How the Gies Memorial Stadium seat and sun data is measured

Every number comes from a USGS lidar survey of the stadium, NOAA solar equations, the Illinois section numbering and published row lists. Nothing is estimated from photos.

Sources

Stadium shape: USGS 3D Elevation Program lidar, Illinois 8 County plus Champaign collection (QL1), flown 16 April 2019, 2 tiles. First-return points gridded to 1 m, noise removed.
Section directions: the section order round the stadium from a ticket map, lined up with the field in the lidar. The north end stand (132 to 137) is not on that map, so its six sections are spaced evenly across the measured stand.
Row lists, covered rows, the student section numbers, the visitor section and the Illinois and visitors' sides: rateyourseats.com section notes.
Name, opening year, gates, bag rules, food and water, re-entry, cashless, alcohol, smoking, parking, shuttles and rideshare: fightingillini.com. Capacity: Wikipedia.
Sun: NOAA solar position equations. Weather: ERA5 reanalysis and forecasts via Open-Meteo.

How shade is computed

Each section is sampled on 3 lines (left, centre, right) at every row, 6615 seat points in total. For each point the surrounding stadium surface is scanned in every direction the sun can come from to give a horizon profile. A seat is in direct sun when the sun is higher than that horizon. Games are sampled every 10 minutes for 3.5 hours. Rows under the balcony above count as shade. The Iowa kickoff is not announced yet, so each Big Ten window (11 am, 2:30 pm, 6:30 pm) is modelled.

How rows are placed

A line is walked out from the field edge through each section, and the measured profile is split into tiers by height: the lower level from the field wall, the balconies from about 19 m up. Where a balcony overhangs the back of the lower level, the hidden rows continue along the measured slope.

How the seat views are made

Each view is drawn from a 3D model built from the lidar, from 1.15 m above the seat (seated eye height), facing the field. Only rows open to the sky get a view.

Limits

The lidar was flown in April 2019. fightingillini.com lists no seating changes since: the 2025 changes were the new name, metal detectors, the Northeast Patio group space and wayfinding.
No current official page says which bench is which. A 2015 fightingillini.com media page puts Illinois on the west sideline; rateyourseats.com tags the west side as the Illinois side and the east side as the visitors' side.
The ticket map is not drawn to scale, so section directions come from it but section edges can be off by a few seats.
Not modelled: the Colonnades Club (301 to 314), the 77 Club (611 to 616) and the suites in the west tower.
Light poles and video boards thinner than the 1 m grid may be missed.

Downloads (CC BY 4.0)

sun-by-section.csv: game, kickoff, section, minutes of sun, shade arrival
sections.json: section geometry and row-by-row sightlines