diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/hardware/gps.h | 39 |
1 files changed, 34 insertions, 5 deletions
diff --git a/include/hardware/gps.h b/include/hardware/gps.h index e264cf5..937436b 100644 --- a/include/hardware/gps.h +++ b/include/hardware/gps.h @@ -293,6 +293,8 @@ typedef uint32_t GpsMeasurementFlags; #define GPS_MEASUREMENT_HAS_DOPPLER_SHIFT_UNCERTAINTY (1<<16) /** A valid 'used in fix' flag is stored in the data structure. */ #define GPS_MEASUREMENT_HAS_USED_IN_FIX (1<<17) +/** The value of 'pseudorange rate' is uncorrected. */ +#define GPS_MEASUREMENT_HAS_UNCORRECTED_PSEUDORANGE_RATE (1<<18) /** * Enumeration of the available values for the GPS Measurement's loss of lock. @@ -1353,6 +1355,9 @@ typedef struct { * * The value contains the 'drift uncertainty' in it. * If the data is available 'flags' must contain GPS_CLOCK_HAS_DRIFT. + * + * If GpsMeasurement's 'flags' field contains GPS_MEASUREMENT_HAS_UNCORRECTED_PSEUDORANGE_RATE, + * it is encouraged that this field is also provided. */ double drift_nsps; @@ -1416,11 +1421,15 @@ typedef struct { * * However, if there is any ambiguity in integer millisecond, * GPS_MEASUREMENT_STATE_MSEC_AMBIGUOUS should be set accordingly, in the 'state' field. + * + * This value must be populated if 'state' != GPS_MEASUREMENT_STATE_UNKNOWN. */ int64_t received_gps_tow_ns; /** * 1-Sigma uncertainty of the Received GPS Time-of-Week in nanoseconds. + * + * This value must be populated if 'state' != GPS_MEASUREMENT_STATE_UNKNOWN. */ int64_t received_gps_tow_uncertainty_ns; @@ -1434,11 +1443,23 @@ typedef struct { /** * Pseudorange rate at the timestamp in m/s. - * The value also includes the effects of the receiver clock frequency and satellite clock - * frequency errors. + * The effects of the receiver clock frequency and satellite clock frequency errors, are known + * as the correction of a given Pseudorange rate value. + * + * If GPS_MEASUREMENT_HAS_UNCORRECTED_PSEUDORANGE_RATE is set in 'flags' field, this field must + * be populated with the 'uncorrected' reading. + * If GPS_MEASUREMENT_HAS_UNCORRECTED_PSEUDORANGE_RATE is not set in 'flags' field, this field + * must be populated with the 'corrected' reading. This is the default behavior. + * + * It is encouraged to provide the 'uncorrected' 'pseudorange rate', and provide GpsClock's + * 'drift' field as well. * * The value includes the 'pseudorange rate uncertainty' in it. - * A positive value indicates that the pseudorange is getting larger. + * A positive 'uncorrected' value indicates that the SV is moving away from the receiver. + * + * The sign of the 'uncorrected' 'pseudorange rate' and its correlation to the sign of 'doppler + * shift' is given by the equation: + * pseudorange rate = -k * doppler shift * * This is a Mandatory value. */ @@ -1462,13 +1483,21 @@ typedef struct { /** * Accumulated delta range since the last channel reset in meters. - * The data is available if 'accumulated delta range state' != GPS_ADR_STATE_UNKNOWN. + * A positive value indicates that the SV is moving away fro the receiver. + * + * The sign of the 'accumulated delta range' and its correlation to the sign of 'carrier phase' + * is given by the equation: + * accumulated delta range = -k * carrier phase + * + * This value must be populated if 'accumulated delta range state' != GPS_ADR_STATE_UNKNOWN. + * However, it is expected that the data is only accurate when: + * 'accumulated delta range state' == GPS_ADR_STATE_VALID. */ double accumulated_delta_range_m; /** * 1-Sigma uncertainty of the accumulated delta range in meters. - * The data is available if 'accumulated delta range state' != GPS_ADR_STATE_UNKNOWN. + * This value must be populated if 'accumulated delta range state' != GPS_ADR_STATE_UNKNOWN. */ double accumulated_delta_range_uncertainty_m; |