Advanced Engines Development (United States)

Zarr is a key component of the Pangeo ecosystem and instrumental for effectively accessing and processing multi-dimensional Earth data in cloud-based systems. More and more leading satellite data providers are exploring the transition of their data archives to a cloud environment. As part of the ESA Copernicus Earth Observation Processor Framework (EOPF), ESA is in the process of providing access to “live” sample data from the Copernicus Sentinel missions -1, -2 and -3 in the new Zarr data format. This set of reprocessed data allows users to try out accessing and processing data in the new format and experiencing the benefits thereof with their own workflows.To help Sentinel data users to experience and adopt the new data format, a set of resources called the Sentinels EOPF Toolkit is being developed. Development Seed, SparkGeo and thriveGEO, together with a group of champion users (early-adopters), are creating a set of Jupyter Notebooks, plug-ins and libraries that showcase the use of Sentinel data in Zarr for applications across multiple domains for different user communities, including users of Python, Julia, R and QGIS.This presentation will give a demo of the first set of notebooks and plugins of the Sentinels EOPF toolkit that were developed and that facilitate the adoption of the Zarr data format for Copernicus Sentinel data users. Additionally, we will give an overview of toolkit developments and community activities that are planned throughout the project period.

Barium ferrite magnetic recording media have demonstrated the capability of achieving much higher recording densities than other particulate media. Even though the best performance is obtained with perpendicularly oriented media, longitudinally oriented and non-oriented Ba-ferrite media also exhibit exceptional recording characteristics. These media have very distinctive magnetic and switching field (SFD) characteristics, exhibiting very small SFD values, almost rectangular remanence loops (indicating no irreversible losses over a wide range of reverse fields), and minor loops very close to the major loop until the driving field becomes almost equal to the coercivity. These unique magnetic and switching field characteristics can explain the very low or negligible demagnetization losses (including recording demagnetization) which we observe in Ba-ferrite media and which result in their outstanding recording performance. The fundamental reasons for these unique magnetic and switching field properties are the predominant high uniaxial crystalline anisotropy of the platelets and their single domain character. On the negative side, the high anisotropy field is directly implicated as the main reason behind the marginal overwrite modulation which characterizes these media.

The recording density that has already been achieved with particulate media undoubtedly exceeds even the most optimistic expectations of most researchers in the field, who, long before the present state of development, had anticipated their replacement by thin metallic coatings or by some new and exotic formulation of novel particles. The old work horse not only survives but continues to lead the pack and even to demonstrate new spritness and vigor everytime it comes around the track! And if one judges by the recent IBM announcements, the old horse will continue to dominate the field well into the next decade. To be sure of course, he is not running unassisted, since the rules of the race permit a formidable array of electronic, electro-mechanical, and other props to be used, and they have been applied profusely and to great advantage. In this paper we do some crystal-ball gazing in trying to look at the future and to assess the attainable extensions in recording density using particulate media. Our analysis is primarily aimed in delineating the role of the magnetic parameters and the thickness of the coating and thus determining the way they would have to evolve in order to accomodate higher recording densities. The fundamental magnetic limits are several orders of magnitude beyond the present state of the art (4700 bits/cm, 235 tracks/cm). Therefore, it appears most likely that future advancements will be paced by other considerations-smaller particles with narrower range of shape and size distributions, uniform and well-aligned dispersions, thinner and smoother coatings, new types of transducers with better fringing field gradients and improved short wavelength and high frequency sensitivity, better track-following servos, more efficient codes, and a host of electronic signal processing, filtering, waveform shaping and compensation techniques. We conclude that these non-magnetic considerations will ultimately impose the upper bounds in recording density, which are estimated to be less than an order of magnitude beyond the present achievements (to about 10,000 bits/cm and 500 tracks/cm). The realization of this potential, however, is going to be increasingly more difficult, and it is not unlikely that we may have to switch horses along the way and to use thin metallic media, perpendicular recording, or some other not yet invented innovation.