cpu sizing vs. latency analysis fts edr latency simulation 5 march 2008 doug shannon
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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?
FTS DRO Mar 05, 2008 4
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
FTS DRO Mar 05, 2008 5
VIIRS Cross-Granule Latency Tiers
+1
+2
+2
+3
+3
+4
+4 +5
+4
+3
+5
SDR
FTS DRO Mar 05, 2008 6
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%
FTS DRO Mar 05, 2008 7
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
FTS DRO Mar 05, 2008 8
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
FTS DRO Mar 05, 2008 9
Algorithm, Timing & Dependency Simulator:FTS IDPS and Algorithm Models
S/W
H/W
Science Algorithms
FTS DRO Mar 05, 2008 10
• 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
FTS DRO Mar 05, 2008 11
• EDR latencies are dynamic as scene content varies – Shows last VIIRS EDR for multiple granules
Example ATDS Simulation results – Omaha FTS scenario
FTS DRO Mar 05, 2008 12
• Latencies varied 1.5 – 7.7 mins– Imagery latency ~3.3 mins
Example ATDS Simulation results – Omaha FTS scenario
FTS IMG
FTS DRO Mar 05, 2008 13
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
FTS DRO Mar 05, 2008 14
VIIRS HRD vs LRD Algorithm Processing
26%
0.3%
5%
9%
2%
14%/10
11%
10%
5%
2%
1%
FTS DRO Mar 05, 2008 15
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.
FTS DRO Mar 05, 2008 16
Backups
• 2005 back-to-back S/C contacts and gap analysis
FTS DRO Mar 05, 2008 17
• 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
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