How to convert WGS84 gps coordinates to xyz

[kgildea]

I am using a Garmin handheld GPS 76 to determine vehicle speed and travel path. The serial output gives altitude and latitude/longitude in WGS84 coordinates. I need to get the distance between two points to calculate speed. Does anyone know how to perform the conversion between the this coordinate system and an xyz system?
Thanks,
Kevin Gildea

[Jeremy Braden]

Look on Google for gps rectangular coordinates latitude longitude .

I found the following link that seemps promising:
http://www.ngs.noaa.gov/TOOLS/XYZ/xyz.html

[Mike]

or post your question on sci.geo.satellite-nav
I have done it for you...

"Jeremy Braden" wrote in message news:506500000005000000041A0100-1042324653000@exchange.ni.com...
> Look on Google for gps rectangular coordinates latitude longitude

[Sam Wormley]

See: http://www.ngs.noaa.gov/TOOLS/XYZ/xyz.html

Conversion from ECEF XYZ to Latitude, Longitude, and Height
http://www.Colorado.EDU/geography/gcraft/notes/datum/gif/xyzllh.gif

Conversion from Latitude, Longitude, and Height to ECEF XYZ.
http://www.Colorado.EDU/geography/gcraft/notes/datum/gif/llhxyz.gif

[FixedWire]

old post, but someone may find this solution helpful:

http://forums.ni.com/t5/LabVIEW/Problem-create-executable/m-p/286248/highlight/true#M150728

[maanupalthiya]

yeah you can use these formulas to convert GPS data into xyz coordinates

x=R*cos(lat)*cos(lon)

y=R*cos(lat)*sin(lon)

z=R*sin(lat)

        if you want to find change in position subtract previous value from present value

  R=Radius of the earth(6371km),take lattitude and longitude in radians

[millonas]

No that is for spherical coordinate system. WGS 84 is an oblate spheriod coordinate system. So the equations are incorrect.