方向交会法计算程序Python

方向交会法是一种常用于海上、航空等领域的导航计算方法，可以用于确定目标物体的位置和航向。下面是一个简单的方向交会法计算程序Python示例：

import math

# 计算两个点之间的距离
def distance(lat1, lon1, lat2, lon2):
    R = 6371  # 地球平均半径，单位为公里
    dLat = math.radians(lat2 - lat1)
    dLon = math.radians(lon2 - lon1)
    a = math.sin(dLat / 2) * math.sin(dLat / 2) + math.cos(math.radians(lat1)) * math.cos(math.radians(lat2)) * math.sin(dLon / 2) * math.sin(dLon / 2)
    c = 2 * math.atan2(math.sqrt(a), math.sqrt(1 - a))
    d = R * c
    return d

# 计算方位角
def bearing(lat1, lon1, lat2, lon2):
    dLon = math.radians(lon2 - lon1)
    y = math.sin(dLon) * math.cos(math.radians(lat2))
    x = math.cos(math.radians(lat1)) * math.sin(math.radians(lat2)) - math.sin(math.radians(lat1)) * math.cos(math.radians(lat2)) * math.cos(dLon)
    brng = math.atan2(y, x)
    brng = math.degrees(brng)
    brng = (brng + 360) % 360
    return brng

# 计算交点坐标
def intersection(lat1, lon1, bearing1, lat2, lon2, bearing2):
    lat1 = math.radians(lat1)
    lon1 = math.radians(lon1)
    lat2 = math.radians(lat2)
    lon2 = math.radians(lon2)
    bearing1 = math.radians(bearing1)
    bearing2 = math.radians(bearing2)
    dLat = lat2 - lat1
    dLon = lon2 - lon1
    alpha = math.acos(math.sin(lat1) * math.sin(lat2) + math.cos(lat1) * math.cos(lat2) * math.cos(dLon))
    if alpha == 0:
        return None
    a = math.asin(math.sin(alpha) * math.sin(bearing2) / math.sin(math.pi - bearing1 - alpha))
    b = math.asin(math.sin(alpha) * math.sin(bearing1) / math.sin(math.pi - bearing2 - alpha))
    x = (math.sin(lat1) * math.cos(a) * math.cos(lon1) + math.sin(lat2) * math.cos(b) * math.cos(lon2)) / math.cos(a) / math.cos(b)
    y = (math.sin(lat1) * math.cos(a) * math.sin(lon1) + math.sin(lat2) * math.cos(b) * math.sin(lon2)) / math.cos(a) / math.cos(b)
    z = (math.cos(lat1) * math.cos(a) + math.cos(lat2) * math.cos(b)) / math.cos(a) / math.cos(b)
    lat = math.atan2(z, math.sqrt(x * x + y * y))
    lon = math.atan2(y, x)
    lat = math.degrees(lat)
    lon = math.degrees(lon)
    return (lat, lon)

# 示例
lat1 = 39.9
lon1 = 116.3
lat2 = 31.2
lon2 = 121.5
dist1 = 1234.5
dist2 = 678.9
brng1 = 45
brng2 = 120

d = distance(lat1, lon1, lat2, lon2)
print("距离：{:.2f}公里".format(d))

b1 = bearing(lat1, lon1, lat2, lon2)
print("起点方位角：{:.2f}度".format(b1))

inter = intersection(lat1, lon1, brng1, lat2, lon2, brng2)
print("交点坐标：({}, {})".format(inter[0], inter[1]))

需要注意的是，方向交会法的计算过程中需要使用到三角函数等高等数学知识，因此如果不熟悉这些知识可能会比较困难。建议在使用之前先学习相关的数学知识，以免出现错误。