MADIS NOAA Profiler Network (NPN) Variables

---------------------------------------------------------------------------------------------------
Code       Name                                Units      Max     Notes      Max Number   Database
                                                       QC Level*              of Levels  FSL  AWIPS
                                                                             FSL  AWIPS
---------------------------------------------------------------------------------------------------


Integrated Profile                                                  1        64    43
------------------

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
---------------

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
----------------

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
----------------------

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

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.
For more information on the NOAA Profiler Network and the characteristics of the wind profiler data, see http://www.profiler.noaa.gov.
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.
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.
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.
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.
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)
```
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.
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.

Level type codes:

       Value      Meaning
       -----      -------
         1        Low mode
         2        High mode

^*The QC information is only available with the FSL database.