Search NASA⌕ Search

NASA NTRS · 20140013219

An Information NEXUS: The NASA Global Hawk Link Module

Abstract

The Link Module described in this paper was first developed for the NASA Global Hawk Pacific Mission (GloPAC), four flights of 30 hour duration, supporting the Aura Validation Experiment (AVE). Its second use was during the Genesis and Rapid Intensification Processes (GRIP) experiment, a NASA Earth Science field experiment to better understand how tropical storms form and develop into major hurricanes. In these missions, the Link module negotiated all communication over the high bandwidth Ku satellite link, archived al the science data from onboard experiments in a spatially enable database, routed command and control of the instruments from the Global Hawk Operations Center, and retransmitted select data sets directly to experimenters control and analysis systems. The availability of aggregated information from collections of sensors, and remote control capabilities, in real-time, is revolutionizing the way Airborne Science is being conducted. Also described is the next generation Link Module now being designed and tested to support the NASA Earth Venture missions, the Hurricane and Severe Storm Sentinel (HS3) mission, and Airborne Tropical Tropopause Experiment (ATTREX) mission. Advanced data fusion technologies being developed will further advance the Scientific productivity, flexibility and robustness of these systems. Historically, the Link module evolved from the instrument and communication interface controller used by NASA's Pathfinder and Pathfinder plus solar powered UAS's in the late 1990's. It later was expanded for use in the AIRDAS four channel scanner flown on the NASA Altus UAS, and then again to a module in the AMS twelve channel multispectral scanner flying on the NASA (Predator-b) Ikhana UAS. The current system is the next step in the evolution, a multi board system packaged in a Curtiss Wright MIL-spec, flight qualified enclosure.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Sullivan, D. V.. 2012-07-22. An Information NEXUS: The NASA Global Hawk Link Module. https://ntrs.nasa.gov/citations/20140013219

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related reports

Spectrally Dependent Radiometric Measurement Errors Due to CCD Serial Pixel-to-Pixel Readout Interference in the Ocean Color Instrument of the NASA PACE Mission

The Ocean Color Instrument on NASA’s PACE mission is a 322 887 nm hyperspectral imager with 1 km x 1 km nadir spatial resolution and 5 nm spectral resolution utilizing charge-coupled devices (CCDs) operating in Time Delay Integration (TDI) mode where each TDI column represents a different wavelength in 0.625 nm increments. After TDI, the charge is moved into serial output pixels and read out. The spatial resolution requires an 8.5 MHz readout rate. This only allows 59 ns for the CCD reset and video to be asserted and settled before sampling. The response exhibits serial pixel-to-pixel readout interference due to the lack of full settling. Each serial pixel value has a dependence on the value of the preceding pixel value. This leads to a spectrally dependent radiometric measurement error of up to 0.3 %. We explain the operation of the detection system, the behavior of the interference, and show the resulting measurement error based on data from both ground testing and on-orbit characterization.

Remote Sensing↗

South Africa Ecological Conservation: Identifying and Mapping Riparian Areas in South Africa with Earth Observations

Riparian zones are thin strips of wetland that occur along the edges of rivers, lakes, and other water bodies. They provide many ecosystem and societal benefits such as stream bank stabilization, flood control, and habitat stability, making these zones very important areas to preserve and protect. Recognizing the need to accurately map these ecosystems in a cost-effective way, we partnered with the South African National Biodiversity Institute (SANBI) and the Biodiversity Survey of the Cape(BioSCape) to develop a GI methodology using Esri's ArcGIS Pro and data from Landsat 9 Operational Land Imager-2, Sentinel-2 Multispectral Instrument, and the Shuttle Radar Topography Mission to identify potential riparian zones (PRZ) and observed riparian vegetation(ORV) in the Southern Cape and the North West Province of South Africa to estimate the actual riparian vegetation (ARV) within those areas. Potential riparian ecosystems were calculated by utilizing a Topographic Wetness Index (TWI) and a water feature layer, while observed riparian vegetation were calculated by overlaying a Normalized Difference Vegetation Index (NDVI) and TWI. Actual Riparian Vegetation is determined by the overlap of ORV with PRZ and is done with conditional statements; ORV within PRZ is ARV. This method significantly improved a current riparian land cover classification since it combined high resolution optical imagery and topographic data. We anticipate such maps will be used by conservationists and practitioners interested in riparian monitoring and management.

Remote Sensing↗

Initial Results of Wyatt EIRP- The Ground Based Power and Ambiguity Function Monitor for P-Band Signals of Opportunity Sources

The Wideband Year-round AmbuguiTy-function Track-ing Effective Isotropic Radiated Power (WYATT EIRP)instrument is designed to support P-Band based Sig-nals of Opportunity (SoOp) remote sensing instrument.SoOp utilizes pre-existing non-cooperative microwavetransmitters as sources of illumination. This remotesensing method requires knowledge of the signals EIRP,position and ambugituty function’s shape.WYATT EIRP is designed to periodically generateEIRP measurements, ambuguity functions and transmit-ter elevation. It uses an array of RHCP and LHCPantennas, mounted on a rotating antenna pedestal togenerate EIRP measurements. A secondary observationantenna is placed to allow time difference of arrival mea-surements for transmitter elevation estimates. Both thepedestal and reference antenana are used to generateamituigyt fionctions. The pedestal will also be used tovalidate existing P-Band background noise temperaturesky maps. WYATT EIRP will be commissioned in thefirst quarter of 2024 and will be used to provide calibra-tion data to the upcoming spaceborne SigNals Of Op-portunity: P-Band Investigation (SNOOPI) instrument.

Remote Sensing↗