How the T-Mobile Park seat and sun data is measured

Every number comes from a King County lidar survey of the ballpark, NOAA solar equations, the official outfield distances and published row lists. Nothing is estimated from photos.

Sources

Ballpark shape: Puget Sound Lidar Consortium King County lidar, 2016 (NOAA Digital Coast dataset 8588), with the roof parked open. First-return points gridded to 1 m, noise removed.
Home plate: placed so the measured outfield wall matches the outfield distances in the scan; the fit is within about 4 m.
Section order and direction from home plate: a public ticket map of the ballpark (section and row centre points only). It is not drawn to scale, so it gives each section's direction; distances and heights come from the lidar.
Row lists and covered rows: rateyourseats.com.
Gates, bags, food and policies: the T-Mobile Park A-Z guide.
Sun: NOAA solar position equations. Weather: ERA5 reanalysis via Open-Meteo.

How shade is computed

Each section is sampled on 3 lines at every row, 7449 seat points in total. For each point the ballpark surface is scanned in every direction the sun can come from, including the upper deck and its roof. A seat is in direct sun when the sun is higher than that horizon. Games are sampled every 10 minutes for 2 hours 50 minutes, on the 15th of each month from April to September, at 1:10 pm, 7:10 pm.

How rows are placed

A line is walked out from home plate through each section and the measured rake is split into decks by height jumps. Rows are spread over the visible slope in front of the published cover row. Premium boxes at the front of the lower bowl use the row positions from the ticket map, with heights from the lidar.

Limits

The lidar is the 2016 King County survey (the files carry no exact flight day). Since then the Mariners turned part of the first base Terrace Club into Terrace Club Tables and Loge Boxes for 2020 (367 fewer Terrace Club seats), built Lookout Landing above the left field foul pole and opened the T-Mobile 'Pen in centre field. No main seating section was removed or renumbered.
Most of the Terrace Club sits under the View Level, so the aircraft scan cannot see its rows. Sections 151, 180, 183, 184, 190, 192, 193, 195, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224, 226, 227, 233, 234, 236, 237, 238, 239, 241, 244, 245, 246, 247, 249 and 349 did not give a clean rake in the scan and are not modelled. Their rows are still listed.
Sun and shade are modelled with the roof open. With the roof closed most seats are in shade all game.
The Mariners dugout side comes from rateyourseats.com (Sections 121 to 124 are tagged 'Near Mariners Dugout') and our map fit puts those sections on the first base side.
The Diamond Club, Terrace Club Tables and Loge Boxes, suites, Hit It Here Cafe, Edgar's Cantina and standing room are not modelled as seats.
Covered rows come from rateyourseats.com: the aircraft scan sees the roof and decks, not the seats under them.
Section directions come from a ticket map that is not to scale, so a few sections may be a row or two off along the stand.

Downloads (CC BY 4.0)

sun-by-section.csv: month, start time, section, minutes of sun, shade arrival
sections.json: section geometry and row-by-row sightlines