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DOE OSTI2020

A Satellite-Based Estimate of Convective Vertical Velocity and Convective Mass Flux: Global Survey and Comparison with Radar Wind Profiler Observations

Convective vertical velocity (w c ) and convective mass flux (M c ) lie at the heart of GCM cumulus parameterizations, but few observations of these critical parameters are available. In this paper, we develop and evaluate a novel, satellite-based method for estimating profiles of w c and M c . Here, comparisons with collocated ground-based radar wind profiler (RWP) observations show that satellite estimated median w c is slightly greater than the RWP estimates, but they show solid agreement when compared at the 95th percentiles (intense updrafts). RWP-derived and satellite estimated M c are broadly comparable in the lower and middle troposphere, with some differences in the upper troposphere due to differences in convective core sampling. A k-means cluster analysis of multiple years of w c data shows that convective characteristics are distinctly different among extratropical convection, tropical land convection, and tropical oceanic convection. Tropical land convection is significantly more intense and more variable than the oceanic counterpart.

54 ENVIRONMENTAL SCIENCES↗

NASA NTRS2011

Quality-Controlled Wind Data from the Kennedy Space Center 915 Megahertz Doppler Radar Wind Profiler Network

The National Aeronautics and Space Administration s (NASA) Kennedy Space Center (KSC) has installed a five-instrument 915-Megahertz (MHz) Doppler Radar Wind Profiler (DRWP) system that records atmospheric wind profile properties. The purpose of these profilers is to fill data gaps between the top of the KSC wind tower network and the lowest measurement altitude of the KSC 50-MHz DRWP. The 915-MHz DRWP system has the capability to generate three-dimensional wind data outputs from approximately 150 meters (m) to 6,000 m at roughly 15-minute (min) intervals. NASA s long-term objective is to combine the 915-MHz and 50-MHz DRWP systems to create complete vertical wind profiles up to 18,300 m to be used in trajectory and loads analyses of space vehicles and by forecasters on day-of-launch (DOL). This analysis utilizes automated and manual quality control (QC) processes to remove erroneous and unrealistic wind data returned by the 915-MHz DRWP system. The percentage of data affected by each individual QC check in the period of record (POR) (i.e., January to April 2006) was computed, demonstrating the variability in the amount of data affected by the QC processes. The number of complete wind profiles available at given altitude thresholds for each profiler in the POR was calculated and outputted graphically, followed by an assessment of the number of complete wind profiles available for any profiler in the POR. A case study is also provided to demonstrate the QC process on a day of a known weather event.

Dryden, Rachel L.↗

NASA NTRS2019

Analyses of Kennedy Space Center Tropospheric Doppler Radar Wind Profiler Data for Space Launch System Program Certification

This paper documents the methodology and results of analyses used to certify the Kennedy Space Center (KSC) Tropospheric Doppler Radar Wind Profiler (TDRWP) as input to launch commit evaluations for the National Aeronautics and Space Administration’s (NASA) Space Launch System Program (SLSP). These analyses, and the requirements that they address, were designed by the Marshall Space Flight Center Natural Environments Branch (MSFC NE) to certify that the TDRWP provides data of sufficient accuracy and resolution for SLSP, and that the instrument provides enough reliability to support Day-of- Launch Initialization Loads Update (DOLILU) operations. On day-of-launch (DOL), space launch vehicle operators have used data from wind profilers to reverse a previous GO call in prelaunch loads and trajectory assessments due to the profiler’s capability to quickly identify changes in the wind profile within a rapidly changing wind environment. Certification of the TDRWP would allow SLSP to use DOL wind data generated by the TDRWP to design the vehicle trajectory and to verify trajectory and load constraints during the countdown for launch commit decision.

Barbre, Robert E., Jr.↗

NASA NTRS1993

Comparison of FPS-16 radar/jimsphere and NASA's 50-MHz radar wind profiler turbulence indicators

Measurements of the wind and turbulent regions from the surface to 16 km by the FPS-11 radar/jimsphere system are reported with particular attention given to the use of these turbulence and wind assessments to validate the NASA 50-MHz radar wind profiler. Wind profile statistics were compared at 150-m wavelengths, a wavelength validated from 20 jimspheres, simultaneously tracked by FPS-16 and FPQ-14 radar, and the resulting analysis of auto spectra, cross-spectra, and coherence squared spectra of the wind profiles. Results demonstrate that the NASA prototype wind profiler is an excellent monitoring device illustrating the measurements of the winds within 1/2 hour of launch zero.

Susko, Michael↗

NASA NTRS2016

Results of the Updated NASA Kennedy Space Center 50-MHz Doppler Radar Wind Profiler Operational Acceptance Test

We present here the methodology and results of the Operational Acceptance Test (OAT) performed on the new Kennedy Space Center (KSC) 50-MHz Doppler Radar Wind Profiler (DRWP). On day-of-launch (DOL), space launch vehicle operators have used data from the DRWP to invalidate winds in prelaunch loads and trajectory assessments due to the DRWP's capability to quickly identify changes in the wind profile within a rapidly-changing wind environment. The previous DRWP has been replaced with a completely new system, which needs to undergo certification testing before being accepted for use in range operations. The new DRWP replaces the previous three-beam system made of coaxial cables and a copper wire ground plane with a four-beam system that uses Yagi antennae with enhanced beam steering capability. In addition, the new system contains updated user interface software while maintaining the same general capability as the previous system. The new DRWP continues to use the Median Filter First Guess (MFFG) algorithm to generate a wind profile from Doppler spectra at each range gate. DeTect (2015) contains further details on the upgrade. The OAT is a short-term test designed so that end users can utilize the new DRWP in a similar manner to the previous DRWP during mission operations at the Eastern Range in the midst of a long-term certification process. This paper describes the Marshall Space Flight Center Natural Environments Branch's (MSFC NE's) analyses to verify the quality and accuracy of the DRWP's meteorological data output as compared to the previous DRWP. Ultimately, each launch vehicle program has the responsibility to certify the system for their own use.

Barbre', Robert E., Jr.↗

DOE OSTI2023

Calibrating radar wind profiler reflectivity factor using surface disdrometer observations

Abstract. This study uses surface disdrometer reflectivity factor estimates to calibrate the vertical and off-vertical pointing radar beams produced by an ultra high frequency (UHF) band radar wind profiler (RWP) deployed at the US Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) program Southern Great Plains (SGP) Central Facility in northern Oklahoma from April 2011 through July 2019. The methodology consists of five steps. First, the recorded Doppler velocity power spectra are adjusted to account for Nyquist velocity aliasing and coherent integration filtering effects. Second, the spectrum moments are calculated. The third step increases the signal-to-noise ratio (SNR) due to inflated noise power estimates during convective rain events that cause SNR to be biased low. The fourth step determines the RWP calibration constant for one radar beam (called the “reference” beam) by comparing uncalibrated RWP reflectivity factors at 500 m above the ground to 1 min resolution surface disdrometer reflectivity factors. The last step uses the calibrated reference beam reflectivity factor to calibrate the other radar beams during precipitation. There are two key findings. The RWP sensitivity decreased by approximately 3 to 4 dB yr−1 as the hardware aged. This drift was slow enough that the reference calibration constant can be estimated over 3-month intervals using episodic rain events. The calibrated moments are available on the DOE ARM data archive, and the Python processing code is available on public repositories.

54 ENVIRONMENTAL SCIENCES↗

NASA NTRS2021

Performance Assessment of the Eastern Range Titusville-Cocoa 915-MHz Doppler Radar Wind Profiler

The United States Space Force (USSF) is responsible for space vehicle launches at its Eastern Range (ER), which includes the Cape Canaveral Space Force Station (CCSFS). Multiple systems are used to measure the atmosphere at the ER, including suites of Doppler Radar Wind Profilers (DRWPs)that operate at 915MHz and measure winds within the lowest few kilometers of the atmosphere. Observations of boundary layer winds can be used for multiple applications, including serving as input to toxic dispersion models and characterizing winds for low-level aborts. The USSF upgraded the Titusville-Cocoa(TICO)DRWP, which collected data during the spring and summer of 2020. The USSF also requested NASA’s Marshall Space Flight Center (MSFC) Natural Environments Branch (NE) to evaluate wind output from this DRWP system. This report describes the system and the analyses that MSFC NE conducted to demonstrate the system’s wind accuracy relative to balloons from the Automated Meteorological Profiling System (AMPS), data availability, and effective vertical resolution (EVR).

B. J. Barbre↗

NASA NTRS2021

Performance Assessment of the Eastern Range False Cape 915-MHz Doppler Radar Wind Profiler

The United States Space Force (USSF) is responsible for space vehicle launches at its Eastern Range (ER), which includes the Cape Canaveral Space Force Station (CCSFS). Multiple systems are used to measure the atmosphere at the ER, including suites of Doppler Radar Wind Profilers (DRWPs) operating at 915 MHz that measure winds within the lowest few kilometers of the atmosphere. Observations of boundary layer winds can be used for multiple applications, including serving as input to toxic dispersion models and characterizing winds for low-level aborts. The USSF upgraded the False Cape DRWP, which collected data during the autumn of 2020. The USSF also requested NASA’s Marshall Space Flight Center (MSFC) Natural Environments Branch (NE) to evaluate wind output from this DRWP system. This report describes the system and the analyses that MSFC NE conducted to demonstrate the system’s wind accuracy relative to balloons from the Automated Meteorological Profiling System (AMPS), data availability, and effective vertical resolution (EVR).

BJ Barbre↗

NASA NTRS2022

Comparison Analysis of the Eastern Range False Cape 915-MHz Doppler Radar Wind Profiler

The United States Space Force (USSF) is responsible for space vehicle launches at its Eastern Range (ER), which includes the Cape Canaveral Space Force Station (CCSFS). Multiple systems are used to measure the atmosphere at the ER, including suites of Doppler Radar Wind Profilers (DRWPs) operating at 915MHz that measure winds within the lowest few kilometers of the atmosphere. Observations of boundary layer winds can be used for multiple applications, including serving as input to toxic dispersion models and characterizing winds for low-level aborts. In fall 2020 the USSF requested NASA’s Marshall Space Flight Center (MSFC) Natural Environments Branch (NE) to evaluate wind output from the False Cape(FC) DRWP system (MSFC NE 2021). In that analysis, it was found that data availability was low in the lowest few hundred meters of a profile, shown in Figure 1. To increase the available data, the USSF modified the quality control (QC) algorithm for the FCDRWP, which collected data from October 2020 to January 2021. In Fall 2021, the USSF requested NASA’s MSFC NE to evaluate the modified QC algorithm by comparing the data processed by the modified method (referred to as beam data) to data processed with the original QC method (referred to as original data). This report describes the system and the analyses that MSFC NE conducted to compare the availability and quality of data from the two QC methods

Maggire Fielder↗

NASA NTRS1983

An evaluation of the accuracy of some radar wind profiling techniques

Major advances in Doppler radar measurement in optically clear air have made it feasible to monitor radial velocities in the troposphere and lower stratosphere. For most applications the three dimensional wind vector is monitored rather than the radial velocity. Measurement of the wind vector with a single radar can be made assuming a spatially linear, time invariant wind field. The components and derivatives of the wind are estimated by the parameters of a linear regression of the radial velocities on functions of their spatial locations. The accuracy of the wind measurement thus depends on the locations of the radial velocities. The suitability is evaluated of some of the common retrieval techniques for simultaneous measurement of both the vertical and horizontal wind components. The techniques considered for study are fixed beam, azimuthal scanning (VAD) and elevation scanning (VED).

Koscielny, A. J.↗

NASA NTRS2012

Quality Control Algorithms for the Kennedy Space Center 50-Megahertz Doppler Radar Wind Profiler Winds Database

This paper presents the process used by the Marshall Space Flight Center Natural Environments Branch (EV44) to quality control (QC) data from the Kennedy Space Center's 50-MHz Doppler Radar Wind Profiler for use in vehicle wind loads and steering commands. The database has been built to mitigate limitations of using the currently archived databases from weather balloons. The DRWP database contains wind measurements from approximately 2.7-18.6 km altitude at roughly five minute intervals for the August 1997 to December 2009 period of record, and the extensive QC process was designed to remove spurious data from various forms of atmospheric and non-atmospheric artifacts. The QC process is largely based on DRWP literature, but two new algorithms have been developed to remove data contaminated by convection and excessive first guess propagations from the Median Filter First Guess Algorithm. In addition to describing the automated and manual QC process in detail, this paper describes the extent of the data retained. Roughly 58% of all possible wind observations exist in the database, with approximately 100 times as many complete profile sets existing relative to the EV44 balloon databases. This increased sample of near-continuous wind profile measurements may help increase launch availability by reducing the uncertainty of wind changes during launch countdown

Barbre, Robert E., Jr.↗

NASA NTRS1994

Application of 50 MHz doppler radar wind profiler to launch operations at Kennedy Space Center and Cape Canaveral Air Station

This paper presents a case study where a significant wind shift, not detected by jimspheres, was detected by the 50 MHz DRWP (Doppler Radar Wind Profiler) and evaluated to be acceptable prior to the launch of a Shuttle. This case study illustrates the importance of frequent upper air wind measurements for detecting significant rapidly changing features as well as for providing confidence that the features really exist and are not due to instrumentation error. Had the release of the jimsphere been timed such that it would have detected the entire wind shift, there would not have been sufficient time to release another jimsphere to confirm the existence of the feature prior to the scheduled launch. We found that using a temporal median filter on the one minute spectral estimates coupled with a constraining window about a first guess velocity effectively removes nearly all spurious signals from the velocity profile generated by NASA's 50 MHz DRWP while boosting the temporal resolution to as high as one profile every 3 minutes. The higher temporal resolution of the 50 MHz DRWP using the signal processing algorithm described in this paper ensures the detection of rapidly changing features as well as provides the confidence that the features are genuine. Further benefit is gained when the profiles generated by the DRWP are examined in relation to the profiles measured by jimspheres and/or rawinsondes. The redundancy offered by using two independent measurements can dispel or confirm any suspicion regarding instrumentation error or malfunction and wind profiles can be examined in light of their respective instruments' strengths and weaknesses.

Schumann, Robin S.↗

DOE OSTI2023

Radar Wind Profiler at McKinleyville, CA

These data are collected as part of an observational database developed to support the floating offshore wind energy research under the ORACLE project funded by DOE Wind Energy Technologies Office (WETO). The radar wind profiler network data are collected by NOAA (https://psl.noaa.gov/data/obs/datadisplay), and only data within the state of California are part of the database.

17 WIND ENERGY↗

DOE OSTI2023

Radar Wind Profiler at Bodega Bay

17 WIND ENERGY↗

DOE OSTI2023

Radar Wind Profiler at Point Sur

17 WIND ENERGY↗

DOE OSTI2023

Radar Wind Profiler at Santa Barbara

17 WIND ENERGY↗

DOE OSTI2023

Radar Wind Profiler at San Nicolas Island

17 WIND ENERGY↗

NASA NTRS1993

Implementation and evaluation of the new wind algorithm in NASA's 50 MHz doppler radar wind profiler

The purpose of this report is to document the Applied Meteorology Unit's implementation and evaluation of the wind algorithm developed by Marshall Space Flight Center (MSFC) on the data analysis processor (DAP) of NASA's 50 MHz doppler radar wind profiler (DRWP). The report also includes a summary of the 50 MHz DRWP characteristics and performance and a proposed concept of operations for the DRWP.

Taylor, Gregory E.↗