Spectral Reflectance Measurements ARCSS grid Atqasuk, Alaska 2010

Spectral measurements were taken on a 30 plot subset within the Arctic System Science (ARCSS) grid in Atqasuk, Alaska during the summer of 2010. Spectral measurements were taken from the north eastern most corner of each plot. The subset is located from E2-E6 & J2-J6 with the 1 km^2 ARCSS grid. The instrumentation used was a Unispec dual channel (DC) spectrometer with fiber optics as sensors. A manfrotto tri-pod with an arm attachment was used to hold the fibers and sensors in place while taking the spectral measurements. The arm had 2 bubble levels to assist in keeping the sensors as level as possible. The calculated foot print cover is about 50-60 cm using a tri-pod height of 1.62 meters. The sensor angle for each scan is 20 degrees. Extra reference scans were taken on a 100 percent reflective white board surface. Some plots contain crosshairs that are used for point framing purposes and might have an effect on the reflectivity of each scan. Therefore, an extra scan was taken adjacent to each plot on the west side.2010年夏季，科研人员在阿拉斯加州阿特卡斯克（Atqasuk）的北极系统科学（Arctic System Science, ARCSS）网格内的30个样地子集上开展了光谱测量工作。光谱测量的采样点位设于每个样地的最东北角。该子集位于面积为1平方千米的ARCSS网格内的E2-E6与J2-J6区域。本次实验采用的仪器为搭载光纤传感器的Unispec双通道（DC）光谱仪；测量过程中，使用曼富图（Manfrotto）三脚架搭配臂架附件固定光纤与传感器，该臂架配备两个气泡水平仪，用于尽可能维持传感器处于水平状态。当三脚架高度设置为1.62米时，测算得到的视场覆盖范围（footprint）约为50至60厘米，单次扫描的传感器角度为20°。此外，科研人员在反射率为100%的白板表面开展了额外的参考扫描。部分样地带有用于点位框定的十字标线，该结构可能会对各次扫描的反射率产生影响，因此研究团队在每个样地西侧的邻近区域额外开展了一次扫描。