track.h
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00001 /*
00002  * Copyright (C) 2012 Swift Navigation Inc.
00003  * Contact: Fergus Noble <fergus@swift-nav.com>
00004  *
00005  * This source is subject to the license found in the file 'LICENSE' which must
00006  * be be distributed together with this source. All other rights reserved.
00007  *
00008  * THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND,
00009  * EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE IMPLIED
00010  * WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR PURPOSE.
00011  */
00012 
00013 #ifndef LIBSWIFTNAV_TRACK_H
00014 #define LIBSWIFTNAV_TRACK_H
00015 
00016 #include "common.h"
00017 #include "ephemeris.h"
00018 
00028 typedef struct {
00029   float pgain;      
00030   float igain;      
00031   float prev_error; 
00032   float y;          
00033 } simple_lf_state_t;
00034 
00038 typedef struct {
00039   float code_freq;             
00040   float carr_freq;             
00041   simple_lf_state_t code_filt; 
00042   simple_lf_state_t carr_filt; 
00043 } simple_tl_state_t;
00044 
00049 typedef struct {
00050   float code_freq;             
00051   float carr_freq;             
00052   simple_lf_state_t code_filt; 
00053   simple_lf_state_t carr_filt; 
00054   u32 sched;                   
00055   u32 n;                       
00056   float A;                     
00057   float carr_to_code;          
00058 } comp_tl_state_t;
00059 
00060 
00064 typedef struct {
00065   float I; 
00066   float Q; 
00067 } correlation_t;
00068 
00072 typedef struct {
00073   float log_bw;     
00074   float A;          
00075   float I_prev_abs; 
00076   float nsr;        
00077 } cn0_est_state_t;
00078 
00081 typedef struct {
00082   u8 prn;
00083   double code_phase_chips;
00084   double code_phase_rate;
00085   double carrier_phase;
00086   double carrier_freq;
00087   u32 time_of_week_ms;
00088   double receiver_time;
00089   double snr;
00090 } channel_measurement_t;
00091 
00092 typedef struct {
00093   u8 prn;
00094   double raw_pseudorange;
00095   double raw_pseudorange_rate;
00096   double pseudorange;
00097   double pseudorange_rate;
00098   gps_time_t tot;
00099   double sat_pos[3];
00100   double sat_vel[3];
00101   double snr;
00102 } navigation_measurement_t;
00103 
00104 void calc_loop_gains(float bw, float zeta, float k, float loop_freq,
00105                      float *pgain, float *igain);
00106 float costas_discriminator(float I, float Q);
00107 float dll_discriminator(correlation_t cs[3]);
00108 
00109 void simple_lf_init(simple_lf_state_t *s, float y0,
00110                     float pgain, float igain);
00111 float simple_lf_update(simple_lf_state_t *s, float error);
00112 
00113 void simple_tl_init(simple_tl_state_t *s, float loop_freq,
00114                     float code_freq, float code_bw,
00115                     float code_zeta, float code_k,
00116                     float carr_freq, float carr_bw,
00117                     float carr_zeta, float carr_k);
00118 void simple_tl_update(simple_tl_state_t *s, correlation_t cs[3]);
00119 
00120 void comp_tl_init(comp_tl_state_t *s, float loop_freq,
00121                     float code_freq, float code_bw,
00122                     float code_zeta, float code_k,
00123                     float carr_freq, float carr_bw,
00124                     float carr_zeta, float carr_k,
00125                     float tau, float cpc, u32 sched);
00126 void comp_tl_update(comp_tl_state_t *s, correlation_t cs[3]);
00127 
00128 void cn0_est_init(cn0_est_state_t *s, float bw, float cn0_0,
00129                   float cutoff_freq, float loop_freq);
00130 float cn0_est(cn0_est_state_t *s, float I);
00131 
00132 void calc_navigation_measurement(u8 n_channels, channel_measurement_t meas[],
00133                                  navigation_measurement_t nav_meas[],
00134                                  double nav_time, ephemeris_t ephemerides[]);
00135 void calc_navigation_measurement_(u8 n_channels, channel_measurement_t* meas[],
00136                                   navigation_measurement_t* nav_meas[],
00137                                   double nav_time, ephemeris_t* ephemerides[]);
00138 
00139 #endif /* LIBSWIFTNAV_TRACK_H */
00140 


enu
Author(s): Mike Purvis
autogenerated on Fri Jan 3 2014 11:21:07