JT/T 681.2-2024 in English

VALID

Inland waterway ship navigation radar Part 2: Performance test method for actual ship

Issued on:2024-04-02
Implemented on:2024-07-01
File Format:PDF
Delivery:Via email within 1~3 business days

Price(USD)： $279.00
$271.00

Standard No:	JT/T 681.2-2024
Document status:	VALID
Title in English:	Inland waterway ship navigation radar Part 2: Performance test method for actual ship
Title in Chinese:	内河船舶导航雷达第2部分：实船性能试验方法
Language:	English
File Format:	Electronic (PDF)
Delivery:	Via email within 1~3 business days
Issued on:	2024-04-02
Implemented on:	2024-07-01
ICS Classification:	47.020.70-Navigation and control equipment
Chinese Classification:	U65-Navigation equipment
Professional Classification:	JT-Transport
Related Keywords:	key test items range measurement accuracy test case shore suction test performance test method core test requirements outliers azimuth resolution test

Introduction

Background of Standard Revision and Technological Evolution

This revision is the second major update after 2007, mainly responding to the following technological development needs:

Technical Dimension	2007 Edition	2024 Edition	Significance of Change
Sensor Technology	Compass	Directional Sensor	Adapt to Modern Ship Integrated Navigation System
Positioning System	GPS-based	Beidou-based	Support Domestic Navigation Systems
Test items	9 items	11 items	New shore suction test

Analysis of core test requirements

4.2 Test instrument configuration

Distance meter: Installed under the radar antenna, accuracy requirement ±5m
Satellite positioning receiving device: Beidou system is preferred, position accuracy 0.01″
Radar reflector: X-band reflection area ＜10m²

5.1 Key test items

Range measurement accuracy test case: Select a range of 3km, measure the buoy target 15 times, and calculate the RMS error after removing 3σ outliers

Azimuth resolution test: The initial azimuth difference between the two target ships is 2°, and they are gradually approached to echo tangency, and the actual angle difference is calculated using Beidou positioning data

Key points of technical changes

Change clauses	Old version requirements	New version requirements
4.2.4 Direction sensor	Compass error ≤1°	Pointing error ≤0.5° and must comply with NMEA0183 protocol
5.6 Minimum operating distance	Visual judgment	Data must be obtained through a satellite positioning device

Implementation suggestions

Before the test, third-party calibration of the rangefinder and Beidou receiver must be completed
Normalization is recommended to eliminate the fixed deviation of the system during azimuth testing
For the newly added shore suction test, a straight channel should be selected, maintaining a distance of 30-40m from the shore

6.3 Key points of data processing

Note that when calculating azimuth accuracy: when there is a fixed deviation between satellite positioning and radar azimuth, all measured values should be normalized, that is:

Normalization value = original value - First measurement value

More samples: DL/T 5154-2012 JGJ 94-2008 JC/T 2453-2018

Sample only — not a preview of JT/T 681.2-2024