3,696 research outputs found
An Integer Linear Programming Solution to the Telescope Network Scheduling Problem
Telescope networks are gaining traction due to their promise of higher
resource utilization than single telescopes and as enablers of novel
astronomical observation modes. However, as telescope network sizes increase,
the possibility of scheduling them completely or even semi-manually disappears.
In an earlier paper, a step towards software telescope scheduling was made with
the specification of the Reservation formalism, through the use of which
astronomers can express their complex observation needs and preferences. In
this paper we build on that work. We present a solution to the discretized
version of the problem of scheduling a telescope network. We derive a solvable
integer linear programming (ILP) model based on the Reservation formalism. We
show computational results verifying its correctness, and confirm that our
Gurobi-based implementation can address problems of realistic size. Finally, we
extend the ILP model to also handle the novel observation requests that can be
specified using the more advanced Compound Reservation formalism.Comment: Accepted for publication in the refereed conference proceedings of
the International Conference on Operations Research and Enterprise Systems
(ICORES 2015
The Zwicky Transient Facility: Surveys and Scheduler
We present a novel algorithm for scheduling the observations of time-domain
imaging surveys. Our Integer Linear Programming approach optimizes an observing
plan for an entire night by assigning targets to temporal blocks, enabling
strict control of the number of exposures obtained per field and minimizing
filter changes. A subsequent optimization step minimizes slew times between
each observation. Our optimization metric self-consistently weights
contributions from time-varying airmass, seeing, and sky brightness to maximize
the transient discovery rate. We describe the implementation of this algorithm
on the surveys of the Zwicky Transient Facility and present its on-sky
performance.Comment: Published in PASP Focus Issue on the Zwicky Transient Facility
(https://dx.doi.org/10.1088/1538-3873/ab0c2a). 13 Pages, 11 Figure
AstroGrid-D: Grid Technology for Astronomical Science
We present status and results of AstroGrid-D, a joint effort of
astrophysicists and computer scientists to employ grid technology for
scientific applications. AstroGrid-D provides access to a network of
distributed machines with a set of commands as well as software interfaces. It
allows simple use of computer and storage facilities and to schedule or monitor
compute tasks and data management. It is based on the Globus Toolkit middleware
(GT4). Chapter 1 describes the context which led to the demand for advanced
software solutions in Astrophysics, and we state the goals of the project. We
then present characteristic astrophysical applications that have been
implemented on AstroGrid-D in chapter 2. We describe simulations of different
complexity, compute-intensive calculations running on multiple sites, and
advanced applications for specific scientific purposes, such as a connection to
robotic telescopes. We can show from these examples how grid execution improves
e.g. the scientific workflow. Chapter 3 explains the software tools and
services that we adapted or newly developed. Section 3.1 is focused on the
administrative aspects of the infrastructure, to manage users and monitor
activity. Section 3.2 characterises the central components of our architecture:
The AstroGrid-D information service to collect and store metadata, a file
management system, the data management system, and a job manager for automatic
submission of compute tasks. We summarise the successfully established
infrastructure in chapter 4, concluding with our future plans to establish
AstroGrid-D as a platform of modern e-Astronomy.Comment: 14 pages, 12 figures Subjects: data analysis, image processing,
robotic telescopes, simulations, grid. Accepted for publication in New
Astronom
Strategy Implementation for the CTA Atmospheric Monitoring Program
The Cherenkov Telescope Array (CTA) is the next generation facility of
Imaging Atmospheric Cherenkov Telescopes. It will reach unprecedented
sensitivity and energy resolution in very-high-energy gamma-ray astronomy. CTA
will detect Cherenkov light emitted within an atmospheric shower of particles
initiated by cosmic-gamma rays or cosmic rays entering the Earth's atmosphere.
From the combination of images the Cherenkov light produces in the telescopes,
one is able to infer the primary particle energy and direction. A correct
energy estimation can be thus performed only if the local atmosphere is well
characterized. The atmosphere not only affects the shower development itself,
but also the Cherenkov photon transmission from the emission point in the
particle shower, at about 10-20 km above the ground, to the detector. Cherenkov
light on the ground is peaked in the UV-blue region, and therefore molecular
and aerosol extinction phenomena are important. The goal of CTA is to control
systematics in energy reconstruction to better than 10%. For this reason, a
careful and continuous monitoring and characterization of the atmosphere is
required. In addition, CTA will be operated as an observatory, with data made
public along with appropriate analysis tools. High-level data quality can only
be ensured if the atmospheric properties are consistently and continuously
taken into account. In this contribution, we concentrate on discussing the
implementation strategy for the various atmospheric monitoring instruments
currently under discussion in CTA. These includes Raman lidars and ceilometers,
stellar photometers and others available both from commercial providers and
public research centres.Comment: (6 pages, 2 figures, Proceedings of the 2nd AtmoHEAD Conference,
Padova, Italy May 19-21, 2014
Study of application of space telescope science operations software for SIRTF use
The design and development of the Space Telescope Science Operations Ground System (ST SOGS) was evaluated to compile a history of lessons learned that would benefit NASA's Space Infrared Telescope Facility (SIRTF). Forty-nine specific recommendations resulted and were categorized as follows: (1) requirements: a discussion of the content, timeliness and proper allocation of the system and segment requirements and the resulting impact on SOGS development; (2) science instruments: a consideration of the impact of the Science Instrument design and data streams on SOGS software; and (3) contract phasing: an analysis of the impact of beginning the various ST program segments at different times. Approximately half of the software design and source code might be useable for SIRTF. Transportability of this software requires, at minimum, a compatible DEC VAX-based architecture and VMS operating system, system support software similar to that developed for SOGS, and continued evolution of the SIRTF operations concept and requirements such that they remain compatible with ST SOGS operation
Working Notes from the 1992 AAAI Spring Symposium on Practical Approaches to Scheduling and Planning
The symposium presented issues involved in the development of scheduling systems that can deal with resource and time limitations. To qualify, a system must be implemented and tested to some degree on non-trivial problems (ideally, on real-world problems). However, a system need not be fully deployed to qualify. Systems that schedule actions in terms of metric time constraints typically represent and reason about an external numeric clock or calendar and can be contrasted with those systems that represent time purely symbolically. The following topics are discussed: integrating planning and scheduling; integrating symbolic goals and numerical utilities; managing uncertainty; incremental rescheduling; managing limited computation time; anytime scheduling and planning algorithms, systems; dependency analysis and schedule reuse; management of schedule and plan execution; and incorporation of discrete event techniques
Workshop proceedings: Information Systems for Space Astrophysics in the 21st Century, volume 1
The Astrophysical Information Systems Workshop was one of the three Integrated Technology Planning workshops. Its objectives were to develop an understanding of future mission requirements for information systems, the potential role of technology in meeting these requirements, and the areas in which NASA investment might have the greatest impact. Workshop participants were briefed on the astrophysical mission set with an emphasis on those missions that drive information systems technology, the existing NASA space-science operations infrastructure, and the ongoing and planned NASA information systems technology programs. Program plans and recommendations were prepared in five technical areas: Mission Planning and Operations; Space-Borne Data Processing; Space-to-Earth Communications; Science Data Systems; and Data Analysis, Integration, and Visualization
- …