Shahin Samadi

Strategies for enabling software reuse within the Earth Science Community

The Earth Sciences software development community is often challenged to provide cost effective, highly reliable and easy-to-use software to achieve scientific missions. In the process, the NASA Earth Science Enterprise (ESE) spends a significant amount of resources developing software components and other software development artifacts that may also be of value if reused in other projects requiring similar functionality. A recent study performed under the NASAs Strategic Evolution of ESE Data Systems (SEEDS) initiative suggests that reuse of ESE software can drive down the cost and time of system development, increase flexibility and responsiveness of these systems to new technologies and requirements; and increase effective and accountable community participation. In 2004, the Earth Science Software Reuse Working Group was created to oversee the development of a process that maximizes the reuse potential of existing software components while recommending strategies for maximizing the reusability potential of yet-to-be-designed components

The NPOESS Preparatory Project Science Data Segment: The Final As Built Description

The NPOESS Preparatory Project (NPP) provides remotely-sensed land, ocean, atmospheric, ozone, and sounder data that will serve the meteorological and global climate change scientific communities while also providing risk reduction for the National Polar-orbiting Operational Environmental Satellite System (NPOESS), the U.S. Governments future low-Earth orbiting satellite system monitoring global weather and environmental conditions. NPOESS is a joint mission of three federal agencies: NASA, NOAA, and DoD. NASA Science Data Segments (SDS) primary role in NPP is to independently assess the quality of the NPP science and environmental data records for climate research. Such assessment is critical for making NPOESS products the best that they can be for operational use and ultimately for climate studies. The SDS supports science assessment by assuring the timely provision of NPP data to NASAs science teams organized by climate measurement themes. The SDS breaks down into ten major elements: an input element that receives data from the operational agencies and acts as a buffer, a calibration analysis element, five elements devoted to measurement based quality assessment, one Production Element for Earth Radiation, an element used to test algorithmic improvements, and an element that coordinates overall science direction and results. This paper describes how the NPP SDS leveraged existing systems, the final system architectures, and lessons learned for the development of mission-reliable research-ready systems capable of supporting the assessment of NPP derived products.

Reuse of software assets for the NASA Earth science decadal survey missions

Software assets from existing Earth science missions can be reused for the new decadal survey missions that are being planned by NASA in response to the 2007 Earth Science National Research Council (NRC) Study. The new missions will require the development of software to curate, process, and disseminate the data to science users of interest and to the broader NASA mission community. In this paper, we discuss new tools and a blossoming community that are being developed by the Earth Science Data System (ESDS) Software Reuse Working Group (SRWG) to improve capabilities for reusing NASA software assets.

Building the Next Generation of Aerospace Data Processing Systems by Reusing Existing Software Components

Software is a key ingredient when developing any aerospace system. It is used in embedded electronics, in flight dynamics, in ground and space data processing, and in the current generation of data products. For example, the National Aeronautics and Space Administration (NASA) Goddard Space Flight Center’s Innovative Partnerships Program Office offers licensing opportunities for software and technologies from a variety of areas relevant to the hardware and software requirements of Earth and space science missions and projects: aerospace/aeronautics, computer software, data processing/analysis, electromechanical devices, electronics, manufacturing equipment, mechanical technologies, nanotechnology, optics and photonics, sensor and detector technologies, subassemblies and components, telecommunications and internet, and test and measurement (IPP Office, 2009). Reuse of existing experience and artifacts eliminates having to “reinvent the wheel” and is a key element to achieving progress in many areas of complex aerospace system development. Originally, in the absence of vendor-provided solutions and commercial off-the-shelf software components, many data and information systems were designed and built as custom applications. However, as the practice of systems and applications development has matured, facilitating reuse of software and reusing previously developed software have been recognized as beneficial for meeting the challenges of developing and maintaining complex systems. Some of the challenges commonly faced by system developers can include dealing with very large quantities of data (e.g., terabytes per day), working with a distributed knowledge base, the expense and complexity of required technology infrastructure, and the need for domain-specific knowledge in software development (Samadi et al., 2007). In software development, reuse can assist today’s development teams in various aspects of the system development life cycle, especially when they share common goals (Samadi et al., 2007). The development of new systems can benefit from the efforts that contributed to the development of current and previous generations of systems. Considering the costs of building new systems, and the learning curve that contributes to such costs, leveraging the results of previous system development activities has the potential to reduce system

A quality screening service for remote sensing data

NASA provides a wide variety of Earth-observing satellite data products to a diverse community. These data are annotated with quality information in a variety of ways, with the result that many users struggle to understand how to properly account for quality when dealing with satellite data. To address this issue, a Data Quality Screening Service (DQSS) is being implemented for a number of datasets. The DQSS will enable users to obtain data files in which low-quality pixels have been filtered out, based either on quality criteria recommended by the science team or on the users particular quality criteria. The objective is to increase proper utilization of this critical quality data in science data analysis of satellite data products.

Reusing Software to Build Data Processing Systems: NPP Science Data Segment Case Study

Over the years, numerous large and complex information systems have been created to store, process, and disseminate vast volumes of remotely-sensed Earth science data. These systems have the potential to be reused to process similar data from other missions or instruments, reducing risk, schedule, and associated development cost for future projects.

The NPOESS Preparatory Project Science Data Segment: Brief Overview

The NPOESS Preparatory Project (NPP) provides remotely-sensed land, ocean, atmospheric, ozone, and sounder data that will serve the meteorological and global climate change scientific communities while also providing risk reduction for the National Polar-orbiting Operational Environmental Satellite System (NPOESS), the U.S. Governments future low-Earth orbiting satellite system monitoring global weather and environmental conditions. NPOESS is a joint mission of three federal agencies, NASA, NOAA, and DoD. NASAs primary science role in NPP is to independently assess the quality of the NPP science and environmental data records for climate research. Such assessment is critical for making NPOESS products the best that they can be for operational use and ultimately for climate studies. The Science Data Segment (SDS) supports science assessment by assuring the timely provision of NPP data to NASAs science teams organized by climate measurement themes. The SDS breaks down into nine major elements, an input element that receives data from the operational agencies and acts as a buffer, a calibration analysis element, five elements devoted to measurement based quality assessment, an element used to test algorithmic improvements, and an element that provides overall science direction. This paper will describe how the NPP SDS will leverage on NASA experience to provide a mission-reliable research capability for science assessment of NPP derived measurements.

A Study of Earth Science Software Reuse Enablement Systems

The reuse of software assets can be critical to the development of large-scale software projects where budget and reliability are paramount. Yet many of the benefits of software reuse are either not recognized or overlooked. The majority of software assets are not made available to peers or a wider community. Therefore, a key activity in promoting software reuse is the initiative to increase the awareness of reuse enablement systems. An ideal Earth science reuse enablement system should ensure that reusable software assets are readily available to the software developers who want to use them to build new or enhance existing Earth science applications. This can be done by placing the assets into a software catalog or repository system. Many such systems exist, mostly outside of the Earth science domain, each designed for a particular purpose. Some are domain- specific, covering one particular subject area, while others are more general, covering a large variety of fields. Each is well- designed for its target audience. Many candidate systems that exist provide open-source software solutions. However, user goals, quality control, and overall usability determine the usefulness of a system to the community of Earth science software developers. The software used to create these systems also varies, ranging from standard HTML to full repository software packages like Repository in a Box (RIB), which uses the Basic Interoperability Data Model (BIDM), IEEE Standard 1420.1. The NASA Earth Science Data System (ESDS) Software Reuse Working Group has examined a variety of these systems, and focused on their applicability to the Earth science domain. Within a set of requirements designed for the Earth science community, this paper compares selected features of these systems, such as providing reviews for assets or the software used to design the site, and how the presence or absence of these features affects the systems ability to promote reuse.

Computing system to support software development, testing, and product quality assurance for an earth observing system instrument: a case study

In 1998 the National Aeronautics and Space Administration (NASA) will launch the first of a series of Earth Observation System (EOS) spacecraft designed to study the environment. The moderate resolution imaging spectroradiometer (MODIS) is a key EOS instrument. Current plans are to fly a series of six MODIS instruments on the EOS-AM and -PM satellite series. The operational life span for the EOS effort is fifteen years (1998 - 2012). Processing the data from the EOS platform and the MODIS instrument will require state of the art jumps in computing, storage and local and wide area networks. The continuous raw data rate from MODIS will average 10 megabits per second or approximately 110 gigabytes per day. The total product storage capacity for the MODIS data and products is estimated to be 650 gigabytes (GB) per day and 230 terrabytes (TB) per year. This paper focuses on the Team Leader Computing Facility (TLCF) which will be used to develop, integrate, optimize, test and validate the operational versions of the MODIS software. Approaches that achieve the high network bandwidth and high performance computing are needed to support MODIS software development and testing on global MODIS data sets. Candidate technologies are evaluated in light of the above requirements on the TLCF.