Javascript DNS spatial discovery

Installation

The npm package is now hosted on npmjs.

npm install @openflam/dnsspatialdiscovery

Usage

Discovery

And then the library can be use in javascript as:

const suffix = "loc." // Suffix to the discovered geodomains
const rootNameserver = "https://loc-nameserver.net"; // By default, Google's DNS server is used (https://dns.google/resolve)
const discoveryObj = new dnsspatialdiscovery.MapsDiscovery(suffix, rootNameserver);

let localizationType = "image";
// Get lat, lon, error_m, vioPose, dataBlob
let circleGeometry = {
    type: 'Circle',
    coordinates: [lon, lat],
    radius: error_m
};
var localizationResult = discoveryObj.localize(
    circleGeometry,
    dataBlob, localizationType, vioPose);

The localize function:

• Disocvers map servers if they have not been discovered yet.
• Uses the currently "active server" -- The server that has been giving good localization result to localize.
• If the active server gives results with a high error, tries to relocalize within the list of discovered servers.
• If best localization result provided all the discovered is high, rediscovered servers and relocalizes.
• If no servers are discovered, returns null.

No discovery

You might want to skip disocvery phase if you already know which map server to use. In that case:

let mapServer = new dnsspatialdiscovery.MapServer("map-server.com");
let emptyBlob = new Blob([image]);
let poseData = await mapServer.localize(emptyBlob, "image");

Events

Following events are raised by dnsspatialdiscovery.Events object:

• "mapfound:good": A map with an error lower than the cofigured bound is found.
• "mapfound:poor": A map is found, but even the best of the discovered maps in the area has a high error.
• "nomap": No map found.

Functions can be attached to events as:

dnsspatialdiscovery.Events.on('mapfound:good', () => {
    // Make location marker green
});
dnsspatialdiscovery.Events.on('mapfound:poor', () => {
    // Make location marker yellow
});

Development

Set up npm, and Node.js using nvm using instruction here.

To install dependencies: npm install and to build npm run build.

Testing

Run tests using: npm run test. It'll start a server at http://localhost:9000. Navigate to /test/test.html to view the rest results.