Jean-Paul Le FèvreCEA Saclay, Irfu France

Adass XXIII September 2013, Waikoloa, Hawaii, USA

The web app architecture

The VHF network

The Svom mission

The registration web site

Contact: jean-paul.lefevre@cea.fr

d

db.sites.insert({ id: id(), name: ‘Saclay’, …});

db.users.insert({ id: id(), login: ‘nabila’, …});

mongoose

var siteSchema = new app.mongoose.Schema({  name: {type: String,

required: true, unique: true},…});

var app = express();var http = require(‘http’)…app.use(app.router);app.use(express.static(

path.join(__dirname, 'client')));…http.createServer(app) .listen(app.get('port'),

function(){    logger.log('info',               'Svom on port %d',               app.get('port'));});

Express framework forNodeJs

mocha

BootstrapToolkit, css, html5 widgets

BootswatchThemes

Client-side frameworkModelView

Controller

The server sideThe client side

In the browser

A 100% javascript web application

Unit testing the server

Svom ( Space-based multi-band astronomical Variable Objects Monitor ) is a Sino-French mission dedicated to the detection, localization and study of GRB (Gamma Ray Bursts) and other high-energy transient phenomena (X-ray bursts, soft gamma repeaters, AGN (Active Galactic Nuclei), novae...).

The observations will follow three main stages:

1. Detecting the gamma-ray bursts using space-based equipment capable of providing their position in quasi real time with an accuracy of a few arc minutes.

2. Observing the region of the burst as rapidly as possible using small robot-controlled telescopes to de tect optical afterglow in the visible and near-infrared wavelengths and to provide its position with an accu racy of one arc second.

3. Detecting the spectrum of the optical afterglow in the visible and near-infrared wavelengths as rapidly as possible using the largest Earth-based telescopes.

To achieve these scientific objectives, the measurements strategy followed for the Svom mission makes the best possible combined use of onboard and ground observations, requiring quasi real time contact with the satellite.

A collection of ground stations, known as the VHF alert network, receives the information concerning onboard detection and location of the burst and sends it automatically to the FSC (French Science Centre) in the CEA at Saclay. The data are processed by an automaton which alerts the ground-based instruments of the Svom sys tem as well as the international community.

Data about the location of a burst must be conveyed to users in less than a minute in more than 85% of cases. This scientific requirement implies that the satellite must be almost permanently visible to at least one station. Considering the satellite’s altitude (600 km) and orbital inclination of 30°relative to the equator, the VHF alert network requires about 40 stations.

The Svom VHF network

svomtest.svom.fr a.k.a goo.gl/g8Ab0n

VHF receivers should be installedinside the strip ±30°latitude.

About 40 locations should be found.

We need help !If you know a place where it will bepossible to set up a VHF station govisit the Svom registration web site.

We are seeking organizations, teamsor people willing to participate to our adventure.