GA Landsat 5 TM Analysis Ready Data Collection 3

BACKGROUNDThe United States Geological Survey's (USGS) Landsat satellite program has been capturing images of the Australian continent for more than 30 years. This data is highly useful for land and coastal mapping studies. In particular, the light reflected from the Earth’s surface (surface reflectance) is important for monitoring environmental resources – such as agricultural production and mining activities – over time. We need to make accurate comparisons of imagery acquired at different times, seasons and geographic locations. However, inconsistencies can arise due to variations in atmospheric conditions, sun position, sensor view angle, surface slope and surface aspect. These need to be reduced or removed to ensure the data is consistent and can be compared over time. &nbspWHAT THIS PRODUCT OFFERSGA Landsat 5 TM Analysis Ready Data Collection 3 takes Landsat 5 Thematic Mapper (TM) imagery captured over the Australian continent and corrects for inconsistencies across land and coastal fringes. The result is accurate and standardised surface reflectance data, which is instrumental in identifying and quantifying environmental change. The TM instrument is an advanced, multispectral scanning, Earth resources sensor which is designed to categorise the Earth's surface. It is particularly useful for agricultural applications and identification of land use. This product is a single, cohesive Analysis Ready Data (ARD) package, which allows you to analyse surface reflectance data as is, without the need to apply additional corrections. It contains three sub-products that provide corrections or attribution information:     1) GA Landsat 5 TM NBAR Collection 3      2) GA Landsat 5 TM NBART Collection 3     3) GA Landsat 5 TM OA Collection 3The resolution is a 30 m grid based on the USGS Landsat Collection 1 archive.

背景
美国地质调查局（United States Geological Survey, USGS）的陆地卫星（Landsat）计划已持续三十余年获取澳大利亚大陆的地表影像。该数据在土地与海岸测绘研究中应用价值显著。尤为关键的是，地球表面反射的光线（表面反射率，surface reflectance）可用于长期监测农业生产、采矿活动等各类环境资源状况。我们需要对不同时间、季节及地理位置获取的影像开展精准对比，但由于大气条件、太阳位置、传感器视角、地表坡度与地表坡向的差异，可能会产生数据不一致的问题，需对其进行削弱或消除，以确保数据一致性并支持跨时间对比。

本产品特性
GA陆地卫星5号专题制图仪（Thematic Mapper, TM）分析就绪数据（Analysis Ready Data, ARD）第三批次，针对澳大利亚大陆获取的陆地卫星5号TM影像进行校正，消除陆地与海岸带的各类数据不一致问题。最终产出精准标准化的表面反射率数据，可用于识别与量化环境变化。TM仪器是一款先进的多光谱扫描地球资源传感器，旨在对地球表面进行分类，在农业应用与土地利用识别场景中尤为实用。
本产品为单一统一的分析就绪数据（ARD）套件，可直接用于表面反射率数据分析，无需额外施加校正操作。其包含三个可提供校正结果或归因信息的子产品：
1）GA陆地卫星5号TM NBAR第三批次
2）GA陆地卫星5号TM NBART第三批次
3）GA陆地卫星5号TM OA第三批次
该数据集基于美国地质调查局陆地卫星档案第一批次（USGS Landsat Collection 1 archive）构建，分辨率为30米网格。