On March 14, 2008, the thermal infrared specific emissivity observation test was carried out in arrou sample 3. The measuring instrument is a portable specific emissivity meter (Patent No.: ZL 02 2 37640.2). During measurement, the quadrat is covered with 100% dry forage, and the height is less than 5cm. Since the grassland is relatively homogeneous, only the center point of each grid in arrou quadrat 3 is measured. The naming rule of each observation point is in the form of a3-9, which is expressed as the No. 9 sampling point of a rou quadrat 3.
Each center point is randomly measured twice. The horizontal surface shall be selected as far as possible to ensure that the measurement angle is 45 degrees; And in strict accordance with the following requirements:
（ 1) Add mirror without cover (tsky);
（ 2) Mirror capping (Tcha);
（ 3) No mirror, no cover (TSM)
（ 4) Complete one measurement without mirror capping (TCM).
To reduce the error, read 4 numbers for each observation. At the same time, the surface thermal infrared temperature (hand-held infrared thermometer) and hand-held thermal imager (FLIR thermacam) were measured simultaneously for 4 times at each central point. The calculation formula of specific emissivity is: specific emissivity = 1 - (TCM ^ 4 – TSM ^ 4) / (Tcha ^ 4 – tsky ^ 4).
This data can provide basic data for remote sensing inversion algorithm of surface temperature and surface radiation energy balance.
The naming rule of each observation point is in the form of a3-9, which is expressed as the No. 9 sampling point of a rou quadrat 3. Each center point is randomly measured twice.
The horizontal surface shall be selected as far as possible to ensure that the measurement angle is 45 degrees; And in strict accordance with (1) adding mirrors without capping (tsky)（ 2) Mirror capping (Tcha)（ 3) Complete one measurement in the order of no mirror and no cover (TSM) and (4) no mirror and no cover (TCM). To reduce the error, read 4 numbers for each observation.
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CSTR:11738.11.ncdc.NIEER.2021.1911
10.12072/ncdc.NIEER.db1919.2022