SBAS电文时序动态编排算法

陈姗姗; 金彪; 赵立谦; 夏川茹; 王雷雷

doi:10.13700/j.bh.1001-5965.2020.0375

SBAS电文时序动态编排算法

doi: 10.13700/j.bh.1001-5965.2020.0375

陈姗姗¹,
金彪^1, ,,
赵立谦^{1, 2},
夏川茹^{1, 3},
王雷雷^{1, 3}

1.
航天恒星科技有限公司, 北京 100094
2.
中国科学院上海天文台, 上海 200030
3.
天津航天中为数据系统科技有限公司, 天津 300450

基金项目:

国家自然科学基金 41974041

装备预研一般基金 61405180103

详细信息

通讯作者:
金彪, E-mail: jinb@spacestar.com.cn

中图分类号: P228
计量
- 文章访问数: 576
- HTML全文浏览量: 64
- PDF下载量: 50
- 被引次数: 0
出版历程
- 收稿日期: 2020-07-31
- 录用日期: 2021-03-14
- 网络出版日期: 2021-10-20

Dynamic SBAS message scheduler algorithm

CHEN Shanshan¹,
JIN Biao^{1
, ,},
ZHAO Liqian^{1, 2},
XIA Chuanru^{1, 3},
WANG Leilei^{1, 3}

1.
Space Star Technology Co., Ltd., Beijing 100094, China
2.
Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030, China
3.
Tian Jin Zhong Wei Aerospace Data System Technology Co., Ltd., Tianjin 300450, China

Funds:

National Natural Science Foundation of China 41974041

Equipment Pre-research Foundation of China 61405180103

More Information

Corresponding author: JIN Biao, E-mail: jinb@spacestar.com.cn

摘要

摘要:
星基增强系统（SBAS）通过GEO卫星转发SBAS电文实现对GNSS服务性能的提升，以满足民航用户不同飞行阶段的导航需求，因此，合理有效的电文内容及播发时序设计是系统实现高质量服务的重要保证。为提高电文编排的灵活性，避免固定时序填补空余电文引起的播发资源浪费，提出了一种SBAS电文时序动态编排算法，在满足国际标准要求的前提下，综合利用SBAS电文龄期和最大播发间隔实现待播发电文的自动选择。利用NTMF实测数据对当前各主要SBAS的电文进行了特性分析，对所提方法的单双频SBAS电文编排效果进行了评估。结果表明：所提算法可保证电文时序符合国际标准要求，实现了重要电文的优先播发，将空余时隙进行动态分配实现了各类型电文播发间隔的近等比例缩短。与固定时序相比，单频SBAS完好性电文播发间隔缩短约15.0%，首次定位时间缩短约8%，双频SBAS电文首次定位时间缩短约6.5%；与固定时序的BDSBAS B1C电文相比，完好性服务能力提升约14.7%，首次定位时间缩短约16.7%。所提算法有效提升了SBAS电文播发的播发效率，实现了SBAS播发资源的100%有效利用。
- 星基增强系统(SBAS) /
- SBAS电文 /
- 电文时序 /
- 动态时序 /
- 固定时序
Abstract:
Satellite Based Augmentation Systems (SBAS) provide SBAS messages through GEO satellites to improve the performance of GNSS in order to meet the navigation needs of civil aviation users, and reasonable and effective message content and broadcast schedule design are important for SBAS to achieve high-quality services. In order to improve the flexibility of message scheduler and avoid the waste of broadcast resources caused by filling the null messages, this paper proposes an automatic scheduler of SBAS message. Under the premise of meeting the requirements of international standards, this scheduler comprehensively uses the age of SBAS message and the maximum broadcast period to realize the automatic selection of the message type to be broadcast. At the same time, this paper uses NTMF data to analyze the characteristics of the current SBAS message, and evaluates the application effect of the proposed scheduler in single- and dual-frequency SBAS message. The results show that this scheduler can ensure that the message schedule meets the requirements of international standards, can achieve the priority broadcast of important messages, and can realize the nearly equal proportion shortening of the broadcast interval of each message type by dynamic allocation of spare time slot. Compared with rigid scheduler, the integrity message broadcast interval is shortened by about 15.0% and the first positioning time is shortened by about 8% for the single-frequency SBAS, and the first positioning time is shortened by about 6.5% for the dual-frequency SBAS message. Compared with BDSBAS B1C rigid scheduler, the integrity message broadcast interval is shortened by about 14.7% and the first positioning time is shortened by about 16.7%. The scheduler can effectively improve the efficiency of SBAS message broadcasting and realize 100% effective use of SBAS broadcast resource.
- Satellite Based Augmentation System (SBAS) /
- SBAS message /
- message schedule /
- dynamic scheduler /
- rigid scheduler

HTML全文

图 1 SBAS电文时序动态编排程序流程

Figure 1. Flowchart for dynamic SBAS message scheduler

下载: 全尺寸图片幻灯片

图 2 四个SBAS播发UDREI分布直方图

Figure 2. UDREI distribution histogram of four SBASs

下载: 全尺寸图片幻灯片

图 3 四个SBAS播发GIVEI分布图

Figure 3. GIVEI distribution histogram of four SBASs

下载: 全尺寸图片幻灯片

图 4 各SBAS电文的平均播发间隔

Figure 4. Mean broadcast intervals of each SBAS message type

下载: 全尺寸图片幻灯片

图 5 各SBAS播发电文时隙占比

Figure 5. Time slot hare of each SBAS message type

下载: 全尺寸图片幻灯片

图 6 动态电文时序与固定电文时序的单频SBAS电文平均播发间隔对比

Figure 6. Comparison of single-frequency SBAS message mean broadcast intervals between dynamic and rigid message scheduler

下载: 全尺寸图片幻灯片

图 7 动态电文时序与固定电文时序的单频SBAS电文时隙占比对比

Figure 7. Comparison of single-frequency SBAS message time slot share between dynamic and rigid message scheduler

下载: 全尺寸图片幻灯片

图 8 动态电文时序与固定电文时序1的SBAS DFMC电文平均播发间隔对比

Figure 8. Comparison of SBAS DFMC message mean broadcast intervals between dynamic and rigid message scheduler 1

下载: 全尺寸图片幻灯片

图 9 动态与固定时序2的SBAS DFMC电文平均播发间隔对比

Figure 9. Comparison of SBAS DFMC message mean broadcast intervals between dynamic and rigid message scheduler 2

下载: 全尺寸图片幻灯片

图 10 动态电文时序与固定电文时序2的SBAS DFMC电文时隙占比对比

Figure 10. Comparison of SBAS DFMC message time slot share between dynamic and rigid message scheduler 2

下载: 全尺寸图片幻灯片

图 11 BDSBAS B1C SBAS电文播发间隔

Figure 11. BDSBAS B1C SBAS message broadcast intervals

下载: 全尺寸图片幻灯片

图 12 BDSBAS B1C SBAS电文增强卫星数

Figure 12. Satellite number augmented by BDSBAS B1C SBAS message

下载: 全尺寸图片幻灯片

图 13 BDSBAS B1C SBAS电文增强格网点分布

Figure 13. IGP distribution of BDSBAS B1C SBAS message

下载: 全尺寸图片幻灯片

表 1 单频SBAS服务的增强电文类型及最大播发间隔^[11]

Table 1. Augmented messages type and maximum update interval of single-frequency SBAS^[11]

电文类型	播发内容	最大播发间隔/s
0	系统不可用标识(测试用)	6
1	PRN掩码	120
2~6, 24	UDREI	6
2~5, 24	快速改正数	6~60
24, 25	长期改正数	120
9	GEO导航信息	120
7	快速改正数降效因子	120
10	降效因子	120
18	电离层网格点掩码	300
26	电离层网格点垂直延迟	300
12	系统时间参数	300
17	GEO历书	300
27	服务区域信息	120
28	钟差-轨道协方差阵	120

下载: 导出CSV

表 2 SBAS DFMC L5的增强电文类型及最大播发间隔

Table 2. Augmented messages type and maximum update interval of SBAS DFMC L5

电文类型	播发内容	最大播发间隔/s
0	系统不可用标识	6
31	卫星掩码	120
34~36, 32, 40	DFREI信息	6
32	改正数及协方差信息	120
39, 40	SBAS卫星星历及协方差	120
37	OBAD及DFREI量化表	120
37	时间参考标识	120
47	SBAS服务编号	120
47	周翻转计数	120

下载: 导出CSV

表 3 固定电文时序与动态电文时序对比

Table 3. Comparison between dynamic and rigid message scheduler

对比项目	固定电文时序	动态电文时序
实现复杂度	简单，只需按设计时序索引待播发电文类型	复杂，需根据电文播发需求等动态确定待播发电文类型
电文灵活性	较差，电文时序确定后，只能按固定策略播发，当信息缺失时，一般用空电文填充	较好，当信息缺失时，可根据优先级确定播发电文，无需空电文填充
播发周期	确定	可根据播发内容动态调整
播发间隔符合性保证	由设计的电文时序保证，需人为或由特定程序对电文播发间隔的标准符合性进行分析	由程序保证，电文时序编排程序在执行过程中使用电文播发间隔对播发电文时序进行约束，保证满足播发要求

下载: 导出CSV

表 4 各SBAS增强的卫星数和IGP数

Table 4. Satellite and IGP numbers augmented by each SBAS

系统	播发卫星数均值	播发IGP数均值
WAAS133	15.5	306
EGNOS123	12.0	287
GAGAN128	11.7	102
MSAS129	9.3	143

下载: 导出CSV

表 5 单频SBAS动态电文时序各类型电文平均播发间隔对比

Table 5. Comparison of mean broadcast intervals of different types of single-frequency SBAS message using dynamic message scheduler

电文类型	预设播发间隔/s	平均播发间隔/s	缩短百分比
1	120	100.7	16.1
2/3/4	6	5.1	15.0
7	120	100.7	16.1
9	120	100.7	16.1
10	120	100.7	16.1
12	300	248.2	17.3
17	300	248.2	17.3
18	300	248.3	17.2
25	120	100.7	16.1
26	300	248.3	17.2
28	120	100.7	16.1

下载: 导出CSV

表 6 BDSBAS B1C SBAS电文平均播发间隔与时隙占比对比

Table 6. Comparison of BDSBAS B1C SBAS message mean broadcast intervals and time slot share

电文变型	平均播发间隔/s			时隙占比/%
电文变型	设计间隔	BDSBAS播发	动态电文时序	BDSBAS播发	动态电文时序
0	6	2.85	5.12	35.0	19.55
1	120	120	99.96	0.83	1.00
2/3/4	6	6	5.12	16.67	19.55
7	120	120	99.96	0.83	1.0
9	120	120	99.96	0.83	1.0
10	120	120	99.96	0.83	1.0
17	120	120	99.96	0.83	1.0
18	240	240	199.45	1.25	1.5
25	120	120	100.07	2.5	3.96
26	240	240	200.8	3.75	4.42
28	120	120	100.25	3.33	6.94

下载: 导出CSV

参考文献(19)

[1]	WALTER T, SHALLBERG K, ALTSHULER E, et al. WAAS at 15[J]. Navigation, 2018, 65(4): 581-600. doi: 10.1002/navi.252
[2]	SCHEMPP T. WAAS development changes since commissioning[EB/OL]. (2019-06-03)[2020-07-01]. https://www.icao.int/APAC/APAC-RSO/GBASSBAS%20Implementation%20Workshop/1-4_WAAS_Development_Changes_Since_Commissioning_final%20(T%20Schemmp).pdf.
[3]	吴云, 杨鑫春, 陈慧. 多系统多频率的EGNOS系统完备性模拟分析[J]. 武汉大学学报(信息科学版), 2012, 37(3): 269-273. https://www.cnki.com.cn/Article/CJFDTOTAL-WHCH201203005.htm WU Y, YANG X C, CHEN H. Simulation and analysis of EGNOS system's integrity under multi-system with multi-frequency[J]//Geomatics and Information Science of Wuhan University, 2012, 37(3): 269-273(in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-WHCH201203005.htm
[4]	SEYNAT C, FLAMENT D. European geostationary navigation overlay service EGNOS status update[C]//The ION 23rd International Technical Meeting, 2010: 1270-1299.
[5]	RAO S. GAGAN-The Indian satellite based augmentation system[J]. Indian Journal of Radio & Space Physics, 2007, 36: 293-302.
[6]	SAITO S. MSAS system development[EB/OL]. (2019-06-03)[2020-07-01]. https://www.icao.int/APAC/APAC-RSO/GBASSBAS%20Implementation%20Workshop/1-6_MSAS%20System%20Development_Rev2%20(S%20Saito).pdf.
[7]	楼益栋, 郑福, 龚晓鹏. QZSS系统在中国区域增强服务性能评估与分析[J]. 武汉大学学报(信息科学版), 2016, 41(3): 298-303. https://www.cnki.com.cn/Article/CJFDTOTAL-WHCH201603003.htm LOU Y D, ZHENG F, GONG X P. Evaluation of QZSS system augmentation service performance in China region[J]. Geomatics and Information Science of Wuhan University, 2016, 41(3): 298-303(in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-WHCH201603003.htm
[8]	The development plan of the BeiDou satellite-based augmentation system (BDSBAS)[EB/OL]. (2017-07-17)[2020-07-01]. https://www.icao.int/APAC/Meetings/2017%20CNSSG21/WP16_China%20AI.5%20-%20Rev%20-%20Beidon%20Augumentation%20System.pdf.
[9]	陈俊平, 杨赛男, 周建华, 等. 综合伪距相位观测的北斗导航系统广域差分模型[J]. 测绘学报, 2017, 46(5): 537-546. https://www.cnki.com.cn/Article/CJFDTOTAL-CHXB201705002.htm CHEN J P, YANG S N, ZHOU J H, et al. A pseudo range and phase combined SBAS differential correction model[J]. Acta Geodaetica et Cartographica Sinica, 2017, 46(5): 537-546(in Chinese). https://www.cnki.com.cn/Article/CJFDTOTAL-CHXB201705002.htm
[10]	ICAO. Annex 10. Vol. I. Radio navigation aids[S]. Montreal: ICAO, 2018.
[11]	RTCA. Minimum operational performance standards for global positioning system/satellite based augmentation system airborne equipment: RTCA DO-229E[S]. Washington, D.C. : RTCA, 2016.
[12]	LAWRENCE D, EVANS J, CHAO Y C, et al. Integration of wide area DGPS with local area kinematic DGPS[C]//IEEE Position Location and Navigation Symposium. Piscataway: IEEE Press, 1996: 524-529.
[13]	WALTER T, NEISH A, BLANCH J. A rigid message scheduler for SBAS[C]//2020 IEEE/ION Position, Location and Navigation Symposium. Piscataway: IEEE Press, 2020: 19674219.
[14]	YUN Y, LEE E, HEO M B, et al. KASS message scheduler design[J]. Journal of Positioning, Navigation, and Timing, 2016, 5(4): 193-202. doi: 10.11003/JPNT.2016.5.4.193
[15]	SALOS D, MABILLEAU M, RODRIGUEZ C, et al. SBAS DFMC performance analysis with the SBAS DFMC service volume software prototype (DSVP)[C]//International Technical Symposium on Navigation and Timing, 2017: 1-7.
[16]	黄双临, 辛洁, 王冬霞, 等. 星基增强系统电文及播发特性研究[J]. 数字通信世界, 2019(2): 4-6. doi: 10.3969/J.ISSN.1672-7274.2019.02.002 HUANG S L, XIN J, WANG D X, et al. Research on propagating message and strategy of satellite-based augmentation system[J]. Digital Communication World, 2019(2): 4-6(in Chinese). doi: 10.3969/J.ISSN.1672-7274.2019.02.002
[17]	梁曦, 陶晓霞, 周昀, 等. 星基增强系统导航电文及完好性信息研究[J]. 空间电子技术, 2016, 13(5): 39-47. doi: 10.3969/j.issn.1674-7135.2016.05.008 LIANG X, TAO X X, ZHOU J, et al. Research of SBAS navigation message and integrity message[J]. Space Electronic Technology, 2016, 13(5): 39-47(in Chinese). doi: 10.3969/j.issn.1674-7135.2016.05.008
[18]	IWG. SBAS DFMC L5 interface control document[R]. [S. l. ]: IWG, 2017.
[19]	EUROCAE. Minimum operational performance standard for galileo/global positioning system/satellite-based augmentation system airborne equipment: ED-259[S]. Saint-Denis: EUROCAE, 2019.