生态系统水热关键参量监测设备研制：中尺度土壤水分测定仪观测数据（2020）

该数据集包含了2020年1月1日至2020年12月31日黑河流域地表过程综合观测网中游大满超级站研制中尺度土壤水分测定仪观测数据。站点位于甘肃省张掖市大满灌区农田内，下垫面是玉米田。观测点的经纬度是100.3722°E, 38.8555°N，海拔1556m。仪器探头底部距地面0.5m，采样频率是1小时。
宇宙射线仪器的原始观测项目包括：电压Batt（V）、温度T（℃）、相对湿度RH（%）、气压P（hPa）、快中子数N1C（个/小时）。发布的数据为经过处理计算后的数据，数据表头包括：Date Time（日期 时间）、P（气压 hPa）、N1C（快中子数 个/小时）、N1C_cor（气压订正的快中子数 个/小时）和VWC（土壤体积含水量 %），其处理的主要步骤包括：
1） 数据筛选
数据筛选共四条标准：（1）剔除电压小于和等于11.8伏特的数据；（2）剔除空气相对湿度大于和等于80%的数据；（3）剔除采样时间间隔不在60±1分钟内的数据；（4） 剔除快中子数较前后一小时变化大于200的数据。剔除及缺失数据用-6999补充。
2） 气压订正
根据仪器说明手册中提到的快中子气压订正公式，对原始数据进行气压订正，得到订正后的快中子数N1C_cor。
3） 仪器率定
在计算土壤水分的过程中需要对计算公式中的N0进行率定。N0为土壤干燥条件下的快中子数，通常使用测量源区内的土样得到实测土壤水分（或者通过比较密集的土壤水分无线传感器获取）θm（Zreda et al. 2012）和对应时间段内的快中子校正数据N，再通过公式反求得到N0。
站点信息请参考Liu et al. (2018)，观测数据处理请参考Zhu et al. (2015)。

This dataset contains observation data from the mesoscale soil moisture meter developed at the Daman Super Station in the middle reaches of the Heihe River Basin Surface Process Comprehensive Observation Network, spanning from January 1, 2020 to December 31, 2020. The station is located in the farmland of Daman Irrigation District, Zhangye City, Gansu Province, with the underlying surface being a corn field. The observation point has coordinates of 100.3722°E, 38.8555°N, and an altitude of 1556 m. The sensor probe is positioned 0.5 m below the ground surface, with a sampling frequency of 1 hour.

The original observation items of the cosmic-ray instrument include: Voltage Batt (V), Temperature T (℃), Relative Humidity RH (%), Atmospheric Pressure P (hPa), and Fast Neutron Count N1C (counts per hour). The released data is post-processed and calculated data, with the data table headers including: Date Time, P (Atmospheric Pressure hPa), N1C (Fast Neutron Count counts per hour), N1C_cor (Pressure-corrected Fast Neutron Count counts per hour), and VWC (Volumetric Soil Water Content %). The main processing steps are as follows:
1) Data Screening
There are four screening criteria: (1) Remove data with voltage less than or equal to 11.8 V; (2) Remove data with relative air humidity greater than or equal to 80%; (3) Remove data with sampling time interval not within 60±1 minutes; (4) Remove data where the fast neutron count changes by more than 200 compared to the counts of the previous and next hour. Removed and missing data are filled with -6999.
2) Atmospheric Pressure Correction
Perform atmospheric pressure correction on the original data using the fast neutron pressure correction formula specified in the instrument instruction manual to obtain the corrected fast neutron count N1C_cor.
3) Instrument Calibration
Calibration of N0 in the soil moisture calculation formula is required during the processing. N0 refers to the fast neutron count under dry soil conditions, which is usually obtained by inversely solving the formula using measured soil moisture θm (Zreda et al. 2012) from soil samples within the measurement source area (or acquired via relatively dense soil moisture wireless sensors) and the corrected fast neutron data N in the corresponding time period.

For station information, please refer to Liu et al. (2018); for observation data processing procedures, please refer to Zhu et al. (2015).