Process
Modern surveying relies as much on software as hardware. In suitable shallow water areas Light Detection and Ranging (LIDAR) may be used. Equipment can be installed on inflatable craft, such as Zodiacs, small craft, AUVs (Autonomous Underwater Vehicles), UUVs (Unmanned Underwater Vehicles) or large ships, and can include sidescan, single beam and multibeam equipment. At one time different data collection methods and standards were used in collecting hydrographic data for maritime safety and for scientific or engineering bathymetric charts. Increasingly with aid of improved collection techniques and computer processing the data is collected under one standard and extracted for the specific use.
After data is collected, it has to undergo post-processing. A massive amount of data is collected during the typical Hydrographic survey, often several soundings per square foot. Depending on the final use (navigation charts, Digital Terrain Model, volume calculation for dredging, topography, Bathymetry) this data must be thinned out. It must also be error corrected (bad soundings,) and corrected for the effects of tides, waves/heave, water level and water temperature differences (thermoclines.) Usually the surveyor has additional data collection equipment on site to record the data required for correcting the soundings. Final output of charts can be created in a combination of specialty charting software or a CAD package, usually Autocad.
With crowd sourced surveying, although the accuracy of the individual measurements are not as accurate as with a traditional survey, the algorithms used rely on a high data density to produce final results that are more accurate than the single measurements. Comparison against multi-beam surveys indicates an accuracy of around +/- 0.1 - 0.2m.
Read more about this topic: Hydrographic Survey
Famous quotes containing the word process:
“I’m not suggesting that all men are beautiful, vulnerable boys, but we all started out that way. What happened to us? How did we become monsters of feminist nightmares? The answer, of course, is that we underwent a careful and deliberate process of gender training, sometimes brutal, always dehumanizing, cutting away large chunks of ourselves. Little girls went through something similarly crippling. If the gender training was successful, we each ended up being half a person.”
—Frank Pittman (20th century)
“The toddler’s wish to please ... is a powerful aid in helping the child to develop a social awareness and, eventually, a moral conscience. The child’s love for the parent is so strong that it causes him to change his behavior: to refrain from hitting and biting, to share toys with a peer, to become toilet trained. This wish for approval is the parent’s most reliable ally in the process of socializing the child.”
—Alicia F. Lieberman (20th century)
“To exist as an advertisement of her husband’s income, or her father’s generosity, has become a second nature to many a woman who must have undergone, one would say, some long and subtle process of degradation before she sunk [sic] so low, or grovelled so serenely.”
—Elizabeth Stuart Phelps (1844–1911)