Many corrections will be made to the data, affecting both the Operational Land Imager (OLI) and the Thermal Infrared Sensor (TIRS). These corrections include all calibration parameter file updates since launch; improved OLI reflectance conversion coefficients for the cirrus band; improved OLI radiance conversion coefficients for all bands; refined OLI detector linearization to decrease striping; a radiometric offset correction for both TIRS bands; and a slight improvement to the geolocation of the TIRS data.
Details about these changes are available on https://www.usgs.gov/landsat-missions/calibration_notices.php.
Source: USGS Landsat

STELLA: A DIY Handheld Scientific Instrument
If you are looking for a do-it-yourself (DIY) handheld spectrometer, you need to meet STELLA. STELLA (Science and Technology Education for Land/Life Assessment) is a portable scientific instrument developed by