Lightweight JavaScript library for parsing and manipulating TAK related messages, primarily Cursor-on-Target (COT)

About

node-cot converts between TAK message protocols and a Javascript object/JSON format. It also can bidirectionally convert CoT messages into GeoJSON

Installation

NPM

To install node-cot with npm run

npm install @tak-ps/node-cot

CoT Spec

The CoT Spec is very informally developed by rough internal concensus of large TAK Clients within the TPC (TAK Product Center). The following is a current understanding of the spec primarily developed through reverse engineering TAK clients

<event version uid type how time start stale/>

Event Attributes

| Name | Description | Example | | ------------- | ----------- | ------- | | version | CoT Version, currently 2.0 | version="2.0" | | uid | Globally unique name for this information on this event | uid="any-unique-string-123" | | type | Hierarchically organized hint about event type | type="a-f-G-E"' | | how | Gives a hint about how the coordinates were generated |how=""|time | The time at which the event was generated |time="2023-07-18T15:25:09.00Z"| |start | The time at which the event starts or is relevant |start="2023-07-18T15:25:09.00Z"| |stale | The time at which the event ends or is not relevant |stale="2023-07-18T15:25:09.00Z"` |

CoT GeoJSON Spec

One of the primary use-cases of this library is to make serialization and deserialiation from more commmon geospatial formats a breeze. This section will walk through CoT options that are exposed via the from_geojson() function.

Supported Geometries

• All Input Geometries must be a GeoJSON Feature type
• Point, Polygon, and LineString are all supported
• Multi Geometries are not supported and must be cast to their non-multi type before being passed to the library
• Centroids are calulated using a PointOnSurface algorithm

Supported Properties

The following are the most important/relevant properties

| Property | Description | | --------------------- | ----------- | | .id | Used as the CoT uid - If omitted a UUID is generated | | .properties.type | CoT type - note this will be overridden if geometry is not a Point | | .properties.how | CoT how | | .properties.time | Time at which CoT was created | | .properties.start | Time at which CoT is relevant | | .properties.stale | Time at which CoT expires | | .properties.callsign| Displayed callsign (basically the name of the feature) | | .properties.speed | Speed in m/s of the object | | .properties.course | Course in degrees from north of the object | | .properties.remarks | Human readable remarks field |

Styles can also be applied to features using the following

| Property | Description | | --------------------------------- | ----------- | | .properties.stroke | Polygon/LineString | | .properties.stroke-opacity | Polygon/LineString: Int from 0-256 | | .properties.stroke-width | Polygon/LineString | | .properties.stroke-style | Polygon/LineString | | .properties.stroke-style | Polygon/LineString | | .properties.fill | Polygon | | .properties.fill-opacity | Polygon: Int from 0-256 |

These are less common properties that can be used:

| Property | Description | | --------------------------------- | ----------- | | .properties.icon | String: Custom Icon Path (string) | | .properties.archived | Boolean: TAK Clients will ignore the stale value and retain the feature | | .properties.dest | Marti API Instructions for sending CoTs to a specific location | | .properties.fileshare | Push Data Packages via CoT |

Usage Examples

Basic Usage

import CoT from '@tak-ps/node-cot';

const message = '<event version="2.0" uid="ANDROID-deadbeef" type="a-f-G-U-C" how="m-g" time="2021-02-27T20:32:24.771Z" start="2021-02-27T20:32:24.771Z" stale="2021-02-27T20:38:39.771Z"><point lat="1.234567" lon="-3.141592" hae="-25.7" ce="9.9" le="9999999.0"/><detail><takv os="29" version="4.0.0.0 (deadbeef).1234567890-CIV" device="Some Android Device" platform="ATAK-CIV"/><contact xmppUsername="[email protected]" endpoint="*:-1:stcp" callsign="JENNY"/><uid Droid="JENNY"/><precisionlocation altsrc="GPS" geopointsrc="GPS"/><__group role="Team Member" name="Cyan"/><status battery="78"/><track course="80.24833892285461" speed="0.0"/></detail></event>'

const cot = new CoT(message);

// Export Formats
cot.to_geojson(); // Output GeoJSON Representation
cot.to_xml(); // Output String XML Representation

cot.raw; // JSON XML Representation

Known Special CoT Types

| CoT Type | Notes | | ----------------- | ----- | | u-d-f | LineString or Polygon | | u-d-r | 4 Cornered Rectangle | | u-d-p | Point |

| CoT Type | Notes | | ----------------- | ----- | | b-a | Alert | | b-a-o-tbl | 911 Alert | | b-a-o-can | Cancel Alert | | b-a-g | GeoFence Breach | | b-a-o-pan | RingTheBell | | b-a-o-opn | TroopsInContact | | b-r-f-h-c | Casevac |

| CoT Type | Notes | | ----------------- | ----- | | b-t-f | Chat | | b-t-f-d | Chat delivery receipt | | b-t-f-r | Chat read receipt | | b-t-f-p | Chat pending receipt | | b-t-f-s | Chat delivery failure |

| CoT Type | Notes | | ----------------- | ----- | | t-x-m | Mission | | t-x-m-n | Mission Created | | t-x-m-d | Mission Deleted | | t-x-m-i | Mission Invite Notification | | t-x-m-c | Mission Change | | t-x-m-c-l | Mission Change: Log | | t-x-m-c-e | Mission Change: External | | t-x-m-c-m | Mission Change: Metadata | | t-x-m-c-k | Mission Change: Keywords |

| CoT Type | Notes | | ----------------- | ----- | | b-i-v | Bits/Imagery/Video | | b-i-r-r | Remote Resource | | b-f-t-r | File Transfer Request | | b-i-x-i | QuickPic |