1. Dual inputs (Single frequency)
2. Two bladeRF (Single frequency)

---

Dual input to a bladeRF (dev6): rx1 = GPS 1, rx2 = GPS 2
 * GPS 1 was originally connected to rx1 of dev6
 * GPS 2 was originally connected to rx1 of dev13

From previous observations, dev13 signals are generally weaker (or unstable) than dev6 signals, so the two GPS antennas are connected to dev6.

• Receivers are aligned to E-W: E (GPS 1) -- W (GPS 2)

Back to top

• doppler-corrected carrier phase $=$ (carrier phase) $+$ cumulative sum(doppler shift) $\times \ dt$

zoom-in (Carrier phase)

zoom-in (Doppler-corrected)

Back to top

zoom-in

Back to top

Back to top

Back to top

Once the navigation solution is obtained, RINEX (Receiver Independent Exchange Format; a data format for raw satellite navigation system data) file can be saved.
The RINEX file includes

• time (the receiver time of the received signals)
• satellite IDs
• pseudo-range [meter], carrier phase [cycle], Doppler frequency [Hz], and signal strength of each satellite.

• cycle → second

	Difference in Carrier phase	Difference in Doppler-corrected carrier phase
	mean (deviation)	mean (deviation)
G19	-149.56 ns (110.76)	112.51 $u\rm s$ (0.11)
G06	-150.76 ns (110.76)	11.90 $u\rm s$ (0.11)
G11	-128.97 ns (110.76)	113.52 $u\rm s$ (0.11)

Back to top

---

Two antennas are connected to different bladeRF
 * GPS 1 is connected to dev6 (both rx1 and rx2 were tested.)
 * GPS 2 is connected to dev13 (both rx1 and rx2 were tested.)
Antenna settings are the same as Setting for dual inputs.

• doppler-corrected carrier phase $=$ (carrier phase) $+$ cumulative sum(doppler shift) $\times \ dt$

zoom-in (Carrier phase)

zoom-in (Doppler-corrected phase)

zoom-in (Carrier phase)

zoom-in (Doppler-corrected phase)

zoom-in (Carrier phase)

zoom-in (Doppler-corrected phase)

zoom-in (Carrier phase)

zoom-in (Doppler-corrected phase)

zoom-in (Carrier phase)

zoom-in (Doppler-corrected phase)

Back to top

Back to top

Once the navigation solution is obtained, RINEX (Receiver Independent Exchange Format; a data format for raw satellite navigation system data) file can be saved.
The RINEX file includes

• time (the receiver time of the received signals)
• satellite IDs
• pseudo-range [meter], carrier phase [cycle], Doppler frequency [Hz], and signal strength of each satellite.

• cycle → second

	Difference in Carrier phase	Difference in Doppler-corrected carrier phase
	mean (deviation)	mean (deviation)
G04	-3.57 ns (184.75)
G08	-31.55 ns (126.84)
G09	-98.49 ns (138.45)
G27	8.88 ns (71.76)

Back to top

---

• GNSS-SDR: https://gnss-sdr.org/docs/
• Live Map of Satellite Positions: https://in-the-sky.org/satmap_radar.php
• NAVSTAR GPS: https://www.n2yo.com/satellites/?c=20
• RINEX ver.2: https://files.igs.org/pub/data/format/rinex211.txt
• RINEX ver.3: https://files.igs.org/pub/data/format/rinex303.pdf

Back to top