On the use of the CRC for decoding Argo data

Slides:

Advertisements

Similar presentations

DIGITAL COMMUNICATION Packet error detection (CRC) November 2011 A.J. Han Vinck.

Advertisements

Computer Interfacing and Protocols

10.1 Chapter 10 Error Detection and Correction Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Ch 2.7 Error Detection & Correction CS-147 Tu Hoang.

Argo Real-time Quality Control Process NOAA/AOML: Y.-H. DANESHZADEH, R. MOLINARI, R. SABINA, C. SCHMID CIMAS/UM: E. FORTEZA, X. XIA, H. YANG.

Argo QC with an emphasis on the North Atlantic Justin Buck British Oceanographic Data Centre Joseph Proudman Building 6 Brownlow Street Liverpool L3 5DA,

Data Communications Chapter 7 Error Detection. Despite the best prevention techniques, errors may still happen. To detect an error, something extra has.

Unit 1 Protocols Learning Objectives: Understand the need to detect and correct errors in data transmission.

Error Detection and Correction Rizwan Rehman Centre for Computer Studies Dibrugarh University.

10th Argo data management 2009 Toulouse User’s manual comment Here is a list of comments received on User’s manual version 2.2 since August 28 th. Jean-Philippe.

Chapter 10 Error Detection and Correction

Editing RT QC flag in delayed mode ? Virginie Thierry DMQC 4 Toulouse, 28 septembre 2009.

CIT 307 Online Data Communications Error Detection Module 11 Kevin Siminski, Instructor.

Practical Session 10 Error Detecting and Correcting Codes.

ECE453 – Introduction to Computer Networks Lecture 4 – Data Link Layer (I)

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Data Link Layer PART III.

Communication Systems 3.1) Characteristics of a Communication System.

COMPUTER NETWORKS Ms. Mrinmoyee Mukherjee Assistant Professor St. Francis Institute of Technology, Mount Poinsur, S.V.P Road, Borivli (west), Mumbai

Overview All data can be corrupted, for reliable communications we must be able to detect and correct errors implemented at the data link and transport.

Computer Communication & Networks Lecture 9 Datalink Layer: Error Detection Waleed Ejaz

CHAPTER 3: DATA LINK CONTROL Flow control, Error detection – two dimensional parity checks, Internet checksum, CRC, Error control, Transmission efficiency.

Error Detection.

10.1 Chapter 10 Error Detection and Correction Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

10.1 Chapter 10 Error Detection and Correction Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

10.1 Chapter 10 Error Detection and Correction Data can be corrupted during transmission. Some applications require that errors be detected and.

Error Detection. Data can be corrupted during transmission. Some applications require that errors be detected and corrected. An error-detecting code can.

Error Detection and Correction

The APEX Truncated Negative Pressure Drifts (TNPDs)

© 2009 Pearson Education, Upper Saddle River, NJ All Rights ReservedFloyd, Digital Fundamentals, 10 th ed Digital Logic Design Dr. Oliver Faust.

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Data Link Layer PART III.

10.1 Chapter 10 Error Detection and Correction Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Data Link Layer. Link Layer The data unit to be transmited at the link layer is called a frame. Why link layer? How can it know where a frame begins and.

Data Link Layer 1. 2 Single-bit error 3 Multiple-bit error 4.

Practical Session 10 Computer Architecture and Assembly Language.

ERROR DETECTION AND CORRECTION Chapter 8 Data Communications & Networking ERROR DETECTION AND CORRECTION Chapter 8 First Semester 2007/2008.

Error Detection and Correction

Computer Architecture and Assembly Language

Introduction to Information Technologies

ERROR DETECTION AND CORRECTION

Data Link Layer.

Error Detection and Correction

Cyclic Redundancy Check (CRC)

ERROR CORRECTING CODES

Many to one/one to many Types of multiplexing Telephone system

Subject Name: COMPUTER NETWORKS-1

Error Detection and Correction

OCR AS Level F451: Data transmission

Part III Datalink Layer 10.

Error Detection Bit Error Rate(BER): It is the ratio of number Ne of errors appearing over a certain time interval t to the number Nt of 1 and 0 pulses.

EEC4113 Data Communication & Multimedia System Chapter 5: Error Control by Muhazam Mustapha, August 2010.

Packetizing Error Detection

Packetizing Error Detection

Basic concepts Networks must be able to transfer data from one device to another with complete accuracy. Data can be corrupted during transmission. For.

Chapter 7 Error Detection and Correction

Introduction to Information Technologies

International Argo Data Management Team

Packetizing Error Detection

DATA COMMUNICATION Lecture-33.

Packets, Frames, Parity, Checksums, and CRCs

COMPUTER NETWORKS CS610 Lecture-5 Hammad Khalid Khan.

Error Detection and Correction

Packets, Frames, Parity, Checksums, and CRCs

Computer Architecture and Assembly Language

Error Detection and Correction

Types of Errors Data transmission suffers unpredictable changes because of interference The interference can change the shape of the signal Single-bit.

Error Detection Learning Objectives:

Data Link Layer. Position of the data-link layer.

Presentation transcript:

On the use of the CRC for decoding Argo data CRC (cyclic redundancy check) = checksum used to detect potential transmission error Argo platforms using CRC : PROVOR, APEX, SOLO WHOI, NEMO Do all DACs use the CRC in a consistent way ? Recommendations for RT decoding: Ignore messages for which CRC check failed Keep all received messages with correct CRC and decode the most redundant message

-*- re-decoded data (CRC used) O data from DAC, flag 1 O data form DAC, flag ≠ 1 Temperature Salinity

Zoom on the temperature profile 5-point message corrupted 1 bad data with a flag ≠ 1 1 bad data with a flag = 1 3 data points are not obviously wrong but are they good ? Potential error in the flagging Extra work for the DM operator