  The Steward Observatory LEO Satellite Photometric Survey is a comprehensive
observational survey to characterize the apparent brightness of the Starlink
and OneWeb low Earth orbit satellites and evaluate the potential impact on
astronomy. We report the results of over 16,000 independent measurements of
nearly 2800 individual satellites. In addition to photometry, we also measured
the astrometric position of each satellite and evaluated the accuracy of
predicting satellite position with the available two-line element sets. The
apparent brightness of a satellite seen in the sky is not constant and depends
on the Sun-satellite-observer geometry. To capture this, we designed the survey
to create an all-geometries set of measurements to fully characterize the
brightness of each population of satellites as seen in the sky. We visualize
the data with sky-plots that show the correlation of apparent brightness with
on-sky position and relative Sun-satellite-observer geometry. The sky-plots
show where in the sky the satellites are brightest. In addition to visual
magnitudes, we also present two new metrics: the expected photon flux and the
effective albedo. The expected photon flux metric assesses the potential impact
on astronomy sensors by predicting the flux for a satellite trail in an image
from a theoretical 1 m class telescope and sensor. The effective albedo metric
assesses where a satellite is more reflective than baseline, which ties to the
physical structure of the satellite and indicates the potential for
brightness-reducing design changes. We intend to use this methodology and
resulting data to inform the astronomy community about satellite brightness.
