GPS北斗双模技术应用开发研究—数据结构扩展
还是从gps.h头文件入手,首先 GpsSvStatus结构体需要改造,GpsSvStatus当时设计的时候是考虑存储gps卫星信息的,但是我们现在是要存储双模的数据,因此我们需要扩展这个数据结构,那怎么扩展呢?
当然要代价小一点,不能完全推倒重来的,笔者想到的就是增加一个北斗卫星数量的变量,以及北斗的epemeris、almanac、还有一个定位的mask,以前数据结构里面的成员全部用着gps存储,这样就相互独立了,但是sv_list笔者就偷懒共用了,只是把这个数组扩大一倍,后半部分存储北斗卫星信息,这样的话第一步就算完成了。基本如下:
/** Maximum number of SVs for gps_sv_status_callback(). */ -#define GPS_MAX_SVS 32 +#define GPS_MAX_SVS 64 /** Requested operational mode for GPS operation. */ typedef uint32_t GpsPositionMode; @@ -306,6 +306,25 @@ typedef struct { * were used for computing the most recent position fix. */ uint32_t used_in_fix_mask; + + /** Number of bd SVs currently visible. */ + int bd_num_svs; + + /** Represents a bit mask indicating which SVs + * have ephemeris data. + */ + uint32_t bd_ephemeris_mask; + + /** Represents a bit mask indicating which SVs + * have almanac data. + */ + uint32_t bd_almanac_mask; + + /** + * Represents a bit mask indicating which SVs + * were used for computing the most recent position fix. + */ + uint32_t bd_used_in_fix_mask; } GpsSvStatus;
解析本身的难度不大,依葫芦画瓢罢了,都是固定的。那就看一下GSV怎么解析的吧!如下:
if ( !memcmp(tok.p, "GSV", 3) ) { int noSatellites; Token satellite_to_view; is_beidou = !memcmp(ptr, "BD", 2); satellite_to_view = nmea_tokenizer_get(tzer, 3); noSatellites = str2int(satellite_to_view.p, satellite_to_view.end); ALOGV(">>>is_beidou (%d) GSV satellite_to_view=%d", is_beidou, noSatellites); if (noSatellites > 0 ) { //tmp int sentence, totalSentences, curr, i, bd_cur; Token num_of_msg; Token no; num_of_msg = nmea_tokenizer_get(tzer, 1); no = nmea_tokenizer_get(tzer, 2); sentence = str2int(no.p, no.end); totalSentences = str2int(num_of_msg.p, num_of_msg.end); D(">>>gsv_index=%d,gsv_total=%d",sentence, totalSentences); if (sentence == 1 && !is_beidou) { r->sv_status.num_svs = 0; r->sv_status.ephemeris_mask = 0ul; r->sv_status.almanac_mask = 0ul; r->sv_status.bd_num_svs= 0; r->sv_status.bd_ephemeris_mask= 0ul; r->sv_status.bd_almanac_mask= 0ul; } curr = r->sv_status.num_svs; bd_cur = r->sv_status.bd_num_svs + 32; i = 0; while (i < 4 && (r->sv_status.num_svs < noSatellites || (is_beidou && r->sv_status.bd_num_svs < noSatellites))) { int prn; Token tok_prn = nmea_tokenizer_get(tzer, i * 4 + 4); Token tok_elevation = nmea_tokenizer_get(tzer, i * 4 + 5); Token tok_azimuth = nmea_tokenizer_get(tzer, i * 4 + 6); Token tok_snr = nmea_tokenizer_get(tzer, i * 4 + 7); prn = str2int(tok_prn.p, tok_prn.end); if (prn <= 0) { i += 1; continue; } if(is_beidou) { if(prn > 400) prn -= 400;//M8 BD base 400 r->sv_status.sv_list[bd_cur].prn = prn; r->sv_status.sv_list[bd_cur].elevation = str2float(tok_elevation.p, tok_elevation.end); r->sv_status.sv_list[bd_cur].azimuth = str2float(tok_azimuth.p, tok_azimuth.end); r->sv_status.sv_list[bd_cur].snr = str2float(tok_snr.p, tok_snr.end); r->sv_status.bd_ephemeris_mask|= (1ul << (prn-1)); r->sv_status.bd_almanac_mask|= (1ul << (prn-1)); r->sv_status.bd_num_svs+= 1;// bd num r->sv_status.num_svs += 1;//total num if(r->sv_status.sv_list[bd_cur].snr > 0) ALOGV("**bd_cur=%d num_svs:%d prn:%d snr=%f\n", bd_cur, r->sv_status.num_svs, r->sv_status.sv_list[bd_cur].prn,r->sv_status.sv_list[bd_cur].snr); bd_cur += 1; } else { r->sv_status.sv_list[curr].prn = prn; r->sv_status.sv_list[curr].elevation = str2float(tok_elevation.p, tok_elevation.end); r->sv_status.sv_list[curr].azimuth = str2float(tok_azimuth.p, tok_azimuth.end); r->sv_status.sv_list[curr].snr = str2float(tok_snr.p, tok_snr.end); r->sv_status.ephemeris_mask |= (1ul << (prn-1)); r->sv_status.almanac_mask |= (1ul << (prn-1)); r->sv_status.num_svs += 1; if(r->sv_status.sv_list[curr].snr > 0) ALOGV("##curr=%d num_svs:%d prn:%d snr=%f\n", curr, r->sv_status.num_svs, r->sv_status.sv_list[curr].prn,r->sv_status.sv_list[curr].snr); curr += 1; } i += 1; }
其他的GGA这些双模不双模都是一样的。下面我们看看在JNI里面,android_location_GpsLocationProvider_read_sv_status上报的各个卫星的情况的,显示他的接口也是需要改造的,要扩展,如下:
@@ -465,17 +465,34 @@ static jint android_location_GpsLocationProvider_read_sv_status(JNIEnv* env, job jfloat* elev = env->GetFloatArrayElements(elevArray, 0); jfloat* azim = env->GetFloatArrayElements(azumArray, 0); jint* mask = env->GetIntArrayElements(maskArray, 0); + int i, j; int num_svs = sGpsSvStatus.num_svs; - for (int i = 0; i < num_svs; i++) { + int bd_num_svs = sGpsSvStatus.bd_num_svs; + + //gps info + for (i = 0; i < (num_svs - bd_num_svs); i++) { prns[i] = sGpsSvStatus.sv_list[i].prn; snrs[i] = sGpsSvStatus.sv_list[i].snr; elev[i] = sGpsSvStatus.sv_list[i].elevation; azim[i] = sGpsSvStatus.sv_list[i].azimuth; } + + //bd info + for (j = 0; j < bd_num_svs; j++) { + prns[i+j] = sGpsSvStatus.sv_list[32+j].prn; + snrs[i+j] = sGpsSvStatus.sv_list[32+j].snr; + elev[i+j] = sGpsSvStatus.sv_list[32+j].elevation; + azim[i+j] = sGpsSvStatus.sv_list[32+j].azimuth; + } + mask[0] = sGpsSvStatus.ephemeris_mask; mask[1] = sGpsSvStatus.almanac_mask; mask[2] = sGpsSvStatus.used_in_fix_mask; + mask[3] = bd_num_svs; + mask[4] = sGpsSvStatus.bd_ephemeris_mask; + mask[5] = sGpsSvStatus.bd_almanac_mask; + mask[6] = sGpsSvStatus.bd_used_in_fix_mask;
这个JNI接口直接就得了gps的location provider了,同样要扩展
@@ -1285,7 +1285,9 @@ public class GpsLocationProvider implements LocationProviderInterface { try { listener.mListener.onSvStatusChanged(svCount, mSvs, mSnrs, mSvElevations, mSvAzimuths, mSvMasks[EPHEMERIS_MASK], - mSvMasks[ALMANAC_MASK], mSvMasks[USED_FOR_FIX_MASK]); + mSvMasks[ALMANAC_MASK], mSvMasks[USED_FOR_FIX_MASK], + mSvMasks[BD_SVS_NUM], mSvMasks[BD_EPHEMERIS_MASK], + mSvMasks[BD_ALMANAC_MASK],mSvMasks[BD_USED_FOR_FIX_MASK]); } catch (RemoteException e) { Log.w(TAG, "RemoteException in reportSvInfo"); mListeners.remove(listener); @@ -1296,22 +1298,33 @@ public class GpsLocationProvider implements LocationProviderInterface { } if (VERBOSE) { - Log.v(TAG, "SV count: " + svCount + + Log.d(TAG, "SV count: " + svCount + " ephemerisMask: " + Integer.toHexString(mSvMasks[EPHEMERIS_MASK]) + " almanacMask: " + Integer.toHexString(mSvMasks[ALMANAC_MASK])); for (int i = 0; i < svCount; i++) { - Log.v(TAG, "sv: " + mSvs[i] + + if(i < (svCount - mSvMasks[BD_SVS_NUM])){ + Log.d(TAG, "sv: " + mSvs[i] + " snr: " + mSnrs[i]/10 + " elev: " + mSvElevations[i] + " azimuth: " + mSvAzimuths[i] + ((mSvMasks[EPHEMERIS_MASK] & (1 << (mSvs[i] - 1))) == 0 ? " " : " E") + ((mSvMasks[ALMANAC_MASK] & (1 << (mSvs[i] - 1))) == 0 ? " " : " A") + ((mSvMasks[USED_FOR_FIX_MASK] & (1 << (mSvs[i] - 1))) == 0 ? "" : "U")); + } else { + + Log.d(TAG, "BD sv: " + mSvs[i] + + " BD snr: " + mSnrs[i]/10 + + " BD elev: " + mSvElevations[i] + + " BD azimuth: " + mSvAzimuths[i] + + ((mSvMasks[BD_EPHEMERIS_MASK] & (1 << (mSvs[i] - 1))) == 0 ? " " : " E") + + ((mSvMasks[BD_ALMANAC_MASK] & (1 << (mSvs[i] - 1))) == 0 ? " " : " A") + + ((mSvMasks[BD_USED_FOR_FIX_MASK] & (1 << (mSvs[i] - 1))) == 0 ? "" : "U")); + } } } // return number of sets used in fix instead of total - updateStatus(mStatus, Integer.bitCount(mSvMasks[USED_FOR_FIX_MASK])); + updateStatus(mStatus, (Integer.bitCount(mSvMasks[USED_FOR_FIX_MASK] + Integer.bitCount(mSvMasks[BD_USED_FOR_FIX_MASK])))); if (mNavigating && mStatus == LocationProvider.AVAILABLE && mLastFixTime > 0 && System.currentTimeMillis() - mLastFixTime > RECENT_FIX_TIMEOUT) { @@ -1895,17 +1908,21 @@ public class GpsLocationProvider implements LocationProviderInterface { } // for GPS SV statistics - private static final int MAX_SVS = 32; + private static final int MAX_SVS = 64; private static final int EPHEMERIS_MASK = 0; private static final int ALMANAC_MASK = 1; private static final int USED_FOR_FIX_MASK = 2; + private static final int BD_SVS_NUM = 3; + private static final int BD_EPHEMERIS_MASK = 4; + private static final int BD_ALMANAC_MASK = 5; + private static final int BD_USED_FOR_FIX_MASK = 6; // preallocated arrays, to avoid memory allocation in reportStatus() private int mSvs[] = new int[MAX_SVS]; private float mSnrs[] = new float[MAX_SVS]; private float mSvElevations[] = new float[MAX_SVS]; private float mSvAzimuths[] = new float[MAX_SVS]; - private int mSvMasks[] = new int[3]; + private int mSvMasks[] = new int[7]; private int mSvCount; // preallocated to avoid memory allocation in reportNmea() private byte[] mNmeaBuffer = new byte[120];
这就已经都java部分了,完成了大半了,后面再讲后半段的处理,也还有很多的道道在里面。
时间: 2024-10-13 09:26:41