Francesco Pierfederici

LSST operation simulator implementation

We have developed an operation simulator for the Large Synoptic Survey Telescope (LSST) that is an implementation in Python language using the SimPy extension, with a modular and object-oriented design. The main components include a telescope model, a sky model, a weather database for 3 sites, a scheduler and multiple observing proposals. All the proposals derive from a parent class which is fully configurable through about 75 parameters to implement a specific science survey. These parameters control the target selection region, the composition of the sequence of observations for each field, the timing restrictions and filter selection criteria of each observation, the lunation handling, seeing limits, etc. The current implemented proposals include Weak Lensing, Near Earth Asteroids, Supernova and Kuiper Belt Objects. The telescope model computes the slew time delay from the current position to any given target position, using a complete kinematic model for the mount, dome and rotator, as well as optics alignment corrections. The model is fully configurable through about 50 parameters. The scheduler module combines the information received from the proposals and the telescope model for selecting the best target at each moment, promoting targets that fulfill multiple surveys and storing all the simulator activities in a MySQL database for further analysis of the run. This scheduler is also configurable; for example, balancing the weight of the slew time delay in selecting the next field to observe. This simulator has been very useful in clarifying some of the technical and scientific capabilities of the LSST design, and gives a good baseline for a future observation scheduler.

New tools and methods to browse HST images and spectra

The joint archive facility of the European Southern Observatory (ESO) and the Space Telescope - European Coordinating Facility (ST-ECF) is undertaking particular efforts in the field of associating (grouping) Hubble Space Telescope (HST) observations for a number of years already. By now their users are given means for browsing associations of HST images. Soon the same capability will be provided for spectra as well. Associations of observations can either be defined and driven by requirements imposed by higher level algorithms like co-adding and drizzling techniques or by user defined constraints. In any case we consider these services an important precursor and testbed to a future virtual observatory. Two components complement an on-line interface (archive.eso.org) to such data products: For one part it is the selection process which can be greatly improved by adding preview capabilities for individual or multiple exposures. On the other hand it requires a request handling system which supports the concept of associations and which can expand a given association and computes and delivers calibrated and combined data products.