Description

Your GPS synchronizes with every satellite by moving the begin's timing of an inside created PRN code. ... The clock flag your GPS uses to create the PRN code is exceptionally ...

Transcripts

How The GPS System Works

How the GPS System Works 24 satellites + saves 6 orbital planes 55° slant Each satellite circles twice at regular intervals. No less than 4 satellites noticeable at whatever time of day, anyplace on the planet.

A 2 Dimensional Example Time for the sign to achieve GPS beneficiary is resolved. Separation is figured by duplicating by the rate of light. Separation from two satellites characterizes 2 focuses (in 2 dimensional space.)

A 2 Dimensional Example The separation from a third satellite limits the area to a "blunder triangle."

A 2 Dimensional Example Assume the mistake in each of our estimations is a consistent, k. Fathom for k, so that the "mistake triangle" is as little as could be expected under the circumstances.

Now for 3 Dimensions Distance from a solitary satellite finds a position some place on a circle.

Now for 3 Dimensions Two estimations put the area some place on a circle at the crossing point of the two circles.

Now for 3 Dimensions Three estimations put the area at one of two focuses at the convergence of the three circles.

Now for 3 Dimensions A fourth estimation chooses one of the two focuses, and gives enough data to comprehend to the steady blunder.

Determining Distance to the GPS Satellites

Spread Spectrum Radio Imagine that a radio transmitter can transmit on 6 stations. Consistently the channel is changed by foreordained grouping.

Spread Spectrum Radio To get the sign, the collector must listen to the same grouping of channels. The transmitter and recipient should likewise be synchronized. The nearer the collector is to being synchronized, the a greater amount of the "discussion" will be listened.

The Coarse Acquisition Code Each satellite uses a special Pseudo Random Noise (PRN) code for spread range adjustment. The C/A code is 1024 bits long, and is sent at a 1 MHz rate. Therefore the code rehashes each millisecond. The clamor like code regulates the L1 bearer signal at 1575.42 MHz. The sign is spread over a 1 MHz data transfer capacity.

The Coarse Acquisition Code Your GPS matches up with every satellite by moving the planning of the begin of an inside produced PRN code.

Time Difference is Distance Timing of the signs transmitted by the satellites is extremely precise because of the double nuclear timekeepers on load up every satellite. The time contrast between the two PRN codes speaks to the time it took the radio sign to make a trip from the satellite to the GPS recipient. The separation or "reach" to the satellite is given by the condition range = time contrast X pace of light

Time Difference is Distance The clock flag your GPS uses to produce the PRN code is exceptionally mistaken contrasted with the nuclear tickers locally available the satellites. Be that as it may this clock blunder is consistent for each of the estimations to the diverse satellites being followed. The clock mistake can be processed when estimations are accessible from four or more satellites.

Satellite Position is Known The position of every satellite is known with awesome exactness. Current orbital position information is transmitted by every satellite. Circles are observed by ground control stations. Adjusted orbital data is transferred a few times each day. Given the position of every satellite and the separation from the GPS recipient to every satellite, the position of the GPS collector can be processed.

GPS Limitations – It\'s an electronic contraption… Failure could come about because of… Low battery Too frosty Got wet Got dropped Forgot how to utilize it! Try not to depend on your GPS as your exclusive method for route!

GPS Limitations – Fewer than 4 satellites noticeable Your GPS should have the capacity to get a solid sign from no less than 4 satellites to report a precise position Problems could be brought about by… The sky is darkened by gulch dividers, mountains, or tall structures. Thick tree overhang. Particularly on the off chance that it\'s wet. Reception apparatus is protected by metal from an auto, airplane or building. Low batteries may decrease recipient affectability.

GPS Limitations – Poor satellite geometry A little group of satellites can bring about a vast position mistake. Like triangulating with mountain tops that are near each other. Check your EPE!