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Conference

IEEE Aerospace Conference 

About: IEEE Aerospace Conference is an academic conference. The conference publishes majorly in the area(s): Spacecraft & Mars Exploration Program. Over the lifetime, 9647 publication(s) have been published by the conference receiving 83806 citation(s).


Papers
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Proceedings ArticleDOI
09 Mar 2002
TL;DR: PEGASIS (power-efficient gathering in sensor information systems), a near optimal chain-based protocol that is an improvement over LEACH, is proposed, where each node communicates only with a close neighbor and takes turns transmitting to the base station, thus reducing the amount of energy spent per round.
Abstract: Sensor webs consisting of nodes with limited battery power and wireless communications are deployed to collect useful information from the field. Gathering sensed information in an energy efficient manner is critical to operate the sensor network for a long period of time. In W. Heinzelman et al. (Proc. Hawaii Conf. on System Sci., 2000), a data collection problem is defined where, in a round of communication, each sensor node has a packet to be sent to the distant base station. If each node transmits its sensed data directly to the base station then it will deplete its power quickly. The LEACH protocol presented by W. Heinzelman et al. is an elegant solution where clusters are formed to fuse data before transmitting to the base station. By randomizing the cluster heads chosen to transmit to the base station, LEACH achieves a factor of 8 improvement compared to direct transmissions, as measured in terms of when nodes die. In this paper, we propose PEGASIS (power-efficient gathering in sensor information systems), a near optimal chain-based protocol that is an improvement over LEACH. In PEGASIS, each node communicates only with a close neighbor and takes turns transmitting to the base station, thus reducing the amount of energy spent per round. Simulation results show that PEGASIS performs better than LEACH by about 100 to 300% when 1%, 20%, 50%, and 100% of nodes die for different network sizes and topologies.

3,605 citations

Proceedings ArticleDOI
06 Mar 2010
Abstract: This paper provides a summary of the 2007 Mars Design Reference Architecture 5.0 (DRA 5.0) [1], which is the latest in a series of NASA Mars reference missions. It provides a vision of one potential approach to human Mars exploration, including how Constellation systems could be used. The strategy and example implementation concepts that are described here should not be viewed as constituting a formal plan for the human exploration of Mars, but rather provide a common framework for future planning of systems concepts, technology development, and operational testing as well as potential Mars robotic missions, research that is conducted on the International Space Station, and future potential lunar exploration missions. This summary of the Mars DRA 5.0 provides an overview of the overall mission approach, surface strategy and exploration goals, as well as the key systems and challenges for the first three concepts for human missions to Mars.1,2

522 citations

Proceedings ArticleDOI
09 Mar 2002
TL;DR: The radiation effects analysis is summarized that suggests that commercial grade processors are likely to be adequate for Mars surface missions, and the level of speedup that may accrue from using these instead of radiation hardened parts is discussed.
Abstract: NASA's Mars Exploration Rover (MER) missions will land twin rovers on the surface of Mars in 2004. These rovers will have the ability to navigate safely through unknown and potentially hazardous terrain, using autonomous passive stereo vision to detect potential terrain hazards before driving into them. Unfortunately, the computational power of currently available radiation hardened processors limits the amount of distance (and therefore science) that can be safely achieved by any rover in a given time frame. We present overviews of our current rover vision and navigation systems, to provide context for the types of computation that are required to navigate safely. We also present baseline timing results that represent a lower bound in achievable performance (useful for systems engineering studies of future missions), and describe ways to improve that performance using commercial grade (as opposed to radiation hardened) processors. In particular, we document speedups to our stereo vision system that were achieved using the vectorized operations provided by Pentium MMX technology. Timing data were derived from implementations on several platforms: a prototype Mars rover with flight-like electronics (the Athena Software Development Model (SDM) rover), a RAD6000 computing platform (as will be used in the 2003 MER missions), and research platforms with commercial Pentium III and Sparc processors. Finally, we summarize the radiation effects analysis that suggests that commercial grade processors are likely to be adequate for Mars surface missions, and discuss the level of speedup that may accrue from using these instead of radiation hardened parts.

408 citations

Journal ArticleDOI
01 Feb 1997
Abstract: This paper describes a new approach to adaptive phase-only nulling with phased arrays. A genetic algorithm adjusts some of the least significant bits of the beam steering phase shifters to minimize the total output power. Using small adaptive phase values results in minor deviations in the beam steering direction and small perturbations in the sidelobe level in addition to constraining the search space of the genetic algorithm. Various results are presented to show the advantages and limitations of this approach, in general, the genetic algorithm proves to be better than previous phase-only adaptive algorithms.

345 citations

Proceedings ArticleDOI
09 Mar 2002
TL;DR: This work proposes a new technique, called sparse topology and energy management (STEM), that dramatically improves the network lifetime by exploiting the fact that most of the time, the network is only sensing its environment waiting for an event to happen.
Abstract: In wireless sensor networks, where energy efficiency is the key design challenge, the energy consumption is typically dominated by the node's communication subsystem. It can only be reduced significantly by transitioning the embedded radio to a sleep state, at which point the node essentially retracts from the network topology. Existing topology management schemes have focused on cleverly selecting which nodes can turn off their radio, without sacrificing the capacity of the network. We propose a new technique, called sparse topology and energy management (STEM), that dramatically improves the network lifetime by exploiting the fact that most of the time, the network is only sensing its environment waiting for an event to happen. By alleviating the restriction of network capacity preservation, we can trade off extensive energy savings for an increased latency to set up a multi-hop path. We will also show how STEM integrates efficiently with existing topology management techniques.

315 citations

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Performance
Metrics
No. of papers from the Conference in previous years
YearPapers
2021369
2020457
2019453
2018409
2017408
2016455