EPS Bridge Low-Cost Satellite

Transcription

1 EPS Bridge Low-Cost Satellite Results of a Concept Study being performed for Dr. Hendrik Lübberstedt OHB-System AG OpSE Workshop Walberberg 8th November 2005

2 EPS Bridge Key System Requirements Minimum Payload complement to NPOESS consisting of IASI - Infrared Atmospheric Sounding Interferometer IMR - Imaging Radiometer to support IASI (successor of AVHRR) Low-Cost Satellite Platform with best possible compliance to existing EPS G/S - Deviations possible if motivated by cost-benefit analysis Lifetime 3-5 years Nominal launch late years Storage EPS-Bridge Launch METOP-A Launch Operations METOP-B Storage Launch Operations METOP-C FAR Launch Storage Operations

3 System Overview EPS Bridge Satellite provides P/L DHS (Payload Data Handling System) GDS (Global Data Stream) X-Band link HRPT real-time L-Band link TTC S-Band link EPS Bridge Satellite IASI IMR P/L DHS TTC GDS HRPT EPS G/S with small modifications in most of its subsystems, e.g. Command & Data Aquisition (CDA) Svalbard User Stations CDA: S/C I/F (IMR data) MCS: Satellite TTC & Dynamics PGF: Advanced IMR Products Mission Control System (MCS) Product Generation, Facility (PGF) OGS Interfaces EUMETSAT Archiving & Dissemination User EPS Overall Ground Segment (OGS)

4 Mission & Operations Orbit as METOP ~825 km) Ground Track (24 h) Svalbard G/S (1 Antenna) Data Aquisition with 100% duty cycle (except of the solar channels) Data Delivery (level 1c) < 3 h (each orbit is required) 16 Access EPS-Bridge to Svalbard 14 Minimum Access 6.6 min X-Band Downlink 70 Mbit/ s => Max possible Net Data Rates: Total 3.4 Mbit/s IASI 1.5 Mbit/s Imager 1.9 Mbit/s Access Duration [min] Elevation 0 Elevation Time [orbits]

5 Core Payload IASI Michelson Interferometer Integrated imaging system (cloud detection) IASI needs supporting Imager Big & complex instrument Parameter Scan type IFOV size at Nadir Swath Characteristics Step and dwell 12 km ± 48.3 (1026 km) Spectral range 3 µm to 16 µm Lifetime Power 5 years 244 W Size 1.2 x 1.1 x 1.3 m 3 Mass Data rate 231 kg 1.5 Mbps

6 Imager requirements Requirement Minimum Advanced Priority Across track field of view ± 55 ± 55 1 GSD across nadir 800 m 400 m 2 GSD along nadir 1100 m 550 m 2 Spectral channels 6 AVHRR channels 11 VIRI-M channels 2 Acquisition of solar channels (up to 1.6 μm) Daytime part of orbit Complete orbit & Low light capability SNR/ NedT AVHRR VIRI-M 2 Absolute radiometric accuracy ±10 % / ±1 K ±5 % / ±0.5 K 1 Polarisation sensitivity 10 % 5 % 2 Pointing knowledge (pitch/ roll) ±0.17 (< ±1.9 km) ±0.17 (< ±1.9 km) Inter-channel co-registration As accurate as possible < 0.1 mrad / < 12 ms 1 Temporal co-registration with IASI < 10 s < 5 s 2 Co-alignment IASI/imager 1 km 500 m 3

7 Imager Options Characteristics Minimum requirements METimage A Rotating telescope Dichroic Beam Splitter Single detector per channel Advanced requirements METimage B1 Rotating telescope and half angle mirror In-plane spectral separation Matrix based detector Channels GSD Nadir 800 m 400 m (solar) 800 m (IR) Data Rate (average) Mbit/ s 1.28 Mbit/ s m 1.56 Mbit/ s m m (half orbit) Mass 36 kg 40 kg Power (average) W 100 W + 50 W for active cooling Volume 74 x 25 x 56 cm³ 56 x 33 x 28 cm³ (incl. OU & EU)

8 SNR Requirements and METimage Performance Minimum Requirements Advanced Requirements METimage A performance METimage B1 performance Central wave length [µm] 0.5% albedo / 300K 0.5% albedo / 300K 800m GSD 800m GSD 400m GSD K K K K K 0.24 K K 1.35 K K 0.10 K 0.45 K K 0.12 K 0.1 K 0.1 K 0.04K 0.08K 0.08 K 0.09 K 0.34 K 0.40 K K 0.19 K 0.83 K

9 Imager Satellite Configuration X-Band Ant. Based on OHB s SAR-Sat Bus PL DHS: IASI Formatter Storage HRPT Ant. Option EPS-1 Minimum EPS-2 Advanced P/L Bus Interfaces 28V Payload Power I/F s S/S Power Payload I/F s PPS/TMTC Parameter P/L mass [kg] Solar Generator Heater s Power Conditioning & Distribution Battery TM/TC Pwr Propulsion S/S OBDH & AOCS Pwr Actuators Sensors TM/TC (serial) TT&C S/S S-Band S-Band Ant. (+z/-z) P/L power (avg.) [W] Data Vol. [Gbit/orbit] S/C mass [kg] S/C power (avg.) [W] Redundancy not shown OHB System AG / 2005 OHB System AG / 2005

10 Satellite Concept IASI Y X - flight direction IMR Z - Nadir Launch adapter Solar Panel S-/ X-Band Antennas HRPT Antenna

11 Small Launcher Candidates EPS-Bridge requirements: Launch mass : 700 kg class 825 km Pre-selection of compliant costeffective launcher: => Two Classes of Launcher Constraints: Small - up to 700 kg: Reference COSMOS Medium - up to 1200 kg: Reference VEGA Launcher Payload Mass* First launch COSMOS 700 kg 1966 TAURUS XL 780 kg 1994 ROCKOT 900 kg 1990 PSLV 1200 kg 1993 VEGA 1300 kg 2007 FALCON 5 >2800 kg 2007 Status > 740 Launches, > 97% reliability 7 launches 1 failure 9 launches 1 failure Availability 2019 TBC 8 launches 1 failure Under development Under development *Payload Mass capability to h=825 km at i=98.7

12 G/S Compatibility Option GS1: Imager similar to AVHRR (GSD, spectral channels) Full compliance to AVHRR formats performed on-board or in CDA Option GS2: Enhanced Imager (GSD, spectral channels) Split into AVHRR- compliant + additional data Imager/IASI L1 Processing to be adapted Expected Changes GS1 Additional expected Changes GS2

13 System Summary System Driver: IASI Accommodation Small Launcher compliance EPS-G/S compliance EPS options : System Impact of EPS-2 in relation to EPS-1 is moderate Delta of EPS-Options < Uncertainties of system drivers in terms of overall effort Configuration Payload Option EPS-1 Minimum IASI METimage A EPS-2 Advanced IASI METimage B1 Platform Bus 1 Bus 2 Ground Segment GS 1 GS 2 S/C Characteristics Satellite mass 688 kg 718 kg Satellite power (orbit average) 518 W 639 W Data Rate 2.6 Mbit/ s 3.4 Mbit/ s EPS-2 option is proposed as baseline on the way towards advanced Post- EPS requirements