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history [2026/07/27 08:28] – pkovarhistory [2026/07/27 08:51] (current) – pkovar
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 The Witch Navigator was a research dual-frequency GNSS receiver designed as a PCMCIA card for a PC. Witch Navigator is absolutely incompatible with a 1U CubeSat platform! The Witch Navigator was a research dual-frequency GNSS receiver designed as a PCMCIA card for a PC. Witch Navigator is absolutely incompatible with a 1U CubeSat platform!
  
-At that time, I had defined the following high-level requirements on the new navigation receiver for a CubeSat that I respected for all years of development of the pNav L1 receiver:+At that time, I had defined the following **high-level requirements** on the **new navigation receiver** for a CubeSat that I respected for all years of development of the pNav L1 receiver:
  
-  * The CubeSat navigation receiver should be as simple as possible.+  * The CubeSat navigation receiver should be as simple as possible
   * It should integrate all necessary parts for navigation in the LEO Orbit, but not more   * It should integrate all necessary parts for navigation in the LEO Orbit, but not more
   * It should be compatible with a 1U CubeSat platform, ie, power consumption should be a fraction of the power budget of 1U satellite. The receiver should be small and light.      * It should be compatible with a 1U CubeSat platform, ie, power consumption should be a fraction of the power budget of 1U satellite. The receiver should be small and light.   
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 ===== pNav Milestones ===== ===== pNav Milestones =====
  
-pNav receiver was developed from the beginning as a private, and private founding project at my private laboratory in our house. +pNav receiver was developed from the beginning as a private, and private founded project at my private laboratory in our house. 
 The receiver is marketed by the company SkyFox of Jaroslav Laifr.  The receiver is marketed by the company SkyFox of Jaroslav Laifr. 
  
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   * **2016: Introduction to the market** - GPS L1 C/A receiver with the 15 GPS L1 E-L correlators. Serial acquisition based on N of M algorithm. The typical receiver's start time in ideal conditions was 300 seconds.   * **2016: Introduction to the market** - GPS L1 C/A receiver with the 15 GPS L1 E-L correlators. Serial acquisition based on N of M algorithm. The typical receiver's start time in ideal conditions was 300 seconds.
  
-  * **2017: Acquisition unit ** The problem of the pNav receiver from the beginning till the introduction of pNav2 is a problematic cold start and restart after position loss. The partial solution was the introduction of the DSP acquisition unit, which can investigate the entire search range in Dooper frequency and code delay for all 32 satellites within 20 seconds. Unfortunately, due to the hardware manufacturer's technological limitations, we cannot use an FPGA with sufficient performance to run GPS correlators and an acquisition unit simultaneously. So the receiver first configures the FPGA with an acquisition unit. After it finishes the signal processing, the FPGA is reprogrammed by a GPS correlatos. The information from the acquisition unit is used for the acceleration of the receiver cold start. Under the ideal conditions, the receiver's cold start was shortened to 60 - 70 seconds. But this receiver configuration does not allow the DSP requisition if the signal or position is lost. +  * **2017: Acquisition unit ** The problem of the pNav receiver from the beginning till the introduction of pNav2 is a problematic cold start and restart after position loss. The partial solution was the introduction of the DSP acquisition unit, which can investigate the entire search range in Dooper frequency and code delay for all 32 satellites within 20 seconds. Unfortunately, due to the hardware manufacturer's technological limitations, we could not use an FPGA with sufficient performance to run GPS correlators and an acquisition unit simultaneously. So the receiver first configures the FPGA with an acquisition unit. After it finishes the signal processing, the FPGA is reprogrammed by a GPS correlatos. The information from the acquisition unit is used for the acceleration of the receiver cold start. Under the ideal conditions, the receiver's cold start was shortened to 60 - 70 seconds. But this receiver configuration does not allow the DSP requisition if the signal or position is lost! 
      
   * **2018: Buying and implementation of a GPS software simulator ReGen** by IPSolutions.   * **2018: Buying and implementation of a GPS software simulator ReGen** by IPSolutions.
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   * **2022: Application of the orbital position propagator** with the aim of overcoming GPS position dropout and improving the receiver reacquisition.    * **2022: Application of the orbital position propagator** with the aim of overcoming GPS position dropout and improving the receiver reacquisition. 
      
-  * **2026: Last update of the original pNav of Almanach memory**+  * **2026: Last update of the original pNav of Almanach memory**. This version is internally assigned as pNav 1.5. Together with the new acquisition unit, it is the first small step towards the new version [[Start|pNav2]].
      
   * **2026: Introduction of [[Start|pNav2]]**   * **2026: Introduction of [[Start|pNav2]]**
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   * **Problematic acquisition and reaqusition** due to the low performance signal processor. The receiver reaquisition in the ideal case lasts tens of minutes   * **Problematic acquisition and reaqusition** due to the low performance signal processor. The receiver reaquisition in the ideal case lasts tens of minutes
 +  * **Basic handling of the navigation signals reception errors**
   * **Non-configurable NMEA protocol**   * **Non-configurable NMEA protocol**
  
history.1785133722.txt.gz · Last modified: by pkovar
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