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Geo Week expects 3,000 attendees from 50 countries to learn more about remote sensing, infrastructure, and advanced airborne/terrestrial technologies February 11-13, 2024, in Denver.

A trio of scientists/engineers from the USGS Earth Resources Observation and Science (EROS) Center will speak at the event, with presentations focused on accuracy and consistency in geospatial data. 

At the Geo Week conference, awards will be handed out by ASPRS (the American Society for Photogrammetry and Remote Sensing), one of the partner organizations sponsoring the event, including two given to scientists/engineers with EROS ties. In addition, EROS Chief of Staff Tim Glynn will present a Pecora award. Here’s a quick summary of what EROS researchers are presenting:

UAS Calibration and Landsat Field Validation 

Three man chatting.
Mahesh Shrestha, a calibration engineer at EROS, chats with Joe Adams (left) and Lance Brady of USGS National Uncrewed Systems Office (NUSO) last summer at EROS.

Mahesh Shrestha, a calibration engineer with the EROS Cal/Val Center of Excellence (ECCOE), is presenting some of the findings from experiments this past summer at EROS in Sioux Falls that tested whether unmanned aircraft systems (UAS) can be used for field validation of Landsat surface reflectance data. 

Mahesh, who has been a contractor at EROS for more than four years, says one key question that must be answered is how reliable the calibration specifications for a UAS, or drone, are—not only out of the box, but also with longer use and wear and tear. “We are using artificial targets to calibrate UAS imagery and compare with ground truth (measured by spectrometer) to evaluate the calibration,” he says, as well as trying to find the optimal target material and size for calibrating UAS imagery. “Without calibration, UAS images and satellite images are just pictures.”

The advantage of using drones for Landsat field validation is that they have the potential to sample larger, and inaccessible, areas within a shorter period of time than a spectrometer carried across a field by humans, which is the current method used to validate surface reflectance products.

Using the Cloud to Quantify Lidar Data Consistency

Aparajithan Sampath (Ajit) is the KBR engineering lead for lidar, UAS and satellite system characterization programs. He has worked for EROS for nearly 15 years as a contractor, currently from his home in North Carolina. At Geo Week, his presentation will focus on quantifying the consistency of 3D lidar data at large scale using cloud computing and open-source software.

Ajit emphasizes the benefits of his work for researchers. “The value that our group brings in is that we are trying to make sure that uncertainty in the data is removed as much as possible,” he said. “And if you remove uncertainty, the value of the data increases, it’s easier for people to use the data, they don't have to worry about whether the data is accurate or not, and they can just say, ‘Yes, it is accurate to this level, and I’m fine with using my own analysis algorithm.’”

Because of his service with ASPRS​​ in setting geospatial accuracy standards for various remote sensing platforms, Ajit will be receiving an award at Geo Week.

3 men
Mahesh Shrestha, Aparajithan Sampath, and Minsu Kim of EROS are presenting at Geo Week.


USGS 3DEP Data Accuracy and Landsat Bathymetric Data

Color photo of USGS researchers in Idaho
Minsu Kim (left) will present at Geo Week this weekend. He and Jeff Danielson, shown here in Idaho during research to measure the topobathymetry of the Kootenai River, will both attend the event in Denver.

Minsu Kim, whose primary work is in satellite data analysis and lidar, has worked as a KBR contractor at EROS for nine years. He will be presenting on two topics at Geo Week.

First, he will review the activity the USGS EROS lidar group did concerning 3D accuracy assessment methods for USGS 3DEP data. Previously, that data was assessed for only vertical accuracy, but the goal is to implement full 3D accuracy in the near future. His group researched and published various methods to assess 3D accuracy.

In his second talk, he will present the algorithm his group developed to derive bathymetric data from Landsat OLI coastal zone images, including several test sites such as Puerto Rico, Key West and Guam.


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