Publications by authors named "Lori Magruder"

3 Publications

  • Page 1 of 1

ICESat-2 Early Mission Synopsis and Observatory Performance.

Earth Space Sci 2021 May 18;8(5):e2020EA001555. Epub 2021 May 18.

NASA Goddard Space Flight Center Greenbelt MD USA.

The Advanced Topographic Laser Altimetry System (ATLAS) onboard the NASA Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) is the newest Earth observing satellite for global elevation studies. The primary objectives for ICESat-2 follow the objectives of its predecessor, ICESat and also focus on providing cryospheric measurements to determine ice sheet mass balance, and monitor both sea ice thickness and extent. However, the global observations support secondary science objectives as well such as biomass estimation, inland water elevation, sea state height and aerosol concentrations. Since launch of ICESat-2, ATLAS has collected more than a trillion measurements. This study provides a mission overview, a description of the operational components that enable the altimeter products for science, on-orbit observatory performance, and assessment of the spacecraft attitude control systems that enable repeat measurements to within 10 m and pointing control within ±45 m. These metrics should be considered for ground-based validation campaigns or science investigations.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1029/2020EA001555DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8265375PMC
May 2021

ICESat-2 Elevation Retrievals in Support of Satellite-Derived Bathymetry for Global Science Applications.

Geophys Res Lett 2021 Mar 8;48(5):e2020GL090629. Epub 2021 Mar 8.

Applied Research Laboratories University of Texas at Austin Austin TX USA.

Bathymetry retrievals from 2D, multispectral imagery, referred to as Satellite-Derived Bathymetry (SDB), afford the potential to obtain global, nearshore bathymetric data in optically clear waters. However, accurate SDB depth retrievals are limited in the absence of "seed depths." The Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) space-based altimeter has proven capable of accurate bathymetry, but methods of employing ICESat-2 bathymetry for SDB retrievals over broad spatial extents are immature. This research aims to establish and test a baseline methodology for generating bathymetric surface models using SDB with ICESat-2. The workflow is operationally efficient (17-37 min processing time) and capable of producing bathymetry of sufficient vertical accuracy for many coastal science applications, with RMSEs of 0.96 and 1.54 m when using Sentinel-2 and Landsat 8, respectively. The highest priorities for further automation have also been identified, supporting the long-range goal of global coral reef habitat change analysis using ICESat-2-aided SDB.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1029/2020GL090629DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7988556PMC
March 2021

The Ice, Cloud, and Land Elevation Satellite - 2 Mission: A Global Geolocated Photon Product Derived From the Advanced Topographic Laser Altimeter System.

Remote Sens Environ 2019 Nov;233

NASA Goddard Space Flight Center, Greenbelt, MD United States.

The Ice, Cloud, and land Elevation Satellite - 2 (ICESat-2) observatory was launched on 15 September 2018 to measure ice sheet and glacier elevation change, sea ice freeboard, and enable the determination of the heights of Earth's forests. ICESat-2's laser altimeter, the Advanced Topographic Laser Altimeter System (ATLAS) uses green (532 nm) laser light and single-photon sensitive detection to measure time of flight and subsequently surface height along each of its six beams. In this paper, we describe the major components of ATLAS, including the transmitter, the receiver and the components of the timing system. We present the major components of the ICESat-2 observatory, including the Global Positioning System, star trackers and inertial measurement unit. The ICESat-2 Level 1B data product (ATL02) provides the precise photon round-trip time of flight, among other data. The ICESat-2 Level 2A data product (ATL03) combines the photon times of flight with the observatory position and attitude to determine the geodetic location (i.e. the latitude, longitude and height) of the ground bounce point of photons detected by ATLAS. The ATL03 data product is used by higher-level (Level 3A) surface-specific data products to determine glacier and ice sheet height, sea ice freeboard, vegetation canopy height, ocean surface topography, and inland water body height.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.rse.2019.111325DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6839705PMC
November 2019
-->