Coordinated Global Measurements of TLE from the Space Shuttle and Ground Stations during

MEIDEX

Yoav Yair1, Colin Price, Zev Levin, Peter Israelevitch, Adam DevirBaruch Ziv1 Joachim Joseph, Yuri Mekler, Meir Moalem

Department of Geophysics and Planetary Sciences, Tel Aviv University, Ramat Aviv, Israel1 Also with: The Open University of Israel, Tel-Aviv, Israel

Upper End Plate w/ Quartz Window

Gimbal Motor & Worm Drive

Worm Gear

SEKAI WFOV Camera

Lower End Plate

Lens & Baffle

Xebion Camera

Avionics Mount Plate and electronics

Overall MEIDEX configuration

E-field response in Israel to sprites in the US.The positive initial field implies

positive lightning flashes caused these sprites

VLF and ELF Antennas, Negev Desert, Israel

Dynamic Spectrum of VLF signal in Israel caused by a sprite observed in the US

(horizontal lines are VLF navigational transmitters)

Time (seconds)

0

10.5

Fre

quen

cy (

kHz)

12.5

0

Field of View for Sprite Observations

The Xybion IMC-201 camera has a rectangular FOV - 14.04(H) x 10.76 (V) degrees.This translates to a volume of 466 km (H) x 358 km (V) at the Earth’s limb, which is 1900km away from the shuttle.The spatial resolution is 665m (H) x 745m (V) per pixel.

The Sekai LL-Video color camera will be used to look for major thunderstorm centers. The FOV covers 2200 km of the horizon.

STS-107Space Shuttle Columbia OV-102Launch Date: June 27th, 2002Altitude: 150 NM , Duration: 16 Days, Crew: 7 Astronauts (double shift)Main Regions of Interest: South-East Asia and Japan, Australia, South and North America, Central Africa

Payload

•5 cubic feet canister + coated quartz window

Xybion IMC- 201 radiometric CCD camera

• CCD Sensor: 756Hx581V, Sensitivity - 10-6fc

• 6 narrow-band filters - Spectral range: 340-860nm

• Exposure Times: 50 nsec - 4 msec

•Wide FOV (50 degrees) - Sekai Color video camera

•3 Digital Sekai VCRs for in-payload recording

During the Mediterranean Israeli Dust Experiment (MEIDEX) Earth-limb observations pointed above thunderstorms will be performed to record the optical emissions from TLEs (Transient Luminous Events - Sprites, ELVEs and Blue Jets). The 39 degrees inclination shuttle orbit covers the major lightning generating regions on Earth, increasing the probability of success in capturing these elusive discharges.

Optical observations from space

Primarily with the 665nm filter that matches the observed wide peak centered at 670nm, which typifies red spritesand with the 380 and 470nm filters to record blue jets.

Observational runs would consist of continuous recording of the Earth’s limb from the direction of the dusk terminator flying towards the night side, preferably before midnight local time at the observed area.

Thunderstorm activity predictions, based on Forecast Models will be uplinked daily to the shuttle, 24 hours prior to the observation.

The astronaut will have the ability to direct the camera toward areas of high lightning activity.

Ground Campaign

During the 16-day flight, two field sites in the Negev Desert in Israel will be used to collect data related to sprite activity in the ELF and VLF frequency range.

Additional ground stations in the USA, Brazil, Germany, Hungary, Japan, Taiwan, Antarctica will record and measure lightning and sprite activity.

MEIDEX is conducted under an agreement between NASA and ISA (Israeli Space Agency)

MEIDEX Emission Filternm Lines

380: 380.5 N2(2P) O-2470: 470.9 N2+(1N) 2-O555: 557.7 O(I) Airglow665: 662.4 N2(1P)6-3860: 857.4 N2(1P) 8-8

http://www.tau.ac.il/geophysics/MEIDEX/home.htm

Sprite Forecasts

In order to observe sprites from space and to photograph them effectively, the astronauts need to have in advance information concerning the location intensity of MCCs and tropical convection centers.Significant Weather Maps produced by aviation centers will be used during the mission. They will be derived subjectively by trained forecasters, based on satellite images and forecasted maps from the available models. Special attention will be directed to areas colder than -70 C, shown to be correlated with sprite occurrence.