Difference between revisions of "HabAlertApp"

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=== System overview ===
 
=== System overview ===
 
The application relies on some additional infrastructure.
 
The application relies on some additional infrastructure.
 +
  
 
In total, the following parts are relevant:
 
In total, the following parts are relevant:
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* google cloud messaging, provides 'push' notifications between the hab alert server and the android app
 
* google cloud messaging, provides 'push' notifications between the hab alert server and the android app
 
* the android app (called 'client'), which interacts with the user
 
* the android app (called 'client'), which interacts with the user
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Responsibilities of the hab alert server:
 
Responsibilities of the hab alert server:
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** register/unregister radio receivers
 
** register/unregister radio receivers
 
** list active balloons with their call-sign, altitude, location, visibility
 
** list active balloons with their call-sign, altitude, location, visibility
 +
  
 
Responsibilities of the android app are:
 
Responsibilities of the android app are:

Revision as of 08:57, 11 August 2014

Project HAB alert app
Status Initializing
Contact bertrik
Last Update 2014-08-11

This project is about creating an Android app to alert you of high-altitude balloons coming near so you can start tracking them.

See also:

Introduction

Regularly, high-altitude balloons (HABs) are released ("launched") in the UK and many other places around the world. These balloons are usually equipped with a GPS receiver, a small micro-controller and an UHF transmitter broadcasting the balloon's callsign/location/altitude/etc. It's a fun hobby to help track these balloons by receiving the coordinates and submitting them to a central web site. RevSpace has a radio reception setup specifically for this, see HAB Tracker Station.

The problem that the Android app aims to solve is that sometimes a HAB is launched and you're not aware that it's coming into range of the RevSpace HAB tracker, missing the opportunity to track it. The HABAlertApp is an application you can install on your Android OS phone that alerts you as soon as a HAB comes in range of your radio receiver.

Design

System overview

The application relies on some additional infrastructure.


In total, the following parts are relevant:

  • the spacenear.us / habhub.org web sites, source of up-to-date balloon data
  • the hab alert server (called 'server'), keeps track of balloons and receivers and sends out alerts
  • google cloud messaging, provides 'push' notifications between the hab alert server and the android app
  • the android app (called 'client'), which interacts with the user


Responsibilities of the hab alert server:

  • communication with the spacenear.us / habhub.org web sites
    • connect and scrape balloon location data
    • interpret the data format and extract the current balloon data
  • business logic
    • keep a list of active balloons
    • keep a list of active radio receivers
    • keep a list of subscribed clients
    • at regular intervals, calculate visibility between balloons and radio receivers and send out notifications to subscribed clients
  • communication with google cloud messaging
  • serving requests from clients
    • add/remove alert subscriptions from clients
    • register/unregister radio receivers
    • list active balloons with their call-sign, altitude, location, visibility


Responsibilities of the android app are:

  • interaction with the user:
    • alerting the user, e.g. by beeping/vibrating and showing an icon in the status bar
    • showing current balloon info, e.g. a list of balloons with their call-signs / radio settings, sorted by visibility
    • setting preferences for alerts:
      • location of the radio receiver
      • alert criteria, e.g. degrees above horizon
      • (optional) back-off time, preventing multiple alerts

Sub-systems

HAB alert server

HAB alert android app

Interfaces

spacenear.us / habhub.org interface

google cloud messaging

android app interface

android user interface