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Comparison of NDVI Values from Multiple Satellite Sensors to Monitor for Public Health in an Urban Sub-tropical Setting

Twelve scatter plots in four rows and three columns are shown. The first and second rows compare datasets for the City of Miami in October and March of 2014. The third and fourth rows compare datasets for Polk County in November of 2020 and February 2014. The first column compares Landsat 8 versus ASTER NDVI values. The second column compares Landsat 7 versus ASTER NDVI values. The third column compares Landsat 8 versus Landsat 7 values. All graphs have an R2 correlation value in the upper left corner and a colorbar legend on the right.
Figure 2. Scatterplots relating NDVI values between the ASTER and Landsat satellite sensors, demonstrated that the relationship between Landsat and ASTER NDVI varies more by season than location within urban subtropical settings.

SOUTHWORTH – Comparison of NDVI Values from Multiple Satellite Sensors to Monitor for Public Health in an Urban Sub-tropical Setting

Julius R. Dewald, Jane SouthworthScott C. Brown, Jose Szapocznik

Article first published online: 24 November 2022

DOI: http://article.sapub.org/10.5923.j.ajgis.20221102.01.html

ABSTRACT: Normalized Difference Vegetation Index (NDVI) is commonly used as a measure of greenness in public health research. Changes in NDVI over time in urbanized areas have been linked to improvements to multiple chronic conditions. Studies have been conducted using ASTER or Landsat, but their equivalence has not been established. To determine the equivalence or lack thereof between ASTER and Landsat, and between Landsat 7 and 8, this study compares NDVI values from ASTER, Landsat 7, and Landsat 8 satellite sensors at different times of the year (Fall and Spring) and at different locations in Florida (the City of Miami and Polk County). Although other studies have examined how Landsat and ASTER NDVI values compare, no study has explicitly investigated how NDVI values differ across ASTER and Landsat for urban areas. A comparison of the scatterplots of ASTER with Landsat satellite sensor NDVI scores, produced R2 values consistently above 0.75 with p-values less than 0.001 across both locations and times of the year, indicating that Landsat and ASTER-derived NDVI values share considerable variance. By repeating these analyses separately by season and location, we demonstrated that the relationship between Landsat and ASTER NDVI varies more by season than location within urban subtropical settings. These findings suggest that studies comparing NDVI values from these different satellite sensors would require calculating separate coefficients for each season.

Read the full publication at the International Journal of Geographic Information System.