S-band waveguide measurements of sea-ice samples ranging from 2.6 to 3.95 GHz during the SIPEX II voyage of the Aurora Australis, 2012

This dataset contains data relating to an experimental method in which sea-ice samples were measured in an S-band microwave waveguide. This was conducted as a part of the 2012 SIPEX 2 (Sea Ice Physics and Ecosystems EXperiment) marine science voyage.A specially designed waveguide apparatus was connected to an Agilent FieldFox Portable Network Analyzer. Small parallelopipeds (7 cm X 3 cm X 1.9 cm) of sea ice were cut with a hand saw in a specially designed jig which holds an initially cylindrical core. The samples were placed at the end of the waveguide, configured to measure the vertical component of the effective complex permittivity tensor, and microwaves of frequency 2.9 GHz were sent down the tube. The samples were sized precisely to fit snugly in the end of the waveguide in order to minimize spurious reflections. The FieldFox recorded the coefficients of the scattering matrix, from which the complex permittivity can be computed. Sample temperature was taken both before and immediately after insertion into the waveguide. In order to assess the presence of off-vertical components of the electromagnetic field and how they may affect the measurements, a second sample was prepared with an orthogonal orientation, adjacent to the first sample. The same microwave measurements were taken on the second sample, to be later correlated with those from the first sample.The samples were stored in the freezer for later crystallographic analysis, and subsequently melted for salinity measurements. Prior to melting the samples were measured using callipers to determine their dimensions precisely. Samples were measured along each face at their minimum and maximum point for their width in the direction of propagation. In most cases samples were measured in all dimensions for better error analysis. A thin vertical section, approximately 5mm thick, was taken from each microwave sample stored for analysis. These sections were placed between a pair of cross polarized plates and photographed. Photos of the crystallography cores can be found in the crystallography folder, in a sub folder titled microwave. Each photo also contains a tag indicating the core number, site taken, date, as well as a V or an H indicating whether the sample was used for measurement of the vertical (V) or off-vertical (H) response.The scattering parameters recorded by the Field Fox can be found in the Data folder. Each file is named according to the microwave core measurement it represents and whether the measurement was of the vertical (V) or off-vertical (H) response. Each contains a standard S11 scattering parameter, stored as a comma separated value (CSV) file. Raw data can be found in the raw folder, and data that has been processed for ease of Matlab import can be found in the Reformatted_for_matlab folder. This processing involves taking output data that by default has four entries in a single column vector and remapping the data to create a four column matrix, each with a single entry.Recorded values for each microwave sample can be found in the Master_Core_List.xls Excel spreadsheet, within the Microwave worksheet. This worksheet was generated directly from notebook data, and contains the date, core number, depth of interface between the two collected samples, the minimum, maximum, and average thickness along the axis of propagation, The recorded temperatures from before and after measurement, the salinity, and calculated brine volume fraction. Finally, the worksheet contains notes, and a column to indicate whether we believe this data is somehow bad. Measurement information for thicknesses along other axis than that of propagation can be found in notes, but this data may at some stage be incorporated into a separate column. Please see the notes section for reasons why a data point was determined invalid. Typically this was due to the corresponding sample breaking while cutting into the parallelepiped shape. Scans of the original notebooks containing measured salinity values, thicknesses, and temperatures from which the Permeability worksheet were created are provided in the notebooks directory.

本数据集包含与一种实验方法相关的数据，该方法采用S波段微波波导（S-band microwave waveguide）对海冰样本进行测量。此实验是2012年SIPEX 2（海冰物理与生态系统实验，Sea Ice Physics and Ecosystems EXperiment）海洋科学航次的一部分。

特制波导装置与安捷伦FieldFox便携式网络分析仪（Agilent FieldFox Portable Network Analyzer）相连。使用手锯在特制夹具（jig）中切割海冰，得到小型平行六面体（parallelopipeds，尺寸7 cm×3 cm×1.9 cm）样本；该夹具可固定初始圆柱形冰芯。样本放置于波导末端，装置配置为测量有效复介电常数张量（effective complex permittivity tensor）的垂直分量，并向波导内发射频率为2.9 GHz的微波。样本尺寸经精确加工，以紧密贴合波导末端，最大限度减少杂散反射。FieldFox记录散射矩阵（scattering matrix）的系数，据此可计算复介电常数。样本温度在插入波导前后均进行测量。

为评估电磁场非垂直分量的存在及其对测量结果的影响，制备了与首个样本相邻且取向正交的第二个样本，并对其进行相同的微波测量，后续将与首个样本的测量结果进行关联分析。

样本储存于冰柜中以备后续晶体学分析，随后融化以进行盐度测量。融化前，使用卡尺（callipers）精确测量样本尺寸：沿传播方向测量各面的最小与最大宽度；多数情况下，为优化误差分析，对样本所有维度进行测量。从每个待分析的微波样本中切取约5mm厚的垂直薄片，置于一对交叉偏振片（cross polarized plates）之间并拍摄照片。

晶体学冰芯照片位于“crystallography”文件夹下的“microwave”子文件夹中。每张照片均带有标签，标注冰芯编号、采集地点、日期，以及标识样本用于垂直（V）或非垂直（H）响应测量的V/H标记。

FieldFox记录的散射参数（scattering parameters）位于“Data”文件夹中。每个文件根据其所代表的微波冰芯测量数据及测量类型（垂直V/非垂直H响应）命名，包含标准S11散射参数（S11 scattering parameter），以逗号分隔值（CSV）文件格式存储。原始数据位于“raw”文件夹，经处理便于Matlab导入的数据位于“Reformatted_for_matlab”文件夹；该处理将默认单列向量中的四个条目重新映射为四列矩阵，每列含一个条目。

每个微波样本的记录值可在Excel电子表格“Master_Core_List.xls”的“Microwave”工作表中找到。该工作表直接由实验记录数据生成，包含日期、冰芯编号、两个采集样本间的界面深度、传播轴方向的最小/最大/平均厚度、测量前后的记录温度、盐度及计算得到的盐水体积分数（brine volume fraction）。最后，工作表含备注栏及一列标识数据是否存在问题的标记。传播轴以外其他方向的厚度测量信息可在备注中找到，未来可能整合至单独列。数据点无效的原因请参见备注部分，通常是由于样本切割为平行六面体时发生断裂。

原始实验记录的扫描件位于“notebooks”目录中，包含用于生成“Permeability”工作表的盐度、厚度及温度测量数据。