PDOP and GDOP single point Navigation Solution GPS/GNNS

1. Jan 15, 2012

Pieter-S

Giving the following satellites positions (coordinates are in meters and in Earth Centered Inertial Frame):

r_(is,1)^i=[1.876371950559744e6 -10.6414313406656e6 24.2697646566144e6]

r_(is,2)^i=[10.97666464137408e6 -13.08147952230029e6 20.35116937827073e6]

r_(is,3)^i=[24.58513954435968e6 -4.335023426659201e6 9.08630032021747e6]

r_(is,4)^i=[3.854136195752833e6 7.248575943442946e6 25.26630462778753e6]

and pseudo range measurements:

ρ ̌_(c,1)=3.669952086784462e+007 (m)
ρ ̌_(c,2)=3.611953237284596e+007 (m)
ρ ̌_(c,3)=3.673710068993442e+007 (m)
ρ ̌_(c,4)=3.635011499119347e+007 (m)

A) how to begin to write a single point navigation solution for this(MATLAB)?

B) how can I calculate the position dilution of precision PDOP and Geometric dilution of precision GDOP (maybe MATLAB)?

A) precise latitude and longitude for receiver position.

Navigation books propose several approach to this problem:
-Newton Raphson iteration for position estimation
-extended Kalman filter

but I think the data which is given, those approaches are already integrated??

2. Jan 17, 2012

Pieter-S

is there anybody with some useful advice?

regards,

Pieter