Twilight observations with MASS-DIMM

TL;DR

This paper details a method for measuring optical turbulence during twilight using MASS-DIMM, showing turbulence characteristics are stable across day-night transition and that twilight seeing measurements can inform telescope scheduling.

Contribution

It introduces a novel approach for twilight turbulence measurement with MASS-DIMM and discusses system upgrades for improved twilight observations.

Findings

Optical turbulence characteristics are stable during twilight.

Twilight seeing measurements can aid in telescope scheduling.

System upgrades can enhance twilight observation capabilities.

Abstract

In this paper we describe the method of measurement of optical turbulence in twilight with MASS-DIMM. Some results of such observations carried out with SAI ASM installed on Mt. Shatdzatmaz: 1) characteristics of optical turbulence don't change significantly in transition between day and night 2) twilight measurements of seeing can be used for selection of observational program for big telescope on condition that program switching is long - longer than 30-40 minutes. In conclusions we list upgrades of ASM system needed to improve capabilities to observe on twilight.