zadeviggers / miniseed-ts

miniSEED implementation in Typescript

miniSEED-ts

miniSEED-ts is a Typescript implementation of the miniSEED V3 binary format.

You can read more about miniSEED here.

miniSEED-ts is powered by jDataView.

Installation

npm i miniseed

Typescript definitions are included.

Usage

import {
	serialiseToMiniSEEDBuffer,
	serialiseToMiniSEEDUint8Array,
	startTimeFromDate,
	Flags,
} from "miniseed";

const data = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11];

const metadata = {
	sourceIdentifier: "FDSN:<network>_<station>_...", // An FDSN ID: http://docs.fdsn.org/projects/source-identifiers/
	// You can manually specify nanoseconds, seconds, etc
	startTime: {
		year: 1978,
		dayOfYear: 264,
		hour: 21,
		minute: 0,
		second: 0, // This needs to be an integer
		// There's no milliseconds field - they're included in nanoSecond
		nanoSecond: 0,
	},
	// Or use a helper function to convert from a Date object
	startTime: startTimeFromDate(new Date()),
	encoding: "Int32", // Or text, Int16, Float32, Float64

	// All other metadata fields are optional, but supported.
	// See the full list here https://docs.fdsn.org/projects/miniseed3/en/latest/definition.html#field-3

	// Flags can be binary OR'd together
	flags:
		Flags.CALIBRATION_SIGNALS_PRESENT |
		Flags.TIME_TAG_IS_QUESTIONABLE |
		Flags.CLOCK_LOCKED,
	sampleRatePeriod: 1.234,
	dataPublicationVersion: 1,
    extraHeaderFields: {
        // This gets turned into JSON
        "FDSN": {
            // This key is reserved
            // See more about this key here: https://docs.fdsn.org/projects/miniseed3/en/latest/fdsn-reserved.html#fdsn-reserved-headers
        }
        // Everything else is free game
        "beans": {
            // But you should still namespace your custom fields
            amount: 20000
        }
    }
};

console.log(serialiseToMiniSEEDUint8Array(data, metadata)); // Uint8Array
console.log(serialiseToMiniSEEDBuffer(data, metadata)); // ArrayBuffer

Notes

• Only miniSEED version 3 is supported. Use mseedconvert to convert between V2 and V3.
• Currently, only serialisation is supported. Deserialisation is planned
• The various compression options offered by miniSEED aren't currently supported

Why not Streams

I wish I could use streams for this. Unfortunately, miniSEED requires a CRC hash of the whole record to be set in the headers. This means we can't start generating the response until we have all the data for the body.

Contributing

Contributions are welcome, especially fixes for things I might have done wrong.

Please write tests for anything you add.

mseed3-utils are very helpful for debugging and validating files.