Spreadsheets were created by Logan Scott using Microsoft Excel
No Warranty is Implied, All Rights Reserved, Spreadsheets
In general, input fields are in color while dependent variables (formula cells) are in black.
gps accuracy mp.xls is the most current spreadsheet for computing GPS accuracy. It computes GPS navigation accuracy as a function of signal in space accuracy, multipath, satellite geometry etc. for varying levels of multipath and as a function of Signal in Space (SIS) accuracy. Age of Data terms are included to model satelite clock drift. 50% and 95% confidence cases are considered. My Linear, Radial, and Spherical Error Probabilities discussion has more information on this topic
computes GPS navigation accuracy as a function of signal in space
multipath, satellite geometry etc. Both PPS and SPS are analyzed for
and differential performance. Selective Availability (SA) is accounted
PPS performance with operational and proposed Wide Area GPS
(WAGE) is also covered. RSS (1 sigma), 50% and 95% confidence cases are
Radial, and Spherical Error Probabilities discussion
information on this topic. See Moeglein et. al
for PPS Space Segment Accuracy Enhancement, Journal of the
ION, Fall 1996 for more discussion on
wage.xls estimates GPS signal in space accuracy as a
Operational Control Segment OCS navigation message upload latency.
one a day uploads leads to 12 hour median latency while WAGE1 obtains 3
median latency. See Moeglein et. al Options for PPS Space Segment
Enhancement, Journal of the ION,
1996 for more discussion on WAGE.
GPS_C_OVER_No.xls calculates baseband C/No as a function of jamming
receiver noise figure, antenna gains etc. Also uses Excel "Solver"
to obtain range to jammer at threshold for free space propagation case
various adaptive antenna/IMU aiding configurations.
VG_GPS_Acquisition.xls determines time to perform direct P-code acquisition as a function of time since last fix. Various types of receiver master oscillator are considered. Range and doppler uncertainty due to geometric effects are not considered.
CEP_and_LEP.xls computes probabilities of linear and radial error
zero mean gaussian errors. More discussion on the mathematics behind
spreadsheet can be found in my
and Spherical Error Probabilities
signal attenuation as a function of elevation angle, forest height and
distance from forest. See chapter 15 of Global Positioning System:
and Applications (ISBN 1-56347-106-X) published by
AIAA for a
of Signal Attenuation Factors. Table 1 has species specific information.
shows channel matching accuracy needed to obtain specified
ratio in an adaptive array. Also includes analysis of I/Q rotation
performance given two sine waves at different frequencies.
rain_attenuation.xls computes signal attenuation as a function of
and distance at 30 GHz. Shows that LMDS (Local Multipoint Distribution
and DEMS (Digital Electronic Message System) are subject to fade out in
heavy rain but otherwise will do OK.
auto and cross correlation of binary codewords as a function of
length and codeword family size.
VSWR_Charts.xls computes transmitted and reflected power levels as
of Voltage Standing Wave Ratio (VSWR). Shows why transmitter power
often require pads to create less reactive loads.
This page last modified 18 March, 2008