Term
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Definition
| Reference frames are used for the quantitative description of positions and motions of Earth. |
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Term
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Definition
| A reference from which measurements are made. Mathematical model to best fit all or part of the geoid. |
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Term
| Earth-centered, Earth-fixed (ECEF) XYZ coordinate systems |
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Definition
| Earth centered , earth-fixed coordinate systems are designed to spin with the earth. |
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Term
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Definition
| Latitude are constant horizontal parallels. Longitudes are constant vertical meridians. |
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Term
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Definition
| Map Projections are representations of the earth in a 2D plane. They are skewed in a particular way to better represent what they are designed for. |
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Term
| Universal Transverse Mercator (UTM) |
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Definition
| UTM is a mapping system designed by the military, earth is broken into 60 zones east-to-west, each 6 deg. Of longitude and two zones north-to-south. |
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Term
| State Plane Coordinate System (SPCS) |
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Definition
| Coordinate system only used in the US. States are subdivided into multiple zones. |
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Term
| Relational database management systems (RDBMS) |
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Definition
| A database management system based on the relational model. Data is stored in the form of tables and the relationship among the data is also stored in the form of tables. |
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Term
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Definition
| Set of guidelines that ask for certain data within a database. |
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Term
| Global Navigation Satellite Systems (GNSS) |
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Definition
| Satellite navigation systems that provide geo-spatial positioning with global coverage. |
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Term
| Control, space, user segments |
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Definition
| User segment creates a formal mechanism for two-communication between the satellite navigation providers and users. Control Segment – Stations on the ground that direct and control the operation system. Space Segment - The part of the whole GPS system that is in space, ie the satellites |
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Term
| Monitor stations, master control station |
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Definition
| Monitor stations are unmanned and collect SV transmissions to all satellites in view every 1.5 seconds. Sends 15 minute average to master control. The Master Control station monitors and controls the constellation, collects the navigation data from the monitoring stations. Creates the broadcast ephemeris which is uploaded to the SV’s. |
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Term
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Definition
| Method for determining the intersections of three sphere surfaces given the centers and radii of the three spheres. |
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Term
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Definition
| The gravitationally curved path of one object around a point or another body |
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Term
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Definition
| Danish nobleman known for his accurate and comprehensive astronomical and planetary observations. |
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Term
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Definition
| Assistant to Tycho Brahe, derived the laws of planetary motion. |
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Term
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Definition
| Table of values that gives the positions of astronomical objects in the sky. |
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Term
| The GPS broadcast ephemeris |
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Definition
| the predictions of the current satellite position and velocity determined by the Master Control Station, uploaded by the Control Segment to the GPS satellites, and transmitted to the user receiver in the Data Message. |
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Term
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Definition
| Ranging is a process or method to determine the distance from one location or position to another location or position. |
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Term
| Time systems (solar, sidereal, GPS/atomic/UTC[NO]) |
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Definition
| - the period of the Earth's rotation with respect to a point nearly fixed with respect to the stars, is the hour angle of the vernal equinox.Solar time – Time kept or measured by the sun. Atomic time - Time based on the atomic second. |
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Term
| Time bias, receiver and SV |
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Definition
| Time bias is the difference between the clock’s indicated time and true universal time. |
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Term
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Definition
| r^2=(px–p2,x)2+ (py–p2,y)2 |
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Term
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Definition
| – C/A code = Coarse/Acquisition Code, L1 only, pseudo-random noise, use to get an initial position and time solution. P code = Precise Code, L1 and L2. |
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Term
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Definition
| The phase of either L1 or L2 carrier of a GNSS signal, measured by a receiver while locked onto the signal. |
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Term
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Definition
| – Maximum allowable error. |
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Term
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Definition
| The mathematics of the properties, measurement, and relationships of points, lines, angles, surfaces, and solids. |
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Term
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Definition
| The difference between the expected and actual orbital position of a GPS satellite. |
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Term
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Definition
| The ionosphere is the uppermost part of the atmosphere, The troposphere is the lowest portion of Earth's atmosphere. |
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Term
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Definition
| - The reception of a satellite signal both along a direct path and along one or more selected paths. |
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Term
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Definition
| Method to greatly improve the accuracy of GPS positioning, used to calculate errors that coincide with field data |
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Term
| Explain how differential correction works |
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Definition
| – Correction data is collected from a GPS base station. The GPS base station is in a fixed location therefore it is used as a reference location of known coordinates. Since the location of the GPS base station is known, the deviation of the moving GPS from its actual location can be calculated. |
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