CPU Sizing vs. Latency Analysis FTS EDR Latency Simulation

5 March 2008

Doug Shannon

FTS DRO Mar 05, 2008 2

Contents

• FTS Latency – Simulation & Analyses – IDPS NPP Status– ATDS/FTS Simulation Overview– Example Simulation Results– ATDS/FTS Demo

• FTS HRD/LRD Latency Requirements: – SYS013230 The LRD Field Terminal software, when installed on NPOESS representative

hardware, shall produce Imagery EDRs within 2 minutes and all other EDRs specified in Appendix G within 15 minutes of receipt of mission data. Class 2

– SYS013235 The HRD Field Terminal software, when installed on NPOESS representative hardware, shall produce Imagery EDRs within 2 minutes and all other EDRs specified in Appendix E, except for EDRs 40.3.1.4, 40.4.10, 40.7.5, and 40.7.8, within 15 minutes of receipt of mission data. Class 2

FTS DRO Mar 05, 2008 3

IDPS NPP Status

• IDPS NPP Build 1.5– 1 orbit NPP processing (101 mins) – 53 mins

• Meets EDR latencies (117.2 mins for 140 mins requirement)• Major speedups in DMS performance• Algorithm development & integration “95% complete”

– Future Builds 1.5.x.1 (3Q 08), B1.5.x.2 (2Q 09).• OMPS, NHF, combined Albedo, Bright Pixel• Move LSA Granulation out of VIIRS SDR (1.5.x.1) to improve IMG

latency

– ATDS/FTS getting new benchmarks on B1.5 algorithms • Faster processing?• Less algorithm sensitivity to scene content?

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Algorithm Timing & Dependency Simulation Field Terminal Latency Analyses

• ATDS supports NPP, NPOESS/NPP & NPOESS performance analyses• FTS latency simulations differences:

– Receives C1/C2 LRD or HRD in real time; no stored data• Sensors collect at 9.1 & 5.0 Mbps (average day/night)

– Various FTS locations and weather/terrain conditions – Smaller EDR granules (NPP 85.7sec & NPOESS 42.9sec)– Processing Architecture -

• Split SDR - generate IMG sooner, after SDR Cal/Geo, before granulation• Pre-load SDR static ancil/aux tiles (TBD) to reduce latency• Assume no/minimal cross-granule dependency

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VIIRS Cross-Granule Latency Tiers

+1

+2

+2

+3

+3

+4

+4 +5

+4

+3

+5

SDR

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FTS Simulation (e.g. Omaha):2 day 19 Passes with NPOESS S/C

1330 1730 FTS Contacts with NPOESS S/C

(1440 minutes = 1 days)

Contact Durations:Max 13.1 minsAvg 10.5 minsMin 2 mins?<4mins 2.3%

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Orbital Position Defines Dynamic Scene Content in Sensor Data

Orbital Position defines Sensor Nadir NCEP Weather Data Base

Scene in VIIRS View

Ocean

Cloudy

Snow/Ice

Dynamic Processing

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Impact of Weather/Terrain on FTS Data

• Algorithm loading for Clear-Ocean is heaviest,21% over average.

• NCEP weather DB for Spring 2003

– 90-100% ocean – 41%– 90-100% clear – 8%– Clear & Ocean – 3%

• User can’t select his weather/terrain

– ATSD can analyze user FTS locations & helpsize for field conditions

>90% Clear>90% ocean

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Algorithm, Timing & Dependency Simulator:FTS IDPS and Algorithm Models

S/W

H/W

Science Algorithms

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• Peak demand (17 CPUs) not equal to CPU requirement.– 2.6 GHz CPUs

• CPU resources driven by contact length & S/C sensors.– No ATMS & CrIS on C2

Example ATDS Simulation results – Omaha FTS scenario

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• EDR latencies are dynamic as scene content varies – Shows last VIIRS EDR for multiple granules

Example ATDS Simulation results – Omaha FTS scenario

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• Latencies varied 1.5 – 7.7 mins– Imagery latency ~3.3 mins

Example ATDS Simulation results – Omaha FTS scenario

FTS IMG

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On-going ATDS/FTS Trades

• Variable number of CPUs & processor speeds• Smaller VIIRS/CrIMSS granules

– Science implications for processing areas and adjacency.

• Weather/Terrain impact on IDPS Latency– Various FTS locations– Various weather & terrain conditions

• SDR architectural trades• Selectable EDR configurations

– HRD vs LRD algorithms– Generate high priority top EDRs only– Generate Imagery only

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VIIRS HRD vs LRD Algorithm Processing

26%

0.3%

5%

9%

2%

14%/10

11%

10%

5%

2%

1%

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Summary

• Due to algorithm scene sensitivity, highly variable weather/terrain are significant factors for latency and CPUs required. – Some new IDPS benchmarks show less than expected sensitivity.

• Ongoing IDPS algorithm optimization are improving FTS latencies.– Improvements to IDPS Infrastructure (DMS) are very good but don’t apply

directly to FTS.

• We continue to add fidelity to our ATDS simulations, bounding nominal performance against worst-case scenarios in order to quantify system processor needs.

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Backups

• 2005 back-to-back S/C contacts and gap analysis

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• Overlapping S/C contacts don’t occur due to spacecraft orbital phasing.• Smallest gap of 10.2 minutes has minimal impact to FTS latency.• Above 60N there is a large increase in contacts and EDRs.

Back-to-back S/C Contacts

Max gap is 2.1 orbits at equator

Gap Time Between Contacts

Analyzed STK 1330/1730/2130 contact data

60N