Future GEO AquaWatch Webinars

April 21, 2021 2pm UTC

Title:  Spectral decomposition using Varimax-rotated, principal component analysis: Transitioning to the Google Earth Environment  by Joseph Ortiz, Kent State University, OH

Abstract:  Varimax-rotated, principal component analysis (VPCA) provides a means of linearly decomposing multispectral and hyperspectral images. This is an important consideration because all remote sensing pixels represent a mixture of spectral responses from the materials present in the pixel. For aquatic systems that mixing occurs at the macroscopic level. While decreasing spectral and spatial dimentions enhances resolution, it cannot fully resolve the mixed pixel problem for that reason. VPCA is a soft unsupervised classification method that partitions image variance into algal and cyanobacterial functional classes, identifies suspended sediment, and pigment degradation products in two complementary way: based on their spectral response or spectral fingerprint and their spatial pattern. The method has been applied to multispectral and hyperspectral sensors in handheld, aerial and orbital applications. This talk will compare several applications and discuss steps currently underway to translate VPCA to the Google Earth Engine environment.

Speaker Bio: Dr. Ortiz earned the Bachelor of Science degree, with honors, from Brown University, Major: Aquatic Biology; and his Ph.D. in Oceanography from  Oregon State University, Corvallis OR, Major: Marine Geology.  “I believe that advances in scientific fields often occur at the interfaces between well established disciplines. Because of this, I have intentionally directed my research objectives toward interdisciplinary paths.  For example, my expertise in aquatic biology allows me to study the response of marine microplankton to their environment to improve the quality of paleoclimate reconstructions. I use my expertise in core and wireline logging methods like diffuse spectral reflectance to quantify physical properties of  deep-sea sediments and to determine provenance of archeological artifacts. Advances in one area often help me to fine tune or develop new approaches for use in other aspects of my research.My research background has provided me with a broad and powerful set of tools with which to attack problems using a multi-dimensional, interdisciplinary approach. My interest in a variety of research topics allows me to continuously refine existing skills while developing new ones. These skills and experiences enable me to conduct significant research on topics ranging from climate change to water quality.  I have received funding for my research through the National Science Foundation, the Ocean Drilling Program, Ohio SeaGrant, NOAA, the KSU Farris Family Innovation Fund for Early Achievement, and the KSU University Research and Teaching Councils.” Find out more here.


April 21st, 2pm UTC

Join on your computer or via the Team App  Microsoft Teams  Webinar login:


GEO AquaWatch Project Update Lightning Talks Webinar Series.

A 3 week series offering an opportunity to hear various speakers provide AquaWatch Community project updates in a series of lightning round talks. More speaker and title details coming soon!

April 29 2pm UTC – Week 1



May 6 2pm UTC – Week 2



May 11, 2021, 2pm UTC






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