diff --git a/server/data/systems.db b/server/data/systems.db
index 95151e106..9a6a5adc2 100644
Binary files a/server/data/systems.db and b/server/data/systems.db differ
diff --git a/tooling/planet-gen/populate_terrain_reference.py b/tooling/planet-gen/populate_terrain_reference.py
new file mode 100644
index 000000000..9b2a28bf2
--- /dev/null
+++ b/tooling/planet-gen/populate_terrain_reference.py
@@ -0,0 +1,139 @@
+#!/usr/bin/env python3
+"""
+Batch populate terrain_reference column in systems.db bodies table.
+
+For each inhabited body with NULL terrain_reference:
+  1. Construct expected wiki heightmap path:
+       wiki/star-systems/{system_slug}/bodies/{body_id}/heightmap.png
+     where system_slug = system_id with spaces replaced by hyphens.
+  2. Verify the file exists.
+  3. Update terrain_reference to the relative path.
+
+Bodies with missing heightmaps are logged to stdout for remediation.
+This is the prerequisite for generate_atlas.py (#832).
+
+Usage:
+    python3 tooling/planet-gen/populate_terrain_reference.py
+    python3 tooling/planet-gen/populate_terrain_reference.py --dry-run
+    python3 tooling/planet-gen/populate_terrain_reference.py --db path/to/systems.db
+
+Decisions: D-191 (atlas pipeline prerequisites)
+"""
+
+import argparse
+import sqlite3
+from pathlib import Path
+
+SCRIPT_DIR = Path(__file__).resolve().parent
+REPO_ROOT = (SCRIPT_DIR / ".." / "..").resolve()
+DB_PATH = REPO_ROOT / "server" / "data" / "systems.db"
+WIKI_DIR = REPO_ROOT / "wiki" / "star-systems"
+
+
+def system_slug(system_id: str) -> str:
+    """Convert a system_id to its wiki directory slug.
+
+    'GJ 71'   → 'GJ-71'
+    'GJ 244A' → 'GJ-244A'
+    'GJ 559B' → 'GJ-559B'
+    """
+    return system_id.replace(" ", "-")
+
+
+def expected_heightmap_path(system_id: str, body_id: str) -> Path:
+    """Return the expected absolute heightmap path for a body."""
+    return WIKI_DIR / system_slug(system_id) / "bodies" / body_id / "heightmap.png"
+
+
+def relative_terrain_reference(system_id: str, body_id: str) -> str:
+    """Return the terrain_reference value to store in the DB.
+
+    Stored as a repo-root-relative path so it is portable across checkouts.
+    """
+    return f"wiki/star-systems/{system_slug(system_id)}/bodies/{body_id}/heightmap.png"
+
+
+def main():
+    parser = argparse.ArgumentParser(
+        description="Populate terrain_reference column in systems.db bodies table"
+    )
+    parser.add_argument("--db", default=str(DB_PATH), help="Path to systems.db")
+    parser.add_argument(
+        "--dry-run",
+        action="store_true",
+        help="Report without writing changes",
+    )
+    args = parser.parse_args()
+
+    db_path = Path(args.db)
+    if not db_path.exists():
+        print(f"error: {db_path} not found")
+        raise SystemExit(1)
+
+    conn = sqlite3.connect(str(db_path))
+    conn.execute("PRAGMA foreign_keys=ON")
+
+    # Fetch all inhabited bodies with NULL terrain_reference.
+    rows = conn.execute("""
+        SELECT b.body_id, b.system_id
+        FROM bodies b
+        WHERE b.terrain_reference IS NULL
+        ORDER BY b.system_id, b.body_id
+    """).fetchall()
+
+    print(f"\n  terrain_reference population pass")
+    print(f"  DB: {db_path}")
+    if args.dry_run:
+        print(f"  Mode: DRY RUN")
+    print(f"\n  {len(rows)} bodies with NULL terrain_reference\n")
+
+    found = []
+    missing = []
+
+    for body_id, system_id in rows:
+        path = expected_heightmap_path(system_id, body_id)
+        if path.exists():
+            found.append((body_id, system_id))
+        else:
+            missing.append((body_id, system_id, str(path)))
+
+    # Report missing heightmaps before writing — helps flag gaps early.
+    if missing:
+        print(f"  MISSING heightmaps ({len(missing)} bodies — no update for these):")
+        for body_id, system_id, path in missing:
+            print(f"    {body_id} ({system_id}) → {path}")
+        print()
+
+    if found:
+        print(f"  Updating {len(found)} bodies with terrain_reference:")
+        for body_id, system_id in found:
+            ref = relative_terrain_reference(system_id, body_id)
+            print(f"    {body_id} ({system_id}) → {ref}")
+            if not args.dry_run:
+                conn.execute(
+                    "UPDATE bodies SET terrain_reference = ? WHERE body_id = ?",
+                    (ref, body_id),
+                )
+
+    if not args.dry_run:
+        conn.commit()
+        print(f"\n  Committed {len(found)} terrain_reference updates.")
+    else:
+        print(f"\n  Dry run — no changes written.")
+
+    conn.close()
+
+    # Summary
+    print(f"\n  Summary:")
+    print(f"    Updated:  {len(found)}")
+    print(f"    Missing:  {len(missing)}")
+    print(f"    Total:    {len(rows)}\n")
+
+    if missing:
+        print(f"  Action required: generate heightmaps for {len(missing)} bodies "
+              f"before running generate_atlas.py (#832).")
+        print(f"  Use: make generate-terrain (or run generate.py per body)\n")
+
+
+if __name__ == "__main__":
+    main()