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نوشته شده در چهارشنبه ٢۸ اسفند ۱۳۸٧ ساعت ٢:٤٦ ‎ب.ظ توسط محمد زراعت پیشه

در شکفتن جشن نوروز در همه ی سال هفت سین:سربلندی سرمستی سلامتی سعادت سخاوت سرور را برایتان آرزومندیم

 

سال نو ایرانی مبارک

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New Oceanography Mission Data Now Available

نوشته شده در شنبه ٢٤ اسفند ۱۳۸٧ ساعت ۱٠:۱۸ ‎ب.ظ توسط محمد زراعت پیشه

PASADENA, Calif. -- Oceanography data that will help scientists around the world better understand climate change are now available. The data come from the Ocean Surface Topography Mission, also known as OSTM/Jason-2, a spacecraft developed jointly by NASA and the French space agency

Launched June 20, 2008, the mission's first validated data products in support of improved weather, climate and ocean forecasts are now being distributed to the public within a few hours of observation. Beginning in 2009, other data products for climate research will be available a few days to a few weeks after observations are taken by the satellite

The satellite is monitoring 95 percent of the world's ice-free oceans every 10 days from its low Earth orbit. Like its predecessor satellites, Topex/Poseidon and Jason-1, OSTM/Jason-2 is extending the climate data record by providing a long-term survey of Earth's ocean. It tracks ocean circulation patterns and measures sea-surface height and the rate of sea-level rise, which are critical factors in understanding climate change

The mission is a joint effort among NASA, the National Oceanic and Atmospheric Administration, or NOAA, France's Centre National d'Etudes Spatiales, or CNES, and the European Organisation for the Exploitation of Meteorological Satellites, or EUMETSAT. An international science team of more than 200 investigators will use data obtained from the satellite's instruments to study the world's ocean and its effect on our society

"The joint development by NASA and CNES during the past 20 years of an effective technique for measuring sea level from space is a tremendous success story for both agencies and the international science community," said Lee-Lueng Fu, OSTM/Jason-2 project scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "With the successful transition of this important measurement to our partners, NOAA and EUMETSAT, a new era has dawned in humankind's long-term monitoring of this vital barometer of our changing climateSea level is rising at a rate of 0.13 inches per year, nearly twice as fast as the previous 100 years," said Laury Miller, chief of NOAA's Laboratory for Satellite Altimetry in Silver Spring, Md. "If this rate continues unchanged during the coming decades, it will have a huge impact on erosion and flooding in coastal regions. We need the OSTM/Jason-2 data to help us monitor what is happening."

Throughout the mission, CNES will continue to monitor and evaluate the spacecraft and instruments it provided. The French space agency also will process, distribute and archive the research-quality data products that will become available next year. EUMETSAT will process and distribute operational data received by its ground station to users in Europe and will archive the data. NOAA will process and distribute operational data received by its ground stations to non-European users and archive that data along with the CNES data products

NOAA will operate the satellite. NASA will evaluate the performance of its instruments: the advanced microwave radiometer, the Global Positioning System payload, and the laser retroreflector assembly. In addition, NASA and CNES will validate scientific data products

CNES provided the OSTM/Jason 2 spacecraft, and NASA and CNES jointly provided the primary payload instruments. The Jet Propulsion Laboratory manages the mission for NASA's Science Mission Directorate in Washington

To learn more about the ocean monitoring mission, visit:
http://www.nasa.gov/ostm

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Mission News

نوشته شده در شنبه ٢٤ اسفند ۱۳۸٧ ساعت ۱٠:۱٠ ‎ب.ظ توسط محمد زراعت پیشه

Ocean Surface a Boon for Extreme Event Forecasts, Warnings

For humans in the path of destructive hurricanes and tsunamis, an accurate warning of the pending event is critical for damage control and survival. Such warnings, however, require a solid base of scientific observations, and a new satellite is ready for the job.

The Ocean Surface Topography Mission (OSTM)/Jason 2 adds to the number of eyes in the sky measuring sea surface and wave heights across Earth's oceans. The increased coverage will help researchers improve current models for practical use in predicting hurricane intensity, while providing valuable data that can be used to improve tsunami warning models.

"When it comes to predicting hurricane intensity, the curve in the last 40 years has been somewhat flat, with little advance in how to reduce error in predicted intensity," said Gustavo Goni, of the National Oceanic and Atmospheric Administration (NOAA) in Miami. Maps of sea surface height created from satellites, however, could help change the curve.

Satellites that measure sea surface height have been running operationally nonstop since November 1992. But more than one is needed to fly at the same time in order to identify all the features that could be responsible for intensification of tropical cyclones all over Earth. The OSTM/Jason 2 mission will help make the additional coverage possible.

NASA, university and NOAA investigators, including Goni, work to transform sea surface height information obtained from satellites, such as OSTM/Jason 2, into maps of ocean heat content. Forecasters can use the maps to develop models to predict how hurricanes will strengthen.

Determining heat content from sea surface height is possible because warm water is less dense and hence sits higher than cooler water. In some regions, such as inside and outside the Gulf Stream current, the temperature differences result in more than a one-meter (three-foot) difference in sea surface height. Goni and colleagues use this established concept to estimate from sea level variations how much heat is stored in the upper ocean in areas where hurricanes typically develop and intensify.

While sea surface height may not necessarily be the most significant parameter for hurricane intensity forecasts, researchers now know that if sea surface height is accounted for in current forecast models, errors in forecasts for the most intense storms are reduced. For weak storms, the reduction in error is not very significant. However, for storms in the strongest category 5 range, the heat content in the upper ocean derived from sea surface height becomes increasingly important. "This is a good thing, because these are the storms that produce the most damage," Goni said.

"OSTM/Jason 2 will help us to keep the necessary coverage that we need to identify ocean features that can be linked to tropical cyclone intensification, because with only one satellite we may miss some of them," Goni said.

Upper ocean heat content derived from sea surface height is now used in operational and experimental forecast models in all seven ocean basins where tropical cyclones exist.

In December 2004, two satellites happened to be in the right place at the right time, capturing the first space-based look at a major tsunami in the open ocean. Within two hours of a magnitude 9 earthquake in the Indian Ocean southwest of Sumatra, the Jason 1 and Topex/Poseidon satellites fortuitously passed over the path of the resulting tsunami as it traveled across the ocean. It measured the leading wave, traveling hundreds of miles per hour in the open ocean, at about 0.5 meters (1.6 feet) tall.

Wave height measurements like those of the Indian Ocean tsunami do not provide an early warning because the information is not relayed to ground stations in real time. That's the job of early warning systems operated by NOAA and other global organizations that currently employ a network of open-ocean buoys and coastal tide gauges. Sea surface height measurements of tsunamis can, however, help scientists test and improve ground-based models used for early warning. One such system developed at NASA's Jet Propulsion Laboratory (JPL), Pasadena, Calif., and undergoing tests at NOAA's Pacific Tsunami Warning Center, Ewa Beach, Hawaii, could become operational within about three years.

Most tsunamis are caused by undersea earthquakes. Using the JPL-developed system, when seismometers first identify and locate a large earthquake, scientists can use GPS measurements to search around the earthquake's source to see if land has shifted, potentially spurring a tsunami. Scientists can then immediately compile the earthquake's size, location, and land movement into a computer program that generates a model tsunami to determine the risk of a dangerous wave. After the wave passes, scientists can search through wave height data from satellites and verify what the model predicted.

"Satellite data play the crucial role of verifying tsunami models by testing real tsunami events," said JPL research scientist Tony Song. "If an earthquake generates a tsunami, does the satellite data match observations on the ground and model predictions?"

"One of the unique pieces of satellite observations is the large-scale perspective," said JPL research scientist Philip Callahan. Tsunamis can have waves more than 161 kilometers (100 miles) long. Such a wave would likely go unnoticed by an observer in a boat on the ocean's surface. But satellite altimeters like OSTM/Jason 2 can see this very long wave and measure its height to an accuracy of about 2.5 centimeters (one inch).

Scientists' ability to test tsunami warning models will be aided by OSTM/Jason 2. With the Topex/Poseidon mission now ended, the currently orbiting Jason 1 has now been joined by and will eventually be replaced by OSTM/Jason 2. This will help ensure that future tsunamis will also be observed by satellites as well as by buoys and tide gauges.

"The biggest value in satellite measurements of sea surface height is not in direct warning capability, but in improving models so when an earthquake is detected, you can make reliable predictions and reduce damage to property and people," Callahan said.

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میلاد بزرگ پیام رسان عدالت و خاتم پیامبران حضرت محمد (ص) بر همگان مبارک باد

نوشته شده در پنجشنبه ٢٢ اسفند ۱۳۸٧ ساعت ٥:۱٢ ‎ب.ظ توسط محمد زراعت پیشه

پایگاه علوم نقشه برداری :میلاد با سعادت نبی اکرم، پیام رسان ایمان،عدالت و شجاعت حضرت محمد(ص) و فرزند گرامیش امام جعفر صادق(ع) بر تمامی مسلمانان جهان به ویژه هم میهنان عزیز مبارکباد.

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با سلام

نوشته شده در چهارشنبه ۱٤ اسفند ۱۳۸٧ ساعت ۸:۳٤ ‎ب.ظ توسط محمد زراعت پیشه

با توجه به پیشنهاد مهندسین و دانشجویان عزیز که در رشته های معماری و عمران مشغول به کار وتحصیل می باشند مدیریت پایگاه علوم نقشه برداری در نظر دارد صفحاتی مختص در مورد رشته های معرفی شده  اختصاص دهد.از کلیه هموطنان عزیز که مایل به همکاری در این زمینه می باشند دعوت به عمل می آید.

 

با تشکر:محمد زراعت پیشه

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The HDS Product Family

نوشته شده در دوشنبه ۱٢ اسفند ۱۳۸٧ ساعت ۱٢:٥٦ ‎ق.ظ توسط محمد زراعت پیشه

Leica Geosystems' product family not only includes powerful and versatile time-of-flight scanners such as the new Leica ScanStation 2 but also features the ultra-high-speed, phased-based laser scanner, the Leica HDS6100. This portfolio of products becomes complete with Leica Cyclone, Leica CloudWorx and Leica TruView software, providing a full set of Leica-quality geo-referencing, surveying, and CAD integrated engineering tools for creating accurate deliverables and working with large scan data sets with unparalleled ease.

High-Definition Surveying not only offers many benefits to the measurement professional, but to the recipients and users of accurate spatial datasets. Civil engineers, plant designers, CAD professionals, architects, contractors, and owner/operators can all reap the cost and added-value benefits that HDS provides.

Cost Saving Benefits
HDS systems can provide significant cost savings in many ways:

  • Lower cost as-built & topographic surveys
  • Reduction or elimination of costly "return visits" to the site
  • More accurate, complete as-builts for retrofit design projects translate into better retrofit designs. These translate, in turn, into (1) less construction rework due to interferences and fit-up problems and (2) the ability to factory-fabricate instead of field-fabricate.
  • Reduced facility downtime due to (1) fast, unobtrusive scene capture and/or (2) minimal field fit-up, field fabrication, and field rework thanks to accurate as-builts

Added Value Benefits
In addition to direct cost savings, HDS systems offer important "added value" benefits:

  • Faster results
  • Shorter project cycle times
  • Better quality results
  • Less ambiguity - more complete
  • Higher level-of-detail
  • Safer data capture
  • Unobtrusive data capture
  • Point clouds can be conveniently used & reviewed by others for more efficient management of projects

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Leica HDS4500 - The ultra-high speed scannner

نوشته شده در دوشنبه ۱٢ اسفند ۱۳۸٧ ساعت ۱٢:٥۱ ‎ق.ظ توسط محمد زراعت پیشه

 
The Leica HDS4500 is an ultra-high speed, phase-based, shorter range scanner. The combination of ultra-high speed scanning and shorter range make it well suited to many plant, tunneling, and architectural interior survey needs.
 
The Leica HDS4500 is an ultra-high speed, phase-based, shorter range scanner. Phase-based scanners utilize a continuous laser beam rather than a pulsing laser beam inherent to time-of-flight ranging systems. Continuous lasers allow ultra-high speed scanning from 100,000 points/sec to 500,000 points/sec. The speed advantage and the full 360 x 310 field of view makes the HDS4500 ideal for projects with very short time windows for field data collection and for other field-efficient needs. Ultra high-speed, shorter range scanners are increasingly proving beneficial for capturing interiors of process plants and tunnels and have shown extensive use in automotive plants and architectural applications.

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All About Laser Distance Measuring Tools

نوشته شده در دوشنبه ۱٢ اسفند ۱۳۸٧ ساعت ۱٢:٤٥ ‎ق.ظ توسط محمد زراعت پیشه

With Laser Distance Measuring Tools you have more accurate readings especially at extended lengths. The longer that a measuring tape measure is extended, the harder it is to get an accurate measurement. You have to worry about slack in the line or applying too much tension on the tape and stretching or possibly even breaking it. You have to line up the foot directly with the starting point. Even temperature can affect your measurement. Laser distance measurers are one of the fastest and most accurate ways to collect measurements. Most base model Laser Distance Measuring Tools will handle a length of 100 feet and if you are using a target and an advanced model it will reach much longer distances.

Easy operation is the same for most Laser Distance Measuring Tools. The distance measurer projects a laser which looks very similar to that of a laser pointer. Simply point and press the button. It will automatically measure to where the laser is pointed. (You can select whether you want the length of the tool itself included in the measurement or not.) Most Laser Distance Measuring Tools can do basic calculation like addition, subtraction, area, and volume. They can also store previous measurements (depending on the model) into internal memory. Some lasers will track minimum and maximum measurements. You can automatically transfer between different units of measure such as feet, inches, tenths, meters, etc. Some lasers have a built in tilt detector to take measurements at an angle, ranging anywhere from 45 to a full 360.

The Pythagorean function is a versatile feature found on most laser distance measurers. With this feature you can calculate the length of an object using 3 points. Using this method you do not have to be at the start or end point when taking the measurement. Use it if you do not have a target point or if you need to find the height of a window that is on the second floor. (A magnified viewfinder is helpful if you are outside and are having trouble seeing your laser dot.) Another great feature is wireless blue tooth connection capabilities, which allows you to automatically transfer your saved measurements to a pocket PC and/or laptop and input them directly in to programs like AutoCad, Excel, and others.

Please note: The options above do not apply to all laser measuring devices. Please check product specifications or contact EngineerSupply to see what options are available with specific models.

Benefits of Laser Distance Measuring Tools

  • Single Person Use (you can take measurements by yourself easily)
  • Records Measurements
  • More Accurate
  • Safer
  • Quicker Measuring
  • Long Distance
  • Basic Calculations Built-in
  • Illuminated
  • Versatile
  • Automatic
  • Compact

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Laser Measurers

نوشته شده در دوشنبه ۱٢ اسفند ۱۳۸٧ ساعت ۱٢:٤۳ ‎ق.ظ توسط محمد زراعت پیشه

Laser Distance Measuring Tools, also known as "Electronic Tape Measures", "Laser Distance Finders" or "Digital Measuring Devices", offer true laser light (not sound) for the most accurate measuring. You simply point the laser distance measuring devices dot at a target like a wall, a house, a utility pole, nearly any object, and the device will show the distance on its LCD screen. These measuring devices will show multiple units of measure, you simply cycle through the units till you get to the units of measure you want to measure in, and then start taking measurements. You can even cycle through the units of measure after taking a measurement. These devices can also be put up against a wall and they measure from the back of the unit so that you get true wall-to-wall distance measurement. Same goes with ceiling measurements, lay the device on the backside, point it up and it will measure from the floor to the ceiling. These measuring devices are true time savers and are very accurate.

When selecting one of these tools to purchase, we recommend you first compare the range or distance they are rated to measure since some have longer ranges than others. Also, some models have greater accuracy than others, and some models have a neat feature called "pythagoras" which basically speaking means it will calculate the third side of a triangle (remember the pythagorean theorem from geometry class?). This means, for example, that you can stand back away from a building, point at one corner of the building taking a measurement, point at the other corner taking a measurement and then hit a pythagoras button to calculate the distance across the face of the building. The device uses the pythagorean theorem to figure the "triangle" you just created and gives you the distance of the side. Think, the two measurements you took were getting the distance of two of the three sides of a triangle. The tool figures the third side using geometry. In all measurements, accuracy is dependent on how well you actually hold or position the laser in its pivot position. Be aware that the models that do have the pythagoras feature, some models have a 2-point feature and some have a 3-point feature.
-EngineerSupply Product Team

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Construction Lasers

نوشته شده در دوشنبه ۱٢ اسفند ۱۳۸٧ ساعت ۱٢:٢٩ ‎ق.ظ توسط محمد زراعت پیشه

Construction Lasers are extreme time-saving tools. The Lasers we represent and sell are rugged, durable, and user-friendly professional-grade tools. Many construction professionals are finding they need laser tools just to compete in the industry. These laser leveling tools are used for leveling, plumbing, machine control, excavation work, landscaping, swimming pool construction, concrete leveling, home building, and many various site tasks. We carry the brand names of Acculine Pro, CST/Berger, David White, Northwest Instrument, Pacific Laser Systems, Sokkia, Stanley, and Topcon. If you need help selecting a Laser, consider contacting the EngineerSupply Product Team.

Line Laser Levels- also known as "Line Generators", are used primarily for single site interior work, such as a wall or ceiling. Most line generators project cross-hair lines. Depending on the model some will project different patterns including crosshair, single lines, and even combinations of both.
Pipe Lasers- used to align pipe and assist in setting grade, produces a single dot towards the front of the laser.
Plumb Lasers- Plumb Lasers or Dot Lasers produce a solid reference dot on the wall or work surface. These are usually used when you want something plumb or level but do not need a laser line produced. They come in a variety of dot patterns for plumb and square configurations.
Rotary Laser Levels- Rotary Laser Levels produce a 360 degrees level laser line around a work space. Some models are for indoor use only, and some models will handle indoor and outdoor use. Rotary lasers have a greater range than line generators and are more ideal for larger and exterior work sites.
Laser Distance Measurers -Laser Distance Measuring Tools (also known as "Electronic Tape Measures", "Laser Distance Finders" or "Digital Measuring Devices") are not used as a reference tool like the lasers listed above. Instead the laser distance measurer employs a laser beam to automatically measure distance at the push of a button.

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Sci-Tech Encyclopedia: Surveying

نوشته شده در یکشنبه ٤ اسفند ۱۳۸٧ ساعت ٩:٢٢ ‎ب.ظ توسط محمد زراعت پیشه

The measurement of dimensional relationships among points, lines, and physical features on or near the Earth's surface. Basically, surveying determines horizontal distances, elevation differences, directions, and angles. These basic determinations are applied further to the computation of areas and volumes and to the establishment of locations with respect to some coordinate system


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GIS and CAD

نوشته شده در یکشنبه ٤ اسفند ۱۳۸٧ ساعت ۳:٢٤ ‎ب.ظ توسط محمد زراعت پیشه

At their core, CAD and GIS are complementary technologies that have evolved largely independently but in parallel over the past 30 years. ESRI's longtime best of breed approach provides value to our customers by building better linkages between CAD and GIS systems

 

 


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