Update links to GPS ICDs

docs/doxygen/other/reference_docs.dox

@@ -12,9 +12,9 @@
 All the current GPS Interface Control Documents can be downloaded from <a href="https://www.gps.gov" target="_blank">GPS.gov</a>, the official U.S. Government webpage for GPS.
 
 
-\li GPS L1 and L2C: Global Positioning System Directorate, <a href="https://www.gps.gov/technical/icwg/IS-GPS-200M.pdf" target="_blank"><b>Interface Specification IS-GPS-200 Revision M</b></a>. May, 2021.
-\li GPS L1C (available with first Block III launch): Global Positioning System Directorate, <a href="https://www.gps.gov/technical/icwg/IS-GPS-800H.pdf" target="_blank"><b>Interface Specification IS-GPS-800 Revision H</b></a>. May, 2021.
-\li GPS L5 (first Block IIF satellite launched on May, 2010): Global Positioning System Directorate, <a href="https://www.gps.gov/technical/icwg/IS-GPS-705H.pdf" target="_blank"><b>Interface Specification IS-GPS-705 Revision H</b></a>. May, 2021.
+\li GPS L1 and L2C: Global Positioning System Directorate, <a href="https://www.gps.gov/sites/default/files/2025-07/IS-GPS-200M.pdf" target="_blank"><b>Interface Specification IS-GPS-200 Revision M</b></a>. May, 2021.
+\li GPS L1C (available with first Block III launch): Global Positioning System Directorate, <a href="https://www.gps.gov/sites/default/files/2025-07/IS-GPS-800H.pdf" target="_blank"><b>Interface Specification IS-GPS-800 Revision H</b></a>. May, 2021.
+\li GPS L5 (first Block IIF satellite launched on May, 2010): Global Positioning System Directorate, <a href="https://www.gps.gov/sites/default/files/2025-07/IS-GPS-705H.pdf" target="_blank"><b>Interface Specification IS-GPS-705 Revision H</b></a>. May, 2021.
 
 
 

docs/doxygen/other/signal_model.dox

@@ -62,7 +62,7 @@ and civilian users on a continuous, worldwide basis. Two GPS services are provid
 the Precise Positioning Service (PPS), available primarily to the military of the United
 States and its allies, and the Standard Positioning Service (SPS) open to civilian users.
 
-\li <b>GPS L1</b>. Defined at <a href="https://www.gps.gov/technical/icwg/IS-GPS-200M.pdf" target="_blank"><b>Interface Specification IS-GPS-200 Revision M</b></a>, this band is centered at \f$f_{\text{GPS L1}}=1575.42\f$ MHz.  The complex baseband transmitted signal can be written as
+\li <b>GPS L1</b>. Defined at <a href="https://www.gps.gov/sites/default/files/2025-07/IS-GPS-200M.pdf" target="_blank"><b>Interface Specification IS-GPS-200 Revision M</b></a>, this band is centered at \f$f_{\text{GPS L1}}=1575.42\f$ MHz.  The complex baseband transmitted signal can be written as
 \f{equation}{
 s^{\text{(GPS L1)}}_{T}(t)=e_{L1I}(t) + j e_{L1Q}(t)~,
 \f}
@@ -76,12 +76,12 @@ s^{\text{(GPS L1)}}_{T}(t)=e_{L1I}(t) + j e_{L1Q}(t)~,
   \f$L_{\text{P(Y)}}=6.1871 \cdot 10^{12}\f$, and \f$p(t)\f$ is a rectangular pulse of a chip-period duration centered at \f$t=0\f$ and filtered at the transmitter.
   According to the chip rate, the binary phase-shift keying modulations in the equations above are denoted as BPSK(10) and BPSK(1), respectively. The precision P codes (named Y codes whenever
   the anti-spoofing mode is activated, encrypting the code and thus denying non-U.S. military users) are sequences of \f$7\f$ days in length. Regarding the modernization plans for GPS, it
-  is worthwhile to mention that there is a new civilian-use signal planned, called L1C and defined at <a href="https://www.gps.gov/technical/icwg/IS-GPS-800H.pdf" target="_blank"><b>Interface Specification IS-GPS-800 Revision H</b></a>,
+  is worthwhile to mention that there is a new civilian-use signal planned, called L1C and defined at <a href="https://www.gps.gov/sites/default/files/2025-07/IS-GPS-800H.pdf" target="_blank"><b>Interface Specification IS-GPS-800 Revision H</b></a>,
   to be broadcast on the same L1 frequency that currently contains the C/A signal. The L1C is available with first Block III launch. The implementation
   provides C/A code to ensure backward compatibility.
 
 
-\li <b>GPS L2C</b>. Defined at <a href="https://www.gps.gov/technical/icwg/IS-GPS-200M.pdf" target="_blank"><b>Interface Specification IS-GPS-200 Revision M</b></a>, is only available on
+\li <b>GPS L2C</b>. Defined at <a href="https://www.gps.gov/sites/default/files/2025-07/IS-GPS-200M.pdf" target="_blank"><b>Interface Specification IS-GPS-200 Revision M</b></a>, is only available on
 Block IIR-M and subsequent satellite blocks. Centered at \f$f_{\text{GPS L2}}=1227.60\f$ MHz, the signal structure is the same than in (\ref{eq:GPSL1}), with the precision code in the In-phase
 component, just as in (\ref{eq:L1CAI}) but with an optional presence of the navigation message \f$D_{\text{NAV}}\f$. For the Quadrature-phase component, three options are defined:
      \f{align}{ e_{L2CQ}(t) =&  \sum_{l=-\infty}^{\infty}     D_{\text{CNAV}}  \Big[ [l]_{10230}  \Big]    \oplus      \left(  C_{\text{CL}} \Big[ |l|_{L_{\text{CL}}} \Big]  p_{\text{\tiny{1/2}}}  \left(  t - lT_{c,L2C}   \right)   +  \right.\\ {} &+ \left. C_{\text{CM}}  \Big[ |l|_{L_{\text{CM}}} \Big] p_{\text{\tiny{1/2}}}\left(t - \left(l+\frac{3}{4}\right)T_{c,L2C}\right) \right),\\
@@ -94,7 +94,7 @@ component, just as in (\ref{eq:L1CAI}) but with an optional presence of the navi
        data than the NAV data. It is transmitted at \f$25\f$ bps with forward error correction (FEC) encoding, resulting in \f$50\f$ sps.
 
 
-\li <b>GPS L5</b>. The GPS L5 link, defined at <a href="https://www.gps.gov/technical/icwg/IS-GPS-705H.pdf" target="_blank"><b>Interface Specification IS-GPS-705 Revision H</b></a>, is only available
+\li <b>GPS L5</b>. The GPS L5 link, defined at <a href="https://www.gps.gov/sites/default/files/2025-07/IS-GPS-705H.pdf" target="_blank"><b>Interface Specification IS-GPS-705 Revision H</b></a>, is only available
 in Block IIF (first satellite launched on May, 2010) and subsequent satellite blocks. Centered at \f$f_{\text{GPS L5}}=1176.45\f$ MHz, this signal in space can be written as:
     \f{equation}{
 s^{\text{(GPS L5)}}_{T}(t)=e_{L5I}(t) +j e_{L5Q}(t)~,

src/core/system_parameters/gps_almanac.h

@@ -30,7 +30,7 @@
 /*!
  * \brief This class is a storage for the GPS SV ALMANAC data as described in IS-GPS-200M
  *
- * See https://www.gps.gov/technical/icwg/IS-GPS-200M.pdf Appendix II
+ * See https://www.gps.gov/sites/default/files/2025-07/IS-GPS-200M.pdf Appendix II
  */
 class Gps_Almanac : public Gnss_Almanac
 {

src/core/system_parameters/gps_cnav_ephemeris.h

@@ -32,7 +32,7 @@
  * \brief This is a storage class for the GPS CNAV ephemeris data as described
  * in IS-GPS-200M
  *
- * See https://www.gps.gov/technical/icwg/IS-GPS-200M.pdf Appendix III
+ * See https://www.gps.gov/sites/default/files/2025-07/IS-GPS-200M.pdf Appendix III
  */
 class Gps_CNAV_Ephemeris : public Gnss_Ephemeris
 {

src/core/system_parameters/gps_cnav_iono.h

@@ -29,7 +29,7 @@
 /*!
  * \brief This class is a storage for the GPS IONOSPHERIC data as described in IS-GPS-200M
  *
- * See https://www.gps.gov/technical/icwg/IS-GPS-200M.pdf Appendix III
+ * See https://www.gps.gov/sites/default/files/2025-07/IS-GPS-200M.pdf Appendix III
  */
 class Gps_CNAV_Iono : public Gps_Iono
 {

src/core/system_parameters/gps_cnav_navigation_message.cc

@@ -2,7 +2,7 @@
  * \file gps_cnav_navigation_message.cc
  * \brief Implementation of a GPS CNAV Data message decoder as described in IS-GPS-200M
  *
- * See https://www.gps.gov/technical/icwg/IS-GPS-200M.pdf Appendix III
+ * See https://www.gps.gov/sites/default/files/2025-07/IS-GPS-200M.pdf Appendix III
  * \author Javier Arribas, 2015. jarribas(at)cttc.es
  *
  * -----------------------------------------------------------------------------

src/core/system_parameters/gps_cnav_navigation_message.h

@@ -39,7 +39,7 @@
 /*!
  * \brief This class decodes a GPS CNAV Data message as described in IS-GPS-200M
  *
- * See https://www.gps.gov/technical/icwg/IS-GPS-200M.pdf Appendix III
+ * See https://www.gps.gov/sites/default/files/2025-07/IS-GPS-200M.pdf Appendix III
  */
 class Gps_CNAV_Navigation_Message
 {

src/core/system_parameters/gps_cnav_utc_model.h

@@ -29,7 +29,7 @@
 /*!
  * \brief This class is a storage for the GPS UTC MODEL data as described in in IS-GPS-200M
  *
- * See https://www.gps.gov/technical/icwg/IS-GPS-200M.pdf Appendix III
+ * See https://www.gps.gov/sites/default/files/2025-07/IS-GPS-200M.pdf Appendix III
  */
 class Gps_CNAV_Utc_Model : public Gps_Utc_Model
 {

src/core/system_parameters/gps_ephemeris.cc

@@ -2,7 +2,7 @@
  * \file gps_ephemeris.cc
  * \brief  Interface of a GPS EPHEMERIS storage and orbital model functions
  *
- * See https://www.gps.gov/technical/icwg/IS-GPS-200M.pdf Appendix II
+ * See https://www.gps.gov/sites/default/files/2025-07/IS-GPS-200M.pdf Appendix II
  * \author Javier Arribas, 2013. jarribas(at)cttc.es
  *
  * -----------------------------------------------------------------------------

src/core/system_parameters/gps_ephemeris.h

@@ -35,7 +35,7 @@
  * \brief This class is a storage and orbital model functions for the GPS SV
  * ephemeris data as described in IS-GPS-200M
  *
- * See https://www.gps.gov/technical/icwg/IS-GPS-200M.pdf Appendix II
+ * See https://www.gps.gov/sites/default/files/2025-07/IS-GPS-200M.pdf Appendix II
  */
 class Gps_Ephemeris : public Gnss_Ephemeris
 {

src/core/system_parameters/gps_iono.h

@@ -30,7 +30,7 @@
 /*!
  * \brief This class is a storage for the GPS IONOSPHERIC data as described in IS-GPS-200M
  *
- * See https://www.gps.gov/technical/icwg/IS-GPS-200M.pdf Appendix II
+ * See https://www.gps.gov/sites/default/files/2025-07/IS-GPS-200M.pdf Appendix II
  */
 class Gps_Iono
 {

src/core/system_parameters/gps_navigation_message.cc

@@ -3,7 +3,7 @@
  * \brief  Implementation of a GPS NAV Data message decoder as described in IS-GPS-200M
  * \author Javier Arribas, 2011. jarribas(at)cttc.es
  *
- * See https://www.gps.gov/technical/icwg/IS-GPS-200M.pdf Appendix II
+ * See https://www.gps.gov/sites/default/files/2025-07/IS-GPS-200M.pdf Appendix II
  *
  *
  * -----------------------------------------------------------------------------
@@ -101,7 +101,7 @@ int32_t Gps_Navigation_Message::subframe_decoder(const char* subframe)
     switch (subframe_ID)
         {
         // --- Decode the sub-frame id -----------------------------------------
-        // ICD (IS-GPS-200M Appendix II). https://www.gps.gov/technical/icwg/IS-GPS-200M.pdf
+        // ICD (IS-GPS-200M Appendix II). https://www.gps.gov/sites/default/files/2025-07/IS-GPS-200M.pdf
         case 1:
             // --- It is subframe 1 -------------------------------------
             // Compute the time of week (TOW) of the first sub-frames in the array ====

src/core/system_parameters/gps_navigation_message.h

@@ -41,7 +41,7 @@
 /*!
  * \brief This class decodes a GPS NAV Data message as described in IS-GPS-200M
  *
- * See https://www.gps.gov/technical/icwg/IS-GPS-200M.pdf Appendix II
+ * See https://www.gps.gov/sites/default/files/2025-07/IS-GPS-200M.pdf Appendix II
  */
 class Gps_Navigation_Message
 {

src/core/system_parameters/gps_utc_model.h

@@ -30,7 +30,7 @@
 /*!
  * \brief This class is a storage for the GPS UTC MODEL data as described in IS-GPS-200M
  *
- * See https://www.gps.gov/technical/icwg/IS-GPS-200M.pdf Appendix II
+ * See https://www.gps.gov/sites/default/files/2025-07/IS-GPS-200M.pdf Appendix II
  */
 class Gps_Utc_Model
 {