Ultra High Resolution Rain Retrieval from QuikSCAT Data

2009 IEEE Radar Conference

Milliff

Rodríguez

2009

Abstract-A satellite mission is proposed to provide frequent, high-resolution measurements of surface winds, rain, and temperature profiles to support critical observations of Mesoscale Convective Systems (MCS) over the global tropical oceans.The proposed mission includes an innovative active/passive microwave system coupled with IR cloud top measurements for multi-layer atmosphere observations.The TropSat system will provide frequent, high-resolution measurements of the near-surface wind vector and rain rate over the tropical oceans. The senor design is based on the proven technology of SeaWinds but includes key innovations and an integral radiometer. The main sensor will include: (1) dual-band (C-and Ku-band) and dual beam (inner/outer beams) operation (C-and Ku-band) at multiple polarizations and (2) groundbased post processing to achieve the desired high spatial resolution. Backscatter measurements over land can support vegetation and climate change studies. This paper provides a brief description of the TropSat mission, discusses various instrument and mission tradeoffs, and presents performance estimates to demonstrate the feasibility of the mission concept.

Section: Iiiscatterometer Systemmentioning

confidence: 99%

The TropSat mission: An observatory for mesoscale convective system processes in the global tropics

2009 IEEE Radar Conference

Milliff

Rodríguez

2009

“…1, whereas it is more difficult to accurately identify them using the lower resolution image (left). Although much more prone to noise and rain contamination [2], UHR images provide more details in the wind speed field compared to L2B images.…”

Section: Advantages Of Uhr Images Over L2bmentioning

confidence: 99%

Effectiveness Of QuikSCAT's Ultra-High Resolution Images in Determining Tropical Cyclone Eye Location

Said

IGARSS 2008 - 2008 IEEE International Geoscience and Remote Sensing Symposium

2008

The 25km resolution standard wind products (L2B) are available operationally in near-real time from SeaWinds on QuikSCAT. This relatively low resolution can be enhanced to yield a 2.5km ultra-high resolution (UHR) product that can be used to identify hurricane eye centers more accurately. A comparison is made between the analyst's choice of eye location based on UHR images and interpolated best-track position. In this analysis, the UHR images are divided into two categories based on the analyst's confidence level of finding the eye center location. In each category, statistical error quantities are computed. UHR images within the high-confidence category can provide, for a given year and basin, mean error distance as small as 15km with a 9km standard deviation. The use of these categories may facilitate the realization of QuikSCAT's effectiveness in helping to identify and track hurricane eye centers.

“…However, where rain rates are large, this method tends to deweight the measurements and impose the model more heavily. The rain contamination issue can be ameliorated using a simultaneous wind and rain retrieval method at ultra-high resolution (UHRSWR) [3]. However, this further increases the variability of the wind estimates and does not deal with ambiguity selection issues.…”

Section: Introductionmentioning

confidence: 99%

Rain and Wind Estimation from Seawinds in Hurricanes at Ultra High Resolution

Williams

IGARSS 2008 - 2008 IEEE International Geoscience and Remote Sensing Symposium

2008

A Bayesian method for estimating wind and rain in hurricanes from SeaWinds at ultra-high resolution is developed. We use a hurricane model to generate prior distributions for the wind speed, wind direction, and rain rate. The rain prior is derived from data from the Tropical Rainfall Measuring Mission Precipitation Radar (TRMM-PR). The new method reduces the variability of the standard simultaneous wind and rain estimates while preserving meso-scale detail.