From ml-meteorite-list-request@mlist-1.sp.cs.cmu.edu Tue Sep 30 11:22:19 1997 Subject: Meeting #6 Notes To: meteorite-list@cs.cmu.edu Date: Tue, 30 Sep 1997 11:18:17 -0400 (EDT) From: Stewart John Moorehead Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Notes for Meeting #6, September 30, 1997 Attendence : Dimi, Pascal Lee from Ames, Liam, Kim, Bill Cassidy, Jim, Scott Eric, Mike Montemerlo, Ben, Alex, Matt and Stewart -introduced Pascal Lee to the group Dimi - Mark Maimone and he worked on proposals, submitted them last week - proposals included in the handout - experiments need to provide a short paragraph with technical content and vision of where going. Due end of the week. - major expedition items ordered - new center # requested for the program - Mark S. and Mike P. heading to Epcot today - drafted requests for permits to Antarctica - meeting will be held next week for paper progress - demonstrate technologies between Oct. 15-20 which are going to Ant. Matt - PO sent out to Dalsa - sent camera to Epcot Alex - Antarctic Chilean Inst. confirmed to send 5 of our people through them - trying to get the number of people and freight increased - backup plan to send additional people through ANI if ACI won't add people - Chilean's interested in radar work - can rent snowmobiles in Punta Arenas - scehduled for 1 month but worst case could shorten this to 3weeks Ben - Nomad back together for Epcot Mike - inclinometer interface working - needs to order cables and do calibration Eric - working on papers - next generation of panoshperic & pointing - working with Deepak on Ben Franklin proposal for direct to satellite pointing. Also writing to Army Scott - has medical forms for those going to Ant. Deepak - Nomad paper - thesis - proposals with Eric Jim - radar unit back from repair - initial tests show gets noisy after long periods of time. May be something else wrong - got generators back. Technician worked on Nomad's internal generator Bill - field equip list in good shape - long lead time items ordered - still open to equipment changes - will freeze list soon - somebody should be thinking of wiring maintenance shelter Liam - has a handout for spectroscopy and imaging experiments - imaging exp. done at camp not in field. Take pictures of calibrated targets. On a tripod with long co-ax going to hut - power is the big issue with experiments 730 Whrs/day @ 12V and 120 Whrs/day @ 120V Presentation on Radar from Alex (slides in a handout) ----------------------------------------------------- Herman -> ground penetrating radar (GPR) Dirk -> millimeter wave radar (MMW) - detect rocks on and under surface - also for navigation, crevasse detection - radar -> active sensor, independent of light -> penetrate ice & snow -> detect buried objects - GPR < 1GHz, MMW > 40GHz - lower freq. more penetration - GPR has low resolution due to larger wavelength (approx. 30cm) - can get sub-wavelength resolution though using multiple measurments - MMW has finer resolution, poor penetration, affected by weather - practical to detect up to a depth of 1ft of snow - also talk of adding measurment of ice thickness to goals of program - radar signal return amplitude not very reliable in classifying objects since also depends on opject shape as well as material - Bill says very rare for meteorites to be deep in ice - may be covered in snow - rocks melt down to 1 foot into ice - MMW radar - Dirks unit uses 96W to get 30mW output. Could be optimized - Dirk used MMW for obstacle detection & navigation using corner reflectors Exp. Plans ---------- -bring GPR to Antarctica. Would also love to bring a MMW unit for comparison -bury objects in snow and or ice at know locations and try to detect with radar -> might be a problem since burial will change characteristics of ice/snow. Also difficult to poor water into an ice hole as it dissappears Deliverables ------------ - radar data, grounf truth data, Ant. radar experience Comments on Presentation ------------------------ Pascal : GPR very good idea. IMportant for meteorite search as well as Mars to look for ground ice. - not realistic to look at deep depths - ice penetration could be on order of 10 wavelengths - interfaces inside ice as well -> reflection might be a problem with high freqs. - Steve Arconi at Cold Regions lab in New Hampshire has been using GPR in Antarctica for years - low freq. will map deeper levels than we need Dirk - very difficult to find deeply buried object - windows and walls in freq. spectrum for different mediums. Different materials absorb or transmit different freqs. - look at absorption & transmission bands for ice & snow - GPR probably hopless for small objects we are looking for - MMW behaves much like ultrasound. Need a perpendicular surface to the beam for reflection - freq. modulated continuous beam more sensitive than pulse systems - look at wavelength usage - under 36 GHz highly regulated by FCC To Do ----- Dimi - 45 day detailed plan - expedition purchases Liam - talk with Pascal on where to search Jim - work on what we need for radar exp. Eric - panospheric , papers Mike - inclinometer, calibration Ben - part count on stuff needs to be made - schedule Alex - radar and snowmobiles Matt - find missing camera, specs to Eric, doctor's appointment