NMEA parser from http://www.gpsinformation.org/dale/nmea.htm#GSV via http://pegjs.org/online

input.txt

$GPGGA,123519,4807.038,N,01131.000,E,1,08,0.9,545.4,M,46.9,M,,*47
$GPGSA,A,3,04,05,,09,12,,,24,,,,,2.5,1.3,2.1*39

nmea.pegjs

data = records:(nmea:nmea '\n' { return nmea; })+

nmea
  = GP_START data:gga { return data; }
  / GP_START data:gsa { return data; }
  
gga
  = GGA_START SEP time:time pos:pos fix:int SEP count:int SEP hdil:dec SEP alt:dist geoid:dist SEP checksum {
      return {type: 'gga', time: time, pos: pos, fix: fix, count: count, hdil: hdil, alt: alt, geoid: geoid}; 
    }
  
gsa
  = GSA_START SEP auto:auto fix:int SEP sat:twelve_sat pdop:dec SEP hdop:dec SEP vdop:dec checksum {
      return {type: 'gsa', auto: auto, fix: fix, sat: sat, pdop: pdop, hdop: hdop, vdop: vdop};
    }
  
time 
  = hour:hour minute:minute second:second SEP { return {hour: hour, min: minute, sec: second}; }
  
hour
  = h:$('0' [1-9]) { return parseInt(h, 10); }
  / h:$('1' [0-2]) { return parseInt(h, 10); }
  
minute
  = m:$([0-5][0-9]) { return parseInt(m, 10); }
  
second
  = s:$([0-5][0-9]) { return parseInt(s, 10); }

pos
  = lat:lat SEP long:long SEP { return {lat: lat, long: long}; }

lat
  = deg:dec SEP 'N' { return {angle: deg, dir: 'n'}; }
  / deg:dec SEP 'S' { return {angle: deg, dir: 's'}; }

long
  = deg:dec SEP 'E' { return {angle: deg, dir: 'e'}; }
  / deg:dec SEP 'W' { return {angle: deg, dir: 'w'}; }

int
  = i:[0-9]+ { return parseInt(i, 10); }

dec
  = d:$(w:[0-9]* '.' d:[0-9]+) { return parseFloat(d, 10); }
  
dist
  = dist:dec SEP 'M' SEP { return {dist: dist, unit: 'm'}; }

twelve_sat
  = sat sat sat sat sat sat sat sat sat sat sat sat

sat
  = id:int? SEP { return id; }
  
checksum
  = '*' cs:int { return cs; }
  
auto
  = 'M' SEP { return false; }
  / 'A' SEP { return true; }
  
GP_START = '$GP'
GGA_START = 'GGA'
GSA_START = 'GSA'
SEP = ','

output.js

[
   {
      "type": "gga",
      "time": {
         "hour": 12,
         "min": 35,
         "sec": 19
      },
      "pos": {
         "lat": {
            "angle": 4807.038,
            "dir": "n"
         },
         "long": {
            "angle": 1131,
            "dir": "e"
         }
      },
      "fix": 1,
      "count": 0,
      "hdil": 0.9,
      "alt": {
         "dist": 545.4,
         "unit": "m"
      },
      "geoid": {
         "dist": 46.9,
         "unit": "m"
      }
   },
   {
      "type": "gsa",
      "auto": true,
      "fix": 3,
      "sat": [
         0,
         0,
         null,
         0,
         1,
         null,
         null,
         2,
         null,
         null,
         null,
         null
      ],
      "pdop": 2.5,
      "hdop": 1.3,
      "vdop": 2.1
   }
]