Initial import of NavSea pbf project

tasks/WeatherServer_GridBuilder

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+# NavSea Weather Server
+Task: WeatherServer_GridBuilder
+Architecture: NavSea V11
+Codex: codex6
+Status: TODO
+
+---
+
+# 1 任务目标
+
+实现 Weather Grid Builder 模块。
+
+功能：
+
+将 GRIB 数据解析为统一的 Weather Grid 数据结构。
+
+输入：
+
+data/grib/*.grib2
+
+输出：
+
+data/grid/*.json
+
+Weather Grid 将作为：
+
+Vector Tile Generator
+Routing Engine
+Weather Analysis
+
+的基础数据源。
+
+---
+
+# 2 输入数据
+
+GRIB 文件来自 Downloader。
+
+示例：
+
+data/grib/
+
+20260312_00_f000.grib2
+20260312_00_f003.grib2
+20260312_00_f006.grib2
+
+变量：
+
+UGRD
+VGRD
+APCP
+PRMSL
+TMP
+
+---
+
+# 3 Weather Grid 数据结构
+
+每个 grid 点结构：
+
+{
+ "lat": float,
+ "lon": float,
+ "wind_speed": float,
+ "wind_dir": float,
+ "rain": float,
+ "temp": float,
+ "pressure": float
+}
+
+说明：
+
+lat 纬度  
+lon 经度  
+
+wind_speed m/s  
+wind_dir 度  
+
+rain mm  
+
+temp 摄氏度  
+
+pressure hPa
+
+---
+
+# 4 风速计算
+
+使用 U/V 分量计算：
+
+wind_speed = sqrt(u² + v²)
+
+---
+
+# 5 风向计算
+
+公式：
+
+wind_dir = (atan2(u, v) * 180 / π + 360) % 360
+
+结果：
+
+0–360°
+
+---
+
+# 6 Grid Builder 输出
+
+文件：
+
+data/grid/
+
+示例：
+
+grid_20260312_00_f000.json
+
+结构：
+
+{
+ "time": "20260312_00_f000",
+ "points": [...]
+}
+
+---
+
+# 7 创建文件
+
+weather_server/grid/grid_builder.py
+
+---
+
+# 8 实现代码
+
+```python
+import os
+import json
+import numpy as np
+import xarray as xr
+
+INPUT_DIR = "data/grib"
+OUTPUT_DIR = "data/grid"
+
+os.makedirs(OUTPUT_DIR, exist_ok=True)
+
+
+def compute_wind(u, v):
+
+    speed = np.sqrt(u**2 + v**2)
+
+    direction = (np.degrees(np.arctan2(u, v)) + 360) % 360
+
+    return speed, direction
+
+
+def process_file(path):
+
+    ds = xr.open_dataset(path, engine="cfgrib")
+
+    u = ds["u10"].values
+    v = ds["v10"].values
+    rain = ds["tp"].values
+    pressure = ds["msl"].values
+    temp = ds["t2m"].values
+
+    lat = ds.latitude.values
+    lon = ds.longitude.values
+
+    wind_speed, wind_dir = compute_wind(u, v)
+
+    points = []
+
+    for i in range(len(lat)):
+
+        for j in range(len(lon)):
+
+            point = {
+
+                "lat": float(lat[i]),
+                "lon": float(lon[j]),
+
+                "wind_speed": float(wind_speed[i][j]),
+                "wind_dir": float(wind_dir[i][j]),
+
+                "rain": float(rain[i][j]),
+
+                "temp": float(temp[i][j]),
+
+                "pressure": float(pressure[i][j])
+            }
+
+            points.append(point)
+
+    return points
+
+
+def main():
+
+    for file in os.listdir(INPUT_DIR):
+
+        if not file.endswith(".grib2"):
+            continue
+
+        path = os.path.join(INPUT_DIR, file)
+
+        print("processing", file)
+
+        points = process_file(path)
+
+        output = os.path.join(
+            OUTPUT_DIR,
+            f"grid_{file.replace('.grib2','')}.json"
+        )
+
+        data = {
+
+            "time": file.replace(".grib2",""),
+            "points": points
+        }
+
+        with open(output, "w") as f:
+
+            json.dump(data, f)
+
+        print("saved", output)
+
+
+if __name__ == "__main__":
+
+    main()