@jbroll/nmea-simple
Version:
NMEA 0183 sentence parser and encoder
85 lines (84 loc) • 3.26 kB
JavaScript
;
/*
* === GSV - Satellites in view ===
*
* ------------------------------------------------------------------------------
* 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
* | | | | | | | | | | | | | | | | | | | | | |
* $--GSV,x,x,xx,xx,xx,xx,xxx,xx,xx,xx,xxx,xx,xx,xx,xxx,xx,xx,xx,xxx,xx,s*hh<CR><LF>
* ------------------------------------------------------------------------------
*
* Field Number:
*
* 1. Number of sentences for full data
* 2. Sentence number out of total
* 3. Number of satellites in view
* 4. PRN of satellite used for fix (may be blank)
*
* 5. Satellite PRN number \
* 6. Elevation, degrees +- Satellite 1
* 7. Azimuth, degrees |
* 8. Signal to noise ratio /
*
* 9. Satellite PRN number \
* 10. Elevation, degrees +- Satellite 2
* 11. Azimuth, degrees |
* 12. Signal to noise ratio /
*
* 13. Satellite PRN number \
* 14. Elevation, degrees +- Satellite 3
* 15. Azimuth, degrees |
* 16. Signal to noise ratio /
*
* 17. Satellite PRN number \
* 18. Elevation, degrees +- Satellite 4
* 19. Azimuth, degrees |
* 20. Signal to noise ratio /
*
* 21. Signal ID (u-blox specific field, optional):
* For GPS (GP):
* 0: All signals (default if field not present)
* 1: L1 C/A
* 6: L2 CL
* 22. Checksum
*/
var __assign = (this && this.__assign) || function () {
__assign = Object.assign || function(t) {
for (var s, i = 1, n = arguments.length; i < n; i++) {
s = arguments[i];
for (var p in s) if (Object.prototype.hasOwnProperty.call(s, p))
t[p] = s[p];
}
return t;
};
return __assign.apply(this, arguments);
};
Object.defineProperty(exports, "__esModule", { value: true });
var helpers_1 = require("../helpers");
var prn_utils_1 = require("../prn-utils");
var PacketStub_1 = require("./PacketStub");
exports.sentenceId = "GSV";
exports.sentenceName = "Satellites in view";
function decodeSentence(stub, fields) {
// Each satellite uses 4 fields
var numRecords = Math.floor((fields.length - 4) / 4);
var sats = [];
var systemId = prn_utils_1.getTalkerSystemId(stub.talkerId || "");
// Process satellite records
for (var i = 0; i < numRecords; i++) {
var offset = i * 4 + 4;
// Only add satellites with valid PRN numbers
var rawPrn = helpers_1.parseIntSafe(fields[offset]);
if (rawPrn > 0) {
var adjustedPrn = prn_utils_1.adjustPRN(rawPrn, systemId);
sats.push({
prnNumber: adjustedPrn,
elevationDegrees: helpers_1.parseIntSafe(fields[offset + 1]),
azimuthTrue: helpers_1.parseIntSafe(fields[offset + 2]),
SNRdB: helpers_1.parseIntSafe(fields[offset + 3])
});
}
}
return __assign(__assign({}, PacketStub_1.initStubFields(stub, exports.sentenceId, exports.sentenceName)), { numberOfMessages: helpers_1.parseIntSafe(fields[1]), messageNumber: helpers_1.parseIntSafe(fields[2]), satellitesInView: helpers_1.parseIntSafe(fields[3]), satellites: sats });
}
exports.decodeSentence = decodeSentence;