location object expected, location array not in correct format

问题

I have spent doing such a straight forward thing. I just want to do a CRUD operation on a user model using nodejs, mongoose, restify stack. My mongo instance is on mongolab. The user should contain a "loc" field . User schema is as follows :

var mongoose = require('mongoose')
var Schema = mongoose.Schema;
var userSchema = new Schema( {
email_id : { type: String,  unique: true },
password: { type: String},
first_name: String,
last_name: String,
age: String,
phone_number: String,
profile_picture: String,
loc: {
     type: {},
    coordinates: [Number]
}  
});
userSchema.index({loc:'2d'});
var User = mongoose.model('user', userSchema);
module.exports = User;

the rest api used to post is as follows :

create_user : function (req, res, next) {
var coords = [];
coords[0] = req.query.longitude;
coords[1] = req.query.latitude;

var user = new User(
    {
        email_id : req.params.email_id,
        password: req.params.password,
        first_name: req.params.first_name,
        last_name: req.params.last_name,
        age: req.params.age,
        phone_number: req.params.phone_number,
        profile_picture: req.params.profile_picture,
        loc: {
                type:"Point",
                coordinates: [1.0,2.0] // hardcoded just for demo
            }
    }
    ); 
user.save(function(err){ 
    if (err) { 
        res.send({'error' : err}); 
    }
        res.send(user);
    });  
return next();
},

Now when i do a POST call on curl -X POST http://localhost:3000/user --data "email_id=sdass@dfAadsfds&last_name=dass&age=28&phone_number=123456789&profile_picture=www.jakljf.com&longitude=1.0&latitude=2.0" I get the following error

{
error: {
code: 16804
index: 0
errmsg: "insertDocument :: caused by :: 16804 location object expected,           location array not in correct format"
op: {
email_id: "sdass@dfAadsfdsadkjhfasvadsS.com"
password: "sdass123DadakjhdfsfadfSF45"
first_name: "shaun"
last_name: "dass"
age: "28"
phone_number: "123456789"
profile_picture: "www.jakljf.com"
loc: {
coordinates: [2]
0:  1
1:  2
-
type: "Point"
}-
_id: "55efc95e0e4556191cd36e5e"
__v: 0
}-
}-    
}

The location field is giving problems as the POST call works just fine if i remove the loc field from model

Below are the hits/trials I did : 1) Change userSchema.index({loc:'2d'}); to userSchema.index({loc:'2dsphere'}); 2) Changing loc schema to everything given in Stackoverflow. I would like to know the right way to define this though. 3) Passing the hardcode 2d array but still it says Location object expected, location array not in correct format" what format is required for this ?

Any help in this regard is greatly appreciated. Thanks.