This paper describes the science motivation, measurement objectives, performance requirements, detailed design, approach and implementation, and calibration of the four Hot Plasma Composition Analyzers (HPCA) for the Magnetospheric Multiscale mission. The HPCA is based entirely on electrostatic optics combining an electrostatic energy analyzer with a carbon-foil based time-of-flight analyzer. In order to fulfill mission requirements, the HPCA incorporates three unique technologies that give it very wide dynamic range capabilities essential to measuring minor ion species in the presence of extremely high proton fluxes found in the region of magnetopause reconnection. Dynamic range is controlled primarily by a novel radio frequency system analogous to an RF mass spectrometer. The RF, in combination with capabilities for high TOF event processing rates and high current micro-channel plates, ensures the dynamic range and sensitivity needed for accurate measurements of ion fluxes between ∼1 eV and 40 keV that are expected in the region of In order to calibrate the four HPCA instruments we have developed a unique ion calibration system. The system delivers a multi-species beam resolved to M/ M ∼ 100 and current densities between 0.05 and 200 pA/cm 2 with a stability of ±5 %. The entire system is controlled by a dedicated computer synchronized with the HPCA ground support equipment. This approach results not only in accurate calibration but also in a comprehensive set of coordinated instrument and auxiliary data that makes analysis straightforward and ensures archival of all relevant data.

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This paper presents the vicarious calibration results of Landsat 8 OLI that were obtained using the reflectance-based approach at test sites in Nevada, California, Arizona, and South Dakota, USA. Additional data were obtained using the Radiometric Calibration Test Site, which is a suite of instruments located at Railroad Valley, Nevada, USA. The results for the top-of-atmosphere spectral radiance show an average difference of −2.7, −0.8, 1.5, 2.0, 0.0, 3.6, 5.8, and 0.7% in OLI bands 1-8 as compared to an average of all of the ground-based measurements. The top-of-atmosphere spectral reflectance shows an average difference of 1.6, 1.3, 2.0, 1.9, 0.9, 2.1, 3.1, and 2.1% from the ground-based measurements. Except for OLI band 7, the spectral radiance results are generally within ±5% of the design specifications, and the reflectance results are generally within ±3% of the design specifications. The results from the data collected during the tandem Landsat 7 and 8 flight in March 2013 indicate that ETM+ and OLI agree to each other to within ±2% in similar bands in top-of-atmosphere spectral radiance, and to within ±4% in top-of-atmosphere spectral reflectance. OPEN ACCESSRemote Sens. 2015, 7 601

This study evaluates the radiometric consistency between Landsat-8 Operational Land Imager (OLI) and Landsat 7 Enhanced Thematic Mapper Plus (ETM+) using cross calibration techniques. Two approaches are used, one based on cross calibration between the two sensors using simultaneous image pairs, acquired during an underfly event on 29-30 March 2013. The other approach is based on using time series of image statistics acquired by these two sensors over the Libya 4 pseudo invariant calibration site (PICS) (+28.55°N, +23.39°E). Analyses from these approaches show that the reflectance calibration of OLI is generally within ±3% of the ETM+ radiance calibration for all the reflective bands from visible to short wave infrared regions when the ChKur solar spectrum is used to convert the ETM+ radiance to reflectance. Similar results are obtained comparing the OLI radiance calibration directly with the ETM+ radiance calibration and the results in these two different physical units (radiance and reflectance) agree to within ±2% for all the analogous bands. OPEN ACCESSRemote Sens. 2014, 6 12620 These results will also be useful to tie all the Landsat heritage sensors from Landsat 1 MultiSpectral Scanner (MSS) through Landsat-8 OLI to a consistent radiometric scale.

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