# Real boulder-inventory data sources (for the trap-number paper)

## Ryugu  (primary source of the -2.665 slope)
Ray, A., Ruj, T., Komatsu, G., Vincent, L. M., Kikuchi, H., Hemmi, R., Ormo, J. (2026).
Boulder populations and orientation trends on asteroid Ryugu: implications for
rubble-pile surface processes. Scientific Reports 16, 14404.
https://doi.org/10.1038/s41598-026-40370-4

  Dataset (49,536 boulders >= 0.75 m; each with long-axis length, position, orientation;
  23,553 boulders >= 3 m used for the global slope):
  figshare  ->  https://figshare.com/s/12d284cd8a0d610861f8

  Coordinate frame: equirectangular (Plate Carree) on a custom Ryugu ellipsoid
  (semi-major 502.0 m, semi-minor 437.744 m), prime meridian 0 deg; SBMT shape
  model SFM20180801. Largest boulder Otohime Saxum ~ 139 m.

Michikami, T. et al. (2019). Boulder size and shape distributions on asteroid Ryugu.
Icarus 331, 179-191.  https://doi.org/10.1016/j.icarus.2019.05.019
  (~4400 boulders >= 5 m; per-boulder counts available from the authors on request.)

Hayabusa2 images / shape models: JAXA DARTS  https://data.darts.isas.jaxa.jp/
Small Body Mapping Tool (SBMT): http://sbmt.jhuapl.edu

## Bennu
Lauretta, D. S. et al. (2019). The unexpected surface of asteroid (101955) Bennu.
Nature 568, 55-60.  https://doi.org/10.1038/s41586-019-1033-6
DellaGiustina, D. N. et al. (2019), Nat. Astron. 3, 341-351; Walsh, K. J. et al. (2019),
Nat. Geosci. 12, 242-246.
  Global boulder map gives boulder locations and sizes; counts complete to > 8 m
  over > 80% of the surface, sizes 1-58 m.
  Archive: NASA Planetary Data System (PDS) Small Bodies Node,
  https://sbn.psi.edu/pds/resource/orex/  (also via SBMT).

## Itokawa
Mazrouei, S., Daly, M. G., Barnouin, O. S., Ernst, C. M., DeSouza, I. (2014).
Block distributions on Itokawa. Icarus 229, 181-189.
https://doi.org/10.1016/j.icarus.2013.11.010
Michikami, T. et al. (2008). Size-frequency statistics of boulders on global surface
of asteroid 25143 Itokawa. Earth Planets Space 60, 13-20.
https://doi.org/10.1186/BF03352757
  Hayabusa imagery / shape via JAXA and NASA PDS; SBMT.

## How to use these with the code
Download the catalogue (start with the Ryugu figshare deposit above), export a table
with columns for longitude (deg E), latitude (deg), and long-axis length (m), then run
run_trap_number_real_catalogue.py after setting the three column names in its CONFIG block.
