Redirect from Page to specific Tab

I have this logic inside app.component:

rootPage: any: LoginPage;
platform.ready().then(() => {
      // Here we will check if the user is already logged in
      // because we don't want to ask users to log in each time they open the app
      let env = this;
      .then( function (data) {
        // user is previously logged and we have his data
        // we will let him access the app
        env.nav.push(UserPage); // Here i want to redirect user to TAB not to PAGE.
      }, function (error) {
        //we don't have the user data so we will ask him to log in


What i want to do is to redirect user from this login page to specific Tab.

tab1Root = OnePage;
tab2Root = TwoPage;
tab3Root = ThreePage;