Twenty-Five Years of Landsat Thermal Band Calibration

Landsat-7 Enhanced Thematic Mapper+ (ETM+), launched in April 1999, and Landsat-5 Thematic Mapper (TM), launched in 1984, both have a single thermal band. Both instruments thermal band calibrations have been updated previously: ETM+ in 2001 for a pre-launch calibration error and TM in 2007 for data acquired since the current era of vicarious calibration has been in place (1999). Vicarious calibration teams at Rochester Institute of Technology (RIT) and NASA/Jet Propulsion Laboratory (JPL) have been working to validate the instrument calibration since 1999. Recent developments in their techniques and sites have expanded the temperature and temporal range of the validation. The new data indicate that the calibration of both instruments had errors: the ETM+ calibration contained a gain error of 5.8% since launch; the TM calibration contained a gain error of 5% and an additional offset error between 1997 and 1999. Both instruments required adjustments in their thermal calibration coefficients in order to correct for the errors. The new coefficients were calculated and added to the Landsat operational processing system in early 2010. With the corrections, both instruments are calibrated to within +/-0.7K

Performance and Mix Measurements of Indirect Drive Cu-Doped Be Implosions

The ablator couples energy between the driver and fusion fuel in inertial confinement fusion (ICF). Because of its low opacity, high solid density, and material properties, beryllium has long been considered an ideal ablator for ICF ignition experiments at the National Ignition Facility. We report here the first indirect drive Be implosions driven with shaped laser pulses and diagnosed with fusion yield at the OMEGA laser. The results show good performance with an average DD neutron yield of ~2 × 10[superscript 9] at a convergence ratio of R[subscript 0]/R ~ 10 and little impact due to the growth of hydrodynamic instabilities and mix. In addition, the effect of adding an inner liner of W between the Be and DD is demonstrated.United States. Dept. of Energy (Lawrence Livermore National Laboratory Contract DE-AC52-07NA27344

Lawson criterion for ignition exceeded in an inertial fusion experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion

Changing the prehistory of Sindh and Las Bela coast: twenty-five years of Italian contribution

The paper discusses the prehistory of Lowr Sindh and Las Bela Coast, and the role played by the Italian archaeologists since the 1980's. New date are presented regarding mainly the radiocarbon chronology the Indus Delta settlement on rocky outcrops and the shell middens of Las Bela