ais-web/dist/aisDecoder.d.ts

Compact AIS decoder in TypeScript for browser and web apps

import { EventEmitter } from 'events';
export interface PositionMessage {
    type: 1 | 2 | 3;
    channel: string;
    repeat: number;
    mmsi: number;
    navStatus: number;
    rateOfTurn: number;
    speedOverGround: number;
    accuracy: boolean;
    lon: number;
    lat: number;
    courseOverGround: number;
    heading: number;
    utcSecond: number;
    specialManoeuvre: number;
    raim: boolean;
    radio: number;
}
export interface StaticVoyageMessage {
    type: 5;
    mmsi: number;
    repeat: number;
    aisVersion: number;
    imo: number;
    callsign: string;
    name: string;
    shipType: number;
    dimensionToBow: number;
    dimensionToStern: number;
    dimensionToPort: number;
    dimensionToStarboard: number;
    epfd: number;
    etaMonth: number;
    etaDay: number;
    etaHour: number;
    etaMinute: number;
    draught: number;
    destination: string;
    dteAvailable: boolean;
    channel: string;
}
interface AisReceiverEvents {
    position: PositionMessage;
    static: StaticVoyageMessage;
}
/**
 * Events emitted by the AisReceiver:
 *
 * - 'position': Emitted when a Position Report message (AIS types 1, 2, or 3) is decoded.
 *   Listener receives a `PositionMessage` object containing dynamic vessel position and navigation data.
 *
 * - 'static': Emitted when a Static and Voyage Related Data message (AIS type 5) is decoded.
 *   Listener receives a `StaticVoyageMessage` object containing vessel identification and voyage details.
 *
 * Usage example:
 * ```ts
 * const receiver = new AisReceiver();
 *
 * receiver.on('position', (posMsg) => {
 *   console.log('Position update:', posMsg);
 * });
 *
 * receiver.on('static', (staticMsg) => {
 *   console.log('Static vessel info:', staticMsg);
 * });
 * receiver.onMessage(aisSentence);
 * ```
 */
type EventNames<T> = keyof T & string;
type EventListener<T, K extends EventNames<T>> = (payload: T[K]) => void;
declare class TypedEventEmitter<T> extends EventEmitter {
    on<K extends EventNames<T>>(eventName: K, listener: EventListener<T, K>): this;
    off<K extends EventNames<T>>(eventName: K, listener: EventListener<T, K>): this;
    once<K extends EventNames<T>>(eventName: K, listener: EventListener<T, K>): this;
    emit<K extends EventNames<T>>(eventName: K, payload: T[K]): boolean;
}
export declare class AisReceiver extends TypedEventEmitter<AisReceiverEvents> {
    private multipartBuffers;
    private static MULTIPART_TIMEOUT_MS;
    /**
     * Process one AIS sentence. Pass your messages to this function, once the message is decoded, it triggers an event
     * on('position') or on('static') depending on the type of sentence decoded.
     * @param sentence Raw NMEA AIS sentence, e.g. "!AIVDM,1,1,,A,...*hh"
     * @param enableChecksum Whether to verify the checksum (default: true)
     */
    onMessage(sentence: string, enableChecksum?: boolean): void;
    /**
     * Extracts raw AIS sentence raw fields along with the decoded MMSI.
     *
     * Parses a raw AIS NMEA sentence (e.g. "!AIVDM,...") to extract:
     * - total number of fragments,
     * - current fragment number,
     * - sequence ID,
     * - radio channel,
     * - payload string,
     * - fill bits,
     * and additionally decodes the MMSI number from the AIS payload.
     *
     * @param sentence - Raw AIS NMEA sentence string.
     * @param enableChecksum - Whether to verify the NMEA checksum (default: true).
     * @returns An object containing:
     *   - channel: radio channel ('A' or 'B'),
     *   - payload: AIS payload string,
     *   - total: total number of sentence fragments,
     *   - part: current fragment number,
     *   - fillBits: number of fill bits in the payload,
     *   - key: sequence ID for multipart messages (or 'noprefix'),
     *   - mmsi: decoded MMSI number extracted from the payload,
     * or undefined if the sentence is invalid or checksum verification fails.
     */
    extractSentenceRawFields(sentence: string, enableChecksum?: boolean): {
        mmsi: number;
        channel: string;
        payload: string;
        total: number;
        part: number;
        fillBits: number;
        key: string;
    } | undefined;
    private extractRawData;
    private verifyChecksum;
    private payloadToBits;
    private processBits;
    private decodePosition;
    private decodeType5;
    private readUInt;
    private readInt;
    private decodeText;
}
export {};