diff --git a/docs/index.rst b/docs/index.rst
index ffff444..99886e0 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -3,13 +3,14 @@ Introduction
 
 The Full-sun Ultraviolet Rocket Spectrometer (FURST) is a NASA sounding rocket
 mission designed to measure the full-disk spectrum of the Sun in the far
-ultraviolet spectral range (120 - 180 nm) with high spectral resolution.
+ultraviolet spectral range (120 - 180 nm) with high spectral resolution, :math:`R > 20,000`.
 FURST is a Rowland circle spectrograph :cite:p:`Rowland1882` which is designed
 to minimize the number of optical surfaces, and provides the maximum possible
 throughput in the ultraviolet.
 
-This package provides a idealized model of the FURST optical system which is
+This package provides an idealized model of the FURST optical system which is
 designed to be used by the FURST data reduction pipeline.
+It uses the :mod:`optika` package to model and simulate the optical system.
 
 Installation
 ============