An integrated telemetry system for multi-satellite operations

Transcription

1 SpaceOps Conferences 6-20 May 206, Daejeon, Korea SpaceOps 206 Conference 0.254/ An integrated telemetry system for multi-satellite operations Hyun Chul Baek and Sang-il Ahn. 2 Korea Aerospace Research Institute, Gwahangno, Yuseong-gu, Daejeon, 3433, Korea and Sang Jeong Lee 3 Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon, 3434, Korea The KOMPSAT satellite can monitor large-scale natural disasters, and identify natural resources for potential utilization and high-resolution earth observation images that can be utilized in geographic applications. The KOMPSAT series are in a circular sun-synchronous orbit with direct injection to 528 ~ 685 km, 97.5 ~ 98.2 degrees inclination, and a 28 day repeating ground track orbit with a nominal Local Time of Ascending Node of 0:50 a.m. ~ 06:00 p.m.. These satellites in low-earth orbit require short contact every 90 ~ 98 minutes and transmit telemetry for 0 ~ 5 minutes per pass. The telemetry system, which verifies the SOH (State Of Health) in orbit, is one of the key systems in multi-satellite operations. Furthermore, an offline telemetry analysis is an essential task to ensure a continued state of health during the lifetime of the mission. In the past few years KGS has increasingly received telemetry because of the launches of new satellites. We are accordingly making strenuous efforts to receive multi-satellite telemetries at the same time. To this end, we are developing an integrated telemetry system that simultaneously receives, processes, displays, stores, alarms, and analyzes the state of health of the satellites through graphical and textual display. In order to satisfy these functions, the integrated telemetry system is composed of server and N clients. The server connects antennas and gateway systems, separates telemetry utilizing the virtual channel ID of the satellite, and provides telemetry to clients based on a database. The client supports multi-account for each satellite, displays telemetry with an alarm, and analyzes telemetry if necessary. Continuous verification and assessment of telemetry are thus essential for safe and successful multi-satellite operations. In this paper, we describe the integrated telemetry system for KOMPSATs and how to use it for multisatellite operations in KGS. I. Introduction HE KOMPSAT satellite can monitor large-scale natural disasters, and identify the utilization of natural Tresources and high-resolution Earth observation images that can be utilized in the field of geographic. A KOMPSAT series are in a circular sun-synchronous orbit with direct injection to 528 ~ 685 km, 97.5 ~ 98.2 degrees inclination, and a 28 day repeating ground track orbit with a nominal 0:50 a.m. ~ 06:00 p.m. Local Time of Ascending Node. These satellites in low-earth orbit require short contact every 90 ~ 98 minutes and transmit telemetry for 0 ~ 5 minutes per pass. In the past few years KGS has increasingly received telemetry because of the launches of the satellites. We are developing an integrated telemetry system that simultaneously receives, processes, displays, stores, alarms, and analyzes the state of health of the satellites through graphical and textual display. In order to satisfy these functions, the integrated telemetry system is composed of server and N clients. The server connects antennas and gateway systems, separates telemetry utilizing the virtual channel ID of the satellite, and provides telemetry to clients based on a database. The client supports multi-account for each satellite, displays telemetry with an alarm, and analyzes telemetry if necessary. Operation Controller, LEO Satellite Mission Ops, Natioanl Satellite Operation & Appliction Center. 2 Head of LEO Satellite Mission Ops. Team, National Satellite Operation & Application 3 Professor, Chungnam National University Copyright 206 by the, Inc. All rights reserved.

2 In this paper, we describe the integrated telemetry system for KOMPSATs and how to use it for multi-satellite operations in KGS. II. KOMPSAT Multi-Operation A. KARI Ground Station (KGS) The goal of the KARI Satellite Ground System Development/Satellite Mission Operations is to successfully operate practical satellites and to receive data from the payload in Figure. For successful current and future operations, we develop and do research on the mission control system, efficient mission operations, image receiving/processing system, flight dynamics and operations technology for KOMPSAT-6 based on the successful mission operations experience achieved form the retired KOMPSAT- and the current KOMPSAT-2, -3, -5, and 3A in operation. Moreover, multi satellite operations concepts are applied to enhance efficiency and safety and reduce operation costs. We continue to make every effort to play a major role in the national space development program. Figure. KARI Ground Station & Mission Control Room B. Multi-Satellite Operation Time line KARI performs multi-satellite operation at KGS in Table. The KOMPSAT is in a circular sun-synchronous orbit with direct injection to 528 ~ 685 km, 97.5 ~ 98.2 degrees inclination, and a 28 day repeating ground track orbit with a nominal 0:50 a.m.~ 06:00 p.m. LTAN. These satellites in low-earth orbit require short contact every 90 ~ 98 minutes and transmit telemetry for 0 ~ 5 minutes per pass with KARI ground stations. KOMPSAT-2 KOMPSAT-3 KOMPSAT-5 KOMPSAT-3A Table. KOMPSAT Orbit Information Satellite Orbit Altitude Inclination LTAN Repeat Day Payload Sun-synch 685km :50 a.m. 28 day MSC Sun-synch 685km :30 p.m. 28 day AEISS Sun-synch Dawn-Dusk 550km :00 p.m. 28 day SAR Sun-synch 528km :30 p.m. 28 day AEISS-A *MSC (Multi Spectral Camera, PAN: m, MS: 4m) *AEISS(Advanced Earth Imaging Sensor System, PAN 0.7m, MS: 2.8m) *SAR(Synthetic Aperture Radar, Wide: 20m, Standard: 3m, High Resolution: m) *AEISS-A(Advanced Earth Imaging Sensor System-A, PAN 0.55m, MS: 2.2m, IR: 5.5m) 2

3 Figure 2. Multi-Satellite contact Scenario with KGS III. KOMPSAT Operation Support Tool A. An outline of KOST The KOMPSAT satellites in low-earth orbit require short contact every 90 ~ 98 minutes and transmit telemetry for 0 ~ 5 minutes per pass. The telemetry system, which verifies the SOH in orbit, is one of the key systems in multi-satellite operations. Furthermore, an offline telemetry analysis is an essential task to ensure a continued state of health during the lifetime of the mission. In the past few years KGS has increasingly received telemetry because of the launches of the satellites. We are developing an integrated telemetry system that simultaneously receives, processes, displays, stores, alarms, and analyzes the state of health of the satellites through graphical and textual display in Figure 3. In order to satisfy these functions, the integrated telemetry system is composed of server and N clients. The server connects antennas and gateway systems, separates telemetry utilizing the VCID (Virtual Channel ID) of the satellite, and provides telemetry to clients based on a database. The client supports multi-account for each satellite, displays telemetry with an alarm, and analyzes telemetry if necessary. Figure 3. Configuration of KOST server & clients B. The function of KOST Server The KOST server has been designed to connect multiple TT&Cs and gateways by using IP address and port information. With one time of link connection, it is possible to connect multiple TT&Cs and gateways simultaneously and, at the same time, receive, process and store multi-satellite state data. In order to do this, we allowed the KOST server to handle the state data for each satellite by using the database and VCID for KOMPSAT- 3, 5 and 3A and to manage client accounts allowed to connect to the server, we also added the function of checking the information on the currently connected account by adding the access restriction function. In addition, to prepare for any connection errors between a specific TT&C and a gateway, we added the : connect/disconnect function so that other links may be not affected, thereby distributing the processed state data to all the clients connected to the server. 3

4 C. The function of KOST Client The KOST client has been designed to represent the satellite state data provided by the server as GUI by converting them into EU value and represent the satellite state in the form of green/yellow/red Alphanumeric (0, or Ok, Not OK) and plot by interworking with the database in Figure 4. In addition, for operation functions, satellite state data format conversion function (220, 224, 256, 288, 324 bytes), time conversion function (OBT(On Board Time), Payload Time, Julian Day, DOY(Day of Year), etc.), command conversion function, function of converting various dumps such as AEISS, GPF, TPF, CODA, Payload Async Event analysis function, function of analyzing satellite state data during real-time pass and file comparison tool for analyzing command log and raw telemetry have been added. When the KOST client is run, the first thing to do is to decide whether to use SQL database or to select Stand Alone using File Database. Generally, for real-time satellite communication, user select SQL Database and after selecting KOMPSAT-3, 5 and 3A, user can activate the system by using login information and password for each satellite. Here, three KOST clients can be activated at the same time, and if each client is connected to the KOST server, the state data for multiple satellites can be received. Also, the function of analyzing the stored satellite state data by using Report Generator, TM Analyzer, etc. even during real-time satellite operation status has been added. When a client is connected to the server, it maintains the connection status until it receives satellite state data, but after it receives satellite state data, if it does not additionally receive any more data, the link connection is cancelled after 20 seconds from the time it stopped receiving data. Automatically being set to link disconnection after 20 seconds from the time satellite state data stop being received is for operators to prevent errors in link connection and link disconnection. Figure 4. The function of KOST client D. The function of stand-alone Inconveniences had to be faced to analyze satellite state data in the non-real-time domain where communication with the satellite is not carried out. For satellite developers in the non-real-time domain to smoothly analyze the state of a satellite, a program that can be run even in the offline status was required, and for this, a functional improvement has been made by converting the database on the KOST server into file format so that when mounted on the KOST client, the database can be fully utilized as Stand Alone in Figure 5. To use Stand Alone through a KOST client, the first thing you should do is to prepare a database by converting SQL database into a file format. The next thing to do is to activate the client, select File Database in the window asking you to choose between SQL Database and File Database, specify the path to the database files and then load the latest file database. However, the function of connecting to the KOST server was removed from Stand-Alone for security reason so that it will not be possible to check the satellite state in real time and its function has been restricted to be used only for analyzing the 4

5 satellite state data. It also includes the inconvenience of converting SQL Database into File Database whenever the database is updated. Figure 5. The function of Stand-alone E. Dataflow of Telemetry Prior to real-time communication with a satellite, the KOST server is link-connected to TT&C and TMTC Gateway, and the KOST clients are connected to the server using their own account in Figure 6. If the KOST server receives satellite status data from the satellite in real time, it provides the satellite status data to all the connected clients. The clients convert the satellite state data into EU Value by using the database and provide the operator with the satellite status data in Green, Yellow, Red through Alphanumeric and Plot. Also, they provide functions necessary for checking if the satellite is operating normally through Event Message, Async Log, etc. After real-time pass is completed, they individually store each data such as Event Message, Async Log and Dump Log by separating them from error information. The domain which was not checked during the real-time pass is either analyzed by reloading the stored data or the satellite state is checked for 24 hours by using Telemetry Analyzer and Telemetry Replay function. Figure 6. Dataflow of Telemetry 5

6 IV. Conclusion A KOMPSAT series are in a circular sun-synchronous orbit with direct injection to 528 ~ 685 km, 97.5 ~ 98.2 degrees inclination, and a 28 day repeating ground track orbit with a nominal 0:50 a.m. ~ 06:00 p.m. Local Time of Ascending Node. These satellites in low-earth orbit require short contact every 90 ~ 98 minutes and transmit telemetry for 0 ~ 5 minutes per pass. In the past few years KGS has increasingly received telemetry because of the launches of the satellites. KGS is developing an integrated telemetry system that simultaneously receives, processes, displays, stores, alarms, and analyzes the state of health of the satellites through graphical and textual display. In order to satisfy these functions, the integrated telemetry system is composed of server and N clients. The server connects antennas and gateway systems, separates telemetry utilizing the virtual channel ID of the satellite, and provides telemetry to clients based on a database. The client supports multi-account for each satellite, displays telemetry with an alarm, and analyzes telemetry if necessary. The KOST server and client have been developed to simultaneously monitor the satellite status data of KOMPSAT-3, 5 and 3A in real time. The KOST server distributes the link connection and state data to TT&C and TMTC Gateway, and the KOST clients provide the satellite operator with the satellite state data in the form of Green, Yellow, Red through Alphanumeric of EU Value and Plot function. In addition, checking the state of a satellite 24 hours a day has been made possible by providing information such as Event Message and Async Log which enable to indirectly check the state of a satellite. The Stand Alone function of KOST provides a method of analyzing the state of a satellite even off-line to engineers, such as satellite developers, who are unable to check the satellite state data during real-time communication. As a result, the efficiency of satellite operation has been increased through functional improvement which enables to monitor and analyze the state of KOMPSAT-3, 5 and 3A in real time and non-real time by utilizing a unit of KOST server and multiple clients. KGS KARI KOMPSAT KOST TMTC VCID KARI Ground Station Korea Aerospace Research Institute Korea Multi-Purpose Satellite KOMPSAT Support Tool Telemetry & Tele-Command Virtual Channel ID Appendix A Acronym List References Hyun Chul Baek, Jung Ku Kwon, Dae Won Chung and Sang Jeong Lee, A test environment for multi satellite data interface verification, Bulletin of The Korean Space Science Society, Vol. 20, No. 2, October 20, pp. 22. Hyun Chul Baek, Jung Ku Kwon, Dae Won Chung and Sang Jeong Lee, An optimized data interface for Multi Satellite Operation, The Korean Society for Aeronautical & Space Sciences, 20 KSAS Fall Conference, Nov. 20, pp. 95. Hyun Chul Baek, Jung Ku Kwon, Hwan Jong Chu, Dae Won Chung and Sang Jeong Lee, Operation concept of overseas ground stations for KOMPSAT series, 204 International Conference on Space Operations. Hyun Chul Baek, Young Wook Kim, Young Cheul Kim, Myung Muk Kim, Sang-il Ahn and Sang Jeong Lee, A test environment for multi-satellite telemetry system verification, Bulletin of The Korean Space Science Society, October