中科微 5T 系列产品
授时专用语句应用说明
V1.21
2018 年 1 月 11 日
一、 概述
中科微 5 T 系列卫星导航产品主要应用于卫星授时领域,并在 NMEA 协议框架下支持专用的
语句。该专用语句的名称为 LPS。
LPS 语句的大致结构如下。具体内容可参考中科微接收机协议规范的 1.5.11 节。
$GPTXT,01,01,02,LS=0,3,17,18,61,138,2,138,0,0,172281,020117,C4008800,00000020,-52*03距离闰秒发生时刻的时间预告的闰秒发生时间卫星时间改变的幅度发生卫星时间跳变的卫星编号闰秒信息存在异常的卫星编号闰秒事件后的闰秒值闰秒事件前的闰秒值系统的授时有效性标志系统标志其它闰秒参数
二、 举例
针对不同的场景,具体说明 LPS 语句。
2.1 正闰秒
在闰秒发生时刻,多插入 1s,即闰秒发生的这一分钟包含了 61 秒。比正常的一分钟多 1 秒。
下面的例子中:在闰秒发生时刻,2016 年 12 月 31 日的 23 时59 分之后,多出了一秒 23:59:60。
时刻 输出语句
T
$GNGGA,235959.000,3159.99999,N,11900.00006,E,1,20,0.6,10.5,M,0.0,M,,*4B
$GNRMC,235959.000,A,3159.99999,N,11900.00006,E,0.00,0.00,311216,,,A,V*05
$GNZDA,235959.000,31,12,2016,00,00*4D
$GPTXT,01,01,02,LS=0,3,17,18,61,138,7,137,0,0,1,311216,,,*6B
T+1
$GNGGA,235960.000,3159.99998,N,11900.00006,E,1,20,0.6,10.5,M,0.0,M,,*40
$GNRMC,235960.000,A,3159.99998,N,11900.00006,E,0.00,0.00,311216,,,A,V*0E
$GNZDA,235960.000,31,12,2016,00,00*47
$GPTXT,01,01,02,LS=0,3,17,18,61,138,7,137,0,0,0,311216,,,*6A
T+2
$GNGGA,000000.000,3159.99998,N,11900.00006,E,1,20,0.6,10.5,M,0.0,M,,*4B
$GNRMC,000000.000,A,3159.99998,N,11900.00006,E,0.00,0.00,010117,,,A,V*05
$GNZDA,000000.000,01,01,2017,00,00*4C
$GPTXT,01,01,02,LS=0,3,17,18,61,138,7,137,0,0,-1,311216,,,*46
2.2 负闰秒
在闰秒发生时刻,去掉 1s,即闰秒发生的这一分钟只有 59 秒。比正常的一分钟少 1 秒。
下面的例子中:在闰秒发生时刻,2016 年 12 月 31 日的 23 时 59 分少了一秒,由 23:59:58
直接跳到 00:00:00。
时刻 输出语句
T
$GNGGA,235958.000,3159.99997,N,11900.00005,E,1,21,0.6,10.4,M,0.0,M,,*47
$GNRMC,235958.000,A,3159.99997,N,11900.00005,E,0.00,0.00,311216,,,A,V*09
$GNZDA,235958.000,31,12,2016,00,00*4C
$GPTXT,01,01,02,LS=0,3,17,16,61,138,7,137,0,0,2,311216,,,*66
T+1
$GNGGA,000000.000,3159.99997,N,11900.00005,E,1,21,0.6,10.4,M,0.0,M,,*47
$GNRMC,000000.000,A,3159.99997,N,11900.00005,E,0.00,0.00,010117,,,A,V*09
$GNZDA,000000.000,01,01,2017,00,00*4C
$GPTXT,01,01,02,LS=0,3,17,16,61,138,7,137,0,0,1,311216,,,*65
T+2
$GNGGA,000001.000,3159.99997,N,11900.00005,E,1,21,0.6,10.4,M,0.0,M,,*46
$GNRMC,000001.000,A,3159.99997,N,11900.00005,E,0.00,0.00,010117,,,A,V*08
$GNZDA,000001.000,01,01,2017,00,00*4D
$GPTXT,01,01,02,LS=0,3,17,16,61,138,7,137,0,0,0,311216,,,*64
2.3 闰秒延后预报
正常情况下,不管是正闰秒还是负闰秒,卫星应该提前播发闰秒电文给接收机。但是如果
延后预报了,接收机在接收到闰秒电文后,立即跟随调整 UTC 时间。
下面的例子中:正常闰秒事件应该于 2016 年 12 月 31 日 23 时 59 分 59 秒发生。但是在该
时刻之前接收机没有接收到卫星播发的闰秒电文,而是于 2017 年 1 月 1 日 0 时 8 分 43 秒才接
收到闰秒电文。
于是在当前时刻将闰秒由 17 秒调整至 18 秒,多输出一组时刻为 00:08:43 的语句。
时刻 输出语句
T
$GNGGA,000842.000,3200.00000,N,11900.00012,E,1,21,0.6,10.4,M,0.0,M,,*47
$GNRMC,000842.000,A,3200.00000,N,11900.00012,E,0.00,0.00,010117,,,A,V*09
$GNZDA,000842.000,01,01,2017,00,00*42
$GPTXT,01,01,02,LS=0,3,17,17,61,138,7,137,0,0,,,,,*53
T+1
$GNGGA,000843.000,3200.00000,N,11900.00012,E,1,21,0.6,10.4,M,0.0,M,,*46
$GNRMC,000843.000,A,3200.00000,N,11900.00012,E,0.00,0.00,010117,,,A,V*08
$GNZDA,000843.000,01,01,2017,00,00*43
$GPTXT,01,01,02,LS=0,3,17,17,61,138,7,137,0,0,,,,,*53
T+2
$GNGGA,000843.000,3200.00000,N,11900.00012,E,1,21,0.6,10.4,M,0.0,M,,*46
$GNRMC,000843.000,A,3200.00000,N,11900.00012,E,0.00,0.00,010117,,,A,V*08
$GNZDA,000843.000,01,01,2017,00,00*43
$GPTXT,01,01,02,LS=0,3,17,18,61,138,7,137,0,0,-524,311216,,,*44
T+3
$GNGGA,000844.000,3200.00000,N,11900.00012,E,1,21,0.6,10.4,M,0.0,M,,*41
$GNRMC,000844.000,A,3200.00000,N,11900.00012,E,0.00,0.00,010117,,,A,V*0F
$GNZDA,000844.000,01,01,2017,00,00*44
$GPTXT,01,01,02,LS=0,3,17,18,61,138,7,137,0,0,-525,311216,,,*45
2.4 闰秒发生时刻错误
正常的闰秒发生时刻一般是在 12 月 31 日的最后 1 秒,或者 6 月 30 日的最后 1 秒。如果卫
星播发的闰秒电文指示的闰秒发生时刻不是这两个时刻,接收机也跟随闰秒电文进行闰秒预报,
同时给出告警标志。
下面的例子中:在 2016.12.31 的 23:41:05 时刻,北斗系统收到新的闰秒预告电文,其闰秒
发生时间变成了 2017 年 1 月 3 日(正常情况的闰秒发生时间应该为 6 月 30 日或 12 月 31 日)。
接收机接受该信息(跟随),但会在 LPS 语句($GPTXT,01,01,02,LS=)中给出告警信息(00000020,
指示北斗的 6 号卫星的闰秒电文异常)。
时刻 输出语句
T
$GNGGA,234104.000,3200.00003,N,11900.00003,E,1,20,0.6,10.4,M,0.0,M,,*4B
$GNRMC,234104.000,A,3200.00003,N,11900.00003,E,0.00,0.00,311216,,,A,V*04
$GPTXT,01,01,02,LS=0,3,17,17,61,138,2,135,0,0,,,,,*54
$GPTXT,01,01,02,LS=1,0,,,,,,,,,,,,,*6E
T+1
$GNGGA,234105.000,3200.00003,N,11900.00003,E,1,20,0.6,10.4,M,0.0,M,,*4A
$GNRMC,234105.000,A,3200.00003,N,11900.00003,E,0.00,0.00,311216,,,A,V*05
$GPTXT,01,01,02,LS=0,3,17,17,61,138,2,135,0,0,,,,,*54
$GPTXT,01,01,02,LS=1,1,3,4,0,61,2,62,0,0,260335,030117,00000020,,*6E
2.5 闰秒电文异常
在 2017.1.3 的 23:48:42 时刻,GPS 系统收到新的闰秒电文,检测到闰秒电文的内容存在明
显的异常(不符合 GPS 或者北斗的官方 ICD 文档),授时接收机直接剔除该闰秒电文(不跟随),
而保持原有的信息;同时在 LPS 语句($GPTXT,01,01,02,LS=)中给出告警信息(00800000,指示
GPS 的 24 号卫星的闰秒电文异常)。
时刻 输出语句
T
$GNGGA,234841.000,3159.99997,N,11900.00005,E,1,21,0.6,10.5,M,0.0,M,,*4E
$GNRMC,234841.000,A,3159.99997,N,11900.00005,E,0.00,0.00,030117,,,A,V*03
$GPTXT,01,01,02,LS=0,3,18,18,124,138,2,136,0,0,,,,,*67
$GPTXT,01,01,02,LS=1,0,,,,,,,,,,,,,*6E
T+1
$GNGGA,234842.000,3159.99997,N,11900.00005,E,1,21,0.6,10.5,M,0.0,M,,*4D
$GNRMC,234842.000,A,3159.99997,N,11900.00005,E,0.00,0.00,030117,,,A,V*00
$GPTXT,01,01,02,LS=0,3,18,18,124,138,2,136,0,0,,,00800000,,*6F
$GPTXT,01,01,02,LS=1,0,,,,,,,,,,,,,*6E
2.6 跳年
这是一种卫星星历电文的异常情况。
正常情况下,星历电文中播发的时间(格式为:周数和周内秒)是连续的,如果卫星出现故
障,导致星历电文中的时间出错,从而引起时间不连续( 跳年)。
接收机可以检测到这种异常,从而剔除该异常电文,保持原来的时间(不跟随)。
下面的例子中:在 2016.1.24 的 08:10:02 时刻,GPS 系统的 6 号卫星出现异常,播发错误的
星历电文,正常的时间时 2016.1.24,但是 6 号卫星的时间为 2017.1.22,向未来跳变了 52 周。
接收机不会跟随跳变至该时间,但是在语句中给出告警信息(00000020,指示 GPS 的 6 号卫
星存在异常)。
时刻 输出语句
T
$GNGGA,081001.000,3200.00001,N,11900.00003,E,1,19,0.7,10.5,M,0.0,M,,*4B
$GNRMC,081001.000,A,3200.00001,N,11900.00003,E,0.00,0.00,240116,,,A,V*08
$GPTXT,01,01,02,LS=0,3,17,17,68,89,2,87,0,0,,,,,*5E
$GPTXT,01,01,02,LS=1,0,,,,,,,,,,,,,*6E
T+1
$GNGGA,081002.000,3200.00001,N,11900.00003,E,1,19,0.7,10.5,M,0.0,M,,*48
$GNRMC,081002.000,A,3200.00001,N,11900.00003,E,0.00,0.00,240116,,,A,V*0B
$GPTXT,01,01,02,LS=0,3,17,17,68,89,2,87,0,0,,,,00000020,-52*76
$GPTXT,01,01,02,LS=1,0,,,,,,,,,,,,,*6E
下面的例子中:在 2016.1.24 的 08 :10:02 时刻,GPS 的 1,2,3 ,6,8,11,19,21,25,28 号卫星出现异
常,播发错误的星历电文,正常的时间时 2016.1.24,但是这些卫星的时间为 2015.1.25,向过去
跳变了 52 周。
接收机不会跟随跳 变至该时间, 但是在语句中 给出告警信息 (091404A7 ,指示 GPS 的
1,2,3,6,8,11,19,21,25,28 号卫星存在异常)。
时刻 输出语句
T
$GNGGA,081001.000,3159.99998,N,11900.00001,E,1,19,0.7,10.6,M,0.0,M,,*4C
$GNRMC,081001.000,A,3159.99998,N,11900.00001,E,0.00,0.00,240116,,,A,V*0C
$GPTXT,01,01,02,LS=0,3,17,17,68,89,2,87,0,0,,,,,*5E
$GPTXT,01,01,02,LS=1,1,3,3,0,13,2,11,0,0,,,,,*6F
T+1
$GNGGA,081002.000,3159.99998,N,11900.00001,E,1,19,0.7,10.6,M,0.0,M,,*4F
$GNRMC,081002.000,A,3159.99998,N,11900.00001,E,0.00,0.00,240116,,,A,V*0F
$GPTXT,01,01,02,LS=0,3,17,17,68,89,2,87,0,0,,,,091404A7,52*27
$GPTXT,01,01,02,LS=1,1,3,3,0,13,2,11,0,0,,,,,*6F