Does GPS also define the vertical position? Can it tell if I am in the 160. floor or in the basement?
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First question, yes.   GPS provides a location in three dimensional space, therefore your receiver can determine your elevation in relation to sea level if equipped (most are).  For best accuracy, you will need at least a 4 satellite position fix...with good satellite geometry (i.e. all the satellites are not lined up in a row in the sky).\n\nSecond question, in theory yes.   Technically, the answer is likely no.  The reason is that GPS signals are very weak by their nature and it requires a sensitive receiver to "hear" them.  While most receivers on the market today will be able to receive signals through tree leaves and other minor obstructions of the sky, the vast majority cannot not receive signals through concrete.  To demonstrate this, just take a walk with your GPS unit underneath an overpass and watch what happens to the signal strength.  \n\nIf you were measuring altitude inside, a barometric altimeter might be a better choice, though be wary of the building's ventilation system, as most are slightly pressurized and would affect this instrument as well.
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Global positioning system
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Global Positioning System\nI  INTRODUCTION \n\nGlobal Positioning System (GPS), space-based radio-navigation system (see Navigation), consisting of 24 satellites and ground support. GPS provides users with accurate information about their position and velocity, as well as the time, anywhere in the world and in all weather conditions.\n\nII  HISTORY AND DEVELOPMENT \n\nGPS, formally known as the Navstar Global Positioning System, was initiated in 1973 to reduce the proliferation of navigation aids. GPS is operated and maintained by the United States Department of Defense. By creating a system that overcame the limitations of many existing navigation systems, GPS became attractive to a broad spectrum of users. GPS has been successful in classical navigation applications, and because its capabilities are accessible using small, inexpensive equipment, GPS has also been used in many new applications.\n\nIII  HOW GPS WORKS \n\nGPS determines location by computing the difference between the time that a signal is sent and the time it is received. GPS satellites carry atomic clocks that provide extremely accurate time (see Clocks and Watches: Atomic Clocks). The time information is placed in the codes broadcast by the satellite so that a receiver can continuously determine the time the signal was broadcast. The signal contains data that a receiver uses to compute the locations of the satellites and to make other adjustments needed for accurate positioning. The receiver uses the time difference between the time of signal reception and the broadcast time to compute the distance, or range, from the receiver to the satellite. The receiver must account for propagation delays, or decreases in the signal's speed caused by the ionosphere and the troposphere. With information about the ranges to three satellites and the location of the satellite when the signal was sent, the receiver can compute its own three-dimensional position.\n\nAn atomic clock synchronized to GPS is required in order to compute ranges from these three signals. However, by taking a measurement from a fourth satellite, the receiver avoids the need for an atomic clock. Thus, the receiver uses four satellites to compute latitude, longitude, altitude, and time.\n\nIV  THE PARTS OF GPS \n\nGPS comprises three segments: the space, control, and user segments. The space segment includes the satellites and the Delta rockets that launch the satellites from Cape Canaveral, in Florida. GPS satellites fly in circular orbits at an altitude of 20,100 km (12,500 mi) and with a period of 12 hours. The orbits are tilted to the earth's equator by 55 degrees to ensure coverage of polar regions. Powered by solar cells, the satellites continuously orient themselves to point their solar panels toward the sun and their antennas toward the earth. Each satellite contains four atomic clocks.\n\nThe control segment includes the master control station at Falcon Air Force Base in Colorado Springs, Colorado, and monitor stations at Falcon Air Force Base and on Hawaii, Ascension Island in the Atlantic Ocean, Diego Garcia Atoll in the Indian Ocean, and Kwajalein Island in the South Pacific Ocean. These stations monitor the GPS satellites. The control segment uses measurements collected by the monitor stations to predict the behavior of each satellite's orbit and clock. The prediction data is uplinked, or transmitted, to the satellites for transmission to the users. The control segment also ensures that the GPS satellite orbits and clocks remain within acceptable limits.\n\nThe user segment includes the equipment of the military personnel and civilians who receive GPS signals. Military GPS user equipment has been integrated into fighters, bombers, tankers, helicopters, ships, submarines, tanks, jeeps, and soldiers' equipment. In addition to basic navigation activities, military applications of GPS include target designation, close air support, “smart” weapons, and rendezvous.\n\nWith mo
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Most land navigation activities focus on a very small portion of the globe at any one time. Typically the area of interest to an outdoorsman is less than 20 miles on a side. This focus on a small area allows us to abbreviate UTM coordinates.\n\nThe zone information and the digits representing 1,000,000m, and 100,000m are dropped. The 1m, 10m and 100m digits are used only to the extent of accuracy desired.\n\nA GPS unit might read\n\n10 S 0559741\n    4282182\n\nUsing a notation similar to the one found on a USGS topographic map, this would be written as:\n\nZone 10 S 559741 mE. 4282182 mN.\n\nAn abbreviated format for the same coordinates would look like:\n\n 59 82 \n  Describes a 1000m by 1000m square. \n \n597 821\n  Describes a 100m by 100m square. \n \n5974 8218\n  Describes a 10m by 10m square. \n \n59741 82182\n  Describes a 1m by 1m square. \n\n\nThe 100m abbreviated format, 597 821, and the 10m abbreviated format, 5974 8218, are the most commonly used.\n\nNotice that the easting is reported first, followed by the northing. Remember the phrase "read right up" to help you remember to read the easting from left to right, followed by the northing from the bottom up.\n\nAlso notice that when you abbreviate coordinates you should not do any rounding. 0559651 becomes 596 not 597. This ensures that your position is still within the reported square. As accuracy decreases, the square gets bigger. \n\nI hope this is what you are looking for.
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Standing up from the couch to ansswer the phone, then returning to the couch =). The displacement is zero because i end where I started, but the distance is twice the distance between the couch and the phone because "negative directions" don't matter with distance.
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Any consumer electronic device containing microchips relies on quantum physics for the diodes and transistors on the chips to work.   The laser in a CD player relies on quantum physics for its operation.   The Global Positioning System depends on very precise timing of satellite radio signals.   A special relativity correction is applied to allow for the motion of the satellite relative to you, and a general relativity correction because you are deeper in the Earth's gravitational potential well than the satellite.   Time passes at a different rate for the satellite than for us.   If these corrections were switched off, your GPS navigator would become less accurate.
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No 911 center I'm aware of uses GPS.  The technology used to locate cellular callers is tower trianguation.  It is also referred to as Phase II wireless.  The 911 call taker will get the cellular call and be able to determine an approximate location based on the callers location and the coordinates sent to the call takers screen from the cell towers.  This technology is not perfect, the best way to gurantee that a 911 Telecommunicator can send the police or fire department to your location is for you to know your location at all times and not rely on others to know where you are at.  The first thing any 911 call taker will ask is your location, know what the answer is!  :-)
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It all depends on the accuracy you want. If you are trying to obtain first order work I would use differential leveling with a closed loop to check closure.\nTrigonometric leveling is only good for short distances and gps still has some accuracy problem. However, it you in the middle of nowhere (desert, natural wilderness) then you should consider gps. \nBut as I mentioned before, for the best results, highest order, and if you are in an urban setting I’d go for differential leveling with a closed loop to check closure.
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Just set it to field altitude when on ground. Then compare bar pressure reading on alttimeter to current pressure from weather station. If they are the same you areOK
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Same as a GPS. It triangulates the exact position
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Check your movement configuration.
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All GPS can tell you is your location on the earth. GPS cannot tell you where your property corners are, unless you already know the coordinates of those property corners. Your GPS unit does not know where your property corners are until you provide it with the information it needs. \n\nIf you knew the coordinates, which could be either latitude and longitude that mappers use, or state plane coordinates that surveyors use, then you could use GPS to guide you to the corner locations. But since you do not know where the corners are, you have no way of entering the required data into the GPS unit. \n\nYou not only need to get a professional surveyor to survey your property, you also need to tell the surveyor that you need him to provide you with the state plane coordinates of those points, so you can enter them into your GPS unit, then you will be able to find them yourself in the future.
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GPS, which usually stands for Global Positioning System, is a way to track your location based on satellite information and triangulation. Why would you need them in a desktop? \n\nSo the answer is no.
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I think that signal comes out of Denver.  I have had several and enjoy the accuracy.  Forget what that other guy said.  All of mine have had a two minute synch time.  If you fail to get a grip on the signal in that amount of time, you have to reset and start over.  You may have to try different placements.  I don't know why but once you get a synch the unit won't lose it if you move it around, as much as it looses it on initializing.
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the location can only be traingulated when brodcasting between two cellphone towers.\n\nthe phone must be in use to do this.
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from the timeyour house is in the air to when its on the ground is a pretty good indicator
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Nowadays, with GPS and diving robots, it is possible to locate where exactly certain position markers are located. Every year, North America and Europe drift apart a few centimetres, and GPS coordinates will have to add another correction. Luckily, neither North America nor the Old World as isolated systems move that fast, so that the regionalized reference systems remain valid. But if you manage to measure a location each in America and Europe to the sub-centimetre, you will notice the change in the last digits of the raw GPS coordinates within very few years.