1/* 2 * Copyright (C) 2016 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17package android.hardware.gnss@1.0; 18 19/** The callback interface to report measurements from the HAL. */ 20interface IGnssMeasurementCallback { 21 /** 22 * Flags to indicate what fields in GnssClock are valid. 23 */ 24 @export(name="", value_prefix="GNSS_CLOCK_") 25 enum GnssClockFlags : uint16_t { 26 /** A valid 'leap second' is stored in the data structure. */ 27 HAS_LEAP_SECOND = 1 << 0, 28 /** A valid 'time uncertainty' is stored in the data structure. */ 29 HAS_TIME_UNCERTAINTY = 1 << 1, 30 /** A valid 'full bias' is stored in the data structure. */ 31 HAS_FULL_BIAS = 1 << 2, 32 /** A valid 'bias' is stored in the data structure. */ 33 HAS_BIAS = 1 << 3, 34 /** A valid 'bias uncertainty' is stored in the data structure. */ 35 HAS_BIAS_UNCERTAINTY = 1 << 4, 36 /** A valid 'drift' is stored in the data structure. */ 37 HAS_DRIFT = 1 << 5, 38 /** A valid 'drift uncertainty' is stored in the data structure. */ 39 HAS_DRIFT_UNCERTAINTY = 1 << 6 40 }; 41 42 /** 43 * Flags to indicate what fields in GnssMeasurement are valid. 44 */ 45 @export(name="", value_prefix="GNSS_MEASUREMENT_") 46 enum GnssMeasurementFlags : uint32_t { 47 /** A valid 'snr' is stored in the data structure. */ 48 HAS_SNR = 1 << 0, 49 /** A valid 'carrier frequency' is stored in the data structure. */ 50 HAS_CARRIER_FREQUENCY = 1 << 9, 51 /** A valid 'carrier cycles' is stored in the data structure. */ 52 HAS_CARRIER_CYCLES = 1 << 10, 53 /** A valid 'carrier phase' is stored in the data structure. */ 54 HAS_CARRIER_PHASE = 1 << 11, 55 /** A valid 'carrier phase uncertainty' is stored in the data structure. */ 56 HAS_CARRIER_PHASE_UNCERTAINTY = 1 << 12, 57 /** A valid automatic gain control is stored in the data structure. */ 58 HAS_AUTOMATIC_GAIN_CONTROL = 1 << 13 59 }; 60 61 /** 62 * Enumeration of available values for the GNSS Measurement's multipath 63 * indicator. 64 */ 65 @export(name="", value_prefix="GNSS_MULTIPATH_") 66 enum GnssMultipathIndicator : uint8_t { 67 /** The indicator is not available or unknown. */ 68 INDICATOR_UNKNOWN = 0, 69 /** The measurement is indicated to be affected by multipath. */ 70 INDICATOR_PRESENT = 1, 71 /** The measurement is indicated to be not affected by multipath. */ 72 INDICATIOR_NOT_PRESENT = 2 73 }; 74 75 /** 76 * Flags indicating the GNSS measurement state. 77 * 78 * The expected behavior here is for GNSS HAL to set all the flags that applies. 79 * For example, if the state for a satellite is only C/A code locked and bit 80 * synchronized, and there is still millisecond ambiguity, the state must be 81 * set as: 82 * 83 * STATE_CODE_LOCK | STATE_BIT_SYNC | STATE_MSEC_AMBIGUOUS 84 * 85 * If GNSS is still searching for a satellite, the corresponding state must be 86 * set to STATE_UNKNOWN(0). 87 */ 88 @export(name="", value_prefix="GNSS_MEASUREMENT_") 89 enum GnssMeasurementState : uint32_t { 90 STATE_UNKNOWN = 0, 91 STATE_CODE_LOCK = 1 << 0, 92 STATE_BIT_SYNC = 1 << 1, 93 STATE_SUBFRAME_SYNC = 1 << 2, 94 STATE_TOW_DECODED = 1 << 3, 95 STATE_MSEC_AMBIGUOUS = 1 << 4, 96 STATE_SYMBOL_SYNC = 1 << 5, 97 STATE_GLO_STRING_SYNC = 1 << 6, 98 STATE_GLO_TOD_DECODED = 1 << 7, 99 STATE_BDS_D2_BIT_SYNC = 1 << 8, 100 STATE_BDS_D2_SUBFRAME_SYNC = 1 << 9, 101 STATE_GAL_E1BC_CODE_LOCK = 1 << 10, 102 STATE_GAL_E1C_2ND_CODE_LOCK = 1 << 11, 103 STATE_GAL_E1B_PAGE_SYNC = 1 << 12, 104 STATE_SBAS_SYNC = 1 << 13, 105 STATE_TOW_KNOWN = 1 << 14, 106 STATE_GLO_TOD_KNOWN = 1 << 15, 107 }; 108 109 /** 110 * Flags indicating the Accumulated Delta Range's states. 111 */ 112 @export(name="", value_prefix="GNSS_") 113 enum GnssAccumulatedDeltaRangeState : uint16_t { 114 ADR_STATE_UNKNOWN = 0, 115 ADR_STATE_VALID = 1 << 0, 116 ADR_STATE_RESET = 1 << 1, 117 ADR_STATE_CYCLE_SLIP = 1 << 2, 118 }; 119 120 /** 121 * Represents an estimate of the GNSS clock time. 122 */ 123 struct GnssClock { 124 /** 125 * A set of flags indicating the validity of the fields in this data 126 * structure. 127 */ 128 bitfield<GnssClockFlags> gnssClockFlags; 129 130 /** 131 * Leap second data. 132 * The sign of the value is defined by the following equation: 133 * utcTimeNs = timeNs - (fullBiasNs + biasNs) - leapSecond * 134 * 1,000,000,000 135 * 136 * If this data is available, gnssClockFlags must contain 137 * HAS_LEAP_SECOND. 138 */ 139 int16_t leapSecond; 140 141 /** 142 * The GNSS receiver internal clock value. This is the local hardware clock 143 * value. 144 * 145 * For local hardware clock, this value is expected to be monotonically 146 * increasing while the hardware clock remains powered on. (For the case of a 147 * HW clock that is not continuously on, see the 148 * hwClockDiscontinuityCount field). The receiver's estimate of GNSS time 149 * can be derived by subtracting the sum of fullBiasNs and biasNs (when 150 * available) from this value. 151 * 152 * This GNSS time must be the best estimate of current GNSS time 153 * that GNSS receiver can achieve. 154 * 155 * Sub-nanosecond accuracy can be provided by means of the 'biasNs' field. 156 * The value contains the timeUncertaintyNs in it. 157 * 158 * This field is mandatory. 159 */ 160 int64_t timeNs; 161 162 /** 163 * 1-Sigma uncertainty associated with the clock's time in nanoseconds. 164 * The uncertainty is represented as an absolute (single sided) value. 165 * 166 * If the data is available, gnssClockFlags must contain 167 * HAS_TIME_UNCERTAINTY. Ths value is ideally zero, as the time 168 * 'latched' by timeNs is defined as the reference clock vs. which all 169 * other times (and corresponding uncertainties) are measured. 170 */ 171 double timeUncertaintyNs; 172 173 /** 174 * The difference between hardware clock ('time' field) inside GNSS receiver 175 * and the true GNSS time since 0000Z, January 6, 1980, in nanoseconds. 176 * 177 * The sign of the value is defined by the following equation: 178 * local estimate of GNSS time = timeNs - (fullBiasNs + biasNs) 179 * 180 * This value is mandatory if the receiver has estimated GNSS time. If the 181 * computed time is for a non-GNSS constellation, the time offset of that 182 * constellation to GNSS has to be applied to fill this value. The error 183 * estimate for the sum of this and the biasNs is the biasUncertaintyNs, 184 * and the caller is responsible for using this uncertainty (it can be very 185 * large before the GNSS time has been solved for.) If the data is available 186 * gnssClockFlags must contain HAS_FULL_BIAS. 187 */ 188 int64_t fullBiasNs; 189 190 /** 191 * Sub-nanosecond bias. 192 * The error estimate for the sum of this and the fullBiasNs is the 193 * biasUncertaintyNs. 194 * 195 * If the data is available gnssClockFlags must contain HAS_BIAS. If GNSS 196 * has computed a position fix. This value is mandatory if the receiver has 197 * estimated GNSS time. 198 */ 199 double biasNs; 200 201 /** 202 * 1-Sigma uncertainty associated with the local estimate of GNSS time (clock 203 * bias) in nanoseconds. The uncertainty is represented as an absolute 204 * (single sided) value. 205 * 206 * If the data is available gnssClockFlags must contain 207 * HAS_BIAS_UNCERTAINTY. This value is mandatory if the receiver 208 * has estimated GNSS time. 209 */ 210 double biasUncertaintyNs; 211 212 /** 213 * The clock's drift in nanoseconds (per second). 214 * 215 * A positive value means that the frequency is higher than the nominal 216 * frequency, and that the (fullBiasNs + biasNs) is growing more positive 217 * over time. 218 * 219 * The value contains the 'drift uncertainty' in it. 220 * If the data is available gnssClockFlags must contain HAS_DRIFT. 221 * 222 * This value is mandatory if the receiver has estimated GNSS time. 223 */ 224 double driftNsps; 225 226 /** 227 * 1-Sigma uncertainty associated with the clock's drift in nanoseconds (per 228 * second). 229 * The uncertainty is represented as an absolute (single sided) value. 230 * 231 * If the data is available gnssClockFlags must contain 232 * HAS_DRIFT_UNCERTAINTY. If GNSS has computed a position fix this 233 * field is mandatory and must be populated. 234 */ 235 double driftUncertaintyNsps; 236 237 /** 238 * When there are any discontinuities in the HW clock, this field is 239 * mandatory. 240 * 241 * A "discontinuity" is meant to cover the case of a switch from one source 242 * of clock to another. A single free-running crystal oscillator (XO) 243 * will generally not have any discontinuities, and this can be set and 244 * left at 0. 245 * 246 * If, however, the timeNs value (HW clock) is derived from a composite of 247 * sources, that is not as smooth as a typical XO, or is otherwise stopped & 248 * restarted, then this value shall be incremented each time a discontinuity 249 * occurs. (E.g. this value can start at zero at device boot-up and 250 * increment each time there is a change in clock continuity. In the 251 * unlikely event that this value reaches full scale, rollover (not 252 * clamping) is required, such that this value continues to change, during 253 * subsequent discontinuity events.) 254 * 255 * While this number stays the same, between GnssClock reports, it can be 256 * safely assumed that the timeNs value has been running continuously, e.g. 257 * derived from a single, high quality clock (XO like, or better, that is 258 * typically used during continuous GNSS signal sampling.) 259 * 260 * It is expected, esp. during periods where there are few GNSS signals 261 * available, that the HW clock be discontinuity-free as long as possible, 262 * as this avoids the need to use (waste) a GNSS measurement to fully 263 * re-solve for the GNSS clock bias and drift, when using the accompanying 264 * measurements, from consecutive GnssData reports. 265 */ 266 uint32_t hwClockDiscontinuityCount; 267 268 }; 269 270 /** 271 * Represents a GNSS Measurement, it contains raw and computed information. 272 * 273 * All signal measurement information (e.g. svTime, 274 * pseudorangeRate, multipathIndicator) reported in this struct must be 275 * based on GNSS signal measurements only. You must not synthesize measurements 276 * by calculating or reporting expected measurements based on known or estimated 277 * position, velocity, or time. 278 */ 279 struct GnssMeasurement{ 280 /** 281 * A set of flags indicating the validity of the fields in this data 282 * structure. 283 */ 284 bitfield<GnssMeasurementFlags> flags; 285 286 /** 287 * Satellite vehicle ID number, as defined in GnssSvInfo::svid 288 * This is a mandatory value. 289 */ 290 int16_t svid; 291 292 /** 293 * Defines the constellation of the given SV. 294 */ 295 GnssConstellationType constellation; 296 297 /** 298 * Time offset at which the measurement was taken in nanoseconds. 299 * The reference receiver's time is specified by GnssData::clock::timeNs. 300 * 301 * The sign of timeOffsetNs is given by the following equation: 302 * measurement time = GnssClock::timeNs + timeOffsetNs 303 * 304 * It provides an individual time-stamp for the measurement, and allows 305 * sub-nanosecond accuracy. 306 * This is a mandatory value. 307 */ 308 double timeOffsetNs; 309 310 /** 311 * Per satellite sync state. It represents the current sync state for the 312 * associated satellite. 313 * Based on the sync state, the 'received GNSS tow' field must be interpreted 314 * accordingly. 315 * 316 * This is a mandatory value. 317 */ 318 bitfield<GnssMeasurementState> state; 319 320 /** 321 * The received GNSS Time-of-Week at the measurement time, in nanoseconds. 322 * For GNSS & QZSS, this is the received GNSS Time-of-Week at the 323 * measurement time, in nanoseconds. The value is relative to the 324 * beginning of the current GNSS week. 325 * 326 * Given the highest sync state that can be achieved, per each satellite, 327 * valid range for this field can be: 328 * Searching : [ 0 ] : STATE_UNKNOWN 329 * C/A code lock : [ 0 1ms ] : STATE_CODE_LOCK set 330 * Bit sync : [ 0 20ms ] : STATE_BIT_SYNC set 331 * Subframe sync : [ 0 6s ] : STATE_SUBFRAME_SYNC set 332 * TOW decoded : [ 0 1week ] : STATE_TOW_DECODED set 333 * TOW Known : [ 0 1week ] : STATE_TOW_KNOWN set 334 * 335 * Note: TOW Known refers to the case where TOW is possibly not decoded 336 * over the air but has been determined from other sources. If TOW 337 * decoded is set then TOW Known must also be set. 338 * 339 * Note: If there is any ambiguity in integer millisecond, 340 * GNSS_MEASUREMENT_STATE_MSEC_AMBIGUOUS must be set accordingly, in the 341 * 'state' field. 342 * 343 * This value must be populated if 'state' != STATE_UNKNOWN. 344 * 345 * For Glonass, this is the received Glonass time of day, at the 346 * measurement time in nanoseconds. 347 * 348 * Given the highest sync state that can be achieved, per each satellite, 349 * valid range for this field can be: 350 * Searching : [ 0 ] : STATE_UNKNOWN set 351 * C/A code lock : [ 0 1ms ] : STATE_CODE_LOCK set 352 * Symbol sync : [ 0 10ms ] : STATE_SYMBOL_SYNC set 353 * Bit sync : [ 0 20ms ] : STATE_BIT_SYNC set 354 * String sync : [ 0 2s ] : STATE_GLO_STRING_SYNC set 355 * Time of day decoded : [ 0 1day ] : STATE_GLO_TOD_DECODED set 356 * Time of day known : [ 0 1day ] : STATE_GLO_TOD_KNOWN set 357 * 358 * Note: Time of day known refers to the case where it is possibly not 359 * decoded over the air but has been determined from other sources. If 360 * Time of day decoded is set then Time of day known must also be set. 361 * 362 * For Beidou, this is the received Beidou time of week, 363 * at the measurement time in nanoseconds. 364 * 365 * Given the highest sync state that can be achieved, per each satellite, 366 * valid range for this field can be: 367 * Searching : [ 0 ] : STATE_UNKNOWN set. 368 * C/A code lock : [ 0 1ms ] : STATE_CODE_LOCK set. 369 * Bit sync (D2) : [ 0 2ms ] : STATE_BDS_D2_BIT_SYNC set. 370 * Bit sync (D1) : [ 0 20ms ] : STATE_BIT_SYNC set. 371 * Subframe (D2) : [ 0 0.6s ] : STATE_BDS_D2_SUBFRAME_SYNC set. 372 * Subframe (D1) : [ 0 6s ] : STATE_SUBFRAME_SYNC set. 373 * Time of week decoded : [ 0 1week ] : STATE_TOW_DECODED set. 374 * Time of week known : [ 0 1week ] : STATE_TOW_KNOWN set 375 * 376 * Note: TOW Known refers to the case where TOW is possibly not decoded 377 * over the air but has been determined from other sources. If TOW 378 * decoded is set then TOW Known must also be set. 379 * 380 * For Galileo, this is the received Galileo time of week, 381 * at the measurement time in nanoseconds. 382 * 383 * E1BC code lock : [ 0 4ms ] : STATE_GAL_E1BC_CODE_LOCK set. 384 * E1C 2nd code lock : [ 0 100ms] : STATE_GAL_E1C_2ND_CODE_LOCK set. 385 * E1B page : [ 0 2s ] : STATE_GAL_E1B_PAGE_SYNC set. 386 * Time of week decoded : [ 0 1week] : STATE_TOW_DECODED is set. 387 * Time of week known : [ 0 1week] : STATE_TOW_KNOWN set 388 * 389 * Note: TOW Known refers to the case where TOW is possibly not decoded 390 * over the air but has been determined from other sources. If TOW 391 * decoded is set then TOW Known must also be set. 392 * 393 * For SBAS, this is received SBAS time, at the measurement time in 394 * nanoseconds. 395 * 396 * Given the highest sync state that can be achieved, per each satellite, 397 * valid range for this field can be: 398 * Searching : [ 0 ] : STATE_UNKNOWN 399 * C/A code lock: [ 0 1ms ] : STATE_CODE_LOCK is set 400 * Symbol sync : [ 0 2ms ] : STATE_SYMBOL_SYNC is set 401 * Message : [ 0 1s ] : STATE_SBAS_SYNC is set 402 */ 403 int64_t receivedSvTimeInNs; 404 405 /** 406 * 1-Sigma uncertainty of the Received GNSS Time-of-Week in nanoseconds. 407 * 408 * This value must be populated if 'state' != STATE_UNKNOWN. 409 */ 410 int64_t receivedSvTimeUncertaintyInNs; 411 412 /** 413 * Carrier-to-noise density in dB-Hz, typically in the range [0, 63]. 414 * It contains the measured C/N0 value for the signal at the antenna port. 415 * 416 * This is a mandatory value. 417 */ 418 double cN0DbHz; 419 420 /** 421 * Pseudorange rate at the timestamp in m/s. The correction of a given 422 * Pseudorange Rate value includes corrections for receiver and satellite 423 * clock frequency errors. Ensure that this field is independent (see 424 * comment at top of GnssMeasurement struct.) 425 * 426 * It is mandatory to provide the 'uncorrected' 'pseudorange rate', and 427 * provide GnssClock's 'drift' field as well. When providing the 428 * uncorrected pseudorange rate, do not apply the corrections described above.) 429 * 430 * The value includes the 'pseudorange rate uncertainty' in it. 431 * A positive 'uncorrected' value indicates that the SV is moving away from 432 * the receiver. 433 * 434 * The sign of the 'uncorrected' 'pseudorange rate' and its relation to the 435 * sign of 'doppler shift' is given by the equation: 436 * pseudorange rate = -k * doppler shift (where k is a constant) 437 * 438 * This must be the most accurate pseudorange rate available, based on 439 * fresh signal measurements from this channel. 440 * 441 * It is mandatory that this value be provided at typical carrier phase PRR 442 * quality (few cm/sec per second of uncertainty, or better) - when signals 443 * are sufficiently strong & stable, e.g. signals from a GNSS simulator at >= 444 * 35 dB-Hz. 445 */ 446 double pseudorangeRateMps; 447 448 /** 449 * 1-Sigma uncertainty of the pseudorangeRateMps. 450 * The uncertainty is represented as an absolute (single sided) value. 451 * 452 * This is a mandatory value. 453 */ 454 double pseudorangeRateUncertaintyMps; 455 456 /** 457 * Accumulated delta range's state. It indicates whether ADR is reset or 458 * there is a cycle slip(indicating loss of lock). 459 * 460 * This is a mandatory value. 461 */ 462 bitfield<GnssAccumulatedDeltaRangeState> accumulatedDeltaRangeState; 463 464 /** 465 * Accumulated delta range since the last channel reset in meters. 466 * A positive value indicates that the SV is moving away from the receiver. 467 * 468 * The sign of the 'accumulated delta range' and its relation to the sign of 469 * 'carrier phase' is given by the equation: 470 * accumulated delta range = -k * carrier phase (where k is a constant) 471 * 472 * This value must be populated if 'accumulated delta range state' != 473 * ADR_STATE_UNKNOWN. 474 * However, it is expected that the data is only accurate when: 475 * 'accumulated delta range state' == ADR_STATE_VALID. 476 */ 477 double accumulatedDeltaRangeM; 478 479 /** 480 * 1-Sigma uncertainty of the accumulated delta range in meters. 481 * This value must be populated if 'accumulated delta range state' != 482 * ADR_STATE_UNKNOWN. 483 */ 484 double accumulatedDeltaRangeUncertaintyM; 485 486 /** 487 * Carrier frequency of the signal tracked, for example it can be the 488 * GPS central frequency for L1 = 1575.45 MHz, or L2 = 1227.60 MHz, L5 = 489 * 1176.45 MHz, varying GLO channels, etc. If the field is not set, it 490 * is the primary common use central frequency, e.g. L1 = 1575.45 MHz 491 * for GPS. 492 * 493 * For an L1, L5 receiver tracking a satellite on L1 and L5 at the same 494 * time, two raw measurement structs must be reported for this same 495 * satellite, in one of the measurement structs, all the values related 496 * to L1 must be filled, and in the other all of the values related to 497 * L5 must be filled. 498 * 499 * If the data is available, gnssClockFlags must contain 500 * HAS_CARRIER_FREQUENCY. 501 */ 502 float carrierFrequencyHz; 503 504 /** 505 * The number of full carrier cycles between the satellite and the 506 * receiver. The reference frequency is given by the field 507 * 'carrierFrequencyHz'. Indications of possible cycle slips and 508 * resets in the accumulation of this value can be inferred from the 509 * accumulatedDeltaRangeState flags. 510 * 511 * If the data is available, gnssClockFlags must contain 512 * HAS_CARRIER_CYCLES. 513 */ 514 int64_t carrierCycles; 515 516 /** 517 * The RF phase detected by the receiver, in the range [0.0, 1.0]. 518 * This is usually the fractional part of the complete carrier phase 519 * measurement. 520 * 521 * The reference frequency is given by the field 'carrierFrequencyHz'. 522 * The value contains the 'carrier-phase uncertainty' in it. 523 * 524 * If the data is available, gnssClockFlags must contain 525 * HAS_CARRIER_PHASE. 526 */ 527 double carrierPhase; 528 529 /** 530 * 1-Sigma uncertainty of the carrier-phase. 531 * If the data is available, gnssClockFlags must contain 532 * HAS_CARRIER_PHASE_UNCERTAINTY. 533 */ 534 double carrierPhaseUncertainty; 535 536 /** 537 * An enumeration that indicates the 'multipath' state of the event. 538 * 539 * The multipath Indicator is intended to report the presence of overlapping 540 * signals that manifest as distorted correlation peaks. 541 * 542 * - if there is a distorted correlation peak shape, report that multipath 543 * is MULTIPATH_INDICATOR_PRESENT. 544 * - if there is no distorted correlation peak shape, report 545 * MULTIPATH_INDICATOR_NOT_PRESENT 546 * - if signals are too weak to discern this information, report 547 * MULTIPATH_INDICATOR_UNKNOWN 548 * 549 * Example: when doing the standardized overlapping Multipath Performance 550 * test (3GPP TS 34.171) the Multipath indicator must report 551 * MULTIPATH_INDICATOR_PRESENT for those signals that are tracked, and 552 * contain multipath, and MULTIPATH_INDICATOR_NOT_PRESENT for those 553 * signals that are tracked and do not contain multipath. 554 */ 555 GnssMultipathIndicator multipathIndicator; 556 557 /** 558 * Signal-to-noise ratio at correlator output in dB. 559 * If the data is available, GnssMeasurementFlags must contain HAS_SNR. 560 * This is the power ratio of the "correlation peak height above the 561 * observed noise floor" to "the noise RMS". 562 */ 563 double snrDb; 564 565 /** 566 * Automatic gain control (AGC) level. AGC acts as a variable gain 567 * amplifier adjusting the power of the incoming signal. The AGC level 568 * may be used to indicate potential interference. When AGC is at a 569 * nominal level, this value must be set as 0. Higher gain (and/or lower 570 * input power) must be output as a positive number. Hence in cases of 571 * strong jamming, in the band of this signal, this value must go more 572 * negative. 573 * 574 * Note: Different hardware designs (e.g. antenna, pre-amplification, or 575 * other RF HW components) may also affect the typical output of of this 576 * value on any given hardware design in an open sky test - the 577 * important aspect of this output is that changes in this value are 578 * indicative of changes on input signal power in the frequency band for 579 * this measurement. 580 */ 581 double agcLevelDb; 582 }; 583 584 /** 585 * Represents a reading of GNSS measurements. For devices where GnssSystemInfo's 586 * yearOfHw is set to 2016+, it is mandatory that these be provided, on 587 * request, when the GNSS receiver is searching/tracking signals. 588 * 589 * - Reporting of GNSS constellation measurements is mandatory. 590 * - Reporting of all tracked constellations are encouraged. 591 */ 592 struct GnssData { 593 /** Number of GnssMeasurement elements. */ 594 uint32_t measurementCount; 595 596 /** The array of measurements. */ 597 GnssMeasurement[GnssMax:SVS_COUNT] measurements; 598 599 /** The GNSS clock time reading. */ 600 GnssClock clock; 601 }; 602 603 /** 604 * Callback for the hal to pass a GnssData structure back to the client. 605 * 606 * @param data Contains a reading of GNSS measurements. 607 */ 608 GnssMeasurementCb(GnssData data); 609}; 610