Denise Cooper

Radiometric Performance of the CERES Earth Radiation Budget Climate Record Sensors on the EOS Aqua and Terra Spacecraft through April 2007

Abstract The Clouds and the Earth’s Radiant Energy System (CERES) flight models 1 through 4 instruments were launched aboard NASA’s Earth Observing System (EOS) Terra and Aqua spacecraft into 705-km sun-synchronous orbits with 10:30 p.m. and 1:30 a.m. local time equatorial crossing times. With these instruments CERES provides state-of-the-art observations and products related to the earth’s radiation budget at the top of the atmosphere (TOA). The archived CERES science data products consist of geolocated and calibrated instantaneous filtered and unfiltered radiances through temporally and spatially averaged TOA, surface, and atmospheric fluxes. CERES-filtered radiance measurements cover three spectral bands: shortwave (0.3–5 μm), total (0.3>100 μm), and an atmospheric window channel (8–12 μm). CERES climate data products realize a factor of 2–4 improvement in calibration accuracy and stability over the previotus Earth Radiation Budget Experiment (ERBE) products. To achieve this improvement there are three...

Radiometric performance of the CERES Earth radiation budget climate record sensors on the EOS Aqua and Terra spacecraft

The CERES Flight Models 1 through 4 instruments were launched aboard NASAs Earth Observing System (EOS) Terra and Aqua Spacecraft into 705 Km sun-synchronous orbits with 10:30 a.m. and 1:30 p.m. equatorial crossing times. These instruments supplement measurements made by the CERES Proto Flight Model (PFM) instrument launched aboard NASAs Tropical Rainfall Measuring Mission (TRMM) spacecraft on November 27, 1997 into a 350 Km, 38-degree mid-inclined orbit. The archived CERES Science data products consist of geolocated and calibrated instantaneous filtered and unfiltered radiances through temporally and spatially averaged TOA, Surface, and Atmospheric fluxes. CERES filtered radiance measurements cover three spectral bands including shortwave (0.3 to 5 micron), total (0.3 to <100 micron) and an atmospheric window channel (8 to 12 micron). Earth Radiation Budget measurements made by the CERES represent a new era in radiation climate data. CERES climate data products realize a factor of 2 to 4 improvement in calibration accuracy and stability over the previous ERBE products. This improvement is derived from two sources: incorporation of lessons learned from the ERBE mission and the development of a rigorous and comprehensive radiometric validation protocol which consists of studies covering different spatial, spectral and temporal time scales on data collected both pre and post launch. This approach has resulted in unprecedented levels of accuracy for radiation budget data products with calibration stability of better than 0.2% and calibration traceability from ground to flight of 0.25%. The current work summarizes the status of the radiometric accuracy and stability of the CERES Edition2 Level 1 data products.

NPP clouds and the Earth's Radiant Energy System (CERES) predicted sensor performance calibration and preliminary data product performance

Continuation of the Earth Radiation Budget (ERB) Climate Data Record (CDR) has been identified as critical in the 2007 NRC Decadal Survey, the Global Climate Observing System WCRP report, and in an assessment titled ‘Impacts of NPOESS Nunn-McCurdy Certification on Joint NASA-NOAA Climate Goals’. In response, the final existing CERES Flight Model (FM-5) will fly on the NPP spacecraft for launch in 2010. The CERES FM-5 pre-flight radiometric characterization program has benefited from the operational experience of the CERES EOS sensors. Improvements to the pre-flight program included increased sampling under vacuum conditions and additional tests to characterize the primary and transfer standards in the calibration facility. Future opportunities for ERB CDR continuity consist of procuring an additional CERES Sensor with modest performance upgrades for flight on the NPOESS C1 spacecraft in 2013, followed by a new CERES follow-on sensor for flight in 2018 on the NPOESS C3 spacecraft.

Lessons Learned in CERES: Integrating Multiple Instruments on Multiple Platforms with Multiple Sources of Data

This paper discussed the complex issues in com bining remote sensing data from a variety of sources into a unified set of data products that can be used in the analysis of climate change. Creation of climate quality data records from remote sensing observations presents special challenges to the scien ce data processing segment of an instrument team. Throughout its history, remote sensing systems have recognized instrument calibration adjustments over time as necessary. Long -term stability over many decades is a unique climate data requirement imposed on remotely sensed data and creates special problems when information technology is rapidly evolving. Over the life of an observational data set, changes in ground processing environments, if not handled correctly, can create unexpected biases in signals and are a special challenge when the hardware, operating systems and processing libraries change on a quarterly basis. Planning for ground processing systems to support climate data records must incorporate requirements for accommodating changes to the t echnology and provide for a means of validating the stability of data products. This planning becomes particularly useful when the observational system lifetime extends through several lifetimes of the ground processing systems, and yet requires the elimi nation of errors created by changing the technologies in science data processing.