TY - Data T1 - Heihe integrated remote sensing joint test: MODIS ground synchronous observation data set in biandukou encrypted observation area (March 14, 2008) A1 - Zhao Shaojie A1 - ZHao Tianjie A1 - Ren Huazhong DO - 10.12072/ncdc.NIEER.db1914.2022 PY - 2022 DA - 2022-03-16 PB - National Cryosphere Desert Data Center AB - On March 14, 2008, MODIS ground synchronous observation was carried out in biandukou intensive observation area. The measurement parameters include: surface infrared radiation temperature, surface physical temperature, soil profile weight and water content (0-1cm, 1-3cm, 3-5cm, 5-10cm and 10-20cm, only 5cm was measured in some quadrats) and surface soil freezing depth. The purpose is to retrieve the soil freezing depth. The ground survey time range on that day is 12:00-15:00. The ground synchronous survey quadrats include Bian Du Kou C1 sample plot, Bian Du Kou W2 sample plot and Bian Du Kou B2 sample plot. 1) The measurement method of soil freezing depth is to judge the freezing and thawing depth by inserting chopsticks into the soil to feel its hardness or directly digging out the frozen layer on the surface of the soil to measure the thickness of the frozen layer. Measured directly with a ruler, when the soil hardness is large and there are ice crystals, it is considered that the soil is frozen; On the contrary, it is considered that the soil is not frozen. The soil roughness data can be considered as unchanged during the test and can be obtained from the roughness data set at other times. The time range is 11:37-12:11.2) The water content measurement method is: take 0-1cm, 1-3cm, 3-5cm, 5-10cm and 10-20cm soil samples, put them into self sealing bags, and then dry them in microwave oven to calculate the soil weight and water content. 3) The surface temperature measuring instrument is a hand-held infrared thermometer, which measures the radiation temperature and physical temperature at the same time, and records the surface coverage type of the measuring location. When measuring, the handheld infrared thermometer adopts the short-range measurement mode. The surface physical temperature adopts the thermocouple thermometer attached to the hand-held infrared thermometer. 4) The soil roughness data can be considered as unchanged during the test and can be obtained fr DB - NCDC UR - http://www.ncdc.ac.cn/portal/metadata/4a89f8ad-f8ff-4000-a6ac-cb43f675b97c ER -