robostrategy: Field and Target Assignment Optimization in the Sloan Digital Sky Survey V

TL;DR

robostrategy is a software tool that optimizes the scheduling and fiber assignment for the SDSS-V multi-object spectroscopy program, ensuring observations meet diverse scientific cadence requirements efficiently.

Contribution

This paper introduces robostrategy, a novel linear programming-based software for optimizing long-term observation planning and fiber assignment in large-scale astronomical surveys.

Findings

Successfully optimized observation schedules for SDSS-V

Achieved efficient target coverage respecting diverse cadences

Demonstrated flexibility and effectiveness of the method

Abstract

We present an algorithmic method for efficiently planning a long-term, large-scale multi-object spectroscopy program. The Sloan Digital Sky Survey V (SDSS-V) Focal Plane System performs multi-object spectroscopy using 500 robotic positioners to place fibers feeding optical and infrared spectrographs across a wide field. SDSS-V uses this system to observe targets throughout the year at two observatories in support of the science goals of its Milky Way Mapper and Black Hole Mapper programs. These science goals require observations of objects over time with preferred temporal spacinges (referred to as "cadences"), which can differ from object to object even in the same area of sky. robostrategy is the software we use to construct our planned observations so that they can best achieve the desired goals given the time available as a function of sky brightness and local sidereal time, and to assign fibers to targets during specific observations. We use linear programming techniques to seek optimal allocations of time under the constraints given. We present the methods and example results obtained with this software.