Azimuth-Elevation Table Definition

Platform signatures (acoustic_signature, infrared_signature, optical_signature, radar_signature),and antenna gain patterns are examples of things that are a function of azimuth and elevation. These commands provide the ability to define the function using a table of discrete values.

There are several formats in which a table definition can be entered.

Define a table with constant value

constant <value> <value-units>

<value-units>

Units of the data value. The units (dB, dBsm, m^2, absolute, etc.) must be consistent with the application (e.g., antenna pattern, signature) for which the table is intended.

Defines a table whose value is constant throughout the whole spherical domain.

Example::

constant -20 dBsm

Define a pattern with an inline table

inline_table … end_inline_table

inline_table *<value-units> <number-of-az-values> <number-of-el-values>*
    *      el1   el2   el3      eln*
    *az1   v11   v12   v13      v1n*
    *az2   v21   v22   v23      v2n*
    *az3   v31   v32   v33      v3n*

    *azm   vm1   vm2   vm3      vmn*
end_inline_table

<value-units>

Units of the data values in the table. The units (e.g., dB, dBsm, m^2, absolute) must be consistent with the application (e.g., antenna pattern, signature) for which the table is intended.

<number-az-values>

Number of azimuth values in the definition. Valid values are >= 2.

<number-of-el-values>

Number of elevation values in the definition. Valid values are >=2.

el_n

Elevation values in degrees. Valid values of -90 deg <= el_n <= 90 deg in increasing order from el1 to eln.

az_m

Azimuth values in degrees. Valid values of -180 deg <= az_m <= 180 deg in increasing order from az1 to azm.

v_mn

Data values in units <value-units>.

Note that the table data does not have to be formatted in rows and columns as illustrated in the above example. WSF simply reads the required number of values.

Example::

inline_table dBsm 5 3
         -90   0    90
   -180   10   20   10
    -90    5   10    5
      0    0    0    0
     90    5   10    5
    180   10   20   10
end_inline_table

Read a table from a file

file <file-name> units <value-units>

Loads the file with <file-name> consistent with the expected format (SALRAM convention).

<value-units>

Units of the data values in the table. The units (e.g., dB, dBsm, m^2, absolute) must be consistent with the application (e.g., antenna pattern, signature) for which the table is intended.

The format of the file is as follows:

*header-line-1*
*header-line-2*
*header-line-3*
*<number-of-az-values> <number-of-el-values>*
*      el1   el2   el3      eln*
*az1   v11   v12   v13      v1n*
*az1   v21   v22   v23      v2n*
*az1   v31   v32   v33      v3n*

*azm   vm1   vm2   vm3      vmn*

Where

header-line-n

Three user-definable header lines. The contents are not used by WSF.

<number-az-values>

Number of azimuth values in the definition. Valid values are >= 2.

<number-of-el-values>

Number of elevation values in the definition. Valid values are >= 2.

el_n

Elevation values in degrees. Valid values of -90 deg <= el_n <= 90 deg in increasing order from el1 to eln.

az_m

Azimuth values in degrees. Valid values of -180 deg <= az_m <= 180 deg in increasing order from az1 to azm.

v_mn

Data values in units <value-units>.

Note

The table data does not have to be formatted in rows and columns as illustrated in the above example. WSF simply reads the required number of values.