12amsa096 - Rft Addendum No.2

7/29/2019 12amsa096 - Rft Addendum No.2

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REQUEST FOR TENDER 12AMSA096 ADDENDUM NO. 2

MEOSAR CAPABILITY FOR AUSTRALIA AND NEW ZEALAND

The following information is provided to assist tenderers in responding to RFT 12AMSA096, whichcloses at 2:00PM, (AEDT) 2 September 2013.

NOTE TO RESPONDENTS

The report on the following page is provided to assist tenderers in responding to RFT 12AMSA096.


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TABLE OF CONTENTS

1 Introduction..................................................................................................................4

2 Considerations Affecting Coverage ...............................................................................4

2.1 Assumptions and Evaluation of Coverage .............................................................4

2.2 Coverage Studies Resulting from New Assumptions .............................................5

2.2.1 Establishing the Baseline ...............................................................................5

2.2.2 Increasing TOA...............................................................................................6

2.2.3 Decreasing Single Satellite Throughput .........................................................72.2.4 Increasing Antennae Elevation Masking ........................................................8

2.2.5 Combined Effects............................................................................................9

2.3 Potential Solutions..................................................................................................10

2.3.1 Adding More Antennae...................................................................................11

2.3.2 Relying More on Internal MEOLUT Networking .............................................12

2.4 Cost Estimates and Recommendations .................................................................13

3 Updated Satellite Launch Predictions and Timeline Matters .........................................14

3.1 Cospas-Sarsat Space Segment..............................................................................14

3.2 Timeline and Related Planning Matters ...................................................................16

3.3 MEOSAR Support for C/S T.001 Beacons ..............................................................17

4 Update to Estimated Costs ...............................................................................................18

5 Antennae Outages ..........................................................................................................19

6 More Realistic Satellite Configuration ............................................................................. 23

6.1 Performance Based on Planned Launches: Year End 2014 to Year End 2017 23

6.2 Future and Operational Use of DASS S-Band Satellites ....................................... .. 26

7 MEOLUT Antenna Size .................................................................................................. 27

8 MEOLUT Networking: Storage and Bandwidth Considerations ........................................29

8.1 Assumptions .............................................................................................................29

8.2 Data Loads.................................................................................................................30

Appendix A: Deliverable / Requests Cross Reference .............................................................32


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ACRONYMS / ABBREVIATIONS

C/S Cospas-Sarsat

DASS Distress Alerting Satellite System

D&E Demonstration and Evaluation

EC European Commission

GEO Geostationary Earth Orbiting

GPS Global Positioning System

GNSS Global Navigation Satellite System

FDOA Frequency Difference of Arrival

FOA Frequency of Arrival

FOC Full Operational Capability

ICSPA International Cospas-Sarsat Programme Agreement

IOC Initial Operational Capability

LEO Low Earth Orbiting

LUT Local User Terminal

MCC Mission Control Centre

MEO Medium Earth Orbiting

MIP MEOSAR Implementation Plan

MOU Memorandum of Understanding

POC Proof of Concept

RLS Return Link Service

ROM Rough Order of Magnitude

SAR Search and Rescue

SPOC SAR Point of Contact

SRR Search and Rescue Region

TDOA Time Difference of Arrival

TOA Time of Arrival


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1 INTRODUCTION

This study is a follow-on effort to the final report delivered to the Australian and New Zealandgovernments on 17 November 2010 under Australian Maritime Safety Authority (AMSA) contractnumber 1023/41168. For ease of reference, the original study is hereafter referred to as AusNZ-Nov2010. New Zealand has provided a list of thirteen requests for additional studies, analysis anddocumentation stemming from the above study and the associated effort to procure and implement thecooperative Australia and New Zealand MEOSAR system ground segment.

2 CONSIDERATIONS AFFECTING COVERAGE

2.1 Assumpt ions and Evaluation of Coverage

As noted in the original study, a large number of factors need to be considered when analyzingMEOSAR performance and coverage, but only several are considered critical. Roughly twentyinteracting variables are used to fully characterize the MEOSAR system in the simulations that supportthese studies, and unless otherwise stated, all assumptions remain the same as those listed in Table 1of AusNZ-Nov2010.

The three most significant factors in evaluating MEOSAR performance are TOA measurementaccuracy, FOA measurement accuracy and single satellite throughput. While the assumption for FOA

of 0.4 Hz appears to still hold, current information (e.g., statistics from experimental MEOLUTs)indicates that the choices for TOA measurement accuracy (20 s) and single satellite throughput(85%) may have been somewhat optimistic.

In addition, New Zealand may have concerns with interference effects that would limit performance, S-Band in particular, at MEOLUT antenna elevation angles lower than 10 or 15 degrees (5 degrees wasused in the original study).

Simulation will be used to evaluate the impact on effective coverage for the following conditions(i.e., the applicable assumptions are changed and simulations are re-run):

a) Higher TOA measurement accuracy (25 s)

b) Lower single satellite throughput (80% and 75%)

c) Higher elevation masking of MEOLUT antennae (10 and 15 degrees)

As with earlier studies, using the general criteria taken from Annex E of Cospas-Sarsat document C/SR.012, MEOSAR performance and its evaluation can be summarized by the following derivedrequirement:

MEOSAR Coverage Requirement: The unambiguous system independent location solutionobtained within 10 minutes from the first beacon message transmission shall be within 5 km from theactual beacon position 95% of the time.


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This 95th

percentile coverage re qu irement is the central de fi ni ng fa ctor in theevaluation of all the ground segment options provided in these studies. Specifically, it defines whatis meant when a given area is said to be covered .

As section 3.2.2 of AusNZ-Nov2010 demonstrated, when all other variables are held constant thegeneral effect of raising TOA measurement accuracy or lowering single satellite throughput is that itreduces the coverage area, analogous to a defined radius around the antennae of a MEOLUT. Theeffect of raising the antennae elevation mask is similar. Results for the specific new assumptions listedabove, as well as their application in several combinatorial scenarios, are provided as follows.

2.2 Coverage Studies Resulting from New Assumptions

2.2.1 Establishing the Baseline

The simulations here start from the configuration given in the final recommendation of AusNZ-Nov2010: one six-antennae MEOLUT in Perth, Australia and one six-antennae MEOLUT inWellington, New Zealand, encouraging the use of MEOLUT networking, but not explicitly requiringit. Specifically, both MEOLUTs are treated as stand-alone systems and coverage is determinedrelative to the Australia / New Zealand search and rescue region (SRR). From this starting point newassumptions are applied and provided side by side for easy comparison with performance results fromthe previous studies.

However, during the interim 18 months since the original studies were provided, enhancements havebeen made in the software underlying the simulations. Specific improvements involve better modellingof satellite orbits and several details within the geo-location algorithms that drive the simulations. Theend result is not only a more accurate picture of MEOSAR performance, but happens to also improvethe predicted performance. Table 1 below shows the baseline result for the above stated groundsegment configuration as per simulations used for AusNZ-Nov2010 alongside the same configurationas simulated using the current capabilities. While the difference in performance is not dramatic, it is

a noteworthy improvement. Specifically, the previously borderline statistic with respect to the 95th

percentile coverage requirement is now comfortably over that mark and the location accuracy isnotably better as well.


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Table 1 Original Study Final Configuration : Previous vs. Current Algo rithms

Configuration

Percentage

Coverage ofSRR

PercentWhere

Networkingis

Beneficial

PercentWhere

Networkingis Required

PercentWhere

NetworkingFulfilled

95thPercentileLocation

Error on 1stBurst

95th

PercentileLocation

Error at 10

Minutes

Perth (6) Wellington (6)

Stand-Alone Original

Study (17 Nov 2010)

94.6% N/A 0.1% N/A 8.5 5.2

Perth (6) Wellington (6)Stand-Alone CurrentSimulation Algorithms

96.9% N/A 0.1% N/A 7.1 4.1

These new simulation algorithms will be used throughout this follow-on study. As such, the newbaseline performance given in the second row in Table 1 is now the standard by which newassumptions and conditions will be measured.

2.2.2 Increasing TOA

The original study applied a TOA measurement accuracy of 20 s. While this value may yet hold,

performance reported by some MEOLUTs indicates that this may be somewhat optimistic. Hence itis worth considering raising the value to 25 s which is also in line with the original estimate fromvery early studies and theoretical predictions.

Table 2 Two MEOLUTs with Six Antennae: TOA of 20 s vs. 25 s

Configuration

PercentageCoverage of

SRR

PercentWhere

Networkingis

Beneficial

PercentWhere


PercentWhere

NetworkingFulfilled


Error on 1stBurst


Error at 10

Minutes


Stand-Alone 20 s

96.9% N/A 0.1% N/A 7.1 4.1


Stand-Alone 25 s

96.1% N/A 0.1% N/A 7.9 4.5


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As indicated in Table 2, this increase in TOA does impact performance, but the effect is relatively

small, and results are still well within the 95th

percentile coverage requirement.

2.2.3 Decreasing Single Satellite Throughput

In order to properly model the impact of typical 406 MHz distress beacon antennae (whipconfiguration), single satellite throughput is modelled using a distribution in five degree segments ofthe elevation angle between the beacon and satellite. Figure 1 below shows an example model for75% throughput and a more complete discussion of this modelling can be found in Appendix B of

AusNZ-Nov2010. The original study applied a single satellite throughput of 85%, and it is importantto note that this was perhaps the most overly optimistic assumption applied.

Figure 1 Single Satellite Throughput Example

Although improvements were anticipated as MEOLUT providers continued to develop their products,results for single satellite throughput have not changed much since the first experimentalMEOLUTs were built some five years ago. It is useful to note that the repeaters on the existingexperimental DASS satellites were not originally designed for the search and rescue (SAR) band,and relay twice the desired bandwidth (2 kHz instead of 1 kHz), and therefore introduce additionalnoise in the signal.

Perhaps even more noteworthy, the available statistics from the first L-Band downlink satellite(Glonass-K launched late in 2011 by Russia) have not yet demonstrated the expected improvementfrom a repeater designed and deployed specifically for the Cospas-Sarsat SAR application.The Glonass-K single satellite throughput statistics are better than DASS, but the difference to dateis not that significant. It should be emphasized that this is the very first deployment of the futureoperational constellations (with L-Band downlinks) and it is much too early to consider thesestatistics to be conclusive. Nonetheless, given both the lack of any improvements in single satellitethroughput from DASS, and the limited improvement from the first satellite of the future Glonass


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constellation, it is prudent to consider the impact of somewhat lower values with respect to thisimportant performance parameter.

Table 3 Two MEOLUTs with Six Ant ennae: Throughput of 85% vs. 80% and 75%

Configuration

Percentage

Coverage ofSRR

PercentWhere

Networking

isBeneficial

PercentWhere

Networking

is Required

PercentWhere

NetworkingFulfilled

95th

PercentileLocation

Error on 1stBurst

95th

PercentileLocation

Error at 10

Minutes


Stand-Alone 85%

96.9% N/A 0.1% N/A 7.1 4.1


Stand-Alone 80%

95.7% N/A 0.7% N/A 8.2 4.7


Stand-Alone 75%

93.6% N/A 2.4% N/A 10.1 5.7

While an 80% throughput does have a notable impact, the degradation in performance still does

not fall below 95

th

percentile coverage requirement until roughly a 77% throughput, clearlybecoming significant at 75%.

2.2.4 Increasing Antennae Elevation Masking

New Zealand has noted a potential concern with respect to the masking of signals receivedat MEOLUT antennae at lower elevation angles due to interference, in particular with respect to S-Band downlink of DASS satellites. In this case, the goal is to evaluate the impact of a 10 or 15degree masking angle over the 5 degrees used in the original studies of AusNZ-Nov2010.


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Table 4 Two MEOLUTs with Six Ant ennae: Elevation Masking o f 5 vs. 10 15 degrees

Configuration

PercentageCoverageofSRR

PercentWhere

Networkingis

Beneficial

PercentWhere


PercentWhere

NetworkingFulfilled

95th

PercentileLocation

Error on 1stBurst


Error at 10

Minutes


Stand-Alone 5 degrees

96.9% N/A 0.1% N/A 7.1 4.1

Perth (6) Wellington (6)Stand-Alone 10degrees

96.7% N/A 0.1% N/A 7.2 4.2


Stand-Alone 15 degrees

95.9% N/A 0.3% N/A 7.8 4.6

As indicated in Table 4, increasing the elevation mask has some impact on performance, but theeffect is comparatively small. It can be noted in the model for single satellite throughput (SeeFigure 1) that the expected throughput is already lower at these low elevation angles which

contributes to limiting the overall impact of these higher elevation masks at the MEOLUT antennae.

2.2.5 Combined Effects

While it may occur that all the original assumptions hold, or only one assumption actuallychanges, it is only practical to consider the impact of these effects in some combinatorial scenarios.

As Table 5 below demonstrates, MEOSAR is a very complex system and while system performancefollows identifiable patterns to some degree, the behaviour is definitely not strictly linear. As such,when the effects of new assumptions are coupled, performance falls off more notably than mighthave been expected.


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Table 5 Two MEOLUTs with Six Antennae: Combined Effects

Configuration


PercentWhere

Networkingis

Beneficial

PercentWhere


PercentWhere

NetworkingFulfilled


Error on 1stBurst

95th

PercentileLocation

Error at 10

Minutes

Perth (6) Wellington (6)Stand-Alone Baseline

96.9% N/A 0.1% N/A 7.1 4.1


Stand-Alone 25 s and

15 degrees

94.9% N/A 0.1% N/A 9.0 5.0

Perth (6) Wellington (6)Stand-Alone 75% and15 degrees

92.3% N/A 3.3% N/A 11.5 6.4

Perth (6) Wellington (6)Stand-Alone 25 s,75% and 15 degrees

90.3% N/A 3.3% N/A 13.7 7.4

For example, adding the effect of TOA of 25 s to the previous scenario of 75% single satellitethroughput and an elevation mask of 15 degrees drops overall performance by an additional 2%,where just increasing the TOA alone only resulted in a 0.8% drop (See Table 2). Most noteworthy,from Table 5 it can be observed that combinations, in particular with the 75% throughput involved,drive performance down to unacceptable values. Even the combination of the two independently

low impact parameters (25 s and 15 degrees) drops performance below the 95th

percentilerequirement.

2.3 Potential Solutions

Single satellite throughput has the highest independent impact as well as the highest potential forfalling short of original expectations. The impacts of the other new assumptions discussed above arenot that significant when taken independently, but performance is notably degraded when they areconsidered in combination. As such, it is appropriate to consider solutions that may compensate forthese degradations in the ground segment performance. There are two key remedies to consider:1) adding more antennae; or 2) relying more heavily on internal networking between the twoMEOLUTs in Perth and Wellington.


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2.3.1 Adding More Antennae

Taking the worst case scenarios from the last two rows of Table 5 above, it is useful to look atperformance results when adding one or two more antennae at each ground station. Tables 6and 7 provide statistics for increasing the number of antennae at each site.

Table 6 Compensating for 75% and 15 degrees w ith More Antennae

Configuration

Percentage

Coverage

ofSRR

PercentWhere

Networking

isBeneficial

PercentWhere

Networking

is Required

PercentWhere

Networking

Fulfilled


Error on 1stBurst

95th

Percentile

Location

Error at 10Minutes


Stand-Alone 75% and 15degrees

92.3% N/A 3.3% N/A 11.5 6.4


93.3% N/A 2.9% N/A 10.4 6.0


93.7% N/A 2.7% N/A 10.1 5.9

Table 7 Compensating fo r 25 s, 75% and 15 degrees with More Antennae

Configuration


PercentWhere

Networkingis

Beneficial

PercentWhere


PercentWhere

NetworkingFulfilled


Error on 1stBurst


Error at 10

Minutes

Perth (6) Wellington (6)Stand-Alone 25 s, 75%

and 15 degrees

90.3% N/A 3.3% N/A 13.7 7.4


Stand-Alone 25 s, 75%

and 15 degrees

91.5% N/A 2.9% N/A 12.4 6.8

Perth (8) Wellington (8)Stand-Alone 25 s,75% and 15 degrees

91.7% N/A 2.7% N/A 12.2 6.6


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It is very interesting to note that adding more antennae does not have much impact onperformance when attempting to compensate for the degradation that arises from changingthese assumptions. The key explanation for this is that the performance is relative to the fixed area ofthe combined Australia and New Zealand SRR. While more antennae would extend the range ofperformance, this change really cant compensate for the effect over the finite area of the SRR.

In effect, given the assumption of a single satellite constellation at least, the throughput and the higherelevation masking directly limit the satellites mutually visible to the beacon and the MEOLUT.More antennae simply cannot compensate for what is, in effect, not being relayed to the groundstation. This analysis could be revisited with satellites from multiple constellations and performancewould likely improve, but given the uncertainties of satellite launch schedules, it is still perhaps

more appropriate to model anticipated performance based on the more prudent case of a singleconstellation.

2.3.2 Relying More on Internal MEOLUT Network ing

Again taking the worst case scenarios from the last two rows of Table 5 above, performance with theaddition of networking between the MEOLUTs is now analyzed and results are provided in Tables 8and 9. The general case of networking the two MEOLUTs is considered first. Then the simulation isrepeated with the added sophistication of coordinating the schedules between the MEOLUTs to ensurethat they are tracking separate satellites as needed to maximize the number in view of the groundstations.

Table 8 Compensating for 75% and 15 degrees w ith Networking

Configuration

Percentage

CoverageofSRR

PercentWhere

Networkingis

Beneficial

PercentWhere


PercentWhere

NetworkingFulfilled


Error on 1st

Burst


Error at 10

Minutes

Perth (6) Wellington (6)Stand-Alone 75% and 15degrees

92.3% N/A 3.3% N/A 11.5 6.4

Perth (6) Wellington (6)Networked 75% and 15degrees

95.5% 53.0% 3.3% 37.5% 8.5 4.8

Perth (6) Wellington (6)Networked and

Coordinated Schedules

75% and 15 degrees

96.0% 61.1% 3.3% 45.7% 7.9 4.5


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Table 9 Compensating for 25 s, 75% and 15 degrees with Networking

Configuration


PercentWhere

Networkingis

Beneficial

PercentWhere


PercentWhere

NetworkingFulfilled

95th

Percentile

LocationError on 1st

Burst

95th

Percentile

Location

Error at 10

Minutes


Stand-Alone 25 s, 75%

and 15 degrees

90.3% N/A 3.3% N/A 13.7 7.4


Networked 25 s, 75%

and 15 degrees

94.2% 53.0% 3.3% 37.5% 10.0 5.4


Networked and


25 s, 75% and 15

degrees

94.9% 61.1% 3.3% 45.7% 9.2 5.0

The resulting performance is still never quite as good as the baseline in Table 1 (96.9%), butnetworking does appear to provide a viable solution, in particular if schedules are coordinated betweenthe two MEOLUTs. The reason this works is that when the MEOLUTs work together to maximizethe detection rate, the degradation due to lower throughput and higher elevation masking can beaddressed more successfully.

2.4 Cost Estimates and Recommendations

Adding one or two antennae would help performance, and perhaps more so as many satellites becomeavailable (i.e., multiple constellations). Adding antennae should not increase the cost for the MEOLUTcore processing unit, but as per the cost estimates in AusNZ-Nov2010 each additional antenna can beassumed to add AU$ 200,000 to the initial cost. Also, each antenna would add perhaps AU$ 20,000 atthe time of installation and AU$ 14,000 per year in maintenance costs (AU$ $70,000 for five years),resulting in a rough total cost of AU$ 290,000 per additional antenna over the contract period. While itmay be viable in the future when more satellites could be in orbit, this cost to benefit ratio is quite hardto justify.

In contrast, the provision of a more robust internal MEOLUT networking capability is significantlyless expensive, as well as more likely to improve performance throughout the SRR. For example


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one significant improvement in networking can be realized by the installation of dedicated circuits (e.g.,frame relay), instead of relying on the Internet as a primary means for data transfer. While this maycost several thousand dollars to install, as well as several thousand each year in monthly fees, thecost is clearly still a small fraction of that for additional antennae, perhaps in total near the cost of themaintenance on one single additional antenna. The majority of other mechanisms to improvenetworking are really at the level of upfront specifications within the tender document to ensure thatthe MEOLUT provider installs appropriate hardware (e.g., routers) and software support (e.g.,coordinated scheduling) to maximize networked performance. Such improvements may add to thebase price of each MEOLUT, but again these costs should be on the order of AU$ 20,000 to AU$40,000, not ten times that amount.

The recommended approach to buffer against the potential impact of degraded performance is toplan for a more robust MEOLUT networking capability. The associated specific cost estimatesare provided in section 4.

3 UPDATED SATELLITE LAUNCH PREDICTIONS AND TIMELINE MATTERS

Given that it has been about 18 months since the original study (AusNZ-Nov2010), it is appropriate toconsider an updated view of the anticipated C-S Space Segment and how it may affect planning andthe implementation timeline. It is also of interest to address planning issues, such as thedecommissioning of the LEOSAR system as well as the capability for MEOSAR to reliably support thecurrent generation of 406 MHz beacons.

3.1 Cospas-Sarsat Space Segment

Table 10 below provides predictions of the numbers of satellites per the end of the given year, basedon launch schedules for the future LEOSAR and MEOSAR space segments. In the case of LEOSARand the MEOSAR DASS constellations, satellite lifetimes and hence resultant decommissioning,are incorporated as well. The nominal operational limit for LEOSAR is four satellites andsituations where available satellites fall below this number are highlighted in red.

Also, LEOSAR and MEOSAR DASS availability are shown as two rows, planned and possible. Inboth cases the distinction is made as experience has indicated that the plans often fall short of thereality for these constellations. Possible LEOSAR limitations stem both from failures in recentlydeployed Russian satellites as well as the uncertainty of future funding for this capability to all thespace segment providers involved. MEOSAR DASS deployments have suffered the ironic fact thatthe older satellites are lasting much longer than their planned lifetimes (7 years by specification and inreality now approaching an average of 12 to 13 years).

So, while there are five satellites considered to be launch ready in both the 2012 and 2013 calendaryears, considerably less may be needed to replace failing satellites. Also, there are no current plansto continue the replenishment beyond the end of 2013. Granted the three oldest with DASS repeaters


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that will reach a 12 year lifespan1

during 2014 as per Table 10, may well last longer, but still therealistic number of DASS satellites will likely be less than once expected.

1

Table 10 has been updated in this document as part of the Phase II effort: Specifically DASS S-Band satellitecounts were readjusted giving them a 12 year lifespan (also in Table 10 an errant entry in L-Band total line has

been corrected (year 2017 was previously 41)).


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3.2 Timeline and Related Planning Matters

Figure 2 below provides a proposed implementation timeline for the combined Australia and NewZealand cooperative MEOSAR ground segment, which is similar to, but not the same as, the oneprovided in AusNZ-Nov2010. Although satellite launch schedules have changed, these updates reallyhave no impact on the recommended plan for the Australia and New Zealand ground segment.However, changes have been made in keeping with the current understanding of the Australia andNew Zealand procurement process which will be executed as a single tender for all MEOSARcomponents: two MEOLUTs and all the MCC functionality. Other changes have been made inresponse to a now internationally agreed upon target date of October 2015 for the MEOSAR systemto enter IOC status. In this case, the goal for an operational Australia and New Zealand ground

segment has been shifted slightly forward from the original 2016 target. For ease of reference, themilestones for MEOSAR IOC and FOC status have been noted on the timeline.

Figure 2 Implementation Timeline

Also in Figure 2, a new item has been added for a possible phase out period for LEOSAR operations,starting at the MEOSAR IOC milestone and ending when MEOSAR reaches FOC. If the LEOSARPossible scenario occurs as depicted by the second row of Table 10 above, the situation may be lessstable and/or accelerated by lack of a LEOSAR space segment, but assuming the planneddeployments hold, it is still possible to consider a phase-out of LEOLUT operations during this period.Table 11 lists the LEOLUTs considered in the brief analysis that follows.


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Table 11 Australia and New Zealand LEOLUTs

Name Latitude Longitude

Albany 35.12 S 117.90 E

Bundaberg 24.76 S 152.41 E

Wellington 41.15 S 175.50 E

Table 12 below summarizes a generalized scenario for LEOSAR performance assuming the phase

out of the Australia and New Zealand LEOLUTs, one at a time. The simulation assumes there is anominal LEOSAR constellation of four satellites, all with on-board memory (i.e., SARP).Performance is modelled by computing the potential wait-time for the generation of a LEOSARlocation (4 bursts are assumed necessary) for each simulated beacon activation throughoutthe SRR over a six day period. Table 12 provides the LEOLUT configuration along withvarious wait-time statistics for each scenario. The purpose is to provide a frame work forunderstanding the impact of phasing out LEOLUTs, not a complete and detailed prediction ofyear by year performance as per the available space segment etc. Wait-time statistics are inminutes.

Table 12 LEOSAR Wait-time Based on 4 Satellites (all w ith SARP)

Configuration Minimum Maximum Average Median 95th

Percentile

Albany, Bundaberg, Wellington 6.5 517 70 60 171

Albany, Bundaberg 6.5 610 94 80 231

Bundaberg 6.5 752 153 115 450

3.3 MEOSAR Support for C/S T.001 Beacons

An important concern is whether or not the planned MEOSAR system will reliably continue the fullsupport of the current generation of 406 MHz beacons, specifically those that meet the specificationsof C/S T.001. Such support has been a basic tenet of the MEOSAR system since its conception,over a decade ago. The compatibility of T.001 beacons with all MEOSAR satellite constellations isexplicitly stated in section 2.1 of the Cospas-Sarsat MEOSAR Implementation Plan (C/S R.012).


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While R.012 does not explicitly state this compatibility for MEOLUTs, it is implied throughout. TheMEOSAR Demonstration and Evaluation (D&E) Plan (C/S R.018) does dictate that the MEOSARsystem will be evaluated upon performance based on the use of T.001 beacons. Also, Annex C,which specifies basic requirements for MEOLUTS participating in the MEOSAR D&E, repeatedlyrefers to the support of T.001 beacons. Likewise, Annex E includes implied compatibilityrequirements for MEOSAR capable MCCs.

In summary, compatibility with T.001 beacons and the MEOSAR space segment is explicitly stated inC/S R.012. And, while perhaps not yet explicit for MEOLUTs and MCCs, the precursors are inplace via C/S R.018, and there is no doubt the future Technical (T Series) and Operational (ASeries) documents will clearly state this requirement.

4 UPDATE TO ESTIMATED COSTS

The original study, AusNZ-Nov2010, outlined estimated costs for various configurations of equipmentand maintenance services required to implement a cooperative Australia and New ZealandMEOSAR system ground segment. The estimated cost for one six- antennae MEOLUT in Perth,Australia and one six-antennae MEOLUT in Wellington, New Zealand, encouraging the use ofMEOLUT networking, but not explicitly requiring it, along with continued support for GEOSAR was AU$8,371,400.

Since November of 2010, there are no updates available on pricing for the major components and

maintenance services . No significant procurements of MEOSAR ground equipment havebeen completed during the 18 month interim, and the available information has been very limited withregard to procurements still in process or the few minor upgrades to existing equipment that haveoccurred. As such, the original conclusion for estimated costs holds, with the onlyexception being to add a comparatively small allowance for a more robust MEOLUTnetworking capability. These additional costs are itemized below in Table 13. The cost under thecomponent column includes: AU$ 25,000 in software, AU$ 4,000 in hardware (router) andAU$2000 for installation of a dedicated communication line. The five year maintenance estimate isgenerated based on monthly fees of AU$ 700.


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Table 13 Updated Costs (AU$)

Five YearsFive Years Multiple

ComponentMaintenance

Software Antennae Total

Subscription Installation

MEOLUT #1

Six Antennae

2,800,000 470,000 250,000 210,700 3,730,700

MEOLUT #2

Six Antennae (with Radomes)

2,860,000 470,000 250,000 210,700 3,790,700

MCC 200,000 100,000 100,000 0 400,000Backup MCC 150,000 50,000 0 0 200,000

GEOLUT Continued

Operations

0 150,000 100,000 0 250,000

AusNZ-Nov2010 TOTAL 8,371,400

MEOLUT #1

Enhanced Networking

31,000 42,000 0 0 73,000

MEOLUT #2

Enhanced Networking

31,000 42,000 0 0 73,000

Follow-on Study TOTAL 8,517,400

As noted in section 2.4, additional antennae could add as much as AU$ 1,160,000 versus

AU$ 146,000 (2 X AU$ 73,000) for an enhanced MEOLUT networking capability. The new finalestimated cost for the cooperative Australia and New Zealand MEOSAR system ground segmentis AU $8,517,400.

5 ANTENNAE OUTAGES

It is useful to consider the impact on coverage when antennae outages occur at the Perth and

Wellington MEOLUTs. Furthermore, when performance drops beneath the 95th

percentile goal it is

appropriate to consider contingency configurations. For these studies the baseline configuration from

AusNZ-Nov2010 is used again as the reference, specifically using the original assumptions, the final

recommended configuration (six antennae at each ground station without dedicated networking)

but with performance results recomputed using the latest simulation software.


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Table 14 Single Antenna Failure

Configuration


PercentWhere

Networkingis

Beneficial

PercentWhere


PercentWhere

NetworkingFulfilled

95th

Percentile

LocationError on 1st

Burst

95th

Percentile

Location

Error at 10

Minutes


Stand-Alone Baseline

96.9% N/A 0.1% N/A 7.1 4.1

Perth (5) Wellington (6)Stand-Alone 1 Outage

95.8% N/A 0.3% N/A 8.1 4.6


Stand-Alone 1 Outage

95.3% N/A 0.3% N/A 8.5 4.9

Table 14 shows that in the event of a single antenna failure between the two ground stations,

performance only suffers slightly and the 95th

percentile target in maintained.

Table 15 Two Antennae Failures

Configuration


PercentWhere

Networkingis

Beneficial

PercentWhere


PercentWhere

NetworkingFulfilled

95th

PercentileLocation

Error on 1stBurst


Error at 10

Minutes



96.9% N/A 0.1% N/A 7.1 4.1

Perth (5) Wellington (5)Stand-Alone 2Outages

93.7% N/A 0.6% N/A 9.8 5.6


Stand-Alone 2 Outages

93.9% N/A 0.7% N/A 10.0 5.6



93.0% N/A 0.8% N/A 10.6 5.9

While performance is still fairly good, Table 15 indicates when there are two

simultaneous antennae failures, the performance falls below the 95th

percentile target.


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Table 16 Two Antennae Failures Add Networking

Configuration

Percentage

CoverageofSRR

PercentWhere

Networkingis

Beneficial

PercentWhere


PercentWhere

NetworkingFulfilled


Error on 1stBurst

95th

Percentile

LocationError at 10

Minutes



96.9% N/A 0.1% N/A 7.1 4.1


Networked 2 Outages

97.0% 66.5% 0.6% 37.0% 6.9 4.0

Perth (4) Wellington (6)Networked 2 Outages

96.6% 53.7% 0.7% 26.7% 7.3 4.2


Networked 2 Outages

96.7% 66.4% 0.8% 28.3 7.2 4.2

Table 16 indicates that adding networking can soundly compensate for all combinations of twoantennae outages.

Table 17 Three and Four Antennae Failures

Configuration


PercentWhere

Networkingis

Beneficial

PercentWhere


PercentWhere

NetworkingFulfilled

95th

PercentileLocation

Error on 1stBurst


Error at 10

Minutes



96.9% N/A 0.1% N/A 7.1 4.1



90.8% N/A 1.2% N/A 12.6 7.0



90.2% N/A 1.5% N/A 13.0 7.2



85.6% N/A 2.7% N/A 16.7 9.5


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As expected and shown in Table 17, the three and four failure cases result in performance well

below the 95th

percentile target.

Table 18 Three and Four Antennae Failures Add Networking

Configuration


PercentWhere

Networkingis Beneficial

PercentWhere


PercentWhere

NetworkingFulfilled


Error on 1stBurst

95th

PercentileLocation

Error at 10

Minutes



96.9% N/A 0.1% N/A 7.1 4.1


Networked 3 Outages

95.8% 66.4% 1.2% 41.1% 8.1 4.6


Networked 3 Outages

95.6% 70.2% 1.5% 48.0% 8.3 4.7


Networked 4 Outages

94.1% 73.0% 2.7% 57.3% 9.8 5.5

Table 18 indicates that both cases of three outages are compensated for by networking, but the

scenario with four outages still falls short of the 95th

percentile target.


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Table 19 Four Antennae Failures Networking and Coordinated Schedules

Configuration


PercentWhere

Networkingis

Beneficial

PercentWhere


PercentWhere

NetworkingFulfilled

95th

PercentileLocation

Error on 1stBurst


Error at 10Minutes



96.9% N/A 0.1% N/A 7.1 4.1


Networked and


4 Outages

96.3% 91.1% 2.7% 94.9% 7.5 4.8

Table 19 shows that adding coordinated schedules produces an acceptable result with as many as two

antennae failed at each MEOLUT.

6 MORE REALISTIC SATELLITE CONFIGURATION

6.1 Performance Based on Planned Launches: Year End 2014 to Year End 2017

All studies provided to date with regard to performance of the cooperative Australia and New ZealandMEOSAR system ground segment have been generated using a single nominal MEOSARconstellation of 24 satellites based on SAR/GPS which happens to apply a six plane orbitalconfiguration. While this yields a consistent and reliable foundation for comparisons between differentground segment configurations, it is noted that for the real world setting, in particular in the nearfuture, other constellations are more likely to be in place.

Specifically, the Galileo constellation (a 27 satellite, three plane orbital configuration) as well as limitedsatellites from SAR/GLONASS and the DASS experimental constellation will supply the actualsatellites expected to be in place in October of 2015 when the cooperative Australia and New ZealandMEOSAR system ground segment is planned to reach an operational status. Section 6.2 furtherdiscusses the practicalities and limitations of actively using the DASS constellation for SAR, but for thesake of analysis, performance results relative to combinations of L-Band Only and L-Band + S-Band constellations are provided below in tables 20 and 21. The rows in these tables correspond toplanned satellite launches as documented in Table 10 above, applying the Possible row in the caseof DASS S-Band satellites.


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Table 20 L-Band Satellit es Only

Configuration


PercentWhere

Networkingis

Beneficial

PercentWhere


PercentWhere

NetworkingFulfilled


Error on 1stBurst


Error at 10

Minutes



96.9% N/A 0.1% N/A 7.1 4.1

Perth (6) Welling ton (6)

Stand-Alone 201417 Satelli tes

84.6% N/A 8.6% N/A------

2

------

Perth (6) Welling ton (6)Stand-Alone 2015

30 Satellites

96.5% N/A 0.1% N/A 7.4 4.3


Stand-Alone 2016

33 Satellites

97.0% N/A 0.1% N/A 7.0 4.0


Stand-Alone 2017

39 Satellites

96.0% N/A 0.4% N/A 7.9 4.4

Table 20 shows that using only the planned L-Band satellites will still yield acceptableperformance by the end of 2015.

2 No value computed as less than 95% of the beacon events resulted in a computed location


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Table 21 L-Band + S-Band Satellit es Only

Configuration

Percentage

CoverageofSRR

PercentWhere

Networkingis

Beneficial

PercentWhere


PercentWhere

NetworkingFulfilled


Error on 1stBurst

95th

Percentile

LocationError at 10

Minutes



96.9% N/A 0.1% N/A 7.1 4.1


Stand-Alone 2014

31 Satellites

93.4% N/A 1.2% N/A 10.8 5.9


42 Satellites

95.0% N/A 0.6% N/A 9.1 5.0


42 Satellites

95.1% N/A 0.5% N/A 8.8 4.9


Stand-Alone 2017

47 Satellites

95.7% N/A 0.4% N/A 8.2 4.6

From Table 21 it is noted that performance using both L-Band and S-Band satellites is close to the

target of the 95th

percentile as early as the end of 2014. It is also interesting to note thatperformance at the end of 2015 is actually lower than the L-Band only case in Table 20, even thoughthere are more satellites. Similarly, both tables show that performance does not change (or even fallsoff slightly) as more satellites are added.

First, it is observed that the satellites from two or three separate constellations will most likely not beas optimally placed in orbit as those from a single constellation. However, the most significant effecthere is the satellite tracking schedules. In short, there are now significantly more satellites in viewthan there are antennae on the ground. A sophisticated enough satellite scheduling algorithmmay gain some performance from many satellites in multiple constellations, but ironically a navealgorithm can actually result in worse coverage.


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The simulation used here selects which satellites are tracked with some care and sophistication, butdoes not necessarily achieve the optimal result. Regardless, the key observation is that moresatellites do not change things that much, as the number of antennae on the ground still remains thesame. This is true in particular for a stand-alone configuration. Networking and the use ofcoordinated schedules both provide more opportunity to benefit from additional satellites, butperformance is still ultimately constrained by the number of antennae available.

6.2 Future and Operational Use of DASS S-Band Satellites

As per the discussion and analysis above, a number of experimental DASS MEOSAR satelliteswith an S-Band downlink will still be available when the cooperative Australia and New Zealand

MEOSAR system ground segment is anticipated to become operational (late in 2015).

By definition, these satellites are experimental, and they specifically employ a downlink frequencydesignated for use in research and development applications. In fact, the repeater on each satellitewas designed for a non-SAR application, and while the SAR band of 406.0 to 406.1 MHz happens tobe included, double that bandwidth is repeated in the S-Band downlink signal. This additionalbandwidth causes some degradation in reception of signals from 406 MHz distress beacons.

Despite limitations, these satellites have been providing a valuable opportunity to build prototypeground stations, perform Proof of Concept studies, and analyze the MEOSAR system with real data.They will continue to provide this benefit throughout the Cospas- Sarsat MEOSAR Demonstration andEvaluation which begins in J anuary of 2013.

The current schedule from the Cospas-Sarsat System perspective could allow MEOSAR to bedeclared at IOC as early as October of 2015. Close to 30 L-Band satellites are planned at thistime, and as per the second row of Table 20 above, this is sufficient to provide acceptable coverage.Hence, operational use of S-Band satellites would not be necessary.

However, planned launches are just that, plans. And, the Galileo launch schedule which provides themajority of those 30 satellites is perhaps amongst the most aggressive ever planned, in particular for afledgling constellation. Hence, it is viable to consider a contingency plan in particular given thepotential concern of keeping the LEOSAR constellation at the operational minimum of 4 satellitesbeyond 2015 (see the second row of Table 10). As such, the possible use of the S-Band satellitesthat will already be in orbit at that time has been discussed at many levels and many forums.

As it stands, operational use of the experimental S-Band, and hence the DASS constellation, is

prohibited by the U.S. National Telecommunications and Information Administration. Should the L-Band launch schedules lag enough, a waiver may be considered, but this will only occur at some futuredate, if and when it is deemed necessary.

Regardless, it is anticipated that some administrations will still use S-Band data for operations, despiteU.S. regulations, as the potential for saving lives will tend to outweigh a concern for regulatory mattersthat may not even strictly apply in a given National setting. In effect, if the data is there and can save alife, most SAR personnel agree that it would be used. As such, as a matter of practicality, many


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administrations will at a minimum be prepared to apply this contingency measure, if it indeed becomesnecessary.

7 MEOLUT ANTENNA SIZE

Most discussion and analysis to date with respect to MEOLUT antennae, both here and in AusNZ-Nov2010, has focused on the number and placement of these components. While there are a numberof other underlying specifications to consider, antennae size is a critical factor with respect tobaseline costs. Also, the larger the antennae, the more there is a need to consider a means towithstand high winds (e.g., the inclusion of radomes) and those associated costs.

Selecting the correct antenna size can be fairly complex, and the ground segment vendors willundoubtedly have varying opinions and recommendations. An exhaustive analysis is beyond the scopeof this effort, but using information available in the Cospas-Sarsat MEOSAR Implementation Plan (C/SR.012) and applying standard antenna analysis computations can provide some useful insights anda foundation for understanding vendor proposals.

As discussed above in Section 3.1, two different downlink frequencies, S-Band (2227.MHz) and L-Band (1544.5 MHz) are associated with MEOSAR constellations and hence both need to becons id ered . Tables 22 and 23 pr ovi de summary computations respectively forantennae dishes ranging in size from 4 meters down to 1.5 meters, with 4 meters assumed to be thelargest practical size necessary for this application at either downlink frequency.

Table 22 Antenna Dish Size Analysis for S-Band Downlink

1 Dish Antenna Diameter (m) 4.0 3.5 3.0 2.5 2.0 1.5

2 Dish Antenna Gain (dB) 36.8 35.6 34.3 32.7 30.8 28.3

3 G/T (gain-to-noise-temperature dB/K) 14.4 13.2 11.9 10.3 8.4 5.9

4 Downlink C/N0 (dB)45.3 44.1 42.8 41.2 39.3 36.8

5 Combined C/N0 (dB) Uplink 36.636.1 35.9 35.7 35.3 34.7 33.7

6 Reduction in C/N0 from 4m dish0.0 0.2 0.4 0.8 1.4 2.4


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Table 23 Antenna Dish Size Analysis for L-Band Downlink

1 Dish Antenna Diameter (m) 4.0 3.5 3.0 2.5 2.0 1.5

2 Dish Antenna Gain (dB) 33.6 32.5 31.1 29.5 27.6 25.1

3 G/T (gain-to-noise-temperature dB/K) 11.2 10.1 8.7 7.1 5.2 2.7

4 Downlink C/N0 (dB)58.2 57.1 55.7 54.1 52.2 49.7

5 Combined C/N0 (dB) Uplink 37.937.9 37.8 37.8 37.8 37.7 37.6

6 Reduction in C/N0 from 4m dish0.0 0.1 0.1 0.1 0.2 0.3

It should be noted that in order to reduce complexity, many intermediate computations and therelated parameters are omitted in the above tables, but a number of them are provided bydiscussion below. For both tables, the main input parameter is the first row which contains theantenna size in meters. The key figures of merit are the G/T given in the third row, and the DownlinkC/N0 found in the fifth row (C/N0 is carrier over noise, often referred to as signal to noise ratio).

Taking Table 22 row by row, the computations are explained as follows. Applying the downlinkfrequency (or actually the corresponding wavelength), the dish size and an Antenna Efficiency (a value

found in the antenna data sheet) of 55% yields the second row, or the Dish Antenna Gain. A valueof 22.4 dBK is computed separately for the system temperature at the LNA input, using among otherparameters two key values, the LNA Noise Figure which is assumed to be 1.0 (again found in anantenna data sheet) and the cable loss between the dish and the LNA which is assumed to be -0.5 dB.Subtracting this value from row two values yields the first figure of merit in row three, the G/T,where a higher value indicates better performance.

Still in Table 22, an S-Band link budget computation yields an input power of -197.0 dBW at the

satellite. This value, the G/T from row three, and the important value of 7 dBW for downlink power

are used to compute the Downlink C/N0 in the fourth row. Applying an uplink C/N0 of 36.6 produces

the values in row five which are the second figure of merit, the Combined C/N0 over the whole link.

Finally, the sixth row compares the Combined C/N0 for each dish size with that for the 4 meter dish,

providing the performance degradation as a function of antenna size.

The exercise is then repeated in Table 23 for the L-Band downlink. Note that due to a longer

wavelength (lower frequency) all the values for G/T are notably smaller. In this case, a full link

budget computation yields an input power of -181.6 dBW at satellite. Using this value and now a

much higher downlink power of 15 dBW along with G/T from row three, the values for row four are

computed. This higher downlink power has a critical effect on performance, and even though G/T is

impacted by the wavelength, the values in row four remain quite high. Also, a better uplink C/N0 of


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37.9 (due to improvement in the link at the satellite input) is then used to produce the values in row five

and ultimately row six.

The most significant observation is that while S-Band performance is impacted notably by reductionin the antenna size, L-Band performance is impacted significantly less (due largely to the highdownlink power). So, if the ground station needs to rely on S-Band, a larger antenna dish of 3.5 m ormore is warranted. If S-Band is considered to be for contingency only, a 3 m dish is likely enough.And, if an L-Band only ground station is anticipated, 2.5 m should work nearly as well. Also, shouldsome combination of the above be deemed prudent, there is no specific impact should the antennaebe of different sizes between MEOLUT sites, or at a given MEOLUT.

Finally, it should be noted that varying the values for Antenna Efficiency, the LNA Noise Figure andantenna to LNA cable loss will raise or lower the G/T, and hence the Combined C/N0, but the overall

trends will stay approximately the same. The values used here are considered to be typical ofcurrent technology, but given significant enough changes in these parameters, G/T values mightalso change by enough to indicate different performance break points relative to antenna size andthis can only be evaluated given the specific values.

8 MEOLUT NETWORKING: STORAGE AND BANDWIDTH CONSIDERATIONS

While the practical goal for the MEOSAR system, as well as the cooperative Australia and New

Zealand MEOSAR system ground segment, is provide complete coverage in a stand-aloneconfiguration, MEOLUT networking provides an important enhancement to performance. Asdetermined in sections 2 and 5 above, networking internally (between Perth and Wellington) alsocompensates effectively for various cases of degraded performance, whether it be lower throughputor antennae outages. Given the merits of networking and the recommendation above to enhance thenetworking capability, it is useful to more closely examine the communication bandwidth requirementsinvolved.

8.1 Assumptions

Data storage requirements are provided in units of gigabytes (GB), 109

bytes Bandwidth is providedin units of kilobits (1000 bits) per second (kbps) and is determined by averaging the total load

over the length of a day (86400 seconds)3

The local MEOLUT shares data internally with one MEOLUT (Perth/Wellington each with six

antennae), and also with four external MEOLUTs4

two assumed to have six antennae and twoassumed to have four antennae yielding a total of 30 data streams for outgoing data and 26 datastreams for incoming data

The local MEOLUT must store its own data as well as all incoming data, and hence storage involves 32data streams


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Current TOA/FOA packet file size is roughly 400 bytes, but to allow for various storage

considerations on different platforms a data/file size of 1024 bytes (1 kilobyte) per TOA/FOA data

pair is applied throughout

A coarse high end estimate of 60000 bursts per day is assumed to be received at each MEOLUT

antenna, each resulting in an outgoing packet (the value of 60000 is based on current experience with

MEOSAR as well as GEOSAR satellites which have a similar ground coverage or footprint)

Overhead for communications (e.g., handshaking, data envelopes etc.) is not included but generally

adds only a small increment in bandwidth

8.2 Data Loads

TOA/FOA packets per day per data stream: 60000

Data/file size per TOA/FOA packet:

Daily storage per data stream:

1024 bytes

0.06144 GB [60000 X 1024 / 109]

3It is noted that times of peak usage could be higher but the overall average throughout a given day is considered to be

more applicable4

For the sake of this analysis it is applicable to make assumptions close to a worst case scenario, and although the

Perth and Wellington MEOLUTs may really only routinely share data with Hawaii (six antennae) it is more pragmatic to

consider the case of sharing data with one more MEOLUT to the east and two more to the west.

Daily storage for all data streams:

90 Day Storage:

1.966 GB

176.95 GB[0.06144 X 32][90 X 1.966]

Data transfer size per TOA/FOA packet:

Bandwidth per data stream:

Bandwidth outgoing data streams:

Bandwidth incoming data streams:

Total Bandwidth:

8.192 kilobits

5.69 kbps

170.7 kbps

147.94 kbps

[1024 X 8 / 1000]

[60000 X 8.192 / 86400]

[5.69 X 30]

[5.69 X 26] [170.7

+147.94]

It is useful to note that even for this worst case scenario, data loads are well within the capabilities ofan industry standard T1 line (1544 kbps), in fact less than a quarter of a T1 line is absolutelynecessary. Regarding storage, current hard disk capacities are often measured in terabytes (1000

GB), no concerns should arise.

It should also be noted that there is an additional data load associated with the data each MEOLUTmust send to the MCC, but this is on the order of half to two thirds the load of a single networkedMEOLUT and hence the impact is relatively small. Adding this load (at two thirds) raises the 90 daystorage to 199.07 GB and the total bandwidth to 341.4 kbps.


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Finally, addressing the specific case of Wellington networking only with Perth and Hawaii, and stillincluding the load for sending data to the MCC, the 90 day storage requirement at Wellington is121.65 GB and the total bandwidth required is 159.32 kbps.


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APPENDIX A: DELIVERABLE / REQUESTS CROSS REFERENCE

Request # Description Section

1 *The assumptions made in the reports: Are they still valid, and if

Not, what changes do you suggest and what is their effect on therecommendations made?

2

2 *Have you any revisions you would see necessary in relation to

the estimates on the costs that you suggest in the report?

2, 4

3 *Update Table 2 (Anticipated C-S Space Segment and include the

S-Band satellites) and then Table 14 (Implementation Timeline notinguse of S-Band satellites) of the 17 November 2010 Re ort.

3

4 Given the most recent 2012 TG on Preparation for a MEOSAR D&EPhase and the 2012 EWG on Second Generation BeaconSpecifications: Update the MEOSAR Coverage Requirement and number ofantennae required taking into account Table 1, Variables and Parametersusing any updates to the Table (need only confirm that the 17November2010 Report, Intermediate Recommended Architecture is stillvalid and this for both L-Band and S-Band operations).

6

5 What effect on coverage will be experienced if the New Zealandnest has

the aerials limited to a mechanical horizon of 15 degrees? The two

sites being considered have clear horizon of five degrees, however, S

Band interference may be a problem if the aerials track below say 10 to 15

degrees in certain sectors.

2

6 Considering the scenario of where both Australia and New

Zealand have installed six antennas what is the effect if:

a) When one Aus or one NZ antenna is u/s;

b) When one Aus and one NZ antenna is u/s: and

c) Similar other scenarios where two antennae are

not functional at each of the Aus/NZ sites?

5

7 Can you confirm that the future MEOSAR will support current

generation 406 MHz beacons and that Aus/NZ can decommission the

LEOSAR system once MEOSAR is at [IOC/FOC] (the AUMCC willcontinue to support LEOSAR processing into the future as other countriesmay continue to support LEOSAR) to the bitter end?

3


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8 Advise on optimal size of antenna to support both L-Band and S- Band andto note that radomes will be used in both Aus and NZ MEOLUTs and toadvise on any impact, if any, this may have. Larry what effect wouldthere be if the antenna in Australia and New Zealand are or different sizes?At this stage in New Zealand we envisage that we would ask the supplierto just provide the system and that it should meet the C/S requirements,we do not see us specifying the antenna type or size, however, at thetwo sites we are considering the wind strength can be as high as 135knots. (They would not want to be too big and would most likely need to bedomed.) Australia may require the biggest antenna but they do not havethe same strong winds as we do apparently.

7

9 It would be appreciated if you would offer an opinion on the

feasibility and possible wording for inclusion in the tender with respect tothe content and format of messages to be exchanged

(MEOLUT to MCC and MCC to MEOLUT) with a MEOLUT provided by onemanufacturer and an MCC provided by another manufacturer. Provide thereference of the C-S message field requirements and all other fields thatshould be supported.

Deferred to Tender

Effort with Australia

10 Can you provide sample wording for the tender document in

respect of MEOLUT pass scheduling and to take into account anynetworking with Aus/NZ MEOLUTs and possibly the Hawaii MEOLUT.The pass scheduling algorithm should be user configurable and take intoaccount the concerns of NZ where tracking may take only occur from 15Degrees elevation?

Deferred to

Tender Effort with

Australia

11 Do you have an example of the likely wording that could be used

in the tender document in respect of provision of two MCCs (primary andbackup) and a third MCC in the most cost effective manner. That is, saythe provision of the software so that it can be installed on a third machineprovided by AMSA for software testing and training or one supplied by thetenderer but may not be a "new" machine.

Deferred to

Tender Effort with

Australia

12 Minimum communication bandwidth requirements when

networking with other MEOLUTs, especially NZ and Hawaii .

8

13 While the system ultimately will be designed to operate on L

Band, the present GPS satellites are using S Band. Do you have anyindication as to how long S Band will be available for C/S use and willreplacement satellites in the current consolation also increase the numberof S Band units available? With the current number of S and L bandsatellites in use what coverage could Australia and New Zealand expect.This has been asked by may as they see the current programme we haveput into place as being part of the R & D which does not sit too comfortablewith some.

3, 6


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Issued on 20th May 2013, and authorised by:

Anita Nyssen ASSISTANT PROCUREMENT OFFICER

FINANCE AND BUSINESS SERVICES

CORPORATE SERVICES DIVISION

Documents

12amsa096 - Rft Addendum No.2