TY  - Data
T1  - Heihe River eco hydrological remote sensing experiment: vegetation coverage data set in the middle reaches of Heihe River Basin (may 25-september 14, 2012)
A1  - Ma mingguo
A1  - Mu xihan
DO  - 10.12072/ncdc.nieer.db3001.2023
PY  - 2021
DA  - 2021-09-01
PB  - National Cryosphere Desert Data Center
AB  - This data is the vegetation coverage data set in a growth cycle of farmland, wetland, Gobi, desert and desert observation in Yingke oasis. Data observation starts from May 25, 2012 to September 14, 2012. It is observed once every 5 days before late July and once every 10 days thereafter.Measuring instrument and principle:The vegetation coverage of farmland, wetland, Gobi, desert and desert in Yingke oasis was measured by digital camera. The quadrat design, photo shooting method and data processing method have been analyzed and considered.It is described in several articles:0    Measuring instrument: a simple observation frame is equipped with a digital camera. The digital camera is placed on the instrument platform at the front end of the support rod to keep the shooting vertical and downward, and remotely control the camera to measure data. The observation frame can be used to change the shooting height of the camera and realize targeted measurement for different types of vegetation.one      Quadrat setting and "true value" acquisition: quadrat size of low vegetation such as corn 10 × 10m, fruit tree quadrat 30m × 30 meters. Take photos along two diagonals in turn during each measurement, and take a total of 9 photos (less than 9 when the surface coverage is very uniform), which are evenly distributed in the quadrat. After 9 photos are processed to obtain their respective coverage, take the average, and finally get the "true value" of the coverage of a quadrat.two      Shooting method: for low vegetation such as corn, directly use the observation frame to ensure that the height of the camera on the observation frame from the vegetation canopy is much greater than the vegetation canopy, sample along the diagonal in the square quadrat, and then make arithmetic average. When the field of view angle is small (< 30 °), the field of view includes more than 2 full cycle ridges, and the side length of the photo is parallel to the ridges; For higher vegetation trees, tak
DB  - NCDC
UR  - http://www.ncdc.ac.cn/portal/metadata/ae99d340-1571-49c6-b467-c5051b768c17
ER  -