Durech J.,Charles University |
Kaasalainen M.,Tampere University of Technology |
Herald D.,International Occultation Timing Association IOTA |
Dunham D.,KinetX, Inc |
And 8 more authors.
Icarus | Year: 2011
Asteroid sizes can be directly measured by observing occultations of stars by asteroids. When there are enough observations across the path of the shadow, the asteroid's projected silhouette can be reconstructed. Asteroid shape models derived from photometry by the lightcurve inversion method enable us to predict the orientation of an asteroid for the time of occultation. By scaling the shape model to fit the occultation chords, we can determine the asteroid size with a relative accuracy of typically ∼10%. We combine shape and spin state models of 44 asteroids (14 of them are new or updated models) with the available occultation data to derive asteroid effective diameters. In many cases, occultations allow us to reject one of two possible pole solutions that were derived from photometry. We show that by combining results obtained from lightcurve inversion with occultation timings, we can obtain unique physical models of asteroids. © 2011 Elsevier Inc.
Shaklan S.B.,Jet Propulsion Laboratory |
Marchen L.,Jet Propulsion Laboratory |
Lisman P.D.,Jet Propulsion Laboratory |
Cady E.,Jet Propulsion Laboratory |
And 4 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2011
We present a starshade error budget with engineering requirements that are well within the current manufacturing and metrology capabilities. The error budget is based on an observational scenario in which the starshade spins about its axis on timescales short relative to the zodi-limited integration time, typically several hours. The scatter from localized petal errors is smoothed into annuli around the center of the image plane, resulting in a large reduction in the background flux variation while reducing thermal gradients caused by structural shadowing. Having identified the performance sensitivity to petal shape errors with spatial periods of 3-4 cycles/petal as the most challenging aspect of the design, we have adopted and modeled a manufacturing approach that mitigates these perturbations with 1-m long precision edge segments positioned using commercial metrology that readily meets assembly requirements. We have performed detailed thermal modeling and show that the expected thermal deformations are well within the requirements as well. We compare the requirements for four cases: a 32 m diameter starshade with a 1.5 m telescope, analyzed at 75 and 90 mas, and a 40 m diameter starshade with a 4 m telescope, analyzed at 60 and 75 mas. © 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).
Farquhar I.,Farquhar Consultants System Analysis and Design |
Dunham D.,KinetX, Inc
Proceedings of the International Astronautical Congress, IAC | Year: 2014
We developed and demonstrated the feasibility of an autonomous architecture-ARCTIC-that will deploy the capabilities of continuous reliable communications, e-navigation and vessel tracking, accurate geodetic framework, dynamic support of operations and logistics, and in-situ ice-sea and Marginal Ice Zone research in the Arctic. ARCTIC is a distributed, dynamic network of autonomous platforms combining sonar, RF, active RFID, laser communication, and power technologies and microsatellite relay. It enables the real-time acoustic and non-acoustic signal processing (image, optic, water properties) and functions from the bottom floor, through the entire water column, on water surface, ground level, and into the atmosphere and beyond. For the global coverage, a constellation of 30-72 microsatellites will support real-time RF communication with intended ground-level assets. The basic system consists of a minimum of 30 microsatellites, in three 530 km, circular, polar orbits whose orbital planes are separated by 120 degrees. With 10 satellites evenly spaced, in each of 3 polar orbits, it is highly likely that at least 2 satellites will be above 5 degrees elevation at any given time. With the basic 30 satellite system, the maximum slant range to any Ground Asset will be 2140 km. The LORAN-type (eLoran) triangulation model is used for determining and dynamic maintenance of the positioning coordinates of the entire architecture and its individual components. The architecture can associate GPS geospatial coordinates with its own organic geospatial reference system. A relay of 3-5 microsatellites will enable the real-time communication over any localized region. The relay of microsatellites (iteratively expandable and reconfigurable) in the calculated polar orbits will remain operational for over hundred years. ARCTIC and most of its platforms will continuously transfer data at 200 Kb/s-to-700Kb/s and, discretely, 10GB every 10 minutes using Earth-to-Space Forward Link (Ground Asset) transmit power of 20 Watts at the RF transmit frequency of 9750 MHz and Space-to-Earth Return Link (Microsatellite) transmit power of 25 Watts at the RF transmit frequency of 8600 MHz. In the short run, the proposed architecture will sustain continuous reliable communications in the region, e-navigation, and VHF data exchange system. In the long-run, the iteratively déployable dynamic network of autonomous platforms will serve multifunctional and multinational purposes of cost-effective maritime safety, Aid(s)-to-Navigation (AtoN), search and rescue, hazardous material spill response, MIZ research, and security of Arctic stakeholders and activities. ARCTIC meets requirements of providing AtoN services in Polar Regions specified by the International Association of Maritime Aids to Navigation and Lighthouse Authorities  and Maritime Transportation Safety information infrastructure laid out in the U.S. Committee on the Marine Transportation System document . Whereas, this paper focuses on the feasibility of operational and technical requirements and the feasibility of ARCTIC to deploy the required capabilities, its companion paper-IAC-14 B5.2.5 Multi-Sensor Architecture for Dynamic Signal Processing and Global Communication-discusses the limitless scope of operational requirements that the real-time information and communication architecture will enable, work breakdown structure (WBS) of the architecture prototype, and proof-of-concept, integrated end-to-end solution for real-time acoustic signatures differentiation and mapping.
Hodgson M.E.,University of South Carolina |
Davis B.A.,Washington Technology |
Cheng Y.,Jet Propulsion Laboratory |
Miller J.,KinetX, Inc
Cartography and Geographic Information Science | Year: 2010
State and local agencies involved in emergency response to natural disasters such as hurricanes have explicidy indicated they need imagery covering the disaster area within diree days of the event; and more desirably within 24 hours of the event. Airborne image collections have often been used but suffer from several problems, most noticeably the collection time (days or week) required for larger areas. The use of remote sensing satellites carrying high spatial resolution sensors has often been touted as the logical response for rapidly collecting post-disaster event imagery for emergency response. Unfortunately, satellites are maintained on fixed orbits. The repeat interval for remote sensing satellites carrying high spatial resolution sensors, even with pointable sensors, is on the order of several days, depending on the latitude for the disaster event. Fortunately, more than one satellite carries high spatial resolution imagery. This combination of requirements and restrictions may result in either a relatively high (or low) likelihood of collecting imagery within the three-day window of opportunity. This research investigated the likelihood of collecting imagery over a hurricane disaster area based on the orbital cycles of diree high spatial resolution imaging satellites. Using the spatial-temporal distribution of historic hurricane landfall locations as a proxy for the probability distribution of future hurricanes by latitude, the "visibility" of each landfall location to future satellite imaging opportunities was determined. The results indicate that the likelihood of collecting imagery within one day of the event varied between 17 and 39 percent by relying on one satellite image provider. However, if either of diree satellite imagery sources (i.e., Ikonos-2, Quickbird-2, and Orbview-3) could be used, then the likelihood increased to 61 percent. By relying on diree satellite imagery providers there is a likelihood of between 94 and 100 percent of collecting imagery within two or diree days, respectively, after the event.
Jackman C.D.,KinetX, Inc |
Dumont P.J.,KinetX, Inc
Advances in the Astronautical Sciences | Year: 2013
KinetX Aerospace, a private corporation, is currently providing navigation for three NASA deep space missions: MESSENGER, New Horizons, and OSIRISREx. Two of these, New Horizons to the Pluto system, and OSIRISREx to the asteroid 1999 RQ36, rely heavily on optical navigation (OpNav) to ensure mission success. KinetX-developed OpNav software uses spacecraft imaging to determine the spacecraft trajectory and targets' ephemerides. This paper describes the KinetX approach to optical navigation, simulating spacecraft images for testing, processing real data, and generating products for orbit determination. Also included are imaging simulations for New Horizons and OSIRIS-REx and real data results from New Horizons. © 2013 2013 California Institute of Technology.
Kidd J.N.,Jr. |
Furfaro R.,127 E. James E. Rogers Way |
Dunham D.,KinetX, Inc
Advances in the Astronautical Sciences | Year: 2014
This paper will concentrate on one mission profile of particular interest, a manned mission to Mars. Specifically, the study will explore the use of HEOs whose line of apsides can be rotated using lunar swingbys to approximate the V∞ vector necessary for such a mission, reducing the required energy cost of such a mission. The HEO also provides a convenient and relatively fast location for rendezvous with crew, or to add propulsion or cargo modules, a technique that we call "Phasing Orbit Rendezvous." From a HEO, a propulsive maneuver, considerably smaller than that needed from a circular low-Earth orbit, can be applied at the right perigee to send the spacecraft on the appropriate departure asymptote. A propulsive maneuver at perigee can be used to re-capture the spacecraft into a loosely-bound orbit at the return, perhaps assisted by a lunar swingby. Earth-Moon (and possibly Sun-Earth) libration point orbits and double-lunar swingby orbits will be used, along with time to change the orbital orientation between missions. There might be wait times of several months to years between missions, when the interplanetary spacecraft could be "parked" in a small-amplitude Lissajous orbit about a libration point, similar to that flown by the WMAP mission.
Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase I | Award Amount: 79.90K | Year: 2012
Communications systems are hindered by inherent system limitations and also by physical attributes. For WCDMA systems three prominent issues are capacity, high latitude performance (for systems based on geosynchronous satellites), and Line Of Sight (LOS) performance. The MUOS system, based on geosynchronous satellites, will be affected by all three issues. Commercial terrestrial systems are affected as well and could benefit from the development of a new solution to these problems. The miniature WCDMA payload addressed by this SBIR can be architected to address these issues for the MUOS system, for commercial systems, and for future WCDMA systems. The KinetX approach is based on the design of a common signal processing architecture that can be re-used for any WCDMA system. Modularity of design allows RF elements to be optimized for a given application while retaining the core signal processing subsystem. Future WCDMA systems can benefit as well, since only the RF elements need to be developed, along with software to configure the signal processing to the waveform parameters. Finally, with relatively straightforward re-packaging, this payload design can be hosted by a number of airborne platforms. The KinetX solution addresses military and commercial systems, and multiple host platforms.
Agency: Department of Defense | Branch: Navy | Program: SBIR | Phase: Phase I | Award Amount: 79.38K | Year: 2013
This offer proposes a set of activities to provide an innovative Deployable WCDMA Multi-Band Radio Base Station. The effort entails investigation, trade studies, and architecture design to support an easily fielded, transportable WCDMA Base Station not typical of mainstream communication deployments. The derived solution will support both military and commercial applications where terrestrial or satellite communications may not be available. The investigations for this project will focus on how multi-band, differing protocol (3GPP and MUOS) WCDMA channels can be supported by a single transportable radio base station, and options for interfacing users on these channels to their respective carriers such as the MUOS geosynchronous satellite system. The investigations will specifically address the challenges associated with interfacing a radio base station to MUOS network infrastructure equipment; resulting in a solution that will ensure communications features that meets the needs of the war fighters.
Agency: Department of Defense | Branch: Air Force | Program: SBIR | Phase: Phase I | Award Amount: 149.54K | Year: 2014
ABSTRACT: This offer proposes a set of activities to provide an innovative, modular, cost-effective and easily deployable AFSCN simulator. The derived solution will support satellite Factory Compatibility Test (FCT) for satellite programs utilizing the AFSCN. Using open architecture, open standards, COTS software and hardware, and a modular approach to develop a largely software-based simulation platform will yield a more compact, lower cost, less complicated, and easily upgradable testing solution. This test simulator will initially support AFSCN satellite compatibility testing, and be modular and upgradeable to support additional satellite testing for military, scientific, and commercial markets. The Phase I investigations for this project will focus on identifying the capabilities required to provide ground system compatibility testing with the AFSCN and generating a complete requirements set for backwards TSTR compatibility. The investigation will utilize these requirements, the current architecture, and current user needs to create a CONOPs and notional architectures. These architectures will be evaluated to produce the most cost effective simulation solution for the USAF. BENEFIT: A user-friendly, easily deployable, and cost-effective AFSCN simulator provides the USAF with near-term cost savings for utilization, training, and sustainment. Additionally, this system alleviates the demand for overburdened Mobile Range Flight (MRF) testing resources. An upgraded simulator provides the USAF and other agencies with a simulation/test system that would benefit many satellite development programs through lower cost AFSCN compatibility testing. KinetX envisions a simulator architecture that is modular, configurable and extensible to support multiple satellite programs testing needs. This simulation architecture will also enable KinetX to commercialize this platform for the growing commercial satellite market. The KinetX solution provides the Air Force with a robust simulator platform that is modular and extendible, easier to deploy with a smaller physical footprint and user-friendly interface, translating to cost savings and improved test coverage for satellite programs.
KinetX, Inc | Date: 2013-05-28