MADIS NOAA Profiler Network (NPN) Variables
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Code Name Units Max Notes Max Number Database
QC Level* of Levels FSL AWIPS
FSL AWIPS
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Integrated Profile 1 64 43
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DD wind direction deg 2 2 X X
FF wind speed m/s 2 2 X X
U u wind component m/s 2 2 X X
V v wind component m/s 2 2 X X
W w wind component m/s 0 3 X X
FFSDEV wind speed std dev m/s 0 4 X X
WSDEV w std dev m/s 0 4 X X
HT geometric height m 0 5 X X
P pressure Pa 0 5 X X
CNUMN consensus number (North) 0 6 X
SGPWRN signal power (North) dB 0 7 X
RAVELN radial velocity (North) m/s 0 7 X
VELVRN velocity variance (North) (m/s)**2 0 7 X
CNUME consensus number (East) 0 6 X
SGPWRE signal power (East) dB 0 7 X
RAVELE radial velocity (East) m/s 0 7 X
VELVRE velocity variance (East) (m/s)**2 0 7 X
CNUMV consensus number (Vertical) 0 6 X X
SGPWRV signal power (Vertical) dB 0 7 X X
RAVELV radial velocity (Vertical) m/s 0 8 X
VELVRV velocity variance (Vertical) (m/s)**2 0
CNUMEN consensus number (East/North) 0 6 X
LEVTYPE level type code 0 9 X X
Low Mode Levels 1 36 36
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DDL wind direction deg 2 2 X X
FFL wind speed m/s 2 2 X X
UL u wind component m/s 2 2 X X
VL v wind component m/s 2 2 X X
WL w wind component m/s 0 3 X X
FFSDEVL wind speed std dev m/s 0 4 X X
WSDEVL w std dev m/s 0 4 X X
HTL geometric height m 0 5 X X
PL pressure Pa 0 5 X X
CNUMNL consensus number (North) 0 6 X
SGPWRNL signal power (North) dB 0 7 X
RAVELNL radial velocity (North) m/s 0 7 X
VELVRNL velocity variance (North) (m/s)**2 0 7 X
CNUMEL consensus number (East) 0 6 X
SGPWREL signal power (East) dB 0 7 X
RAVELEL radial velocity (East) m/s 0 7 X
VELVREL velocity variance (East) (m/s)**2 0 7 X
CNUMVL consensus number (Vertical) 0 6 X X
SGPWRVL signal power (Vertical) dB 0 7 X X
RAVELVL radial velocity (Vertical) m/s 0 7 X
VELVRVL velocity variance (Vertical) (m/s)**2 0 7 X
CNUMENL consensus number (East/North) 0 6 X
High Mode Levels 1 36 15
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DDH wind direction deg 2 2 X X
FFH wind speed m/s 2 2 X X
UH u wind component m/s 2 2 X X
VH v wind component m/s 2 2 X X
WH w wind component m/s 0 3 X X
FFSDEVH wind speed std dev m/s 0 4 X X
WSDEVH w std dev m/s 0 4 X X
HTH geometric height m 0 5 X X
PH pressure Pa 0 5 X X
CNUMNH consensus number (North) 0 6 X
SGPWRNH signal power (North) dB 0 7 X
RAVELNH radial velocity (North) m/s 0 7 X
VELVRNH velocity variance (North) (m/s)**2 0 7 X
CNUMEH consensus number (East) 0 6 X
SGPWREH signal power (East) dB 0 7 X
RAVELEH radial velocity (East) m/s 0 7 X
VELVREH velocity variance (East) (m/s)**2 0 7 X
CNUMVH consensus number (Vertical) 0 6 X X
SGPWRVH signal power (Vertical) dB 0 7 X X
RAVELVH radial velocity (Vertical) m/s 0 7 X
VELVRVH velocity variance (Vertical) (m/s)**2 0 7 X
CNUMENH consensus number (East/North) 0 6 X
Station Identification
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ABAN Antenna beam azimuth (North) deg 0 X
ABEN Antenna beam elevation (North) deg 0 X
ABAE Antenna beam azimuth (East) deg 0 X
ABEE Antenna beam elevation (East) deg 0 X
ABAV Antenna beam azimuth (Vertical) deg 0 X
ABEV Antenna beam elevation (Vertical) deg 0 X
Notes
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1. The NOAA wind profilers use two modes of operation: a low mode that starts
at 500 m AGL and goes up to 9250 m AGL; a high mode that starts at 7500 m AGL
and goes up to 16250 m AGL. The low and high modes overlap at 8 levels
reported between 7500 and 9250 AGL. For both modes, the height increment
between levels is 250 m. The user can choose to retrieve each mode
separately, or can request an integrated profile where the MADIS API will
decide which mode to use for each of the 8 levels in the overlap region.
The returned signal strength is lower at the top of the low mode than it is
at the bottom of the high mode, thus all things being equal, the high mode
data is probably of better quality. Therefore, the API will select high mode
data if both low and high mode wind QC values are good. Otherwise, if one
mode has good quality then its data will be selected.
The level type variable can be obtained by users wishing to know which modes
were actually used in the integrated profile.
With the FSL database, all 72 levels are available, with a maximum of 64 in
the integrated profile. The AWIPS database only has 43 levels available:
Levels 1-28 Low mode levels 1-28
29-36 Overlap region (same logic as above)
37-43 High mode levels 12, 16, ..., 36 (every 4th level)
A user requesting low and high mode profiles from the AWIPS database should
reserve 36 and 15 levels, respectively, even though that adds up to greater
than the 43 levels actually available. This allows for the overlap region
levels to appear in whichever mode may happen to be the case. In other
words, high mode levels 1-8 (overlap region, if they exist) will be returned
in the first 8 levels of the user's arrays, followed by the 7 high mode
levels as described above, for a total of 15 user levels.
2. The u and v wind components are reported and stored in the database. The user
can optionally select wind speed and direction and those will be calculated
and returned. In either case, the results of QC checks applied to any form
of the winds will be used, and if one of the map projections has been
selected via the MSETDOM call, the winds will be rotated to match the
projection.
3. The w wind component is actually the radial velocity measured with the
vertically-pointing antenna beam (with the sign negated). Because the level
of error in the observed velocities is of the same magnitude as that expected
for this observation, the user should take care when interpreting this
variable.
4. The wind speed and w standard deviations are derived from the velocity
variance observations, and the latter should be used for most applications.
However, these are included as they are the only variance information
reported in the AWIPS database, and on NWS and international communications
circuits for the profilers.
Wind speed standard deviation is reported instead of the standard deviation
of the u and v wind components because the NPN profiler beams are not, in
general, oriented north and east in spite of the common terminology
"north beam" and "east beam". Wind speed standard deviation Ws is determined
as follows:
Wv**2 = velocity variance of the vertical beam
We**2 = velocity variance of the east beam
Wn**2 = velocity variance of the north beam
theta = angle between the vertical beam and the east or north beam
Ws = [ (We**2 + Wn**2 - 2 cos**2(theta) Wv**2) ]**0.5 csc(theta)
As a reasonable approximation, the u and v component standard deviations are
equal and either equals Ws/(2**0.5).
The reported W standard deviation is Wv defined above.
5. The geometric heights are actually static, and can easily be calculated (see
note 1). For ease of use, however, the MADIS API will return the heights
above MSL in this variable. If the user selects pressure as the vertical
coordinate, the heights are converted to pressure using the U.S. Standard
Atmosphere calculation.
6. The consensus numbers show how many 6-minute samples were used (4-10) to
create the hourly-averaged radial velocity for each level and antenna
direction. If this number is 0, then less than 4 6-minute samples were
avaiable that were within a given velocity range of one another, and no
hourly average was created.
The FSL database contains the consensus numbers for all 3 beams. With the
AWIPS database, there are only two consensus numbers available:
East/North Minimum of the East and North consensus numbers
Vertical Vertical consensus number (same as FSL database)
7. The signal power is not calibrated, therefore comparisons between profilers
are not recommended.
The FSL database contains the signal powers for all three beams. With the
AWIPS database, only the vertical beam signal power is available.
8. The radial velocity uses the convention that positive values are towards the
radar receiver (e.g., the ground), and negative values are away from the
receiver.
The radial velocities are not available in the AWIPS database.
9. Level type codes:
Value Meaning
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1 Low mode
2 High mode
* The QC information is only available with the FSL database.