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Pharr, James

Publications and source records attributed to Pharr, James.

First Results from Laser-Based Spectral Characterization of Landsat 9 Operational Land Imager-2

Landsat 9 will continue the Landsat data record into its fifth decade with launch scheduled for December 2020. The two instruments on Landsat 9 are Thermal Infrared Sensor-2 (TIRS-2) and Operational Land Imager-2 (OLI-2). OLI-2 is a nine-channel pushbroom imager with a 15-degree field of view that will have a 16-day measurement cadence from its nominal 705-km orbit altitude. A key aspect of the data that will be produced by OLI-2 is its spectral fidelity which enables countless science applications. The prelaunch test campaign for spectral characterization of OLI-2 was substantially improved relative to the methodology used for OLI: the full spectral response of every detector was characterized with greater accuracy, sampling, and precision. This paper will describe how this was accomplished with a tunable laser-based light source called Goddard Laser for Absolute Measurement of Radiance (GLAMR).

tunable laser↗

Aqua vs TanSat: A Long-Term Analysis

A six-year analysis between Aqua and TanSat was conducted in order to assess whether or not TanSat would be a continued threat to Aqua. It is predicted that TanSat will cross Aqua seven times prior to Aqua's predicted constellation exit and lowering in February 2022. The predicted crossing geometry is generally favorable at any of the crossings due to TanSat's orbit eccentricity.

Pharr, James↗