RECOMMENDATIONS SEEKING AFFORDABLE FUTURE RECEIVING STATIONS OR ALTERNATIVES TO DIRECT READ-OUT SOLUTIONS

Transcription

1 Prepared by NOAA Agenda Item: I.3 Discussed in WGI RECOMMENDATIONS SEEKING AFFORDABLE FUTURE RECEIVING STATIONS OR ALTERNATIVES TO DIRECT READ-OUT SOLUTIONS In response to CGMS WGI IS-1 NOAA-WP-09 provided recommendations and background information on previous activities involving the development on the affordable user terminals and their investigation of alternative method for disseminating satellite. The most reliable and cost effective method for disseminating satellite data is via re-broadcast. This primary method of distributing satellite data allows environment users to obtain this critical information by means of a low cost receive terminal. In addition, this data can exploited to meet the specific mission requirements of an organization or satisfy needs of the users. Future environmental satellites will produce far more data than the current satellite series. The next generation geostationary and polar-orbiting environmental satellite constellations will employ new downlink frequency allocations, larger bandwidths, and faster data rates. Environmental data users must employ new field terminal receivers unique to that particular broadcast service. The cost of these new terminals, even though they have come down in cost, is relatively expensive. To ensure a broader use of the data, alternative methods and affordable user station should be made available. In comparison, the cost of the new terminals overshadows price of an existing receive station. Several surveys have shown that the primary reason for NOT considering the new high rate date (HRD) stations is cost. If cost was not a factor, the new systems would be in prime demand. The old (current) systems are not compatible with the new (future) terminals. A legacy of services for more than fifty (50) years will cease with the operation of the next generation of satellites. The cost of transition is extremely high. Affordable receive stations as well as alternative dissemination systems will promote full use of the next generation of satellite data. NOAA invites CGMS and the WMO to help make acquiring this data affordable to all. Recommendation proposed: None.

2 RECOMMENDATIONS SEEKING AFFORDABLE FUTURE RECEIVING STATIONS OR ALTERNATIVES TO DIRECT READ-OUT SOLUTIONS 1. Introduction During the planning for the development and implementation of the Low Rate Information Transmission (LRIT) service, it became apparent that data dissemination across the NOAA constellation will change dramatically. In preparation for the GOES-R and JPSS series of satellites, NOAA did comparative analysis of the data volumes and data rate to access the new data dissemination technologies. Considering the current technology for acquiring the GVAR and HRPT/APT broadcasts, satellite direct readout users must either upgrade their existing system or purchase new state-of-the-art technology. NOAA has learned that the APT community, as it exists today, will start a far-reaching transition with the launch of METOP- 1. At the end-of-life for NOAA-19, the APT service will no longer exist. The Weather Facsimile (WEFAX) users replaced their old reception terminals to obtain the LRIT service. The HRPT community has several options. These include users upgrading their existing system, purchasing a Low Rate Data (LRD) or a High Rate Data (HRD) system. The GOES- R users, will have to purchase a new GOES ReBroadcast (GRD) system. The transition from LRIT/EMWIN to HRIT/EMWIN will be seamless. Each satellite program has spent enormous resources to develop direct readout capabilities for their respective system. These dissemination systems are well suited to meet the individual mission requirements. When these changes are scored across the entire NOAA environmental satellite constellation, the transition is dramatic. Change in data rates and data volume prompts new methods in data dissemination. Users of environmental data have expressed a desire to receive a combination of polarorbiting and geostationary in a single source. In addition, it was articulated that the acquisition of environmental data should be affordable and available in realtime. NOAA started to investigate new methods and technologies for the distribution of environmental data by means of internet-like systems using push-pull FTP, regional distribution and point to multi-point services. 2. Direct Services Branch NOAA s Direct Readout and Direct Broadcast services are manage by the Office of Satellite Data Processing and Distribution. The Direct Services Branch (DSB) is responsible for administering the processing and procedures required to meet the environmental user needs and expectations. Planning and coordination of the data content, data quality, transmission schedules and, interface with the users and manufacturers are critical to the efficient performance of these services. Over the next seven (7) years, direct readout and direct broadcast services will changes significantly as the future spacecraft constellations become operational. Transition to the new data formats and adjusting for the increased data volume are concerns that DSB will provide continued support to current and future direct users. DSB will spearhead activities to addressing the new technology for data reception as well as alternative Page 2 of 7

3 methods for data distribution. Future planning will enable DSB to coordinate the expiration of the legacy services while preparing the user community for the new direct services. Several of the direct readout communities will not be supported on future NOAA environmental satellites. These groups will either upgrade to a new service or find an alternative method to acquire the data they need to support their mission. To improve customer relations and provide up-to-date information about the applications of the direct services, DSB will continue to support those services that are not a part of the future satellite constellations. DSB will investigate alternative dissemination means, including those that would take advantage of internet-like systems using push-pull ftp or commercial point to multi-point services. DSB plans to re-examine the downlink specifications for both the JPSS HRD and the GOES- R GRB services to determine if any alternative low-cost, common-off-the shelf, equipment can be used to develop affordable receive terminal specifications. These specifications will be provided to industry to build affordable terminals. 3. Recommendations for the Development of an Affordable User Terminal The evolution of Direct Broadcast services for polar-orbiting and geostationary environmental satellites has continued to accelerate in recent years. CGMS has attempted to provide guidance and standards to ensure interoperability between the various polar satellites from different countries; however adherence to these standards is at the discretion of each country. Typically each country s satellite broadcast system specifies receiver or user station technical parameters to satisfy its own broadcast, reception and processing requirements. Although there are some differences between the technical parameters for these various polar direct broadcast systems, there are also similarities. For example most systems use either VHF or the L-band frequency for their current broadcasts, X-band for their future service and even geostationary systems utilize L-band for their low rate direct broadcasts. These similarities lead to the possibility of developing a multi-purpose receiver station that can satisfactorily receive and manage data from multiple direct broadcast meteorological satellite constellations. The development of an affordable receive terminal requires the development of a prototype user station that demonstrates the potential for receiving and managing data from multiple polar-orbiting and/or geostationary environmental satellites. The proof of concept demonstration should focus on exploiting the latest technology to meet each constellations performance and reliability objectives as well as facilitating the low cost development and availability of these multi-purpose stations. We should expect an operational multi-purpose receiving station that is capable of receiving and displaying signals from as many meteorological satellites constellations as practical. The practicality of the station must be defined by predetermined cost objectives that determine the final market costs of the station, focusing on the number of different constellations that the receiver can satisfactorily acquire. It is anticipated that a multi-purpose low rate receiver (e.g., < 50 mbps) can be made available for a relatively low cost; whereas the higher rate receivers (e.g.> 100 mbps) may require incremental cost increases. We must determine if practical demarcations should be established to guide the development and offering of these multi-purpose receivers. Consideration should also be given to at least two standard antenna systems: 1) a non-tracking gain antenna for geostationary direct broadcasts and 2) a tracking Page 3 of 7

4 gain antenna that is generally required for higher data rate polar systems. The final multipurpose system should include optional components that may be readily added or deleted, depending on the technical needs of each particular constellation. The particular meteorological constellations and associated direct broadcast services to be considered are: 1) SNPP HRD 2) Metop AHRPT 3) FY AHRPT 4) GOES-R GRB 5) JPSS HRD 6) FY MPT 7) Meteor HRPT The receiver should employ reliable, low cost components that exploit the latest technologies in a cost effective manner. The receiver needs to consist of an antenna, pre-amplifier, down converter, demodulator and a processor with basic data management and display capabilities. The S/W elements can utilize freeware (e.g. CSPP, etc.) to facilitate the low cost production and offering of this multi-purpose receiver system by industry. We shall clearly specify the specific constellations that the receiver can reliably receive from and the specific conditions for this reliable reception. The parameters should be considered in the constellation s system design, link budgets and other relevant technical parameters for the individual constellations. Potential benefits from the development of an affordable low cost terminal were likely to bring significant advantages in the following areas: - the availability of low cost user terminals would make data access affordable for a larger number of users; - flexibility allowing enhancement of dissemination during the lifetime of a satellite generation with additional products that were not included in the initial design of a satellite system, in response to evolving requirements and latest R&D results; - demonstrates the ability to receive and process meteorological data from diverse polar orbiting and geostationary satellite systems; - develop a design that allows reception of higher data rate transmissions from both S-NPP/JPSS and the soon to be launched GOES-R GRB; - leverages highly on readily available, inexpensive components developed for wireless and cellular telephone applications; - the relatively inexpensive terminal design that could potentially be mass produced to meet the principal needs of meteorological users worldwide. Recommendation: CGMS create an Ad Hoc Workstation Development Team to investigate techniques and new technologies to provide specifications to build affordable receive terminals. Page 4 of 7

5 Page 5 of 7 CGMS-41 NOAA-WP Data Dissemination Considerations for Polar-orbiting and Geostationary Satellites NESDIS's operational weather satellite system is composed of two types of satellites: geostationary operational environmental satellites (GOES) for short-range warning and "nowcasting" and polar-orbiting satellites for longer-term forecasting. Both types of satellite are necessary for providing a complete global weather monitoring system. The methods discussed here can be equally applied to both polar-orbiting and geostationary constellations. NOAA s National Weather Service, Alaska Region has been involved in direct readout since As they move into the X-band era, the Region is looking to utilize the resources of the NESDIS Fairbanks CDA for the capture of the X-band satellite direct readout. The CDA at present has 5 X-band antennas, the NWS has put a number of computers at the CDA to process and distribute the data and products. The computers are remotely controlled and maintained by the NWS Alaska Region minimizing any impact on employees at the CDA. Products and data will flow to the NWS offices via a wide bandwidth communication line. The importance of direct readout at high resolution to the Alaska NWS forecaster is the reduced latency of the data and products to the forecaster. Alaska over 20% the size of the CONUS has a very sparse surface observational network. The NWS relies on high resolution products to meet the NWS mission of timely and accurate forecasts and warnings to save lives and property and enhance the economy of the U.S. Satellite data available in real-time is critical. Since, the state of Alaska extends from 54N to 71N both GOES-R and JPSS will be required. The method proposed by the Alaska Region is a point-to-multipoint distribution that can be affordably managed to provide data to many sites where the cost of acquisition (single receive station) can be shared among the users. The cost of the terminal, maintenance and communications can be shared among the users. This method can reduced the overall cost of acquiring the data needed to support the various missions. Recommendation: CGMS consider investigating the use of share acquisition among satellite users to reduce the cost of getting the satellite on a regional and/or local scale. Currently, NOAA does not operate or maintain a regional distribution system (RARS). However, NOAA does participate in the European Advance Retransmission System (EARS). NOAA has recognized the benefits of these systems to provide near real-time observations to the NWS s numerical weather prediction models. Over the next two (2) years, NOAA plans to upgrade it fleet of HRPT sites form L-band only capability to L-band/X-band capability to continue the support for our legacy POES spacecraft and transition to the new generation of polar-orbiting constellations providing higher quality instrument data. The data from the upgraded receive network will be centralized at Space Science and Engineering Center (SSEC) in Madison Wisconsin and at the NOAA Satellite Operations Facility at Suitland, Maryland. Methods to allow outside users access to the data is still under investigation. The use of the RARS technique and procedures can be a real cost saving for direct readout users on a regional as well as a global basis. Depending on the volume of data, communication lines may be a factor. Recommendation: Satellite operators the use of regional system to support the time distribution of satellite data to direct readout users in near real-time.

6 4. Strategy on Data Dissemination from Current and Future Meteorological Satellites The Direct Services Branch (DSB) is actively engaged in reviewing direct readout user requirements. Through several surveys and questionnaires, it was brought to the attention of DSB that the cost of the new direct receive terminal is a major factor in using the data from future meteorological satellite. Given the fact that the HRPT community spent roughly $100K USD per station, the cost of a new L-band/X-band system would be cost approximately $400K+ USD. This amount is huge when taking in to account the operating budget for a lot of countries. To address the issue of affordability and alternative dissemination methods, DSB proposes the following: Recommendation: CGMS coordinate with other satellite operators to review satellite operation plans for data dissemination from present and planned satellite systems; Recommendation: CGMS evaluate the potential volume of data to be disseminated; Recommendation: CGMS coordinate with other satellite operators to determine a common frequency in the MHz band and a common bandwidth (50 Mbps); Recommendation: CGMS coordinate the data content with other satellite operators; Recommendation: CGMS evaluate the receiver specifications in terms of low cost, common-off-the-shelf, components; Recommendation: CGMS investigate alternative dissemination means for future direct broadcast services, including internet-like systems using push-pull FTP, regional distribution and point to multi-point services. Summary The most reliable and cost effective method for disseminating satellite data is via rebroadcast. This primary method of distributing satellite data allows environment users to obtain this critical information by means of a low cost receive terminal. In addition, this data can exploited to meet the specific mission requirements of an organization or satisfy needs of the users. Future environmental satellites will produce far more data than the current satellite series. The next generation geostationary and polar-orbiting environmental satellite constellations will employ new downlink frequency allocations, larger bandwidths, and faster data rates. Environmental data users must employ new field terminal receivers unique to that particular Page 6 of 7

7 broadcast service. The cost of these new terminals, even though they have come down in cost, is relatively expensive. To ensure a broader use of the data, alternative methods and affordable user station should be made available. In comparison, the cost of the new terminals overshadows price of an existing receive station. Several surveys have shown that the primary reason for NOT considering the new high rate date (HRD) stations is cost. If cost was not a factor, the new systems would be in prime demand. The old (current) systems are not compatible with the new (future) terminals. A legacy of services for more than fifty (50) years will cease with the operation of the next generation of satellites. The cost of transition is extremely high. Affordable receive stations as well as alternative dissemination systems will promote full use of the next generation of satellite data. NOAA invites CGMS and the WMO to help make acquiring this data affordable to all. Page 7 of 7