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Literature Review of Approaches Used to Combine Satellite Observations with Ground-Level Monitoring in Urban Areas
The review of the scientific literature focused on identifying approaches to using satellite aerosol-optical-depth (AOD) observations that could provide city-scale, daily average PM2.5 (particulate matter with an aerodynamic diameter less than or equal to 2.5 microns) monitoring in low- and middle-income countries (LMICs). This chapter discusses the approaches used in each of the three key steps in combining satellite observations with ground-level monitoring (GLM) of PM2.5 for estimating ground-level concentrations in a given city: 1. The retrieval of AOD from satellite observations of reflected solar radiation (figure 2.3)
2. The translation of the vertically integrated AOD observation into an estimate of the ground-level PM2.5 concentration, including any bias corrections (figure 2.4) and 3. Simultaneously interpolating these satellite-derived PM2.5 estimates and the available GLM data to high-resolution grids centered on selected cities (figure 3.1).
The major findings of the review are presented below (see also table 3.1). The full literature review is provided in appendix A.
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