Slashdot Mirror
Mapping Ground Zero with Lasers
securitas writes: "Amazing how the WTC disaster has shone a light on technology (pun intended). LIDAR (Light Detecting and Ranging) is the optical equivalent of RADAR. It's being used to create hyper-detailed maps of the WTC disaster site from an altitude of 5000 feet to detect shifts in the rubble as well as areas in danger of collapse."
Just in case anyone is interested, LIDAR is actually what 'Laser radar guns' use to track your speed. So if someone ever tells you that they got pulled over because of a Laser gun, tell them it was LIDAR they should blame.
Try telling that to a cop... "No officer, its LIDAR! Really!"
jason
Quote the article:
"A week ago, with billows of gray smoke still pouring from the remnants of the World Trade Center, a twin-propeller plane flew 5,000 feet overhead, bouncing pulses of infrared laser light off the scarred terrain below."
So I guess they don't actually monitor it constantly.
"Total destruction the only solution" - Bob Marley
not sure about any real attempt to dig it out, there's lots of problems there.
First the WTC was built in a "bathtub" because the foundation is below sea level so if the bathtub is cracked mud could rush in and de-stablize near by structures like subways, utility conduits and other building foundations. The WTC actualy re-inforced the tub internaly to prevent its colapse; now its rubble. To do this there is talk that they may have to drill through the tub and sink tie-backs into the bedrock or build cross-bracing beams and remove the rummble between the openings.
FYI Infrared lasers LIDAR is helpful here because of its excellent smoke-haze penetration and higher detail. Microwave side-looking radar might work but I think that the dust would either block or distorte the data. The sonar is probably used to probe the columns in near by buildings for hidden internal damage
Apocalypse Cancelled, Sorry, No Ticket Refunds
How do they monitor the site constatly from 5000 feet? is there a plane constantly circling around the site or is it done by a sort of balloon? can't this monitoring be achieved by satellites?
A satellite can't monitor such an area constantly, since Manhatten isn't on the equator.
The easiest way would be a teathered balloon.
I'm not sure about the specifics, but if you pulse a very low-intensity sound wave through any substance, you can measure the distortion of the wave to see whether the material is behaving as you expect it to. If it is not, it is often because of miscroscopic structural defects.
Virtue finds and chooses the mean.
Aristotle, Ethica Nichomachea
Lynn Edward Harris, born Lynn Elizabeth Harris, 09/13/50 at 6:12 p.m. P.D.T. in the city of Orange, California, USA, south of the Los Angeles County line.
On November 8th, 1973 at age 23 Harris was clinically diagnosed by a team of specialists as possessing a rare, complex, congenital condition known as "True Hermaphroditism" [Intersex] with undescended, sub-sized ovotestes i.e. "gonadal mosaicism" found in approximately 1-in-25,000 births. [Statistic source: New England Journal of Medicine, 01/14/98.]
Due to ambiguously-formed genitalia at birth [stunted penis; divided scrotum; and vagina], Harris, (mal)assigned "female" by both parents and pediatrician, was raised as such and continued living in said social gender role until age 29 (1979) --- six years after the disclosure of this fixed, irreversible, yet-evolving biological state.
After puberty, minor neurological problems eventually abated. Sexual development remained at a pubertal level while naturally-occurring virilization of secondary characteristics compounded. As Harris' anatomy had developed clearly along non-female lines i.e. no breasts, no milk glands, no child-bearing hips, no menses, sterility; early beard growth, male vocal chords, male skeletal structure, male musculature, male libido, male genetic patterning, he felt justified to elect to live full-time in the male social gender role beginning February, 1979.
For the following four years (1979 to 1983) he lived in a sexual legal limbo, still carrying the original-and-only, valid female I.D. which now appeared both obsolete and fraudulent. On numerous occasions when asked for proof of identification, he was accused of strangely utilizing a 'counterfeit' or 'stolen' I.D. card belonging to some woman.
Desire for a permanent legal remedy to rectify all I.D., thus making it consistent with his outward persona, had become crucial. The subject approached the Superior Court, County of Los Angeles, wrote his own petition and pled his own case for 1) a change of middle name from "Elizabeth" to "Edward"; and 2) a re-issued birth certificate changing the sex designation from "female" to "male".
Based upon his unusual, documented medical history, on February 18, 1983 the Court, realizing the case had merit, granted the two-part request by favorably adjudicating Case # 437625. With the judge's signature, Lynn Elizabeth Harris no longer existed: She had become a legal non-entity.
Within a 30-day grace period following the Court proceeding, said change was registered as legally required with the Social Security Administration, the Secretary of State, and the State Registrar of Vital Statistics. State and public agencies, intended to function as "subservient" to the courts, are obligated to enforce and comply with all rulings as handed down.
In a blatant and unconscionable fashion the Vital Statistics Branch dared to supersede the Superior Court and rejected the simple filing of the matter because -- as was stipulated in their California Health and Safety Code -- 'no plastic surgeon's affidavit of surgery had accompanied the approved, submitted petition.'
However, within said code, no clause existed which mandated one's person to 'go under the knife' in order to obtain "characteristics of the opposite sex" -- whatever they may be. Since any type of "sex reassignment" surgical procedure to define his ambiguous anatomy had never been his objective at any time, in his petition Harris -- even after having investigated the pros and cons -- disavowed any need for possible risk of mutilation, disfigurement, and / or rejection of foreign implants. Unequivocally, Lynn Edward Harris had proven to the Court -- but not to the Sacramento bureaucrats who, then, deigned to issue an amended Birth Certificate reading "Lynn Edward Harris" / "Female" -- that Nature had bestowed upon him "characteristics of the opposite sex" from birth.
Harris, denigrated by this mockery of his civil status, was already making preparations to sue the state and / or approach an Appellate Court for enforcement of his case which had seen prior favorable adjudication.
After a four-month delay, the Chief of the Vital Statistics Branch fully recanted and admitted to having mis-handled the filing from the start. Finally, the preferred middle name combined with, not an amended, but a brand new Certificate of Live Birth with sex designation listed as "male" was formally issued on June 2, 1983. All records of the original female middle name and female birth certificate from 1950 were permanently frozen and sealed for life.
This case, which the Vital Statistics Branch could never define in their terms as having "an opposite sex," has gone uncontested and unchallenged by other bureaucratic, legal, and medical authorities. Subsequently, Harris is presumed to have set the landmark or legal precedent in California, if not the nation, of one's obtaining a legal sex revision without benefit of any cosmetic or reconstructive "sex reassignment"-type surgery.
Further details are outlined in Harris' copyrighted [as yet unpublished] autobiographical manuscript, "More Lives Than One".
Harris has become a pioneer / spokesman for Intersex freedoms and transgender social justice; an advocate for a moratorium on surgeons' gratuitous, so-called "corrective" or "normalizing" genital operations, customarily performed on Intersexed neonates before they reach an age to render informed consent --- unless dramatic genital ailments or malformations (often caused by life-threatening metabolic disorders) are present and surgery is warranted. Genital modification is not a panacea. It could facilitate one's "apparent" social sex (re)classification on paper; but it could never automatically revamp ones "actual" or "true" (often inconsistent and conflicting) chromosomes, genes, gonadal composition, glandular / hormonal output, overall brain circuitry and, in turn, one's inherent gender identification and sexual proclivity.
Mr. Harris and his case since garnered publicity and media exposure in six different countries and now appears on the world wide web. He has also amassed over 100 credits as a widely-published author, collaborator and contributor of articles in academic textbooks, journals, anthologies, and popular books in the burgeoning field of Human Sexuality; and as a guest lecturer / panelist at universities, colleges, medical trade seminars, private sector organizations; and on nationally-syndicated radio and television programs.
Lynn Edward Harris is single, resides in Los Angeles, California, leads a mainstream lifestyle and is a devotee of all classic arts, cultural events, antiques, travel, and metaphysics.
LIDAR technology is not soemthing new out of the blue. It has ben used quite a bit before. I saw it once at SIGGRAPH 99 (2 years ago). It's very useful for creating detailed 3D models. Kind of like a range finder, but it sweeps an area to get 3D range data out of it. It has even been used in films like in End of Days and What Dreams May Come. Here are a couple of articles from VFXPro.com
Panavision: Cinema in a New LightPanavision's Panascan LIDAR System Integrates Cinematography
Interesting to see how this technology can be applied for a critical job. Especially when they start diging deeper below the level of the Hudson to detect any shifts.
http://www.cnn.com/SPECIALS/2001/trade.center/dama ge.map.html
Note that a High speed line would nice to have when viewing this
"It is a greater offense to steal men's labor, than their clothes"
Zeitgeist type stuff for the 11th.
Krispy Cream is people