ESSIC researcher launches website for satellite measurement project

Uncertainty can be a dangerous force of doubt when dealing with research data. Dr. Yudong Tian, an associate research scientist at ESSIC, is nearing the end of the first phase of a project to address this issue by developing a way to accurately predict uncertainties in satellite precipitation measurements.

The first year of the three-year project has focused on collecting “huge amounts” of satellite data. The next two years will focus on analyzing this data and creating models that can be used for predicting uncertainties in future measurements.

Tian, who said he has worked for NASA Goddard Space Flight Center for ten years and came to ESSIC as two years ago, said he had found an “urgent need” to narrow down uncertainties in precipitation measurements.

“We need to be able to scientifically determine the information content from these numbers. You need to determine the uncertainties,” Tian said, noting that data from satellites with less uncertainty can be trusted more.

The project itself is a collaboration between NASA and ESSIC. He said that he is collaborating with ESSIC Senior Research Scientist Robert Adler, who is working on a companion project that will deal with data in a more mature stage, merging data streams from several sensors.

Adler said Tian’s research is linked to a companion effort led by Adler to provide error estimates for existing satellite precipitation products both on the monthly scale and on the three-hourly scale.

Tian recently launched a project website, He said the website is designed to facilitate collaboration and transparency by making their data available on the website, as well as posting updates on the project there.

He also said that the “sigma” in the URL was chosen because the sigma symbol is often used to mathematically represent uncertainty.

Tian’s team members include NASA Physical Scientist Dr. Christa Peters-Lidard, ESSIC Research Associate Dr. Ling Tang and graduate student Rebekah Esmaili.

Esmaili said that precipitation, a “very exciting” field, is becoming a vaster research frontier due to improvements in satellite data maturity and availability. She also said she has already benefited form the team’s partnerships.

“While working in Dr. Tian’s group, I’ve gained an appreciation for the importance of a collaborative and interdisciplinary approach,” Esmaili said. “Within our own group, we all come from different scientific and engineering backgrounds and professional affiliations. As a “next generation” scientist, there is the ever present need to not only strengthen research skills, but also to synergize expertise.”

Tian spoke in favor of involving students like Esmaili, also, because of the aspect of the “next generation” of scientists.

“It’s great because we can expose students to a unique opportunity to work with NASA scientists,” Tian said. “This is an advantage of ESSIC over other departments. A lot of people at ESSIC are either working for NASA or NOAA, so you can get exposed to a much bigger community.”