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Merge "Fixed the sign error in GnssClock" into nyc-dev

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Wyatt Riley 2016-04-08 23:41:16 +00:00 committed by Android (Google) Code Review
commit 446c2bc137
1 changed files with 14 additions and 10 deletions
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24
include/hardware/gps.h
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@ -1469,7 +1469,7 @@ typedef struct {
/**
* Leap second data.
* The sign of the value is defined by the following equation:
* utc_time_ns = time_ns + (full_bias_ns + bias_ns) - leap_second *
* utc_time_ns = time_ns - (full_bias_ns + bias_ns) - leap_second *
* 1,000,000,000
*
* If the data is available 'flags' must contain GNSS_CLOCK_HAS_LEAP_SECOND.
@ -1483,8 +1483,9 @@ typedef struct {
* For local hardware clock, this value is expected to be monotonically
* increasing while the hardware clock remains power on. (For the case of a
* HW clock that is not continuously on, see the
* hw_clock_discontinuity_count field). The real GPS time can be derived by
* adding the 'full_bias_ns + bias_ns' (when it is available) to this value.
* hw_clock_discontinuity_count field). The receiver's estimate of GPS time
* can be derived by substracting the sum of full_bias_ns and bias_ns (when
* available) from this value.
*
* This GPS time is expected to be the best estimate of current GPS time
* that GNSS receiver can achieve.
@ -1513,20 +1514,22 @@ typedef struct {
* and the true GPS time since 0000Z, January 6, 1980, in nanoseconds.
*
* The sign of the value is defined by the following equation:
* local estimate of GPS time = time_ns + (full_bias_ns + bias_ns)
* local estimate of GPS time = time_ns - (full_bias_ns + bias_ns)
*
* This value is mandatory if the receiver has estimated GPS time. If the
* computed time is for a non-GPS constellation, the time offset of that
* constellation to GPS has to be applied to fill this value. The value
* contains the 'bias uncertainty' in it, and the caller is responsible of
* using the uncertainty. If the data is available 'flags' must contain
* GNSS_CLOCK_HAS_FULL_BIAS.
* constellation to GPS has to be applied to fill this value. The error
* estimate for the sum of this and the bias_ns is the bias_uncertainty_ns,
* and the caller is responsible for using this uncertainty (it can be very
* large before the GPS time has been solved for.) If the data is available
* 'flags' must contain GNSS_CLOCK_HAS_FULL_BIAS.
*/
int64_t full_bias_ns;
/**
* Sub-nanosecond bias.
* The value contains the 'bias uncertainty' in it.
* The error estimate for the sum of this and the full_bias_ns is the
* bias_uncertainty_ns
*
* If the data is available 'flags' must contain GNSS_CLOCK_HAS_BIAS. If GPS
* has computed a position fix. This value is mandatory if the receiver has
@ -1549,7 +1552,8 @@ typedef struct {
* The clock's drift in nanoseconds (per second).
*
* A positive value means that the frequency is higher than the nominal
* frequency.
* frequency, and that the (full_bias_ns + bias_ns) is growing more positive
* over time.
*
* The value contains the 'drift uncertainty' in it.
* If the data is available 'flags' must contain GNSS_CLOCK_HAS_DRIFT.