MISR Level 3 FIRSTLOOK Global Land product in netCDF format covering a month V002

MI3MLSNF_2 is the Multi-angle Imaging SpectroRadiometer (MISR) Level 3 FIRSTLOOK Global Land product in netCDF format covering a month version 2 data product. It contains a monthly statistical summary of directional hemispherical reflectance (DHR), photosynthetically active spectral region (DHR-PAR), DHR for near-infrared band (DHR-NIR), fractional absorbed photosynthetically active radiation (FPAR), DHR-based normalized difference vegetation index (NDVI) and land surface bidirectional reflectance factor (BRF) model parameters. It is classified into six vegetated and one non-vegetated types. This data product is a global summary of the Level 2 land/surface parameters of interest averaged over a month and reported on a geographic grid, with resolution of 0.5 degree by 0.5 degree. Data collection for this product is ongoing. This collection contains Leaf Area Index (LAI).

FIRSTLOOK processing uses the new time dependence of the Atmospheric and Surface Climatology (TASC) from the same month/previous year. The TASC data set now contains snow-ice and ocean surface wind speed values that are updated on a monthly basis. Therefore, these data sets cannot be generated until the end of the month. Products generated are distinguished by the presence of FIRSTLOOK in the file names. The MISR instrument consists of nine pushbroom cameras which measure radiance in four spectral bands. Global coverage is achieved in nine days. The cameras are arranged with one camera pointing toward the nadir, four cameras pointing forward, and four cameras pointing aftward. It takes seven minutes for all nine cameras to view the same surface location. The view angles relative to the surface reference ellipsoid, are 0, 26.1, 45.6, 60.0, and 70.5 degrees. The spectral band shapes are nominally Gaussian, centered at 443, 555, 670, and 865 nm.

MISR itself is an instrument designed to view Earth with cameras pointed in 9 different directions. As the instrument flies overhead, each piece of Earth's surface below is successively imaged by all 9 cameras, in each of 4 wavelengths (blue, green, red, and near-infrared). The goal of MISR is to improve our understanding of the affects of sunlight on Earth, as well as distinguish different types of clouds, particles and surfaces. Specifically, MISR monitors the monthly, seasonal, and long-term trends in three areas: 1) amount and type of atmospheric particles (aerosols), including those formed by natural sources and by human activities; 2) amounts, types, and heights of clouds, and 3) distribution of land surface cover, including vegetation canopy structure.

MI3MLSNF_2 为多角度成像光谱辐射计（MISR）第三级首次观测全球陆地产品，以 netCDF 格式提供，涵盖一个月版本 2 的数据产品。该产品包含方向性半球反射率（DHR）、光合有效光谱区域（DHR-PAR）、近红外波段 DHR（DHR-NIR）、吸收光合有效辐射分数（FPAR）、基于 DHR 的归一化植被指数（NDVI）和地表双向反射率因子（BRF）模型参数的月度统计摘要。该数据产品被划分为六种植被类型和一种非植被类型。该产品是全球层面上对一个月内感兴趣的二级陆地/地表参数的平均值汇总，并以地理网格形式报告，分辨率为 0.5 度×0.5 度。该产品的数据收集工作正在进行中。该收集内容包含叶面积指数（LAI）。

首次观测处理采用了来自同一月份/上一年度的新的大气和地表气候学（TASC）的时间依赖性。TASC 数据集现在包含雪冰和海洋表面风速值，这些值每月更新一次。因此，这些数据集只能在月底生成。生成的产品通过文件名中存在首次观测标识来区分。MISR 仪器由九台推帚式相机组成，测量四个光谱带的辐射亮度。全球覆盖在九天内完成。相机以一台朝向 nadir，四台朝前，四台朝后的方式排列。所有九台相机观察同一地表位置需要七分钟。相对于地表参考椭球体的观测角度为 0、26.1、45.6、60.0 和 70.5 度。光谱带形状为标准高斯形状，中心位于 443、555、670 和 865 纳米。

MISR 本身是一种设计用于以九个不同方向指向地球的相机观测地球的仪器。当仪器从上方飞行时，地球表面的每一部分依次被所有九台相机在四个波长（蓝光、绿光、红光和近红外）中逐一成像。MISR 的目标是提升我们对阳光对地球影响的理解，以及区分不同类型的云、颗粒和地表。具体而言，MISR 监测了以下三个方面的月度、季节性和长期趋势：1）大气粒子（气溶胶）的数量和类型，包括自然来源和人类活动形成的；2）云的数量、类型和高度；3）地表覆盖分布，包括植被冠层结构。