Planet, a commercial company, has achieved a key milestone by launching a large fleet of small satellites (smallsats) that provide high spatial resolution imagery of the entire Earth’s surface on a daily basis with its PlanetScope sensors. Given the potential utility of these data, this study explores the use for fine particulate matter (PM_2.5) air quality applications. However, before these data can be utilized for air quality applications, key features of the data, including geolocation accuracy, calibration quality, and consistency in spectral signatures, need to be addressed. In this study, selected Dove-Classic PlanetScope data is screened for geolocation consistency. The spectral response of the Dove-Classic PlanetScope data is then compared to Moderate Resolution Imaging Spectroradiometer (MODIS) data over different land cover types, and under varying PM_2.5 and mid visible aerosol optical depth (AOD) conditions. The data selected for this study was found to fall within Planet’s reported geolocation accuracy of 10 m (between 3–4 pixels). In a comparison of top of atmosphere (TOA) reflectance over a sample of different land cover types, the difference in reflectance between PlanetScope and MODIS ranged from near-zero (0.0014) to 0.117, with a mean difference in reflectance of 0.046 ± 0.031 across all bands. The reflectance values from PlanetScope were higher than MODIS 78% of the time, although no significant relationship was found between surface PM_2.5 or AOD and TOA reflectance for the cases that were studied. The results indicate that commercial satellite data have the potential to address Earth-environmental issues.

中文翻译：

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探索使用 PlanetScope 数据进行颗粒物空气质量研究

Planet 是一家商业公司，通过发射大量小型卫星 (smallsats) 实现了一个重要的里程碑，这些卫星每天使用其 PlanetScope 传感器提供整个地球表面的高空间分辨率图像。鉴于这些数据的潜在效用，本研究探讨了细颗粒物 (PM _2.5) 空气质量应用。然而，在将这些数据用于空气质量应用之前，需要解决数据的关键特征，包括地理定位精度、校准质量和光谱特征的一致性。在这项研究中，筛选了选定的 Dove-Classic PlanetScope 数据以确保地理位置的一致性。然后将 Dove-Classic PlanetScope 数据的光谱响应与不同土地覆盖类型和不同 PM _2.5下的中分辨率成像光谱仪 (MODIS) 数据进行比较和中可见气溶胶光学深度 (AOD) 条件。为这项研究选择的数据被发现属于 Planet 报告的 10 m（3-4 个像素之间）的地理定位精度。在比较不同土地覆盖类型样本的大气顶部 (TOA) 反射率时，PlanetScope 和 MODIS 之间的反射率差异范围从接近零 (0.0014) 到 0.117，反射率的平均差异为 0.046 ± 0.031所有乐队。PlanetScope 的反射率值在 78% 的情况下高于 MODIS，尽管在所研究的案例中未发现地表 PM _2.5或 AOD 与 TOA 反射率之间存在显着关系。结果表明商业卫星数据具有解决地球环境问题的潜力。