Seminarvortrag am 20.04.2004Schwerpunktseminar Multimedia

Eric Lüer

Multimedia im Weltall

Overview

- History of astronautics

- Satellites (remote sensing satellite)

- Mars missions - Mars Exploration Rover (NASA) - Mars Express (ESA) - HRSC (ESA)

2. History of astronautics

1940-1949

- 1942 „Development of V2“

Wernher von Braun

2. History of astronautics

1950-1959

- 04.10.1957 „Sputnik1“- 02.11.1957 „Sputnik2“- 1958 „Formation of NASA“- 31.01.1958 „Explorer“- 04.10.1959 „Pictures of the moon´s

backside“

2. History of astronautics

1960-1969

- 12.04.1961 „The first human being in space“- 05.05.1961 „The first American in space“- 25.05.1961 „Start of the Apollo-Program“- 20.02.1962 „John Glenn orbits the earth“- 18.03.1965 „Alexej Leonow goes for a walk

in space“- 24.12.1968 „Apollo 8 orbits the moon“- 21.06.1969 „That is one small step for ....“

2. History of astronautics

1970-1979

- 19.04.1971 „Saljut 1 “- 14.05.1973 „SkyLab“- 20.07.1977 „Viking1 on Mars“- 20.08.1977 „Start of Voyager1“- 03.09.1977 „Viking2 on Mars“- 05.09.1977 „Start of Voyager2“

2. History of astronautics

1980-1989

- 12.04.1981 „The Space Shuttle“- 28.11.1983 „SpaceLab“- 28.01.1986 „The Challenger tragedy “- 20.02.1986 „MIR“

2. History of astronautics

1990-1999

- 24.04.1990 „Hubble Space Telescope“- 04.07.1997 „Pathfinder“- 22.11.1998 „ISS “

2. Geschichte der Raumfahrt

2000-2004

- 30.11.2000„The first crew of ISS“- 23.03.2001„The end of MIR“- 2003/2004 „Mars Express“- 2003/2004 „Mars Exploration Rovers“

3. Satellites

3.1. Orbits

Geostationary Earth Orbit(GEO)

36000 km

Medium Earth Orbit(MEO)

5.000 km - 13.000 km

Low Earth Orbit(LEO)

600 - 1.600 km

3.2. Parts of a satellite

- EPS (Electronic Power Subsystem)- The EPS accomodates the satellite at any time with the necessary energy.

- AOCS (Attitude and Orbit Control Subsystem)- The AOCS calculates the satellites position and navigates it into the right position during the whole mission.

- OBDH (On Board Data Handling)- The OBDH-subsystem is the control unit of the satellite.

- RFS (Radio Frequency Subsystem)- The „Radio Frequency Subsystem“ is the receiving- and sending unit of every satellite.

- TCS (Thermal Control Subsystem)- The TCS has to regulate the temperature of the satellite.

3.3. Different types of satellites

- weather satellite- remote sensing satellite- communication satellite- satellites for navigation and position finding (GPS)- spying satellite (keyhole-program)

3.3. remote sensing satellite

- GIS Updates- environment monitoring - recording/ascertaining of changes (agricultural use ...)- street designing- city designing/-development- ...

3.3. remote sensing satellite

3.3.1 The Spot-Program

- 22.02.1986 Spot 1 ( pan. 10m, multi. 20m)- 22.01.1990 Spot 2 ( pan. 10m, multi. 20m)

- Spot 1 & 2 delivered ca. 6 mill. pictures

- 26.09.1993 Spot ( pan. 10m, multi. 20m)- broke down after three years

The Spot satellites were saving their data on astreaming recorder, which had a storage capacity of 120Gbit ( ca. 280 pictures).

3.3.1 The Spot-Program

- 24.3.1998 Spot 4 ( pan. 10m, multi. 20m)

Laserlink:Spot-4 and Artemis transmitted with laserlink 50 Mbit\s.

3.3.1 The Spot-Program

- 04.05.2002 Spot5 ( pan. 5m, multi. 10m)- 90 Gbit Ram- 27° steerable mirror

3.3.1 The Spot-Program (Spot5)

multispectral panchromatic

Ground resolution 10 m 5 m

Scene size 60 x 60 km 60 x 60 km

Spectral information 3 spectral channel visible + infrared

1 panchromatic channel

Proposed maximum scale

1:50 000 1:25 000

3.3.2 Ikonos

- 24.9.1999 Launching with a Athena-rocket- speed: 7 kilometres per second - weight: 725 kg- first commercial satellite (SpaceIMAGING)- The DoD purchased all pictures, wich were taken during the Afghanistan conflict and the Iraq-war ( ca. 2 mill. US-Dollar/year)

3.3.2 Ikonos

multispectral panchromatic

Ground resolution 4 m 1 m

Scene size 11 x 11 km 11 x 11 km

Spectral information 3 spectral channel visible + infrared

1 panchromatic channel

Proposed maximum scale

1:20 000 1:5 000

3.3.2 Ikonos Ground resolution 1 m (Sydney)

3.3.3 QuickBird

- 18.10.2001Launching (DigitalGlobe)- 128 Gbit memory (ca. 57 pictures)- max. 320 MBit/sec in X-Band (6,2-10,9 GHz)- Scene Dimensions:

- pan. : 27,552 x 27,424 pixels- multi.: 6,888 x 6,856 pixels

- QuickBird is fueled for seven years- 2100 pounds, 3.04-meters (10-ft) in length

3.3.3 QuickBird

multispectral panchromatic

Ground resolution 2,8 m 0,6 m

Scene size 16,5 x 16,5 km 16,5 x 16,5 km

Spectral information 3 spectral channel visible + infrared

1 panchromatic channel

Proposed maximum scale

1:12 000 1:3 000

3.3.3 QuickBird Ground resolution 2,8 m ( Dresden )

3.3.3 QuickBird Ground resolution 0,6 m ( Hamburg )

3.3.3 QuickBird

Pan-sharpened

+

multispectral 2,8m panchromatic 0,6m

4. Mars missions NASA/ESA

Since the beginning of the year 2004 two mars missions are proceeding atthe same time.

While the NASA tries to find traces of water and life with the mars exploration rovers (Spirit and Opportunity),the main challenge of ESA is to generate a 3D map of the red planet.

4.1 Mars Exploration Rover (NASA)

4.1 Mars Exploration Rover (NASA)

An assortment of instruments

- Pancam use visible light to gather panoramic, three-dimensional (3D) imagery

- Mini-TES (Mini-Thermal Emission Spectrometer)

- Microscopic Imagerprovides close-up images of rocks and soil

- Mössbauer-Spektrometeranalyzes the iron in rocks and soil

4.1 Mars Exploration Rover (NASA)

The rover´s “brains“

- Onboard memory includes 128 MB of DRAM with error detection and correction and 3 MB of EEPROM- 25 Mhz PowerPC-CPU (32-bit RAD6000-RISC-Prozessor)- OS: VxWorks from Wind River ( Realtime OS)

- The PowerPC-platform is specified since 1991 by a consortium of Apple, IBM and Motorola (AIM).

The rover´s antennas (best transfer rate until now: 256 Kbit\s)

- low-gain antenna: transmits radio waves at a low rate to the Deep Space Network antennas on Earth

- high-gain antenna: sends a "beam" of information in a specificdirection and it is steerable, so the antenna canmove to point itself directly to any antennaon Earth.

4.2 Mars Express & Mars Lander (ESA)

4.2.1 Beagle 2

Targets in two different regions: - biochemistry and geology

- Beagle 2's Mossbauer spectrometer(produced by the University of Mainz)

- panoramic cameras - on-board analytical laboratory

4.2.2 High Resolution Stereo Camera (HRSC)

1. HRSC: 10 meters / pixel at an altitude of 250 km

2. SRC (Super Resolution Channel 2.3 m per pixel

3. The Instrument Frame is the structure for the Camera Head (HRSC) and the SRC.

4. Digital Unit (next Site)

4.2.2 High Resolution Stereo Camera (HRSC)

Camera Control Processor (CCP)

The CCP controls the entire camera system as its central processing unit. It interprets and executes the serial telecommands and control data of the spacecraft. The CCP is based on a microprocessor (80C86), a boot PROM, a RAM for data handling and program execution, and an EEPROM for application software. The EEPROM can be up and downloaded via normal telecommand / telemetry links for updating the software.

Data Compression Electronics (DCE)

The DCE consists of 4 Compression Units (CU) and the microcontroller (MC). The input buffers of the 4 CUs are directly linked to the four signal chains of the Camera Head. Each CU works individually and uses a parameter table controlled JPEG compression algorithm. After compression, an 80C31 microcontroller combines the data streams via multiplexing to a serial output.

Power Supply Subsystem (PSS)

The PSS supplies the DU itself and the Camera Head. The power converterof the SRC is also located within the DU.

4.2.2 High Resolution Stereo Camera (HRSC)

Interface Electronics (IFE)

The IFE comprises two boards:

The IFE01 includes the low data rate interfaces between Camera Head, the Data Compression Electronics, spacecraft and the Camera Control Processor.

The second board IFE02 includes the fast interface electronics used for the transfer of the scientific image data to the spacecraft mass memory.

Heater Control Electronics (HCE)

The heater control system controls the thermal condition of the camera, which is thermally decoupled from the spacecraft. The dissipated energy from the Camera Head is removed via cooling straps and an external radiator. Simultaneously the camera is heated to a temperature of around 20°C via a system of 6 independent analogue heater control loops comprising thermistors and heaters on the optical bench and inside the Front End Electronics. The heater control logic can be switched on independently from the camera electronics.

4.2.2 High Resolution Stereo Camera (HRSC)

1. the farthest position to Mars, lowest velocity,mainly for data downlink and battery

2. the closest position to Mars, highest velocity,mainly for imaging (40 min)

4.2.2 High Resolution Stereo Camera (HRSC)

The two graphs show the relation between altitude and camera resolution.

4.2.2 High Resolution Stereo Camera (HRSC)

9 single CCD-lines: - one red

- one blue- one green- one near-infrared- 5 stereo and photometric-

channels

One CCD-lines consists 5184 lightsensitive cells (pixels).

SRC:- working with an area-sensor- 1024 X 1032 - a square with the edges of

2.35 km

4.2.2 High Resolution Stereo Camera (HRSC)

Data reduction and output

two methods: (pixel summation and compression)

1. pixel summation

- 2X2 summation creates an average of a square with an edge-length of 2 pixels (decreases the data volume

by a factor of four)- Further options are a 4X4 and an 8X8 summation

2. compression

- JPEG based data compression - compression factor (4 - 10)

4.2.2 High Resolution Stereo Camera (HRSC)

The spacecraft with a camera moves over the mars`surface and scans it step by step.

4.2.2 High Resolution Stereo Camera (HRSC)

HRSC and SRC

4.2.2 High Resolution Stereo Camera (HRSC)

- five ccd-lines ( 1 vertical, 2 forward and 2 backward)

4.2.2 High Resolution Stereo Camera (HRSC)

- four CCD- lines (blue, green, red and near IR)

4.2.2 High Resolution Stereo Camera (HRSC)