View source for Precision Differential GPS

{{Project
 |founder=skirit
 |status=active
 |shortdesc=Stationary GPS receiver will compute correction data for nearby GPS receivers.
 |coops=lnovy,nio
 |hwlic=GPL
 |tags=hw
 |created=2020-11-05
}}

== Goal of a project ==

== Theory ==

[https://en.wikipedia.org/wiki/Differential_GPS wikipedia: Differential GPS]

== sw for experimentation ==

Receive GPS signals using SDR and do custom calculations: [https://gnss-sdr.org/ https://gnss-sdr.org/]

== hw for experimentation ==

limeSDR mini 1 RX input 1 TX output SDR (nio has 1): [https://limemicro.com/products/boards/limesdr-mini/ LimeSDR Mini from limemicro.com]

Cheap ceramic active antenna (nio has 1): [https://www.ebay.com/itm/28dB-LNA-Gain-1575-42MHz-Male-SMA-Male-GPS-Active-Antenna-Stronger-Singal-NEW/172823660693?hash=item283d17c895:g:qV4AAOSwaYpZlP01 ebay 28dB LNA Gain 1575 42MHz Male SMA Male GPS Active Antenna Stronger Singal NEW]

Cheap bias tee to insert power to active antenna coax feed (nio has 1): [https://www.ebay.com/itm/283227114649 6GHz 10MHz-6000MHz Wideband Amplifier Broadband RF Feeder RF Isolator Bias Tee]

Filter out noise using bandpass filter to allow SDR to receive GPS signal: [https://www.tindie.com/products/gpio/1575-mhz-gps-l1-bandpass-filter-band-pass/ Tindie - 1575 MHz GPS L1 Bandpass Filter Band Pass, by GPIO Labs]

== Other RF pages to read ==

[[Active_GPS_antenna_from_ebay]]

== ideas to evaluate ==

* calculate corrections for individual sattelite pseudoranges

== URL's to explore ==

[https://github.com/rs1729/RS/blob/master/rs92/nav_gps.c simple gps receiver calculation]