Here is an interesting report by Phil Langill using two SQM-LU meters strapped to the side of an airplane:
Measuring and Monitoring Darkness at 10,000 feet (PDF) Measuring a darkness baseline for new developments near the Rothney Astrophysical Observatory Poster presented at the Starlight Conference in Lake Tekapo NZ back in October 2019
By Phil Langill – RAO Director, University of Calgary