Carl F. Schueler

Accurate Monitoring of Terrestrial Aerosols and Total Solar Irradiance: Introducing the Glory Mission

The NASA Glory mission is intended to facilitate and improve upon long-term monitoring of two key forcings influencing global climate. One of the missions principal objectives is to determine the global distribution of detailed aerosol and cloud properties with unprecedented accuracy, thereby facilitating the quantification of the aerosol direct and indirect radiative forcings. The other is to continue the 28-yr record of satellite-based measurements of total solar irradiance from which the effect of solar variability on the Earths climate is quantified. These objectives will be met by flying two state-of-the-art science instruments on an Earth-orbiting platform. Based on a proven technique demonstrated with an aircraft-based prototype, the Aerosol Polarimetry Sensor (APS) will collect accurate multiangle photopolarimetric measurements of the Earth along the satellite ground track within a wide spectral range extending from the visible to the shortwave infrared. The Total Irradiance Monitor (TIM) is an ...

The NPOESS VIIRS Day/Night Visible Sensor

The National Polar-orbiting Operational Environmental Satellite System (NPOESS) will feature the Visible-Infrared Imager-Radiometer Suite (VIIRS), a 22-channel imager that will contribute to nearly half of the NPOESS environmental data records. Included on VIIRS will be the Day/Night band (DNB), a visible channel designed to image the Earth and its atmosphere in all conditions ranging from bright solar illumination, to nocturnal lunar illumination, and negligible external illumination. Drawing heritage from the Defense Meteorological Satellite Program (DMSP) Operational Linescan System (OLS) instruments orbiting since the late 1960s, the DNB will be used to detect clouds at night, understand patterns of urban development based on the emissions of cities, monitor fires, and image scenes of snow and ice at the surface of the Earth. Thanks to significant engineering improvements, the DNB will produce superior capabilities to the OLS for a number of new applications.

NPOESS VIIRS sensor design overview

A new era in remote sensing will begin with the launch of the National Polar-orbiting Operational Environment Satellite Systems (NPOESS) Preparatory Project (NPP) spacecraft in 2005, and the multiple operational NPOESS launches in sun-synchronous orbital planes (nominally 13:30, 17:30, or 21:30 local equatorial crossing times) starting in 2008. Users of polar-orbiting environmental satellite data will see a profound improvement in the radiometric quality, spectral coverage, and spatial resolution of routinely available visible and infrared data relative to current operational civilian and military polar-orbiting systems. The improved data will be provided by the NPOESS Visible Infrared Imaging Radiometer Suite (VIIRS). VIIRS will provide Environmental Data Records (EDRs) to meet civilian and national defense operational requirements, including day and night cloud imagery, sea surface temperatures (SST), and ocean color. EDRs will be produced by ground processing of raw data records (RDRS) from the VIIRS sensor. VIIRS will replace three currently operating sensors: the Defense Meteorological Satellite Program (DMSP) Operational Line- scanning System (OLS), the NOAA Polar-orbiting Operational Environmental Satellite (POES) Advanced Very High Resolution Radiometer (AVHRR), and the NASA Earth Observing System (EOS Terra and Aqua) MODerate-resolution Imaging Spectroradiometer (MODIS). This paper describes the VIIRS all-reflective 22-band single-sensor design. VIIRS provides low noise (driven by ocean color for the reflective visible and near-IR spectral bands and by SST for the emissive mid and long-wave IR spectral), excellent calibration and stability (driven by aerosol, cloud, and SST), broad spectral coverage, and fine spatial resolution driven by the imagery EDR. In addition to improved radiometric, spectral, and spatial performance, VIIRS features DMSP OLS-like near- constant resolution, global twice-daily coverage in each orbit plane, and direct heritage to proven design innovations from the successful Sea-viewing Wide Field-of- view Sensor (SeaWiFS) and Earth Observing System (Terra) MODIS.

VIIRS (Visible Infrared Imager Radiometer Suite): a next-generation operational environmental sensor for NPOESS

This paper describes the Visible/Infrared Imager Radiometer Suite (VIIRS), the next-generation instrument for the U.S. future converged civilian and military operational polar-orbiting environmental satellite system.

NASA MODIS Previews NPOESS VIIRS Capabilities

Abstract The Visible/Infrared Imager Radiometer Suite (VIIRS), scheduled to fly on the satellites of the National Polar-orbiting Operational Environmental Satellite System, will combine the missions of the Advanced Very High Resolution Radiometer (AVHRR), which flies on current National Oceanic and Atmospheric Administration satellites, and the Operational Linescan System aboard the Defense Meteorological Satellite Program satellites. VIIRS will offer a number of improvements to weather forecasters. First, because of a sophisticated downlink and relay system, VIIRS latencies will be 30 min or less around the globe, improving the timeliness and therefore the operational usefulness of the images. Second, with 22 channels, VIIRS will offer many more products than its predecessors. As an example, a true-color simulation is shown using data from the Earth Observing System’s Moderate Resolution Imaging Spectroradiometer (MODIS), an application current geostationary imagers cannot produce because of a missing “g...

The Visible Infrared Imaging Radiometer Suite

The Visible Infrared Imaging Radiometer Suite (VIIRS) is used to obtain measurements of the Earth’s oceans, land surface and atmosphere to make a wide range of Environmental Data Records (EDR’s). These standard products, which have been defined in the Integrated Operational Requirements Document (IORD) (JARG, 2005), are listed in Table 11.1. VIIRS is designed to provide global coverage at least once per day, with moderate (better than 1 km) spatial resolution. This combination of spatial and temporal scales has been chosen to provide needed input to operational weather and environmental models while sampling the natural variability of biological processes on the land surface and in the oceans. It has very high radiometric and geometric fidelity, enabling its use in the acquisition of long-term data records suitable for the study of climate and climate change as well as being a powerful tool for studies designed to increase our understanding of specific geophysical processes such as the interaction of the biological and physical mechanisms in ocean plankton blooms.

Using VIIRS to provide data continuity with MODIS

Comparisons are made between the key properties of the MODIS and VIIRS sensors. Long-term continuity of the data series being initiated by the MODIS (MODerate Resolution Imaging Spectroradiometer) on NASAs Terra mission will be obtained using the VIIRS (Visible Infrared Imaging Radiometer Suite) flying on the converged National Polar-Orbiting Environmental Satellite System (NPOESS) and on the NPOESS Preparatory Project (NPP). The data series include critical parameters such as cloud and aerosol properties, vegetation index, land use and land cover, ocean chlorophyll and sea surface temperature. VIIRS is being designed and built by Raytheon for the Integrated Program Office (IPO), the DoD, NOAA and NASA consortium that is responsible for NPOESS. In addition to meeting the requirements for operational environmental monitoring, VIIRS will meet the needs of the global change research community through the use of state-of-the-art algorithms and calibration and characterization activities.

NPOESS VIIRS design process

This paper presents an overview of the Visible and Infrared Imaging Radiometer Suite (VIIRS) design process that achieved exceptional competitive IPO ratings for system optimization, sensor system design, and systems engineering, integration and test (SEIT). A novel aspect of the competition was provision to the sensor competitors of a specification of geophysical measurement requirements called Environmental Data Records (EDRs), rather than a sensor hardware specification. The contractors were required to derive optimal VIIRS hardware specifications from the EDRs and Raytheons process is the subject of this paper. VIIRS will become the next-generation United States polar-orbiting Operational Environmental Satellite System (MPOESS) Preparatory Project (NPP) spacecraft. Beginning in 2008, the NPOESS VIIRS instrument will be launched into 1370, 1730, and 2130 local-time ascending-node sun-synchronous polar orbits as the single operational source for dozens of civil and defense environmental and weather products, as well as climate research data. VIIRS will replace three different currently operating sensors: the Defense Meteorological Satellite Program (DMSP) Operational Line-scan System (OLS), the NOAA Polar-orbiting Operational Environmental Satellite (POES) Advanced Very High Resolution Radiometer (AVHRR), and the NASA Earth Observing System (EOS Terra and Aqua) MODerate-resolution Imaging Spectroradiometer (MODIS). A critical VIIRS challenge was design optimization to differing requirements from the three user agencies (DoD, NOAA, and NASA) represented by the NPOESS Integrated Program Office.

VIIRS sensor performance

This paper summarizes the anticipated performance of the National Polar-orbiting Operational Environmental Satellite System (NPOESS) Visible Infrared Imaging Radiometer Suite (VIIRS) sensor. Predictions are generated from models and demonstration hardware based on the design described in a companion paper. VIIRS risk-reduction will continue as the Engineering Development Unit (EDU) is assembled and tested over the next year facilitating performance verification and lowering flight unit development risk.

Design evolution of the NPOESS VIIRS instrument since CDR

This paper summarizes recent design refinements to the National Polar-orbiting Operational Environmental Satellite System (NPOESS) Visible Infrared Imager Radiometer Suite (VIIRS) sensor. These design changes reduced manufacturing and performance risk to meet VIIRS sensor performance specifications. Two key design changes affected mass and optical design. Electro-Magnetic Compatibility (EMC) and Electro-Magnetic Interference (EMI) requirements led to mass growth due to increased shielding and cable complexity. A telescope design modification was required to remove modulated instrument background (MIB) discovered in the Critical Design Review (CDR) optical design. VIIRS risk reduction continues as the Engineering Development Unit (EDU) is assembled and tested in advance of the first flight unit.