Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.mrao.cam.ac.uk/projects/cmb/workshop_jul09/talks/mactavish.pdf Дата изменения: Wed Jul 29 18:31:06 2009 Дата индексирования: Tue Aug 18 10:28:43 2009 Кодировка: Поисковые слова: m 8

Balloon or Ground-based?
Boomerang VSA CBI EBEX


Sub-orbital CMB Experiments
15 EXPTS

10 EXPTS

MUCH OF THIS DATA FROM: HTTP://LAMBDA.GSFC.NASA.GOV/PRODUCT/SUBORBIT/SU_EXPERIMENTS.CFM


Multipole Range: Ground


Multipole Range: Balloon


Multipole Range: Balloon

HIGHER MULTIPOLE EASIER FROM THE GROUND


Multipole Range: Ground
l < 100

50% OF GROUND-BASED EXPT. COVER L<100


Multipole Range: Balloon
l < 100
100% OF BALLOON-BASED EXPT. COVER L<100


Frequency Coverage


Atmospheric Loading
ATMOSPHERIC LOADING BELOW 0.1% IN ALL BANDS AT 89,000 FT


Atmospheric Loading


Ballooning Specs

HTTP://SITES.WFF.NASA.GOV/CODE820/OPSSUPPORT.HTML


ULDB
·
Jan. 08, 2009 NEW NASA BALLOON SUCCESSFULLY FLIGHT-TESTED OVER ANTARCTICA WASHINGTON -- NASA and the National Science Foundation have successfully launched and demonstrated a newly designed super pressure balloon prototype that may enable a new era of high-altitude scientific research. The super-pressure balloon ultimately will carry large scientific experiments to the brink of space for 100 days or more. This seven-million-cubic-foot super-pressure balloon is the largest single-cell, super-pressure, fully-sealed balloon ever flown. When development ends, NASA will have a 22 million-cubic-foot balloon that can carry a one-ton instrument to an altitude of more than 110,000 feet, which is three to four times higher than passenger planes fly.

Payload position as of: 15:53:15Z 01/14/09 Columbia Scientific Balloon Facility

http://www.nasa.gov/topics/earth/features/ superpressure_balloon.html

Mission Complete 54 Days 1 Hour 29 Min

Image, taken through a telescope, of super pressure balloon at float altitude over Antarctica. Columbia Scientific Balloon Facility


Summary
LARGE SCALE MEASUREMENTS EASIER FROM A BALLOON BUT NOT IMPOSSIBLE FROM THE GROUND RESOLUTION LIMIT FROM A BALLOON..PAYLOADS CAN ONLY BE SO BIG FREQUENCY RANGE LIMITED FROM THE GROUND SATELLITE B-MODE PROJECT UNTHINKABLE WITHOUT BALLOON TESTBED BALLOONING HIGH RISK...HIGHER REWARD?