Data for "Novel insight into the spatiotemporal distribution of Greenland ice sheet surface densities from eleven years of satellite radar altimetry "

Version HistoryVersion 1: originalVersion 2: monthly data files corrected for missing fieldPlease use the most recent version----The RSR results are provided in 129 individual netCDF files; one for the locations of the contemporaneous in situ measurements used as part of calibration and validation (InSitu_RSR_Results.nc) and 128 monthly (May 2013-December 2023) pan-Greenland data files organised as _.nc.The organisation of the data in the two types of files is slightly different. Units for the different data can be found in the netCDF metadata.A) InSitu_RSR_Results.nc1) In situ results are organised following the measurement identification scheme used in the community database (Vandercrux et al., 2023, DOI: 10.18739/A2M61BR5M)2) For each in situ location, relevant metadata are provided (i.e., year and month in which the in situ data were collected, wgs-84 latitude and longitude, and eps:3413 X and Y coordinates)3) RSR results are broken down by dataset (i.e., CryoSat-2 LRM, CryoSat-2 SARIn, and SARAL)4) Under each dataset, the main RSR outputs are provided (i.e., correlation coefficient, total/coherent/incoherent power, and search radius)5) Finally, in a Conversion_Models group within each dataset, the inverted surface properties (i.e., relative dielectric permittivity, density, and surface roughness) are then provided for each of the 10 different permittivity-to-density conversion models considered. The 'long name' variable for each conversion model contains the associated DOI.B) Monthly pan-Greenland (_.nc) results1) Location metadata (eps:3413 x and y coordinates in meters) are given as X and Y variables under the main netCDF file. These locations correspond to the nodes of the 5-by-5 km grid over which the RSR method is applied and apply to all subsequent variables.2) RSR results are broken down in to one of three groups based on satellite dataset (i.e., CryoSat-2 LRM, CryoSat-2 SARIn, and SARAL)3) Under each dataset group, there are 8 equal sized arrays corresponding to the various RSR outputs and corresponding metadata.4) The eight RSR outputs are the correlation coefficient (crl), the search radius (R), the total power (Pt), the coherent power (Pc), the incoherent power (Pn), the relative dielectric permittivity of the surface (eps), the surface roughness (sigh), and the surface density (rho)5) The Pomerleau et al. (2020) (DOI:10.3390/s20143909) permittivity-to-density conversion model is used to convert the RSR-derived permittivities to densities. If a different model is to be used, densities can be recalculated from the permittivity results.This dataset contains the following files:InSitu_RSR_Results.nc_.ncExplanation of different variables:Not all of these variables are found in all files, but this is a complete list of all variables contained within the different files.Year: year of the in-situ measurementMonth: month of the in-situ measurementLatitude: in-situ measurement latitude coordinate [deg]Longitude: in-situ measurement longitude coordinate [deg]X: in-situ measurement epsg:3413 X coordinate [m]Y: in-situ measurement epsg:3413 Y coordinate [m]Pt: uncalibrated RSR total power at the in-situ location [dB]Pc: uncalibrated RSR coherent power at the in-situ location [dB]Pn: uncalibrated RSR incoherent power at the in-situ location [dB]R: RSR search radius around the in-situ location [m]crl: RSR statistical fit correlation coefficienteps: surface relative dielectric permittivity derived from the RSR results [-]sigh: surface roughness derived from the RSR results [m]rho: surface density derived from RSR results [g/cm**3]

版本历史
版本1：初始版本
版本2：修正了缺失字段的月度数据文件。请使用最新版本。

本数据集的RSR结果以129个独立的网络公共数据格式（netCDF）文件提供：其中1个文件用于存放校准与验证所用的同步原位测量点位数据（InSitu_RSR_Results.nc），其余128个为2013年5月至2023年12月的泛格陵兰月度数据文件，命名格式为_.nc。两类文件的数据组织方式略有差异。各数据的单位可在netCDF元数据中查询。

A) 原位测量RSR结果文件（InSitu_RSR_Results.nc）
1) 原位结果遵循社区数据库所采用的测量标识体系进行组织（Vandercrux等，2023，数字对象标识符（DOI）：10.18739/A2M61BR5M）
2) 针对每个原位点位，提供相关元数据：包括原位数据采集的年、月，世界大地测量系统1984（WGS-84）经纬度坐标，以及EPSG:3413投影下的X、Y坐标
3) RSR结果按卫星数据集分类：CryoSat-2 LRM、CryoSat-2 SARIn及SARAL
4) 每个数据集下包含主要的RSR输出结果：相关系数、总/相干/非相干功率，以及搜索半径
5) 最后，在每个数据集下的Conversion_Models组中，提供经反演得到的地表属性数据，包括相对介电常数、密度及表面粗糙度，共涉及10种不同的介电常数-密度转换模型。每个转换模型的"long name"变量包含对应的DOI。

B) 泛格陵兰月度RSR结果文件（_.nc）
1) 主netCDF文件下的X、Y变量为点位元数据（EPSG:3413投影下的X、Y坐标，单位：米），这些点位对应RSR方法所采用的5×5千米网格节点，适用于所有后续变量
2) RSR结果按卫星数据集分为三类：CryoSat-2 LRM、CryoSat-2 SARIn及SARAL
3) 每个数据集组下包含8个大小一致的数组，分别对应各类RSR输出结果及相关元数据
4) 这8项RSR输出分别为：相关系数（crl）、搜索半径（R）、总功率（Pt）、相干功率（Pc）、非相干功率（Pn）、地表相对介电常数（eps）、表面粗糙度（sigh）及表面密度（rho）
5) 本数据集采用Pomerleau等（2020，DOI:10.3390/s20143909）提出的介电常数-密度转换模型，将RSR反演得到的介电常数转换为密度。若需使用其他转换模型，可基于介电常数结果重新计算密度。

本数据集包含以下文件：InSitu_RSR_Results.nc、_.nc

变量说明：
不同文件并非均包含所有变量，但以下为所有文件中包含的变量的完整列表：
Year：原位测量年份
Month：原位测量月份
Latitude：原位测量纬度坐标 [单位：度]
Longitude：原位测量经度坐标 [单位：度]
X：原位测量的EPSG:3413投影X坐标 [单位：米]
Y：原位测量的EPSG:3413投影Y坐标 [单位：米]
Pt：原位点位的未校准RSR总功率 [单位：分贝（dB）]
Pc：原位点位的未校准RSR相干功率 [单位：分贝（dB）]
Pn：原位点位的未校准RSR非相干功率 [单位：分贝（dB）]
R：原位点位周围的RSR搜索半径 [单位：米]
crl：RSR统计拟合相关系数
eps：由RSR结果反演得到的地表相对介电常数 [-（无量纲）]
sigh：由RSR结果反演得到的表面粗糙度 [单位：米]
rho：由RSR结果反演得到的表面密度 [单位：克/立方厘米（g/cm³）]