Clarifiy ADR states in documentation
Bug: 167930284
Test: n/a
Change-Id: Ifa0633b2cfa7bb80e32d2c68d70992bc1b0c5461
diff --git a/gnss/1.0/IGnssMeasurementCallback.hal b/gnss/1.0/IGnssMeasurementCallback.hal
index 2d44766..d219af0 100644
--- a/gnss/1.0/IGnssMeasurementCallback.hal
+++ b/gnss/1.0/IGnssMeasurementCallback.hal
@@ -106,8 +106,63 @@
STATE_GLO_TOD_KNOWN = 1 << 15,
};
- /**
+ /**
* Flags indicating the Accumulated Delta Range's states.
+ *
+ * See the table below for a detailed interpretation of each state.
+ *
+ * +---------------------+-------------------+-----------------------------+
+ * | ADR_STATE | Time of relevance | Interpretation |
+ * +---------------------+-------------------+-----------------------------+
+ * | UNKNOWN | ADR(t) | No valid carrier phase |
+ * | | | information is available |
+ * | | | at time t. |
+ * +---------------------+-------------------+-----------------------------+
+ * | VALID | ADR(t) | Valid carrier phase |
+ * | | | information is available |
+ * | | | at time t. This indicates |
+ * | | | that this measurement can |
+ * | | | be used as a reference for |
+ * | | | future measurements. |
+ * | | | However, to compare it to |
+ * | | | previous measurements to |
+ * | | | compute delta range, |
+ * | | | other bits should be |
+ * | | | checked. Specifically, it |
+ * | | | can be used for delta range |
+ * | | | computation if it is valid |
+ * | | | and has no reset or cycle |
+ * | | | slip at this epoch i.e. |
+ * | | | if VALID_BIT == 1 && |
+ * | | | CYCLE_SLIP_BIT == 0 && |
+ * | | | RESET_BIT == 0. |
+ * +---------------------+-------------------+-----------------------------+
+ * | RESET | ADR(t) - ADR(t-1) | Carrier phase accumulation |
+ * | | | has been restarted between |
+ * | | | current time t and previous |
+ * | | | time t-1. This indicates |
+ * | | | that this measurement can |
+ * | | | be used as a reference for |
+ * | | | future measurements, but it |
+ * | | | should not be compared to |
+ * | | | previous measurements to |
+ * | | | compute delta range. |
+ * +---------------------+-------------------+-----------------------------+
+ * | CYCLE_SLIP | ADR(t) - ADR(t-1) | Cycle slip(s) have been |
+ * | | | detected between the |
+ * | | | current time t and previous |
+ * | | | time t-1. This indicates |
+ * | | | that this measurement can |
+ * | | | be used as a reference for |
+ * | | | future measurements. |
+ * | | | Clients can use a |
+ * | | | measurement with a cycle |
+ * | | | slip to compute delta range |
+ * | | | against previous |
+ * | | | measurements at their own |
+ * | | | risk. |
+ * +---------------------+-------------------+-----------------------------+
+ *
*/
@export(name="", value_prefix="GNSS_")
enum GnssAccumulatedDeltaRangeState : uint16_t {