XFsolver writes multiple output files of volumetric SAR data per steady-state frequency. Each file includes the SAR value—either raw or averaged—for any Yee cell where SAR was computed in a single planar slice of the mesh. The file is then written to the appropriate steady-state frequency directory.
The files utilize the following naming systems:
- Raw SAR data: SAR_Raw_Sensor.[SliceDirection]_[SliceIndex].sar.bin
- 1-gram averaged SAR: SAR_Averaging_[ModifiedSensorName]_[uniqueNumber].[SliceDirection]_[SliceIndex].1gsar.bin
- 10-gram averaged SAR: SAR_Averaging_[ModifiedSensorName]_[uniqueNumber].[SliceDirection]_[SliceIndex].10gsar.bin
The [SliceDirection] in the above file names indicates the planar direction of the associated mesh slice with either xy, yz, or xz. The [SliceIndex] indicates the magnetic calculation grid index of that planar slice. For instance, SAR_Raw_Sensor.xy_5.sar.bin contains raw SAR data for the Yee cells with magnetic calculation grid index k = 5.
The [ModifiedSensorName] is the sensor's name as it appears in the XF project, with a [_] symbol replacing all characters other than letters and numbers. SAR averaging sensors are typically named SAR_Averaging_Sensor, although a different name may be assigned during SAR post-processing. The [uniqueNumber] is an XF-generated integer.
Users can read each planar slice SAR data file—either raw or averaged—as follows:
- Read !remcomfdtd as eleven, 1-byte characters.
- Read L as a 1-byte character. It indicates little-endian, multi-byte integer format.
- Read 13 as a 2-byte unsigned integer.
- Read the version number as a 2-byte unsigned integer.
Only version numbers 0 and 1 are defined. All SAR values reported in the file are contained in a single planar slice of Yee cells. Grid index i, j, or k is constant for the file.
Users can read the remaining file data as follows:
- Read the plane normal direction as a 1-byte unsigned integer. A value of 0 indicates a plane of constant X, or fixed grid index i. A value of 1 indicates a plane of constant Y, or fixed grid index j. A value of 2 indicates a plane of constant Z, or fixed grid index k. This value is related to the [SliceDirection] utilized in the output file naming convention described above.
- Read the plane normal grid index as a 4-byte unsigned integer. This value indicates the planar slice's location in the mesh, as defined by the [SliceIndex] utilized in the file naming convention described above.
- Read the number of records stored in the file and assign this value to a variable N. Users should read either version 0 as a 4-byte unsigned integer (uint32), or version 1 as an 8-byte unsigned integer (uint64).
- The following 12-byte SAR value record specifies a location and computed SAR value. Read N records.
- The X-index in the magnetic calculation grid for the measurement point is read as a 4-byte unsigned integer. This value is not present if the plane normal direction is 0, in which case the X-index is the plane normal grid index.
- The Y-index in the magnetic calculation grid for the measurement point is read as a 4-byte unsigned integer. This value is not present if the plane normal direction is 1, in which case the Y-index is the plane normal grid index.
- The Z-index in the magnetic calculation grid for the measurement point is read as a 4-byte unsigned integer. This value is not present if the plane normal direction is 2, in which case the Z-index is the plane normal grid index.
- The SAR value in W/kg is read as a 4-byte float.
Users should note that the SAR records are not in any predefined order. Additionally, some Yee cells within the plane have no corresponding value for SAR, such as cells in freespace or cells that touch a perfect conductor edge, and are therefore omitted.