Land deformation estimates over Central Valley California associated with Water Resources Research Publication: Sustained Groundwater Loss in California’s Central Valley Exacerbated by Intense Drought Periods by Ojha et al. 2018

This dataset contains rate and seasonal variations in line of site (LOS) of ALOS-1 satellite as calculated from an interferrometric analysis of synthetic aperture radar aquisitions over Central Valley, California, from December 24th, 2006 to January 1st, 2010. Details of the processing are provided in the work of Ojha et al. (2018):
C. Ojha, M. Shirzaei, S. Werth, D. F. Argus, T. G. Farr, Sustained Groundwater Loss in California’s Central Valley Exacerbated by Intense Drought Periods. Water Resour. Res. 54, 4449–4460 (2018).
Land deformation in line of site can be converted to vertical land motion given incidence (~34.5°) and heading angle (~240°) of the ALOS-1 satellites (see Ojha et al., 2018).
LOS rates and seasonal variations are provided in two separate files Rate_all.csv and SeasnCoef_InSAR_CV_Anu_krig.csv respectively. Rates are given for all elite pixel from the InSAR analysis of each aquisition. Seasonal variations are provided in form of sine and cosine amplitudes (sine_amp, cosine_amp) for pixel within the Central Valley aquifer only. To retrieve seasonal amplitude and phase of VLM, the amplitudes should be combined as of the following equations:
- seas_amplitude_VLM = sqrt(sine_amp2 + cosine_amp2)
- seas_phase_VLM = atan(sine_amp / cosine_amp)
Units of the rates and seasonal amplitudes are given in mm and cm/year respectively.

本数据集收录了由 ALOS-1 卫星对加利福尼亚州中部谷地合成孔径雷达获取数据进行的干涉测量分析所计算的视距（LOS）的速率及季节性变化。具体处理细节可参考 Ojha 等人于 2018 年发表的研究成果：《加州中部谷地因连续干旱期而加剧的持续地下水流失》。在视距方向上的地壳形变可通过 ALOS-1 卫星的入射角（约 34.5°）和航向角（约 240°）转换为垂直地面运动（参见 Ojha 等人，2018 年）。速率和季节性变化分别以 Rate_all.csv 和 SeasnCoef_InSAR_CV_Anu_krig.csv 两个独立文件提供。速率针对每个获取数据的 InSAR 分析中的所有精英像素给出。季节性变化以正弦和余弦振幅（sine_amp、cosine_amp）的形式提供，仅限于中部谷地含水层内的像素。要获取垂直地面运动的季节振幅和相位，应将振幅按以下公式组合：- seas_amplitude_VLM = sqrt(sine_amp^2 + cosine_amp^2)；- seas_phase_VLM = atan(sine_amp / cosine_amp)。速率和季节振幅的单位分别为毫米和每年厘米。