J. Robert Jensen

The Near Spacecraft Telecommunications System

Robert S. Bokulic, J. Robert Jensen, T.R. McKnight

The Near Earth Asteroid Rendezvous (NEAR) mission, first in NASA's Discovery series, is designed to gather scientific data about the near-Earth asteroid 433 Eros. Due to launch in February 1996, the spacecraft will rendezvous with and eventually orbit the asteroid. The telecommunications …

us (code pays fourni par la source)

Enhancements to Mini-RF X/C-band Data Quality through Cross-Channel Calibration and Reprocessing Strategies

Kristian Chan, Gerald Wesley Patterson, J. Robert Jensen, F. S. Turner et autres

Since 2009, the Mini-RF synthetic aperture radar (SAR) onboard NASA’s Lunar Reconnaissance Orbiter (LRO) has been collecting both S-band (12.6 cm) or X/C-band (4.2 cm) observations to provide near-global coverage of the Moon, including large portions of permanently-shadowed regions. Mini-RF currently operates …

us (code pays fourni par la source)

A Wide-Bandwidth Polarimetric Inverse SAR (PINSAR) for Characterizing Small, Irregular-Shaped Bodies

Gerald Wesley Patterson, H.B. Sequeira, R. S. Schulze, J. Robert Jensen et autres

Initial results from the New Horizons exploration of 2014 MU 69 , a small Kuiper Belt object

S. A. Stern, H. A. Weaver, John R. Spencer, Catherine B. Olkin et autres

New Horizons flies past MU 69 After flying past Pluto in 2015, the New Horizons spacecraft shifted course to encounter (486958) 2014 MU 69 , a much smaller body about 30 kilometers in diameter. MU 69 is part of the Kuiper Belt, …

us, pl, de, gb, fr (code pays fourni par la source)

Deep learning for remote sensed target classification in maritime satellite radar images

Abdarahmane Traoré, J. Robert Jensen, Moulay A. Akhloufi

Detecting drifting icebergs is an important task to avoid threats to navigation and offshore activities. Government and companies use aerial reconnaissance and shore-based observation platforms to detect these icebergs. However, in some areas with harsh weather conditions only satellite imagery can be …

ca (code pays fourni par la source)

Mini-RF S- and X-Band Bistatic Radar Observations of South Polar Craters on the Moon and their Implications for the Presence of Water Ice

Gerald Wesley Patterson, A. M. Stickle, J. T. S. Cahill, F. S. Turner et autres

A Comparison of Radar Polarimetry Data of the Moon From the LRO Mini-RF Instrument and Earth-Based Systems

Lynn M. Carter, Bruce A. Campbell, C. D. Neish, M. C. Nolan et autres

The Mini-RF radar, launched on the Lunar Reconnaissance Orbiter, imaged the lunar surface using hybrid-polarimetric, transmitting one circular polarization and receiving linear H and V polarizations. Earth-based radar operating at the same frequency has acquired data of the same terrains using circular-polarized …

us, ca (code pays fourni par la source)

Bistatic radar observations of the Moon using Mini-RF on LRO and the Arecibo Observatory

Gerald Wesley Patterson, A. M. Stickle, F. S. Turner, J. Robert Jensen et autres

us, ca (code pays fourni par la source)

Mini-RF/AO Bistatic Observations of the Floor of Cabeus Crater and Their Implications for the Presence of Water Ice

Gerald Wesley Patterson, A. M. Stickle, F. S. Turner, J. Robert Jensen et autres

Estimation of the Dynamics of Frequency Drift in Mature Ultra-stable Oscillators: A Study Based on the In-flight Performance from New Horizons

Gregory L. Weaver, J. Robert Jensen, Cristina Zucca, Patrizia Tavella et autres

Since launch on Jan 19th, 2006, the frequencies of the two ultra-stable oscillators (USOs A & B) on-board the New Horizons spacecraft have been determined using the application of non-coherent Doppler radiometric data. The two resulting histories are approaching nearly ten years …

Mini-RF and Arecibo Observatory Bistatic Observations of the Moon

Gerald Wesley Patterson, Ben J. Bussey, A. M. Stickle, F. S. Turner et autres

us (code pays fourni par la source)

Frequency performance of the New Horizons ultra-stable oscillators nine years of continuous in-flight monitoring

J. Robert Jensen, Gregory L. Weaver

The New Horizons mission has provided an unprecedented opportunity to observe the evolution two ultra-stable oscillators in deep space for over nine years. The unusual architecture of the New Horizons communications system allows for direct observation of one of the two USOs …

us (code pays fourni par la source)