气候变化领域集成服务门户(CCPortal): Mean TerraSAR-X backscatter and in-situ measurements of near surface soil moisture and temperature including vegetation survey in August 2015 on central Yamal (Vaskiny Dachi CALM site)

CCPortal

DOI	https://doi.org/10.1594/PANGAEA.874619
	Mean TerraSAR-X backscatter and in-situ measurements of near surface soil moisture and temperature including vegetation survey in August 2015 on central Yamal (Vaskiny Dachi CALM site)
	Widhalm; Barbara; Bartsch; Annett; Leibman; Marina O; Khomutov; Artem V
发布日期	2017-04-13
数据集类型	dataset
英文简介	The active layer above the permafrost, which seasonally thaws during summer, is an important parameter for monitoring the state of permafrost. Its thickness is typically measured locally, but a range of methods which utilize information from satellite data exist. Mostly, the normalized difference vegetation index (NDVI) obtained from optical satellite data is used as a proxy. The applicability has been demonstrated mostly for shallow depths of active-layer thickness (ALT) below approximately 70 cm. Some permafrost areas including central Yamal are, however, characterized by larger ALT. Surface properties including vegetation structure are also represented by microwave backscatter intensity. So far, the potential of such data for estimating ALT has not been explored. We therefore investigated the relationship between ALT and X-band synthetic aperture radar (SAR) backscatter of TerraSAR-X (averages for 10 × 10 m window) in order to examine the possibility of delineating ALT with continuous and larger spatial coverage in this area and compare it to the already-established method of using NDVI from Landsat (30 m). Our results show that the mutual dependency of ALT and TerraSAR-X backscatter on land cover types suggests a connection of both parameters. A range of 5 dB can be observed for an ALT range of 100 cm (40-140 cm), and an R² of 0.66 has been determined over the calibration sites. An increase of ALT with increasing backscatter can be determined. The root mean square error (RMSE) over a comparably heterogeneous validation site with maximum ALT of > 150 cm is 20 cm. Deviations are larger for measurement locations with mixed vegetation types (especially partial coverage by cryptogam crust) with respect to the spatial resolution of the satellite data.
空间范围	Median Latitude: 70.284208 * Median Longitude: 68.906784 * South-bound Latitude: 70.283628 * West-bound Longitude: 68.905067 * North-bound Latitude: 70.284788 * East-bound Longitude: 68.908506
时间范围	2015-08-19T00:00:00 - 2015-08-27T00:00:00
语种	英语
国家	国际
学科大类	气候变化
学科子类	气候变化
文献类型	数据集
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/215329
推荐引用方式 GB/T 7714	Widhalm,Barbara,Bartsch,et al. Mean TerraSAR-X backscatter and in-situ measurements of near surface soil moisture and temperature including vegetation survey in August 2015 on central Yamal (Vaskiny Dachi CALM site).2017-04-13.https://doi.org/10.1594/PANGAEA.874619.