**RCG-18**

**SUMMARY MINUTES**

**Working Party 8B Radar Correspondence Group (RCG) Meeting**

**British Standards Institute, London, England**

**June 16-18, 2003**

**Purpose of Meeting**

The meetings of the RCG have the ultimate aim of presenting the views
and proposals of the radar community to the ITU-R for the development of
radar related issues in future ITU-R Administrative Conferences. At this
time, June 2003, the outstanding issue concerns the "design objectives"
highlighted in ITU-R Recommendation SM.1541 Annex 8 -- Primary radars.

This "design objective" concerns the possibility of making more
stringent the requirement for radars with regard to the "roll-off" of
OOB emissions. This is a significant and important issue for the
world-wide radar community.

It is believed that it is important that the radar community should
address and propose solutions to this "objective" through ITU-R WP8B.
Therefore this meeting in the UK in June 2003 is part of the process
that should lead to the RCG making proposals to ITU-R WP 8B on these
matters to their meeting in 2005 or 2006. Other items of interest to the
radar community will also be addressed if time permits. See agenda
below.

**Summary Minutes**

**Agenda Item 1. Welcome/Opening Remarks**

The chairman welcomed attendees of the meeting to the third meeting of
the Radar Correspondence Group (RCG). The meeting was attended by
fifteen people representing five administrations. See attached List of
Participants. The chairman stated that the major output from this
meeting should be a Work Program to address the "Design Objective"
contained in Annex 8 of Recommendation ITU-R SM.1541. The Work Program
should include a detailed approach (specified tasks) and milestones
(target dates) for completing each task. It was suggested that the
previous RCG Work Program contained in ITU-R Document 8B/222-E, 23 April
2002, be used as a starting point. The RCG members agreed that the major
output from the meeting should be a revised Work Program.

Some members of the RCG expressed concern that the goals of the "Design
Objective" may be too ambitious, and that the RCG has a difficult task
before them. It was mentioned that it is key to include the radar
manufacturers and radar output device manufacturers in the study.

Martin Weber mentioned that SM.1541 is a Study Group 1 recommendation,
and asked how does the RCG and Working Party 8B intend to convey the
results of our studies to Study Group 1. It was mentioned that in the
past that Working Party 8B has sent Liaison Statements to Study Group 1
and Working Party 1A regarding work of the RCG. It was the consensus of
the RCG that they would continue to inform Study Group 1 of the progress
on addressing "Design Objectives" in SM1541 via liaison statements. The
chairman suggested that Study Group 1 representatives were welcome to
attend the RCG meetings, and have participated in the previous two RCG
meetings. Later in the meeting, Peter Griffiths provided a paper trail
of previous liaison statements to SG-1 and WP-1A from the RCG on
previous matters addressed by the RCG.

Martin Weber asked why the RCG does not use the ITU-R server instead of
the RCG website in Boulder. Martin stated that the ITU site is visited
by ITU members regularly. The Chairman stated that in most cases
documents posted on the RCG website were sent out over the ITU-R server.
The chairman suggested that in the future that all documents should be
sent to the ITU-R server, and then reference the dedicated RCG website
in the e-mails sent to the ITU-R server. The question was asked if the
ITU-R could handle on-line registration similar to that provided on the
RCG website. It was agreed that the on-line registration was convenient.

Also, later in the meeting Peter Griffiths also provided a copy of the
Terms of reference (TOR) of the RCG dated 18 January 2001. It was agreed
that the Chairman would provide a draft revised TOR as input to the next
WP8B meeting in November 2003.

**Agenda Item 2. Approval of Agenda**

Members of the RCG approved the agenda as provided in document RCG-1
with one minor change. It was proposed to address agenda item 4 after
agenda items 5 and 6. Also, Agenda item 12 was renumbered 11, agenda
item 13 was renumbered 12.

**Agenda Item 3. Introductions of Contributions to the Meeting**

At the start of the meeting there was a total of five contributions
(RCG-5, and RCG 7-10). The other RCG documents were previous ITU-R
documents, or were information documents. .

Bob Hinkle stated that the U.S. has no contributions for this meeting
due to the RCG meeting overlapping the WRC. Papers submitted through the
U.S. National committee could not be approved in a timely manner. It was
stated that U.S. papers planned for the meeting would be briefed, but no
document would be distributed to the RCG. The papers were promised to be
posted on the RCG website after clearance by the National committee.
Future RCG document numbers for the U.S. discussions were assigned as
indicated below:

RCG-13: U.S. Study of Radar Emission Masks

RCG-14: Variation in Measured Levels of OOB and Spurious Emissions with
Measurement Bandwidth

RCG-15: Near-field and far-field spectrum measurements on a Maritime
Radar

The U.K. had an additional contribution that was assigned document
number RCG-16 titled Report of an Investigation into Characteristics,
Operational and Protection requirements of Civil Aeronautical and Civil
Maritime Radar Systems.

There was also a contribution from the U.K. to be presented by John
Holloway who was not able to attend the meeting. This contribution was
titled Preliminary Parametric Study of the Bandwidth Requirements for FM
modulated Pulse Radars, and assigned document number RCG-17.

Documents RCG 13 through 17 will be posted on the RCG website as they
become available.

Each contribution was introduced by the cognizant administration.

**Agenda Item 4. Review of DRAFT WORK PROGRAM regarding "Design
Objective" of Recommendation ITU-R SM.1541 Annex 8 - Study of Emission
Characteristics of Radiodetermination Radar Systems, Document 8B/222. 23
April 2002**

Members of the RCG developed a revised Work Program to address the
"Design Objectives" contained in Annex 8 of Recommendation ITU-R
SM.1541. The revised Work Program was developed working from Document
RCG-3 (Document 8B/222). It was the consensus of the RCG members that
the Chairman of the RCG submit the revised Work Program as a
contribution to the Working Party 8B meeting in November 2003. The
revised Work Program is attached.

Peter Griffiths informed the meeting that there were other Agencies
involved in radar performance standards and their work programs were not
necessarily in line with the projected time-scales of the ITU-R. The IMO
(International Maritime Organization) was revising their radar
performance standards and this might not be completed before mid-2005.

**Agenda Item 5. Status report on studies regarding "Design Objective"
contained in Recommendation ITU-R SM.1541, Annex 8**

Peter Griffiths provided an overview of the ECC Recommendation (02)05
addressing unwanted emissions (RCG-5). The ECC document recommends that
the ITU-R Recommendations on unwanted emissions be used as general
guidance. Specifically, it recommends limits for unwanted emissions in
the spurious domain for Category B limits in Recommendation ITU-R
SM.329, and that Recommendation ITU-R SM.1539 Annex to be used for
guidance on the boundary for those radar systems. In addition, ITU-R
Recs. 1535 and 1542 should be used for guidance on generic mitigation
techniques for reduction of unwanted emissions.

Martin Edwards presented a paper on comments on RCG input paper 5 -- EEC
Recommendation (02)05 (See document RCG-8). The point was made that the
European recommendation makes the point strongly "that the limits for
unwanted emissions in the out-of-band domain (out of band domain
emission limits) as given in ITU-R Rec SM1541 are only generic "safety
net limits" since they generally constitute the least restrictive
out-of-band domain emission limits that have been successfully
implemented in national or regional regulations. It was stated that
until ITU-R Rec SM.1541 was introduced there were actually NO limits
applying to OOB emissions from maritime mobile radar systems, and that
the 20 dB / decade roll off to the --60dB point have proved challenging
for many manufacturers and have necessitated the development of new
components, including magnetrons. The view was that a change of output
device e.g. from a magnetron to a solid-state pulsed impatt diode will
not improve the situation and it seems unreasonable to assume that the
proposed design objective of SM1541 can be applied to these types of
radar systems. Mr. Edwards suggested the RCG consider seriously the idea
of recommending separate categorisation of maritime radar systems with
OOB domain limits no more stringent than those already defined in ITU-R
1541. This view was strongly supported by Mr. Abbas.

Peter Griffiths presented the U.K. paper on Bandwidths for FMCW radars
(Document RCG-10). He stated that Recommendation ITU-R SM.1541 defines
in Annex 8 the necessary bandwidths for various radar systems. In
particular, at 3.1 of Annex it provides equations for FMCW radar systems
and that various organizations are considering the possibilities of FMCW
for future radar systems to meet possible ITU requirements for unwanted
emissions. There is a current view that the equations for FMCW that are
currently contained in SM.1541 for the 40 dB bandwidth result in an
unrealistic and narrow value of the necessary bandwidth. The RCG was
invited to comment on this supposition and consider the possibility of
amending, in the future, the present equations in SM.1541.

Bob Hinkle gave an overview of the on-going U.S. studies regarding the
revision of the Radar Spectrum Engineering Criteria (RSEC) contained in
the NTIA Manual of Federal Regulations. The RSEC contains emission
limits for radar systems operated by Federal agencies. He stated that
NTIA initiated a comprehensive review of the RSEC in January 2003. The
study will involve contacts with the radar manufacturers and the
research laboratories. Based on previous measurements conducted by NTIA,
it was the view that emission characteristics of radar systems using
magnetron, coaxial magnetrons and klystrons output devices were well
understood, and that further studies would be directed more towards
travelling-wave tubes (TWTs) and solid state output devices. It was
mentioned that the trend was toward radars with solid state output
devices. Particular concern was mentioned on achievable unwanted
emission levels from electronic scanning array radars, but studies are
on-going. In the past NTIA has based emission limits of radar systems on
measured data, and planned to continue this practice. A copy of the
briefing will be provided to the RCG at a later date.

Frank Sanders presented a briefing on the variation in measured levels
of OOB and spurious emissions with maritime radars. This study was
conducted in response to an NTIA action item agreed to at the August
2002 RCG meeting. The findings of the study were that in the spurious
domain that the measured emission levels varied more like 15-18 log
rather than a 10 log trend. A copy of the briefing will be provided to
the RCG at a later date.

Frank Sanders presented a briefing on near-field and far-field spectrum
measurements on a maritime radar. The measurement results indicated that
for a maritime radar with a slotted array antenna their was very little
difference in the emission characteristics measured in the near-field
and far-field. A copy of the briefing will be provided to the RCG at a
later date.

**Agenda Item 6. Demonstration of ITU-R radar emission mask model (Excel
Program)**

Fred Najmy presented a demo of an ITU-R Radar Emission Mask model. The
software was a result of a commitment made at the August 2002 RCG
meeting. After completion of the demo, proposed changes to the software
were discussed. They include:

1\. the K factor in the 40 dB bandwidth equations which is a function of
radar ouput power and operating frequency band needed to be reviewed,

2\. the box for providing the measurement bandwidth, B~m~, should have a
pop-up window providing the information for determining the value of
B~m~ contained in SM.1541,

3\. the column labeled reference bandwidth, B~ref~, should be labeled
peak envelope power bandwidth, B~PEP,~

4\. add a new column for reference bandwidth, B~ref,~ but limit the
reference bandwidth to be no greater than 1 MHz.

5\. Change the Chirp Bandwidth column to read Total Frequency Deviation,
B~c~,

6\. Eliminate the button for X- dB floor level.

The above changes would be incorporated into the software, and a revised
version will be distributed the first week of July. It was also
suggested that some sample data be provided with the revision to the
software.

It was requested that a Help tab be added to the software, or a users
manual be provided. Bob Hinkle stated that the USA could not make a
commitment to providing a Help tab or a users manual at this time, but
he would get back with the RCG in regards to the request. It was also
suggested that instructions for loading Excel on the PC be provided
since some people could not run the model due to not having the
necessary Excel functions loaded on their computer. Bob Hinkle stated
that this would be provided.

**Agenda Item 7. Discussion on working document towards a preliminary
draft revision of Recommendation ITU-R M.1314 -- Reduction of unwanted
emissions of radar systems, Document 8B/268. 22 August 2002**

Martin Edwards presented a paper on comments on proposed changes to
Recommendation ITU-R M.1314 (RCG-7). His concern is with the fact that
the current recommendation mainly addresses the 3 and 5 GHz bands, and
that it does not include newer technology magnetrons or TWTs.

It was the consensus of the RCG members that the revision to
Recommendation ITU-R M.1314 is a key document pertaining to addressing
the "Design Objective" in annex 8 of SM.1541. Therefore, there was an
urgent need to encourage administrations to provide contributions
towards a revision of the recommendation at the next meeting of Working
Party 8B in November 2003. The Chairman stated that he would provide a
cover letter, containing requested changes from Martin Edwards, for the
Recommendation and submit it as a new contribution to the November
meeting.

**Agenda Item 8. Discussion of Recommendation ITU-R M.1177 - Techniques
for measurement of unwanted emissions of radar systems, Document 8/103.
Far field/Near field measurements.**

A general discussion of Recommendation ITU-R M.1177 was held at the
meeting. It was the general view that the document was complete with
respect to techniques to measure radar emission characteristics, but
that techniques to measure radar waveform parameters used in SM.1541 to
determine the emission mask were not complete. Also, there was concern
that it may not be appropriate to open the recommendation for revision
for two years. It was the consensus that administrations could provide
contributions proposing revisions to the recommendation as desired.

**Agenda Item 9. Discussion on possible revisions to Question ITU-R
35-1/8 -- Efficient use of the Radio spectrum by radar stations in the
radiodetermination service, and Question ITU-R 202-1/8 -- Spurious
emissions of radar systems.**

The chairman distributed the above subject Questions, and stated that
Question 35 had not been updated in twenty-five years. Also, the
Question 202 does not reflect the need to address the "Design Objective"
in Annex 8 of Sm.1541. There seemed to be no strong desire of the RCG
members to revise or combine the Question. The chairman indicated that
the U.S. may consider taking on this task.

**Agenda Item 10. Participation in Ultrawideband Task Group 1/8.**

It was the general view of the RCG members that administrations should
participate in Task Group 1//8 as desired to address the interests of
the radiodeterminations services.

**Agenda Item 11. Participation in JRG 8A-9B regarding WLANS dynamic
frequency selection (DFS).**

It was the general view of the RCG members that administrations should
participate in JRG 8A-9B as desired to address the interests of the
radiodeterminations services.

**Agenda Item 12. Date/location of the next meeting of the RCG.**

It was the general view of the RCG members that it would take a year to
make significant progress on addressing the "Design Objective" in Annex
8 of Recommendation. SM.1541. Therefore, the next meeting of the RCG was
tentatively scheduled for May/June 2004. Mr. Von Arnim offered to host
the meeting at the BSH in Hamburg, Germany.

It was also suggested that there would be an attempt to have a short
meeting of the RCG at the next meeting of WP 8B, should time permit.

# ATTACHMENT 1

# 

# 

# LIST OF PARTICIPANTS

# FOR

## RADAR CORRESPONDENCE GROUP MEETING

##  June 16-18, London U.K.4th Meeting

## 

+-----------------------+-----------------+----------------------------+
| **NAME**              | **A             | **PHONE \#**               |
|                       | DMINISTRATION** |                            |
|                       |                 | **FAX \#**                 |
|                       |                 |                            |
|                       |                 | **E-MAIL ADDRESS**         |
+-----------------------+-----------------+----------------------------+
| Abbas, Adil           | United Kingdom  | 44 (0) 2392 69 36 11 Ext.  |
|                       |                 | 1602                       |
|                       |                 |                            |
|                       |                 | 44 (0) 2392 79 40 90       |
|                       |                 |                            |
|                       |                 | Adil.abbas@raymarine.com   |
+-----------------------+-----------------+----------------------------+
| Airs, John            | United Kingdom  | 44 (0)20 86 55 83 04       |
|                       |                 |                            |
|                       |                 | john.airs@ra.gsi.gov.uk    |
+-----------------------+-----------------+----------------------------+
| Clark, Lisa           | Canada          | 613 998-7326               |
|                       |                 |                            |
|                       |                 | 613 991 3961               |
|                       |                 |                            |
|                       |                 | <clark.lisa@ic.gc.ca>      |
+-----------------------+-----------------+----------------------------+
| Edwards, Martin       | United Kingdom  | +44 0 1245 453665          |
|                       |                 |                            |
|                       | E2V             | +44 0 1245 453476          |
|                       | Technologies    |                            |
|                       |                 | [martin.edwards@](m        |
|                       |                 | ailto:martin.edwards@marco |
|                       |                 | ni.com)e2vtechnologies.com |
+-----------------------+-----------------+----------------------------+
| Fremd, Rod            | United States   | 01 410 765 5623            |
|                       |                 |                            |
|                       |                 | 01 410 981 4771            |
|                       |                 |                            |
|                       |                 | rod                        |
|                       |                 | .fremd@northropgrumman.com |
+-----------------------+-----------------+----------------------------+
| Griffiths, Peter      | United Kingdom  | 44 (0) 1329 84 50 84       |
|                       |                 |                            |
|                       |                 | 44 (0) 1329 84 50 84       |
|                       |                 |                            |
|                       |                 | <pfcg@btinternet.com>      |
+-----------------------+-----------------+----------------------------+
| Hinkle, Robert        | United States   | 01 202 482 3212            |
|                       |                 |                            |
|                       |                 | 01 202 482 4595            |
|                       |                 |                            |
|                       |                 | <rhinkle@ntia.doc.gov>     |
+-----------------------+-----------------+----------------------------+
| Kitazawa, Hironori    | Japan           | > 81 422 45 9061           |
|                       |                 | >                          |
|                       |                 | > 81 422 45 9961           |
|                       |                 | >                          |
|                       |                 | > <j04                     |
|                       |                 | 481_kitazawa@m1.jrc.co.jp> |
+-----------------------+-----------------+----------------------------+
| Najmy, Frederick      | United States   | 01 202 482 6099            |
|                       |                 |                            |
|                       |                 | <fnajmy@ntia.doc.gov>      |
+-----------------------+-----------------+----------------------------+
| Sanders, Frank        | United States   | 01 303 497 5727            |
|                       |                 |                            |
|                       |                 | 01 303 497 3680            |
|                       |                 |                            |
|                       |                 | [fsan                      |
|                       |                 | ders@its.bldr.gov](mailto: |
|                       |                 | fsanders@its.bldr.doc.gov) |
+-----------------------+-----------------+----------------------------+
| Shiota, Sadaaki       | Japan           | 81 287 43 7608             |
|                       |                 |                            |
|                       |                 | 81 287 43 3218             |
|                       |                 |                            |
|                       |                 | <s-shiota@tokimec.co.jp>   |
+-----------------------+-----------------+----------------------------+

##  

## 

+-----------------------+-----------------+----------------------------+
| **NAME**              | **A             | **PHONE \#**               |
|                       | DMINISTRATION** |                            |
|                       |                 | **FAX \#**                 |
|                       |                 |                            |
|                       |                 | **E-MAIL ADDRESS**         |
+-----------------------+-----------------+----------------------------+
| Sole, Robert          | United States   | 01 202 482 1245            |
|                       |                 |                            |
|                       |                 | 01 202 482 4595            |
|                       |                 |                            |
|                       |                 | <rsole@ntia.doc.gov>       |
+-----------------------+-----------------+----------------------------+
| Stove, Andrew         | United Kingdom  | 44 (0) 1293 644 291        |
|                       |                 |                            |
|                       |                 | 44 (0) 1293 644 788        |
|                       |                 |                            |
|                       |                 | <andy                      |
|                       |                 | .stove@uk.thalesgroup.com> |
+-----------------------+-----------------+----------------------------+
| Von Arnim, Hans Karl  | Germany         | 04 93 190 7310             |
|                       |                 |                            |
|                       |                 | 04 93 190 5000             |
|                       |                 |                            |
|                       |                 | <hans-karl.arnim@bsh.de>   |
+-----------------------+-----------------+----------------------------+
| Weber, Martin         | Germany         | > 49 61 31 1834 16         |
|                       |                 | >                          |
|                       |                 | > 49 61 31 1856 04         |
|                       |                 | >                          |
|                       |                 | > martin.weber@regtp.de    |
+-----------------------+-----------------+----------------------------+
|                       |                 |                            |
+-----------------------+-----------------+----------------------------+