Daniel Cahn Nunes
California Institute of Technology
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Publication
Featured researches published by Daniel Cahn Nunes.
Science | 2011
Roger J. Phillips; Brian J. Davis; Kenneth L. Tanaka; Shane Byrne; Michael T. Mellon; Nathaniel E. Putzig; Robert M. Haberle; Melinda A. Kahre; Bruce A. Campbell; L. M. Carter; Isaac B. Smith; J. W. Holt; Suzanne E. Smrekar; Daniel Cahn Nunes; Jeffrey J. Plaut; Anthony F. Egan; Timothy N. Titus; Roberto Seu
Radar measurements reveal a substantial buried deposit of carbon dioxide in the south pole of Mars. Shallow Radar soundings from the Mars Reconnaissance Orbiter reveal a buried deposit of carbon dioxide (CO2) ice within the south polar layered deposits of Mars with a volume of 9500 to 12,500 cubic kilometers, about 30 times that previously estimated for the south pole residual cap. The deposit occurs within a stratigraphic unit that is uniquely marked by collapse features and other evidence of interior CO2 volatile release. If released into the atmosphere at times of high obliquity, the CO2 reservoir would increase the atmospheric mass by up to 80%, leading to more frequent and intense dust storms and to more regions where liquid water could persist without boiling.
Geophysical Research Letters | 2015
Marco Restano; Jeffrey J. Plaut; Bruce A. Campbell; Yonggyu Gim; Daniel Cahn Nunes; Fabrizio Bernardini; Anthony F. Egan; Roberto Seu; Roger J. Phillips
The close passage of Comet C/2013 A1 (Siding Spring) to Mars provided a unique opportunity to observe the interaction of cometary materials with the Martian ionosphere and atmosphere using the sounding radar SHARAD (SHAllow RADar) aboard Mars Reconnaissance Orbiter. In two nightside observations, acquired in the 10 h following the closest approach, the SHARAD data reveal a significant increase of the total electron content (TEC). The observed TEC values are typical for daylight hours just after dawn or before sunset but are unprecedented this deep into the night. Results support two predictions indicating that cometary pickup O+ ions, or ions generated from the ablation of cometary dust, are responsible for the creation of an additional ion layer.
IEEE Transactions on Geoscience and Remote Sensing | 2014
David R. Thompson; Robert O. Green; Didier Keymeulen; Sarah K. Lundeen; Yasha Mouradi; Daniel Cahn Nunes; Rebecca Castano; Steve Chien
Next-generation orbital imaging spectrometers will generate unprecedented data volumes, demanding new methods to optimize storage and communication resources. Here, we demonstrate that onboard analysis can excise cloud-contaminated scenes, reducing data volumes while preserving science return. We calculate optimal cloud-screening parameters in advance, exploiting stable radiometric calibration and foreknowledge of illumination and viewing geometry. Channel thresholds expressed in raw instrument values can be then uploaded to the sensor where they execute in real time at gigabit-per-second (Gb/s) data rates. We present a decision theoretic method for setting these instrument parameters and characterize performance using a continuous three-year image archive from the “classic” Airborne Visible/Infrared Imaging Spectrometer (AVIRIS-C). We then simulate the system onboard the International Space Station, where it provides factor-of-two improvements in data volume with negligible false positives. Finally, we describe a real-time demonstration onboard the AVIRIS Next Generation (AVIRIS-NG) flight platform during a recent science campaign. In this blind test, cloud screening is performed without error while keeping pace with instrument data rates.
Icarus | 2011
Alex S. Konopliv; Sami W. Asmar; William M. Folkner; Ozgur Karatekin; Daniel Cahn Nunes; Suzanne E. Smrekar; Charles F. Yoder; Maria T. Zuber
Journal of Geophysical Research | 2007
Roberto Seu; Roger J. Phillips; D. Biccari; Roberto Orosei; A. Masdea; Giovanni Picardi; Ali Safaeinili; Bruce A. Campbell; Jeffrey J. Plaut; Lucia Marinangeli; Suzanne E. Smrekar; Daniel Cahn Nunes
Journal of Geophysical Research | 2006
Daniel Cahn Nunes; Roger J. Phillips
Journal of Geophysical Research | 2005
Rebecca Rose Ghent; Roger J. Phillips; Vicki L. Hansen; Daniel Cahn Nunes
Journal of Geophysical Research | 2010
Daniel Cahn Nunes; Suzanne E. Smrekar; Ali Safaeinili; J. W. Holt; Roger J. Phillips; Roberto Seu; Bruce A. Campbell
Journal of Geophysical Research | 2011
Daniel Cahn Nunes; Suzanne E. Smrekar; Brian Fisher; Jeffrey J. Plaut; J. W. Holt; James W. Head; Seth J. Kadish; Roger J. Phillips
Geophysical Research Letters | 2016
C. J. Bierson; Roger J. Phillips; Isaac B. Smith; Stephen Wood; Nathaniel E. Putzig; Daniel Cahn Nunes; Shane Byrne