{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T03:02:24Z","timestamp":1760238144420,"version":"build-2065373602"},"reference-count":55,"publisher":"MDPI AG","issue":"14","license":[{"start":{"date-parts":[[2020,7,16]],"date-time":"2020-07-16T00:00:00Z","timestamp":1594857600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["41531068"],"award-info":[{"award-number":["41531068"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Hunan Provincial Natural Science Foundation of China","award":["2018JJ3871"],"award-info":[{"award-number":["2018JJ3871"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Increasing the area of planted forests is rather important for compensation the loss of natural forests and slowing down the global warming. Forest growing stem volume (GSV) is a key indicator for monitoring and evaluating the quality of planted forest. To improve the accuracy of planted forest GSV located in south China, four L-band ALOS PALSAR-2 quad-polarimetric synthetic aperture radar (SAR) images were acquired from June to September with short intervals. Polarimetric characteristics (un-fused and fused) derived by the Yamaguchi decomposition from time series SAR images with different intervals were considered as independent variables for the GSV estimation. Then, the general linear model (GLM) obeyed the exponential distribution were proposed to retrieve the stand-level GSV in plantation. The results show that the un-fused power of double bounce scatters and four fused variables derived from single SAR image is highly sensitive to the GSV, and these polarimeric characteristics derived from the time series images more significantly contribute to improved estimation of GSV. Moreover, compared with the estimated GSV using the semi-exponential model, the employed GLM model with less limitations and simple algorithm has a higher saturation level (nearly to 300 m3\/ha) and higher sensitivity to high forest GSV values than the semi-exponential model. Furthermore, by reducing the external disturbance with the help of time average, the accuracy of estimated GSV is improved using fused polarimeric characteristics, and the estimation accuracy of forest GSV was improved as the images increase. Using the fused polarimetric characteristics (Dbl\u00d7Vol\/Odd) and the GLM, the minimum RRMSE was reduced from 33.87% from single SAR image to 24.42% from the time series SAR images. It is implied that the GLM is more suitable for polarimetric characteristics derived from the time series SAR images and has more potential to improve the planted forest GSV.<\/jats:p>","DOI":"10.3390\/s20143957","type":"journal-article","created":{"date-parts":[[2020,7,16]],"date-time":"2020-07-16T10:54:46Z","timestamp":1594896886000},"page":"3957","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["Estimating the Growing Stem Volume of the Planted Forest Using the General Linear Model and Time Series Quad-Polarimetric SAR Images"],"prefix":"10.3390","volume":"20","author":[{"given":"Jiangping","family":"Long","sequence":"first","affiliation":[{"name":"Key Laboratory of Forestry Remote Sensing Based Big Data &amp; Ecological Security for Hunan Province, Changsha 410004, China"},{"name":"Key Laboratory of State Forestry Administration on Forest Resources Management and Monitoring in Southern Area, Changsha 410004, China"},{"name":"Department of Surveying Engineering, College of Civil Engineering, Central South University of Forestry and Technology, Changsha 410004, China"}]},{"given":"Hui","family":"Lin","sequence":"additional","affiliation":[{"name":"Key Laboratory of Forestry Remote Sensing Based Big Data &amp; Ecological Security for Hunan Province, Changsha 410004, China"},{"name":"Key Laboratory of State Forestry Administration on Forest Resources Management and Monitoring in Southern Area, Changsha 410004, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5419-4547","authenticated-orcid":false,"given":"Guangxing","family":"Wang","sequence":"additional","affiliation":[{"name":"Key Laboratory of Forestry Remote Sensing Based Big Data &amp; Ecological Security for Hunan Province, Changsha 410004, China"},{"name":"Key Laboratory of State Forestry Administration on Forest Resources Management and Monitoring in Southern Area, Changsha 410004, China"},{"name":"Department of Geography and Environmental Resources, Southern Illinois University, Carbondale, IL 62901, USA"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5401-6783","authenticated-orcid":false,"given":"Hua","family":"Sun","sequence":"additional","affiliation":[{"name":"Key Laboratory of Forestry Remote Sensing Based Big Data &amp; Ecological Security for Hunan Province, Changsha 410004, China"},{"name":"Key Laboratory of State Forestry Administration on Forest Resources Management and Monitoring in Southern Area, Changsha 410004, China"}]},{"given":"Enping","family":"Yan","sequence":"additional","affiliation":[{"name":"Key Laboratory of Forestry Remote Sensing Based Big Data &amp; Ecological Security for Hunan Province, Changsha 410004, China"},{"name":"Key Laboratory of State Forestry Administration on Forest Resources Management and Monitoring in Southern Area, Changsha 410004, China"}]}],"member":"1968","published-online":{"date-parts":[[2020,7,16]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1016\/j.foreco.2015.06.014","article-title":"Dynamics of global forest area: Results from the FAO Global Forest Resources Assessment 2015","volume":"352","author":"Keenan","year":"2015","journal-title":"For. Ecol. Manag."},{"unstructured":"Editorial Office (2014). The Eighth National Forest Resources Inventory Indicates Area of Plantation Forest in China Continues to Rank First in the World. China Popul. Today, 2, 40.","key":"ref_2"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"21","DOI":"10.1016\/j.foreco.2015.05.036","article-title":"Changes in forest production, biomass and carbon: Results from the 2015 UN FAO Global Forest Resource Assessment","volume":"352","author":"Lasco","year":"2015","journal-title":"For. Ecol. Manag."},{"key":"ref_4","first-page":"1","article-title":"On the Maintenance of Long-term Productivity of Plantation in China","volume":"31","author":"Sheng","year":"2018","journal-title":"For. Res."},{"unstructured":"Kimura, H., Mizuno, T., Papathanassiou, K.P., and Hajnsek, I. (2004, January 20\u201324). Improvement of Polarimetric SAR Calibration Based on the Quegan Algorithm. Proceedings of the IEEE International Geoscience & Remote Sensing Symposium, Anchorage, AK, USA.","key":"ref_5"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1007\/s11676-010-0001-7","article-title":"Improved strategy for estimating stem volume and forest biomass using moderate resolution remote sensing data and GIS","volume":"21","author":"Wijaya","year":"2010","journal-title":"J. For. Res."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"129","DOI":"10.1016\/j.rse.2014.05.007","article-title":"Growing stock volume estimation from L-band ALOS PALSAR polarimetric coherence in Siberian forest","volume":"155","author":"Chowdhury","year":"2014","journal-title":"Remote Sens. Environ."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"197","DOI":"10.1016\/j.rse.2015.12.012","article-title":"Prediction of stem volume in complex temperate forest stands using TanDEM-X SAR data","volume":"174","author":"Abdullahi","year":"2016","journal-title":"Remote Sens. Environ."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"5725","DOI":"10.3390\/rs5115725","article-title":"Polarimetric Parameters for Growing Stock Volume Estimation Using ALOS PALSAR L-Band Data over Siberian Forests","volume":"5","author":"Chowdhury","year":"2013","journal-title":"Remote Sens."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"352","DOI":"10.1016\/j.rse.2017.12.002","article-title":"The global forest\/non-forest map from TanDEM-X interferometric SAR data","volume":"205","author":"Martone","year":"2018","journal-title":"Remote Sens. Environ."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"3505","DOI":"10.1038\/s41598-017-03469-3","article-title":"Understanding \u2018saturation\u2019 of radar signals over forests","volume":"7","author":"Joshi","year":"2017","journal-title":"Sci. Rep."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"3058","DOI":"10.3390\/rs4103058","article-title":"Characteristics of Decomposition Powers of L-Band Multi-Polarimetric SAR in Assessing Tree Growth of Industrial Plantation Forests in the Tropics","volume":"4","author":"Kobayashi","year":"2012","journal-title":"Remote Sens."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"849","DOI":"10.1109\/TGRS.2005.862523","article-title":"Capabilities of a Forest Coherent Scattering Model Applied to Radiometry, Interferometry, and Polarimetry at P- and L-band","volume":"44","author":"Thirion","year":"2006","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"3937","DOI":"10.1109\/TGRS.2013.2278171","article-title":"Model-Based Analysis of the Influence of Forest Structures on the Scattering Phase Center at L-Band","volume":"52","author":"Ni","year":"2014","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"503","DOI":"10.1080\/01431160903475217","article-title":"Stem volume of tropical forests from polarimetric radar","volume":"32","author":"Santos","year":"2011","journal-title":"Int. J. Remote Sens."},{"doi-asserted-by":"crossref","unstructured":"Zhang, H., Zhu, J., Wang, C., Lin, H., Long, J., Zhao, L., Fu, H., and Liu, Z. (2019). Forest Growing Stock Volume Estimation in Subtropical Mountain Areas Using PALSAR-2 L-Band PolSAR Data. Forests, 10.","key":"ref_16","DOI":"10.3390\/f10030276"},{"doi-asserted-by":"crossref","unstructured":"Antropov, O., Rauste, Y., H\u00e4me, T., and Praks, J. (2017). Polarimetric ALOS PALSAR Time Series in Mapping Biomass of Boreal Forests. Remote Sens., 9.","key":"ref_17","DOI":"10.3390\/rs9100999"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1041","DOI":"10.1109\/36.312892","article-title":"Backscattering Properties of Boreal Forests at the C- and X-Bands","volume":"32","author":"Pulliainen","year":"1994","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"35","DOI":"10.1109\/JSTARS.2013.2241018","article-title":"Stand-Level Stem Volume of Boreal Forests from Spaceborne SAR Imagery at L-Band","volume":"6","author":"Antropov","year":"2013","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"927","DOI":"10.1109\/36.752211","article-title":"Multitemporal ehavior of L- and C-band SAR observations of boreal forests","volume":"37","author":"Pulliainen","year":"1999","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"unstructured":"Wagner, W., Vietmeier, J., Schmullius, C., Davidson, M., Toan, T.L., Quegan, S., Yu, J.J., Luckman, A., Tansey, K., and Balzter, H. (2000, January 24\u201328). The Use of Coherence Information from ERS Tandem Pairs for Determining Forest Stock Volume in SIBERIA. Proceedings of the IEEE International Geoscience & Remote Sensing Symposium, Honolulu, HI, USA, USA.","key":"ref_21"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1016\/S0034-4257(01)00329-7","article-title":"Stem volume retrieval in boreal forests from ERS-1\/2 interferometry","volume":"81","author":"Santoro","year":"2002","journal-title":"Remote Sens. Environ."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"258","DOI":"10.1016\/j.rse.2015.10.030","article-title":"The potential of ALOS PALSAR backscatter and InSAR coherence for forest growing stock volume estimation in Central Siberia","volume":"173","author":"Thiel","year":"2016","journal-title":"Remote Sens. Environ."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"232","DOI":"10.5589\/m13-031","article-title":"Investigating ALOS PALSAR interferometric coherence in central Siberia at unfrozen and frozen conditions: Implications for forest growing stock volume estimation","volume":"39","author":"Thiel","year":"2013","journal-title":"Can. J. Remote Sens."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"5294","DOI":"10.1109\/JSTARS.2015.2487503","article-title":"Yearly Variation of Acacia Plantation Forests Obtained by Polarimetric Analysis of ALOS PALSAR Data","volume":"8","author":"Kobayashi","year":"2016","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"490","DOI":"10.1016\/j.rse.2010.09.018","article-title":"Retrieval of growing stock volume in boreal forest using hyper-temporal series of Envisat ASAR ScanSAR backscatter measurements","volume":"115","author":"Santoro","year":"2011","journal-title":"Remote Sens. Environ."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"466","DOI":"10.1016\/j.rse.2012.05.029","article-title":"Mapping forest aboveground biomass in the Northeastern United States with ALOS PALSAR dual-polarization L-band","volume":"124","author":"Cartus","year":"2012","journal-title":"Remote Sens. Environ."},{"doi-asserted-by":"crossref","unstructured":"Lee, J.S., and Pottier, E. (2016). Polarimetric Radar Imaging: Basics to Applications, CRC Press. [2nd ed.].","key":"ref_28","DOI":"10.1201\/9781420054989"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"53","DOI":"10.1063\/1.3502550","article-title":"Polarisation: Applications in Remote Sensing","volume":"63","author":"Cloude","year":"2010","journal-title":"Phys. Today"},{"doi-asserted-by":"crossref","unstructured":"Fu, H., Zhu, J., Wang, C., Wang, H., and Rong, Z. (2017). Underlying Topography Estimation over Forest Areas Using High-Resolution P-Band Single-Baseline PolInSAR Data. Remote Sens., 9.","key":"ref_30","DOI":"10.3390\/rs9040363"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"63525","DOI":"10.1117\/1.JRS.6.063525","article-title":"Backscattering characteristics of L-band polarimetric and optical satellite imagery over planted acacia forests in Sumatra, Indonesia","volume":"6","author":"Kobayashi","year":"2012","journal-title":"J. Appl. Remote Sens."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"556","DOI":"10.1038\/nclimate1601","article-title":"Radar backscatter is not a \u2018direct measure\u2019 of forest biomass","volume":"2","author":"Woodhouse","year":"2012","journal-title":"Nat. Clim. Chang."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"125","DOI":"10.1016\/S0034-4257(02)00198-0","article-title":"Large-scale mapping of boreal forest in SIBERIA using ERS tandem coherence and JERS backscatter data","volume":"85","author":"Wagner","year":"2003","journal-title":"Remote Sens. Environ."},{"key":"ref_34","first-page":"35","article-title":"Assessment of Potentiality of L-Band Quadpol Radar for the Retrieval of Growing Stock Volume and Forest Structural Parameters in Central Siberia","volume":"686","author":"Chowdhury","year":"2010","journal-title":"ESASP"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"3425","DOI":"10.1080\/01431160600646037","article-title":"Assessment of stand-wise stem volume retrieval in boreal forest from JERS-1 L-band SAR backscatter","volume":"27","author":"Santoro","year":"2006","journal-title":"Int. J. Remote Sens."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"4503","DOI":"10.3390\/rs5094503","article-title":"Estimates of Forest Growing Stock Volume for Sweden, Central Siberia, and Qu\u00e9bec Using Envisat Advanced Synthetic Aperture Radar Backscatter Data","volume":"5","author":"Santoro","year":"2013","journal-title":"Remote Sens."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"154","DOI":"10.1016\/j.rse.2006.08.004","article-title":"Properties of ERS-1\/2 coherence in the Siberian boreal forest and implications for stem volume retrieval","volume":"106","author":"Santoro","year":"2007","journal-title":"Remote Sens. Environ."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"1617","DOI":"10.1109\/TGRS.2004.830161","article-title":"Calibration of linearly polarized polarimetric SAR data subject to Faraday rotation","volume":"42","author":"Freeman","year":"2004","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"38","DOI":"10.1016\/j.rse.2018.08.003","article-title":"Potential of a two-component polarimetric decomposition at C-band for soil moisture retrieval over agricultural fields","volume":"217","author":"Hongquan","year":"2018","journal-title":"Remote Sens. Environ."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"2496","DOI":"10.1109\/LGRS.2015.2487450","article-title":"Model-Based Decomposition with Cross Scattering for Polarimetric SAR Urban Areas","volume":"12","author":"Xiang","year":"2015","journal-title":"IEEE Geosci. Remote Sens. Lett."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1559","DOI":"10.3390\/rs4061559","article-title":"Three-Component Power Decomposition for Polarimetric SAR Data Based on Adaptive Volume Scatter Modeling","volume":"4","author":"Cui","year":"2012","journal-title":"Remote Sens."},{"key":"ref_42","first-page":"3497","article-title":"Modifying the Yamaguchi Four-Component Decomposition Scattering Powers Using a Stochastic Distance","volume":"8","author":"Bhattacharya","year":"2015","journal-title":"Mathematics"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"3911","DOI":"10.1109\/JSTARS.2014.2371468","article-title":"An Iterative Generalized Hybrid Decomposition for Soil Moisture Retrieval Under Vegetation Cover Using Fully Polarimetric SAR","volume":"8","author":"Jagdhuber","year":"2015","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"1561","DOI":"10.1109\/TGRS.2003.814131","article-title":"Multitemporal JERS repeat-pass coherence for growing-stock volume estimation of Siberian forest","volume":"41","author":"Eriksson","year":"2003","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"doi-asserted-by":"crossref","unstructured":"Mohanty, S., Singh, G., and Yamaguchi, Y. (2016, January 10\u201315). Faraday Rotation Correction and Total Electron Content Estimation Using ALOS-2\/PALSAR-2 full Polarimetric SAR Data. Proceedings of the 2016 IEEE International Geoscience and Remote Sensing Symposium (IGARSS), Beijing, China.","key":"ref_45","DOI":"10.1109\/IGARSS.2016.7730240"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"263","DOI":"10.1016\/j.rse.2005.05.002","article-title":"Multi-temporal JERS SAR data in boreal forest biomass mapping","volume":"97","author":"Rauste","year":"2005","journal-title":"Remote Sens. Environ."},{"doi-asserted-by":"crossref","unstructured":"Santoro, M., Askne, J.I.H., Beer, C., Cartus, O., Schmullius, C., Wegm\u00fcller, U., and Wiesmann, A. (2008, January 7\u201311). Automatic Model Inversion of Multi-Temporal C-band Coherence and Backscatter Measurements for Forest Stem Volume Retrieval. Proceedings of the 2008 IEEE International Geoscience and Remote Sensing Symposium, Boston, MA, USA.","key":"ref_47","DOI":"10.1109\/IGARSS.2008.4780043"},{"doi-asserted-by":"crossref","unstructured":"Shao, Y., Zhang, F., Xu, M., Xia, Z., and Touzi, R. (2011, January 24\u201329). Forest Mapping Using Multi-Temporal Polarimetric SAR Data in Southwest China. Proceedings of the 2011 IEEE International Geoscience and Remote Sensing Symposium, Vancouver, BC, Canada.","key":"ref_48","DOI":"10.1109\/IGARSS.2011.6048916"},{"key":"ref_49","first-page":"82","article-title":"Compatibility of Stand Volume Model for Chinese Fir Based on Tree-Level and Stand-Level","volume":"50","author":"Zhang","year":"2014","journal-title":"Sci. Silvae Sin."},{"key":"ref_50","first-page":"74","article-title":"The Selection and Error Analysis of the Angle Gauge Constant in the Chinese-fir Plantation at Different Ages","volume":"2","author":"Zheng","year":"2006","journal-title":"For. Resour. Manag."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"2712","DOI":"10.1109\/TGRS.2011.2109065","article-title":"Calibration of Spaceborne CTLR Compact Polarimetric Low-Frequency SAR Using Mixed Radar Calibrators","volume":"49","author":"Chen","year":"2011","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"2153","DOI":"10.1109\/36.868874","article-title":"Polarimetric SAR data compensation for terrain azimuth slope variation","volume":"38","author":"Lee","year":"2000","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"1266","DOI":"10.1109\/36.536542","article-title":"Measurement of topography using polarimetric SAR images","volume":"34","author":"Schuler","year":"1996","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"30","DOI":"10.1109\/36.981347","article-title":"On the estimation of radar polarization orientation shifts induced by terrain slopes","volume":"40","author":"Lee","year":"2002","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"340","DOI":"10.1080\/2150704X.2016.1271159","article-title":"Improvement of PolSAR decomposition scattering powers using a relative decorrelation measure","volume":"8","author":"Ratha","year":"2017","journal-title":"Remote Sens. Lett."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/14\/3957\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T09:49:03Z","timestamp":1760176143000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/20\/14\/3957"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,7,16]]},"references-count":55,"journal-issue":{"issue":"14","published-online":{"date-parts":[[2020,7]]}},"alternative-id":["s20143957"],"URL":"https:\/\/doi.org\/10.3390\/s20143957","relation":{},"ISSN":["1424-8220"],"issn-type":[{"type":"electronic","value":"1424-8220"}],"subject":[],"published":{"date-parts":[[2020,7,16]]}}}