1、 Recommendation ITU-R RS.2106-0 (07/2017) Detection and resolution of radio frequency interference to Earth exploration-satellite service (passive) sensors RS Series Remote sensing systems ii Rec. ITU-R RS 2106-0 Foreword The role of the Radiocommunication Sector is to ensure the rational, equitable
2、, efficient and economical use of the radio-frequency spectrum by all radiocommunication services, including satellite services, and carry out studies without limit of frequency range on the basis of which Recommendations are adopted. The regulatory and policy functions of the Radiocommunication Sec
3、tor are performed by World and Regional Radiocommunication Conferences and Radiocommunication Assemblies supported by Study Groups. Policy on Intellectual Property Right (IPR) ITU-R policy on IPR is described in the Common Patent Policy for ITU-T/ITU-R/ISO/IEC referenced in Annex 1 of Resolution ITU
4、-R 1. Forms to be used for the submission of patent statements and licensing declarations by patent holders are available from http:/www.itu.int/ITU-R/go/patents/en where the Guidelines for Implementation of the Common Patent Policy for ITU-T/ITU-R/ISO/IEC and the ITU-R patent information database c
5、an also be found. Series of ITU-R Recommendations (Also available online at http:/www.itu.int/publ/R-REC/en) Series Title BO Satellite delivery BR Recording for production, archival and play-out; film for television BS Broadcasting service (sound) BT Broadcasting service (television) F Fixed service
6、 M Mobile, radiodetermination, amateur and related satellite services P Radiowave propagation RA Radio astronomy RS Remote sensing systems S Fixed-satellite service SA Space applications and meteorology SF Frequency sharing and coordination between fixed-satellite and fixed service systems SM Spectr
7、um management SNG Satellite news gathering TF Time signals and frequency standards emissions V Vocabulary and related subjects Note: This ITU-R Recommendation was approved in English under the procedure detailed in Resolution ITU-R 1. Electronic Publication Geneva, 2017 ITU 2017 All rights reserved.
8、 No part of this publication may be reproduced, by any means whatsoever, without written permission of ITU. Rec. ITU-R RS 2106-0 1 RECOMMENDATION ITU-R RS 2106-0 Detection and resolution of radio frequency interference to Earth exploration-satellite service (passive) sensors (Question ITU-R 255/7) (
9、2017) Scope Administrations operating EESS passive sensors which encounter instances of harmful radio frequency interference (RFI) should use the information in this Recommendation and its RFI reporting form in recording and reporting the RFI instance to the administration with jurisdiction over the
10、 transmitting stations which are causing the interference. The attached RFI reporting form should be provided in addition to the form in Appendix 10 of the Radio Regulations and is intended for use by administrations to report additional detailed information on interference to EESS passive sensors.
11、Keywords Harmful interference, RFI, passive sensors, reporting form The ITU Radiocommunication Assembly, considering a) that Resolution 673 (Rev.WRC-12) The importance of Earth observation radiocommunication applications, urges administrations to take into account Earth observation radio-frequency r
12、equirements and in particular protection of the Earth observation systems in the related frequency bands; b) that recent microwave images derived from the operation of EESS (passive) sensors have shown an increasing number of events where the retrieved data are corrupted by interference; c) that, in
13、 particular, harmful interference is experienced in frequency bands identified under RR No. 5.340 which prohibits all emissions in the bands identified in that footnote; d) that the interference experienced by EESS (passive) sensors typically originates from terrestrially based emitters; e) that the
14、 number of individual interference sources encountered by EESS (passive) sensors is typically greater than 100 and dispersed over the surface of the Earth; f) that passive sensor operators have experienced difficulties in resolving these interference cases, and in particular, the need to address num
15、erous interference instances occurring globally imposes costly efforts on passive sensor operators in interacting with all relevant Administrations; g) that the duration of this interference resolution process typically spans many years, recognizing a) that, according to the Constitution and Convent
16、ion of the ITU, one purpose of the ITU is to coordinate efforts to eliminate harmful interference; b) that RR Article 15 and in particular its provisions No. 15.21 (section on Reports on Infringements) and Nos. 15.22-15.46 (section on Procedure in case of harmful interference) are applicable in case
17、s of harmful interference; 2 Rec. ITU-R RS 2106-0 c) that full particulars relating to harmful interference shall, whenever possible, be given in the form indicated in Appendix 10 of the Radio Regulations; d) that RR Appendix 10 states that sufficient information shall be provided to the administrat
18、ion receiving the report of interference so that an appropriate investigation can be conducted; e) that Appendix 10 was designed for the reporting of harmful interference involving terrestrial services and that its applicability related to radio frequency interference (RFI) events detected by EESS (
19、passive) sensors is limited; f) that Report ITU-R SM.2181 provides information on how, in addition to the particulars indicated in RR Appendix 10, other data fields and information can be documented in the Report of harmful interference originating from space stations; g) that the provisions of the
20、ITU-R Radio Regulations cited under recognizing b) and c), were formulated to address instances of interference between communication services that occur on a single entry basis, recommends that, in addition to the information contained in the RR Appendix 10 form, the form provided in the Annex to t
21、his Recommendation should be used to report cases of harmful interference received by EESS (passive) sensors to the Administrations having jurisdiction over the interfering stations. Annex Form for the Reporting of interference to EESS (passive) sensor 1 Particulars concerning the general reporting
22、information The following Table 1 defines the General Reporting Information fields that should be completed by the administration reporting an RFI event. TABLE 1 General Reporting Information Administration or Entity Submitting Report: Name of the Administration (or other entity) submitting Interfer
23、ence Report Contact person: POC within the Administration submitting the report of interference Name Resolution 750 (WRC-15) on the Compatibility between the EESS (passive) and relevant active services Report cc: to Copies of Report provided to ITU-BR, sensor operating entity, etc. depending on send
24、er and recipient 2 Particulars concerning the impacted EESS (passive) system The following Table 2 defines the fields for reporting the system characteristics of the affected EESS (passive) system. TABLE 2 Impacted EESS (passive) system characteristics Satellite Example: name of the space mission Mi
25、ssion web site http:/XXX.YYY Launch date DD-MM-YYYY Payload Description of payload instrument affected Payload Sensor Characteristics Sensor freq. response/bandwidth/RF selectivity, etc. Main objective Top level function of the payload instrument affected. Swath width (km) Linear ground distance cov
26、ered in the cross-track direction. Spatial resolution (km) Ability to distinguish between two closely spaced objects on an image. Polarization vertical/horizontal/circular, etc. 4 Rec. ITU-R RS 2106-0 TABLE 2 (end) Type of orbit Such as: circular or elliptical, sun-synchronous (SSO) or non-sun-synch
27、ronous (NSS) Altitude (km) The height above the mean sea level Inclination (degrees) Angle between the equator and the plane of the orbit Ascending Node LST The local solar time (LST) of the ascending node is that local solar time for which the ascending orbit of the spacecraft crosses the equator E
28、ccentricity The ratio of the distance between the foci of the (elliptical) orbit to the length of the major axis Revisit Time (days) The time for the footprint of the antenna beam to return to (approximately) the same geographic location. This is somewhat different than the “Repeat Period” in which
29、a satellite returns to the same geographic location at the same local time. 3 Particulars concerning the interferenc 3.1 Summary of the RF Interference sources The following Table 3 defines the fields in the Summary of RFI Sources form that should be completed by the administration reporting an RFI
30、event. TABLE 3 Summary of RFI Sources Date of this RFI status update Date(s) of the sensor observations used for the RFI identification to be provided here TOTAL number of RFI cases detected Total number of RFI cases detected, including RFI ON and OFF. To be noted that typically each RFI case is ass
31、ociated to a single RFI source or interferer, however in some cases the interference is due to the aggregate effect of multiple sources Active RFI sources Number of reported RFI sources which are unresolved * Old RFI active sources Number of un-resolved RFI sources RFIs Listing of resolved RFI sourc
32、es with unique ID number starting at “ID 001” and relevant notes EXAMPLE ENTRY: ID 035 (15,000 K). Very strong. Pulsed emission. Consistent with radar emission. * New RFI active sources Number of new RFI sources detected since previous reporting RFIs EXAMPLE ENTRY: ID 036 (1,000 K) in location, only
33、 descending passes. Consistent with radiolink emission. RFI sources OFF Number of resolved RFI instances since initiation of this report RFIs Rec. ITU-R RS 2106-0 5 3.2 Geo-location and other detailed RFI information This section contains detailed information about the RFI instances detected in the
34、territory of the administration where RFI has been detected. These particulars are provided in the “Interference Source Detail Log” presented in Table 4. The accuracy of RFI location is an important parameter that the administration providing the report of RFI must provide in this section. Investiga
35、tions are typically iterative where the reporting administration provides updates to previously submitted reports. It is useful to the administration receiving the report to be informed of changes to previously reported information. For this purpose, it is recommended that new reports of RFI be high
36、lighted in yellow. The different fields considered in Table 4 are described here below: Field 1: Source Id Unique identification number of the RFI source: XXX-01, XXX-02, etc. For easier reference it is recommended that the ITU letter codes be used in place of XXX identifying the country where the R
37、FI source has been detected. Field 2: Observed geo-location Geographic location of the RFI source, given as longitude and latitude in decimal degrees. The number of decimal points provided will be consistent with the accuracy of RFI location. For example, 10 km accuracy is equivalent to about 0.008
38、degrees of the circumference of the Earth. Field 3: Centre frequency Generally, the strongest part of the emission, or where a distinct carrier can be observed, provides the best starting search frequency for investigative agents. The frequency of the strongest part of the interfering emission, (or
39、centre frequency if no part of the emission is clearly the strongest) should be listed under the column “Centre Frequency”. Field 4: Source detection characteristics Point or extended RFI source. The emission causing the interference may be detected by the radiometer as a point or an extended RFI so
40、urce A point source is when there is only one interfering emitter within the sensor spatial resolution on the ground. When this type of RFI sources are due to single emissions that These RFIs, when surrounded by interference free areas, can be more accurately detected, characterised, and geo-located
41、. When there are multiple emitters within the sensor footprint, the source is referred as extended. Extended sources, when there are caused by tens or hundreds of RFI interferers, are usually linked to a deployed system (for example, a network of transmitters) on-the ground. The sensor is not able t
42、o distinguish the geo-location of each individual source contributing to the extended interference, therefore just a reference location can be provided. This type of interference imposes an increase in the background noise detected by the sensor. The resolution of extended RFI cases is typically mor
43、e complex than the point RFI cases. Directivity of the RFI source. Directive sources may be suspected when the interference is detected stronger in a sensor pass in one direction (e.g. North-South versus South-North). Pulsed or continuous emission. Pulsed emissions may indicate that the RFI source i
44、s due to a radar system. 6 Rec. ITU-R RS 2106-0 Field 5: Level of interference detected by the sensor This field is an indication of the strength of the interference, and it is provided as Brightness Temperature (TB in degrees Kelvin) or other sensor metric. Field 6: Estimated received power level A
45、dministration spectrum enforcement agencies are familiar with reporting RFI received power (PR) into receivers as measured in watts and prefer receiving reports of RFI in those units. Generally, to approximate TB to a single RFI source EIRP, the Friis formula can be used when substituting for PR as
46、a function of e.i.r.p. as described in Attachment 2. However, for some sensors with many antennas (e.g. interferometric radiometers such as SMOS) this approach may not be very accurate. In these cases the remote sensing systems may use another metric, such as brightness temperature (TB, in degrees K
47、elvin). Field 7: City/State/Region where the RFI source has been located Field 8: Other Observations This column is used to provide additional RFI characteristics that may be useful to facilitate the work of the enforcement agencies in the identification of the interference sources. The factors to b
48、e reported here will depend on the type of RFI, and can include comments such as: estimated accuracy radius around the identified coordinates, other factors can be reported here, such as whether the interference: is pulsed or continuous; has an observable bandwidth; is observed in horizontal, vertic
49、al and/or circular polarization; is intermittent in nature, etc. In some cases, the interference may not be observed in all passes and this is also relevant to investigators. Field 9: Date/time log This column may contain the following information: Date when the RFI was first detected. Date when the RFI has been reported for the 1st time. Date/time of last sensor observation, Monitoring and processing the sensor data to detect any interference can take several days. Therefore, this date, if a few weeks old,
