Popup notification/ GPS ready from within app

I'm writing an app which checks the GPS quality and then records this to the activity.

I've got the position quality working ok and a little icon showing the various strengths. I would like to have a popup like the native device software uses to show the message "GPS is ready" when it reaches QUALITY_USABLE.

How can I call a popup/ notification from within my app which does not involve user interaction? I don't want the user to have to click a button to remove the notification.


Thank you.