look‐up Tablesmentioning

confidence: 99%

Probability of intense precipitation from polarimetric GNSS radio occultation observations

Cardellach

Padullés

Tomás

et al. 2017

Quart J Royal Meteoro Soc

View full text Add to dashboard Cite

There is currently a gap in satellite observations of the moisture structure during heavy precipitation conditions, since infrared and microwave sounders cannot sense water-vapour structure near the surface in the presence of intense precipitation. Conversely, Global Navigation Satellite System (GNSS) radio occultations (RO) can profile the moisture structure with high precision and vertical resolution, but cannot indicate the presence of precipitation directly. Polarimetric RO (PRO) measurements have been proposed as a method to characterize heavy rain in GNSS RO, by measuring the polarimetric differential phase delay induced by large size hydrometeors. Previous studies have shown that the PRO polarimetric phase shift is sensitive to the path-integrated rain rate under intense precipitation scenarios, but there is no current method to invert PRO measurements into quantitative estimates of the path-averaged rain rate. In this manuscript, a probabilistic inversion approach to the GNSS PRO observables is proposed, where the GPM precipitation products are used for the construction of an a priori look-up table (LUT) database. The performance of the LUTs is assessed for use in the inversion of satellite-based GNSS PRO observations, based on synthetically generated PRO data of actual events, which correspond to co-locations between GNSS RO profiles and the TRMM observations. The synthetic data include end-to-end propagation effects of the polarimetric observables and a simple separation algorithm to isolate the hydrometeor component of the observation. The assessment results in agreement better than ±1 mm h −1 between the reference LUT and the actual rain statistics of the synthetic data, proving the suitability of the GPMbased probabilistic inversion tool. These findings indicate that the GNSS PRO products are capable of extending the current GNSS RO ones by associating indications of rainrate probabilities at different altitudes, at ∼250 m vertical resolution and under intense precipitation scenarios with the standard vertical thermodynamic profiles.

show abstract

Section: Generation Of Reference Probability Look‐up Tablesmentioning

confidence: 99%

Probability of intense precipitation from polarimetric GNSS radio occultation observations

Cardellach

Padullés

Tomás

et al. 2017

Quart J Royal Meteoro Soc

View full text Add to dashboard Cite

show abstract

“…The higher frequency bands generally enable 70 to 100 Mbps and 2.5 to 30 Mbps data rates to the aircraft and from the aircraft, respectively [51], [52]. However, the high-frequency bands can suffer from the atmospheric attenuation, and free space path loss risk as shown in Table 3 [53]. 2) Optical Communication: The optical links could also be used for satellite-to-aircraft communications based on the Line-of-Sight (LOS) concept [56].…”

Section: ) Low Earth Orbit (Leo)mentioning

confidence: 99%

Aeronautical Networks for In-Flight Connectivity: A Tutorial of the State-of-the-Art and Survey of Research Challenges

et al. 2022

View full text Add to dashboard Cite

The aeronautical networks attract the attention of both industry and academia since Internet access during flights turns to the crucial demand from luxury with the evolving technology. This In-Flight Connectivity (IFC) necessity is currently dominated by the satellite connectivity and Air-to-Ground (A2G) network solutions. However, the high installation/equipment cost and latency of the satellite connectivity reduce its efficiency. The A2G networks are utilized through the 4G/5G ground stations deployed on terrestrial areas to solve these satellites' problems. This terrestrial deployment reduces the coverage area of A2G networks, especially for remote flights over the ocean. The Aeronautical Ad-hoc Networks (AANETs) are designed to provide IFC while solving the primary defects of dominating solutions. The AANET is an entirely novel solution under the vehicular networks since it consists of aircraft with ultra-dynamic and unstructured characteristics. These characteristics separate it from the less dynamic Flying Ad-Hoc Networks (FANETs). Therefore, the environmental and mobility effects cause specific challenges for AANETs. This article presents a holistic review of these open AANET challenges by investigating them in data link, network, and transport layers. Before giving the details of these challenges, this article explores the state-of-the-art literature about satellite and A2G networks for IFC. We then give our specific interest to the AANET by investigating its particular characteristics and open research challenges. The main starting point of this study is that there is a lack of compact research on this exciting topic, although IFC is an inevitable need for the aeronautical industry. Also, the AANET could be underlined by giving all state-ofthe-art about the dominating IFC solutions. Therefore, this is the first work exploring the state-of-the-art for all the existing aeronautical networking technologies under a single comprehensive survey by deeply analyzing specific characteristics and open research challenges of AANETs. Additionally, the AANET is a novel topic and should be separately investigated from the FANETs as given in current literature.

show abstract

“…Attenuation corrections for Ka-band reflectivity for precipitation particles or cloud droplets have been proposed using dual-wavelength radars (Chandrasekar et al 2003), a vertical pointing radar (Matrosov 2005), and dual Ka-band radars (Nishikawa et al 2016). However, the main target of this study is early convective echoes, which appear in environments where the attenuation due to other convective echoes is negligible.…”

Section: A Radarsmentioning

confidence: 99%

Early Detection of Convective Echoes and Their Development Using a Ka-Band Radar Network

Yoshida

Misumi

Maesaka

2021

Weather and Forecasting

View full text Add to dashboard Cite

Cumulonimbus clouds, which cause local heavy rainfall and urban floods, can develop within 20 minutes after being detected by operational centimeter-wavelength (X-, C-, or S-band) weather radars. To detect such clouds with greater lead times, Ka-band radars at a wavelength of 8.6 mm together with operational X-band radars were used in this study. The vertically averaged radar reflectivity (VAR) of convective echoes detected by the Ka-band and X-band radars were defined as mesoscale cloud echoes (MCEs) and mesoscale precipitation echoes (MPEs), respectively. The time series of each echo was analyzed by an echo tracking algorithm. On average, MCEs that developed into MPEs (denoted as developed MCEs) were detected 17 minutes earlier than the MPEs and 33 minutes earlier than the peak time of the area-averaged VAR (VARa) for MPEs. Some MCEs dissipated without developing into MPEs (denoted as non-developed MCEs). There were statistically significant differences between the developed and non-developed MCEs in terms of the maximum VARa values, maximum MCEs areas, and increase amounts of the VARa values and MCE areas for the first 6 to 12 minutes after their detection. Among these indicators, the maximum VARa for the first 9 minutes showed the most significant differences. Therefore, an algorithm for predicting MCE development using this indicator is discussed.

show abstract

Global mapping of attenuation at ku- and ka-band

Cited by 20 publications

References 10 publications

Probability of intense precipitation from polarimetric GNSS radio occultation observations

Probability of intense precipitation from polarimetric GNSS radio occultation observations

Aeronautical Networks for In-Flight Connectivity: A Tutorial of the State-of-the-Art and Survey of Research Challenges

Early Detection of Convective Echoes and Their Development Using a Ka-Band Radar Network

Contact Info

Product

Resources

About