Space launch vehicles incorporate upper-level wind profiles to determine wind effects on the vehicle and for a commit to launch decision. These assessments incorporate wind profiles measured hours prior to launch and may not represent the actual wind the vehicle will fly through. Uncertainty in the upper-level winds over the time period between the assessment and launch can be mitigated by a statistical analysis of wind change over time periods of interest using historical data from the launch range. Five sets of temporal wind pairs at various times (.75, 1.5, 2, 3 and 4-hrs) at the Eastern Range, Western Range and Wallops Flight Facility were developed for use in upper-level wind assessments. Database development procedures as well as statistical analysis of temporal wind variability at each launch range will be presented

Barbre, Robert E.

Decker, Ryan

NASA Technical Reports Server

Resultant Wind Pairs
Resultant wind pairs (Table 1) in databases can consist of the following:
• 2 Jimsphere profiles.
• 2 rawinsonde profiles.
• 1 Jimsphere and 1 rawinsonde profile.
• 2 spliced DRWP profiles.
o The Jimsphere and rawinsonde pairs the time ranged by +/- 15 minutes on either side of
the desired time interval to increase the wind pair sample size. For example, profile pairs
spaced between 2.75 to 3.25 hours were treated as 3-hour pairs.
o For the ER DRWP pairs, two profiles defined a pair if the desired time separation of the
pair +/- two minutes separated the profiles’ timestamps. For example, a 0.75-hour (45-
minute) pair has two profiles spaced anywhere from 43-47 minutes apart.
TEMPORAL VARIABILITY OF UPPER-LEVEL WINDS AT THE EASTERN 
RANGE, WESTERN RANGE AND WALLOPS FLIGHT FACILITY
Ryan Decker
NASA/Marshall Space Flight Center
Huntsville, AL
Robert E. Barbré, Jr.
Jacobs Technology, ESSSA Group, MSFC 
Huntsville, AL
Abstract
Space launch vehicles incorporate upper-level wind profiles to determine wind effects on
the vehicle and for a commit to launch decision. These assessments incorporate wind
profiles measured hours prior to launch and may not represent the actual wind the
vehicle will fly through. Uncertainty in the upper-level winds over the time period
between the assessment and launch can be mitigated by a statistical analysis of wind
change over time periods of interest using historical data from the launch range. Five
sets of temporal wind pairs at various times (.75, 1.5, 2, 3 and 4-hrs) at the Eastern
Range (ER), Western Range (WR) and Wallops Flight Facility (WFF) were developed for
use in upper-level wind assessments. Database development procedures as well as
statistical analysis of temporal wind variability at each launch range will be presented.
Data Sources
Upper atmospheric wind data (600-60,000 ft) obtained from multiple systems used at
some or all of the facilities:
• Rawinsondes
• Jimspheres
• Vertically pointing Doppler Radar Wind Profilers (DRWP)
WFF
- National Climatology Data Center (NCDC) Integrated Global Radiosonde Archive
(IGRA) (Durre et al. 2006) October 1963 through January 2000 period of record
(POR).
- WFF weather balloon archive February 2000 through January 2013 consisting of
rawinsondes released at the NWS site and at WFF in support of range operations.
WR
- NCDC IGRA data from January 1965 through January 2013.
- USAF-provided WR data from February 2008 through April 2012.
- WR Jimsphere database from January 1965 through September 2001.
ER
- Profiles from the 50-MHz and 915-MHz DRWP systems. Data from both systems
used to generate spliced wind profiles (Barbré 2013); POR - April 2000 through
December 2009.
Data Processing and Quality Control (QC) Procedures 
Automated and manual QC checks were applied on the data from each measurement
source (Decker and Barbré 2013).
Checks consisted of automated and manual QC checks.
• Minimum altitude
• More than 50% of wind data must exist in both profiles
• Vertical wind shear
Manual profile inspection was required to check consistence within a profile pair.
Jimsphere data had to be filtered to remove the small-scale wavelengths in order to
maintain an equivalent effective vertical resolution with rawinsonde systems (Wilfong et
al., 1997). An 800-ft filter was applied to the Jimsphere based on a mean normalized
power spectrum density (PSD) analysis of the Jimsphere and rawinsonde data (Figure
1).
10
2
10
3
10
4
10
5
10
-5
10
-4
10
-3
10
-2
10
-1
10
0 WR Mean-Normalized U PSD, 10-50 kft
Wavelength (ft)
M
N
P
S
D
 
(
D
i
m
e
n
s
i
o
n
l
e
s
s
)
 
 
RTAMPS (n = 1403)
Jimsphere (n = 662)
10
2
10
3
10
4
10
5
10
-5
10
-4
10
-3
10
-2
10
-1
10
0 WR Mean-Normalized V PSD, 10-50 kft
Wavelength (ft)
M
N
P
S
D
 
(
D
i
m
e
n
s
i
o
n
l
e
s
s
)
 
 
RTAMPS (n = 1403)
Jimsphere (n = 662)
ryan.k.decker@nasa.gov
Time Interval 
(hours) ER WR WFF
0.75 273,265 435 78
1.5 260,878 401 54
2 297,491 548 75
3 273,189 508 127
4 276,108 366 74
TOTAL 1,380,931 2258 408
0 5 10 15 20
0.01
0.05
0.1
0.25
0.5
0.75
0.9
0.95
0.99
0.995
0.999
ER Maximum 1.5-hr u-component Change Magnitudes
with Generalized Extreme Value Fit and
95% Confidence Bounds, n = 260878
u-component Change Magnitude (kt)
P
r
o
b
a
b
i
l
i
t
y
 
 
Data
GEV fit
95% GEV CB
0 5 10 15 20
0.01
0.050.1
0.25
0.5
0.75
0.9
0.95
0.99
0.995
0.999
ER Maximum 1.5-hr v-component Change Magnitudes
with Generalized Extreme Value Fit and
95% Confidence Bounds, n = 260878
v-component Change Magnitude (kt)
P
r
o
b
a
b
i
l
i
t
y
 
 
Data
GEV fit
95% GEV CB
10 20 30 40 50 60 70
0.01
0.05
0.1
0.25
0.5
0.75
0.9
0.95
0.99
0.995
WFF Maximum 1.5-hr u-component Change Magnitudes
with Generalized Extreme Value Fit and
95% Confidence Bounds, n = 54
u-component Change Magnitude (kt)
P
r
o
b
a
b
i
l
i
t
y
 
 
Data
GEV fit
95% GEV CB
5 10 15 20 25 30 35 40 45 50
0.01
0.05
0.1
0.25
0.5
0.75
0.9
0.95
0.99
0.995
WFF Maximum 0.75-hr v-component Change Magnitudes
with Generalized Extreme Value Fit and
95% Confidence Bounds, n = 78
v-component Change Magnitude (kt)
P
r
o
b
a
b
i
l
i
t
y
 
 
Data
GEV fit
95% GEV CB
Wind Pair Statistical Analysis
The analyses examine extreme wind change population distributions. Extreme wind
change distributions are usually non-Gaussian (Merceret 1997), so the use of an
extreme theoretical probability function was used to fit the data. The generalized extreme
value (GEV) probability distribution function (PDF) (Coles, 2001, Kotz and Nadarajah,
2000) provided a good fit of the extreme u- and v-component wind changes in each pair
up to roughly the 99th percentile level. The GEV PDF is expressed by:
where x represents each value in a distribution of maximum wind changes, and k, µ, and
σ denote the scale, shape, and location parameters, respectively, of the GEV estimate.
Using the results from the GEV, 95% CB at various percentile levels were calculated
using the Asymptotic Distribution of Percentiles (ADP) method (DasGupta 2008). The
analysis uses the 95% CB as a conservative approach to assess the range of extreme
wind change for selected percentile levels (Figures 2-3).
y  f (x | k,, )  1



exp  1 k
x  





1
k






1 k x  




11
k
k  0,1 k x    0
Sample Population 
Because of the large uncertainty at the extreme empirical percentile for pairs of small sample
size (Figure 3), another approach was applied to quantify the confidence of the empirical
wind change data. This approach uses a function from Smith and Adelfang (1998) that
approximates the probability level of a sample population with a specified sample size to a
probability level of the universal population. The function makes no assumption to the form of
the probability distribution function of the wind change and is defined as
where Pu is the probability that the sample contains the universal population at the sample
probability Ps given the sample size, n. Tables 2-4 presents the confidence level of the
sample containing the universal population at various sample probability levels for the sample
sizes at the three locations.
Pu 1 (n1) nPs



Ps
n
Table 1: Total number of wind pairs at each location.
Figure 1: Mean-normalized power spectral density (PSD) for the WR Jimsphere and
Real-Time Automated Meteorological Profiling System (RTAMPS) rawinsonde systems.
Figure 2: Maximum wind change from the
1.5-hour wind pairs at the ER with 95% CB
for the u-(top) and v-component (bottom)
wind changes. The number of pairs (n) in
the analysis is 260,878.
Figure 3: Maximum wind change from the
1.5-hour wind pairs at WFF with 95% CB
for the u-(top) and v-component (bottom)
wind changes. The number of pairs (n) in
the analysis is 54.
Table 2: Confidence levels of the
universal population for arbitrarily
selected sample probability levels and
the WR sample size for each wind pair
time interval (Smith and Adelfang 1998).
Table 3: Confidence levels of the universal
population for arbitrarily selected sample
probability levels and the WFF sample size for
each wind pair time interval (Smith and
Adelfang 1998).
Table 4: Confidence levels of the
universal population for arbitrarily
selected sample probability levels and
the ER sample size for each wind pair
time interval (Smith and Adelfang 1998).
Conclusion
Databases for five time intervals (0.75, 1.5, 2-, 3- and 4 hours) at the USAF ER and WR, as
well as NASA’s WFF were generated through use of historical data at each location.
Databases were compiled using wind profiles from rawinsonde, Jimsphere, and DRWP
systems. Extensive QC checks were applied on the data to remove unacceptable profiles,
and statistical analyses of the resultant wind pairs from each site were performed to
determine if the observed extreme wind changes in the sample pairs represent extreme
temporal wind change.
• ER wind pair databases yielded sample sizes
that characterize the extreme wind change
environment.
• WR wind pair database sample size is large
enough to characterize extreme wind change
environment up to the 99th percentile level.
• WFF wind pair database has a low confidence
that the observed extremes in each time
period characterize the extreme wind change
environment. Therefore, for any application
using WFF wind pairs, the recommendation is
to apply the extreme 4-hour wind change
values for all time change intervals of interest.
Acknowledgements
Thanks to NASA’s Launch Services Program (LSP) office who sponsored the task, staff at
NASA’s Applied Meteorology Unit (AMU) who provided technical review and members of the
MSFC Natural Environments (NE) Branch for the technical discussions on wind statistics and
spectral analysis. This analysis could not have been conducted without data provided by the
following personnel:
• Mr. Tyler Brock (VAFB/USAF): Providing Vandenberg Air Force Base (VAFB) Rawinsonde
data
• Mr. Brian Cunningham (WFF/LIT and Associated, Inc.): Providing Wallops Flight Facitily
(WFF) rawinsonde data and answering questions relating to timestamp discrepancies.
• Mr. Matt McClelland, United Launch Alliance: Providing VAFB Jimsphere and rawindsonde
data.
• Dr. Brian Sako, Aerospace Corp.: Providing VAFB Jimsphere data.
https://ntrs.nasa.gov/search.jsp?R=20140008732 2019-08-29T13:51:54+00:00Z


Temporal Variability of Upper-level Winds at the Eastern Range, Western Range and Wallops Flight Facility

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