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Efficient Lossy Compression of Weather Radar Data

IP.com Disclosure Number: IPCOM000249784D
Publication Date: 2017-Apr-04
Document File: 3 page(s) / 222K

Publishing Venue

The IP.com Prior Art Database

Related People

Wei Cui and Lin Wang: INVENTOR

Abstract

With the development of more connected aircraft technology, the volume of weather radar data communication is increasing. The current system for data transfer between the ground system and aircraft suffers from low transmission rate and high latency. To improve the transmission rate and reduce latency, the proposed solution uses lossy compression formats. The use of lossy compression reduces the size of weather data which is transmitted.

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1

Efficient Lossy Compression of Weather Radar Data

Wei Cui and Lin Wang

ABSTRACT

With the development of more connected aircraft technology, the volume of weather radar

data communication is increasing. The current system for data transfer between the

ground system and aircraft suffers from low transmission rate and high latency. To

improve the transmission rate and reduce latency, the proposed solution uses lossy

compression formats. The use of lossy compression reduces the size of weather data

which is transmitted.

1. INTRODUCTION

Connection of a weather radar to a Communications Management Unit (CMU) can enable

meteorological data transfers between airborne and ground based systems by HF, VHF

(POA/AOA) and SATCOM. The content of the weather radar data primarily includes, but

is not limited to, meteorological bitmap images, 3D reflectivity images, 2D hazard images,

and 2D and/or 3D turbulence data.

The data transfer of such weather data, however, is affected by air-ground subnetworks

that tend to have low transmission rates. Most air-ground subnetworks run over a

narrowband physical layer, over which the maximum bit rate is 31,500 bps for VDL Mode

2 (VHF AOA), 2,400 bps for VHF (POA), 1,800 bps for HF, and 10,500 bps for SATCOM.

For a full weather downlink message (request all items), the size of weather radar is about

200k bytes. This requires a transmission time greater than 60 seconds from the aircraft

to ground station. The low data transmission rate and the high message latency does not

provide a good user experience.

To improve the user experience, the data transmission speed can be increased by using

data compression techniques. In current systems, weather radar data is often

compressed by using zlib, which operates as an open source software library and uses a

DEFLATE lossless data compression algorithm to compress the weather images.

Although efficient, the size of compressed data depends on the content and the upper

bound as follows:

2

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In a worst case scenario, the compressed data may be larger than the original...