The idea behind differential GPS is to remove as much errors as possible from the range measurements by establishing these errors at a reference site. In its most simple setup, a GPS receiver is located at a well surveyed pOSition and its (pseudo) range measurements are compared with the actual calculated range from this receiver to the SV s. The differences between measured ranges and calculated ranges at the reference receiver are applied as corrections to the ranges measured by other receiver(s) close by.
GPS 接收程序 DEMO。
HsGpsDll Library 1.1
A GPS Control/Component for C/C++
HsGpsDll is a Windows Dynamic Link Library which provides access to any NMEA-183 compliant GPS receiver via a serial communications port. HsGpsDll is designed for use from Visual C, Visual Basic or other languages, capable of calling DLL functions. HsGpsDll allows a user application to read from a GPS device the current GPS pOSition fix, velocity over ground (speed in kilometers per hour), plus number of of sattelites in view, current altitude (against mean sea level) and UTC date and time
This is GPS in matlab calculatePseudoranges finds relative pseudoranges for all satellites
listed in CHANNELLIST at the specified millisecond of the processed
signal. The pseudoranges contain unknown receiver clock offset. It can be
found by the least squares pOSition search procedure.
Basic function to locate and measure the positive peaks in a noisy
data sets. Detects peaks by looking for downward zero-crossings
in the smoothed third derivative that exceed SlopeThreshold
and peak amplitudes that exceed AmpThreshold. Determines,
pOSition, height, and approximate width of each peak by least-squares
curve-fitting the log of top part of the peak with a parabola.
This file is distributed in the hope that it will be useful, but WITHOUT
WARRANTY OF ANY KIND.
Author(s): Ole Saether
DESCRIPTION:
This example should be used together with ex2a-tx433.asm. One nRF9E5
evaluation board (receiver) should be programmed with the hex-file generated
from assembling this file and the other evaluation board (transmitter)
programmed with the hex-file generated from assembling ex2a-tx433.asm.
All switches on the DIP-swith S206 on the receiver must be set to the "on"
pOSition and all switches on the DIP-swith S205 on the transmitter must be
set to the "on" pOSition.
When one of the switched SW1-SW4 on the transmitter is pressed the
corresponding LED on the receiver is turned on.
The functionality is the same as in ex2c-rx.c.
This code outputs various NMEA strings to a com port. The code was
originally used to test naviation programmes.
First select the required com port and the required NMEA message string.
There is a default starting pOSition but this can be changed to suit just by typing
in a new pOSition.
Click on the Start button the current pOSition displayed will change according
to the speed and heading selected and the selected NMEA string will be output to the com port
and will reflect the current pOSition as displayed.
There is a text box which is normally not visible. If you change this to visible the relevant
NMEA string can be displayed.
This program contains the iterative methods of finding solutions of the equation f(x)=0, which are also known as the roots of the equation f(x)=0
The methods are:
-bisection
-false pOSition
-newton raphson
-secant
