From June 28 to 29, 2012, airborne flight ground synchronous observation was carried out in Yingke oasis and huazhaizi desert plmr quadrat. Plmr (polarimetric L-band multibeam radiometer) is a dual polarization (H / V) L-band microwave radiometer with center frequency of 1.413 GHz, bandwidth of 24 MHz, resolution of 1 km (relative altitude of 3 km), simultaneous observation of 6 beams, incident angle of ± 7 º, ± 21.5 º, ± 38.5 º, sensitivity & lt; 1K。 The flight mainly covers the ecological and hydrological test area of artificial oasis in the middle reaches. The local surface synchronous data set can provide a basic ground data set for the development and verification of passive microwave remote sensing soil moisture retrieval algorithm.
Quadrat and sampling strategy: the observation area is located in the south edge of Zhangye Oasis anyangtan Desert Transition Zone, the west side of Zhang (Zhangye) - Da (Daman) highway, across the Longqu main canal from north to south, and is divided into two parts, 1 km in the southwest × For the 1km desert quadrat, because the desert is relatively homogeneous, the soil moisture of 5 points (1 point around and the center point. In the actual measurement process, several more points can be measured during walking along the road). The four corners are separated by 600m except the diagonal direction. The southwest corner is huazhaizi desert station, which is convenient for comparison with the data of meteorological station. On the northeast side, an area of 2.4 km was selected × Synchronous observation of oasis underlying surface is carried out according to the 2.4 km large-scale sample policy. The selection basis of quadrat is mainly to consider the representativeness of surface coverage, avoid residential houses and greenhouses as far as possible, cross oasis farmland and some deserts in the south, accessibility and observation (road consumption) time, so as to obtain the comparison with the brightness temperature observed by plmr.
This data set includes two parts: soil moisture observation and vegetation observation. The former saves data in vector file, the spatial location is the location of each sampling point (WGS84 + UTM 47N), and the measurement information such as soil moisture is recorded in the attribute file; Vegetation sampling information is recorded in Excel table
About 500 points on the quadrat were obtained, and each point was observed twice, that is, for the film covered corn field, twice were observed at each sampling point, once inside the film (marked as a in the data record) and once outside the film (marked as B in the data record). Because the HDAS system adopts pogo portable soil sensor, the soil temperature, soil moisture (volume moisture content), loss tangent, soil conductivity, real and imaginary parts of soil complex dielectric are observed and obtained. Vegetation parameter observation was carried out at some representative soil water sampling points, and the plant height and biomass (vegetation water content) were measured
Plmr (polarimetric L-band multibeam radiometer) is a dual polarization (H / V) L-band microwave radiometer with center frequency of 1.413 GHz, bandwidth of 24 MHz, resolution of 1 km (relative altitude of 3 km), simultaneous observation of 6 beams, incident angle of ± 7 º, ± 21.5 º, ± 38.5 º, sensitivity< 1K。 The flight mainly covers the ecological and hydrological test area of artificial oasis in the middle reaches. The local surface synchronous data set can provide a basic ground data set for the development and verification of passive microwave remote sensing soil moisture retrieval algorithm
Observation No. 28 started at about 11:00am and completed about 1 / 3 of the workload. Due to the dual reasons of plmr instrument problems and rainfall, the observation was forced to stop at 4:00pm. The remaining workload was completed at 10:30am-5:30pm on the 29th. The observation date coincides with the large-scale irrigation of farmland in the area, which makes it difficult for observers to move forward, the field is difficult to enter, and there is a deviation between the observation point and the preset point.
Data: this data set includes two parts: soil moisture observation and vegetation observation. The former saves data in vector file, the spatial location is the location of each sampling point (WGS84 + UTM 47N), and the measurement information such as soil moisture is recorded in the attribute file; Vegetation sampling information is recorded in Excel table
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CC BY 4.0 (Creative Commons Attribution 4.0 International License).
CSTR:11738.11.ncdc.nieer.2020.1604
10.12072/ncdc.nieer.db3468.2023
