具有近球条件的MongoDB查找表达式

我有一个场景，我必须加入我的餐厅和拉链收集基于他们的位置

餐厅

[{
    "_id" : ObjectId("55cba2486c522cafdb059deb"),
    "location" : {
        "coordinates" : [
            -74.138492,
            40.631136
        ],
        "type" : "Point"
    },
    "name" : "Indian Oven"
}]

[{
    "_id" : "99950",
    "city" : "KETCHIKAN",
    "loc" : [
        -133.18479,
        55.942471
    ],
    "pop" : 422,
    "state" : "AK"
}]

拉链

[{
    "_id" : ObjectId("55cba2486c522cafdb059deb"),
    "location" : {
        "coordinates" : [
            -74.138492,
            40.631136
        ],
        "type" : "Point"
    },
    "name" : "Indian Oven"
}]

[{
    "_id" : "99950",
    "city" : "KETCHIKAN",
    "loc" : [
        -133.18479,
        55.942471
    ],
    "pop" : 422,
    "state" : "AK"
}]

现在我必须加入这两个基于集合的近球地理空间查询。我应该在$lookup管道中使用什么标准

我试过的是

db.restaurants.aggregate([
    {
        $lookup:
            {
                from: "zips",
                let: { location: "$location" },
                pipeline: [{
                    $match: {
                        'loc': { $nearSphere: '$$location' }
                    }
                }],
                as: "t"
            }
    }
]);

但这是行不通的

需要帮助吗