diff --git a/meisei/meisei_rs.c b/meisei/meisei_rs.c
new file mode 100644
index 0000000..2d10c2c
--- /dev/null
+++ b/meisei/meisei_rs.c
@@ -0,0 +1,644 @@
+
+/*
+ * big endian forest
+ * 
+ * Meisei radiosondes
+ * author: zilog80
+ * 
+ */
+
+/*
+PCM-FM, 1200 baud biphase-S
+1200 bit pro Sekunde: zwei Frames, die wiederum in zwei Subframes unterteilt werden koennen, d.h. 4 mal 300 bit.
+
+Variante 1 (RS-11G ?)
+<option -1>
+049DCE1C667FDD8F537C8100004F20764630A20000000010040436 FB623080801F395FFE08A76540000FE01D0C2C1E75025006DE0A07
+049DCE1C67008C73D7168200004F0F764B31A2FFFF000010270B14 FB6230000000000000000000000000000000000000000000001D59
+
+0x00..0x02 HEADER  0x049DCE
+0x03..0x04 16 bit  0.5s-counter, count%2=0:
+0x1B..0x1D HEADER  0xFB6230
+0x20..0x23 32 bit  GPS-lat * 1e7 (DD.dddddd)
+0x24..0x27 32 bit  GPS-lon * 1e7 (DD.dddddd)
+0x28..0x2B 32 bit  GPS-alt * 1e2 (m)
+0x32..0x35 32 bit  date jjJJMMTT
+
+0x00..0x02 HEADER  0x049DCE
+0x03..0x04 16 bit  0.5s-counter, count%2=1:
+0x17..0x18 16 bit  time ms xxyy, 00.000-59.000
+0x19..0x1A 16 bit  time hh:mm
+0x1B..0x1D HEADER  0xFB6230
+
+
+0x049DCE ^ 0xFB6230 = 0xFFFFFE
+
+
+Variante 2 (iMS-100 ?)
+<option -2>
+049DCE3E228023DBF53FA700003C74628430C100000000ABE00B3B FB62302390031EECCC00E656E42327562B2436C4C01CDB0F18B09A
+049DCE3E23516AF62B3FC700003C7390D131C100000000AB090000 FB62300000000000032423222422202014211B13220000000067C4
+
+0x00..0x02  HEADER  0x049DCE
+0x03..0x04  16 bit  0.5s-counter, count%2=0:
+0x17..0x18  16 bit  time ms yyxx, 00.000-59.000
+0x19..0x1A  16 bit  time hh:mm
+0x1B..0x1D  HEADER  0xFB6230
+0x1E..0x1F  16 bit  ? date (TT,MM,JJ)=(date/1000,(date/10)%100,(date%10)+10)
+0x20..0x23  32 bit  GPS-lat * 1e4 (NMEA DDMM.mmmm)
+0x24..0x27  32 bit  GPS-lon * 1e4 (NMEA DDMM.mmmm)
+0x28..0x2A  24 bit  GPS-alt * 1e2 (m)
+
+0x00..0x02  HEADER  0x049DCE
+0x03..0x04  16 bit  0.5s-counter, count%2=1:
+0x17..0x18  16 bit  1024-counter yyxx, +0x400=1024; rollover synchron zu ms-counter, nach rollover auch +0x300=768
+0x1B..0x1D  HEADER  0xFB6230
+
+
+Die 46bit-Bloecke sind BCH-Codewoerter. Es handelt sich um einen (63,51)-Code mit Generatorpolynom
+x^12+x^10+x^8+x^5+x^4+x^3+1;
+gekuerzt auf (46,34), die letzten 12 bit sind die BCH-Kontrollbits.
+
+Die 34 Nachrichtenbits sind aufgeteilt in 16+1+16+1, d.h. nach einem 16 bit Block kommt ein Paritaetsbit,
+dass 1 ist, wenn die Anzahl 1en in den 16 bit davor gerade ist, und sonst 0.
+*/
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+// #include <math.h>
+#ifdef WIN
+  #include <fcntl.h>  // cygwin: _setmode()
+  #include <io.h>
+#endif
+
+typedef unsigned char  ui8_t;
+typedef unsigned short ui16_t;
+typedef unsigned int   ui32_t;
+
+typedef struct {
+    int jahr; int monat; int tag;
+    int std; int min; int sek;
+    double lat; double lon; double alt;
+} datum_t;
+
+datum_t datum;
+
+
+int option_verbose = 0,  // ausfuehrliche Anzeige
+    option_raw = 0,      // rohe Frames
+    option_inv = 0,      // invertiert Signal
+    option_res = 0,      // genauere Bitmessung
+    option1 = 0,
+    option2 = 0,
+    wavloaded = 0;
+
+/* -------------------------------------------------------------------------- */
+
+#define BAUD_RATE 2400
+
+int sample_rate = 0, bits_sample = 0, channels = 0;
+float samples_per_bit = 0;
+
+int findstr(char *buff, char *str, int pos) {
+    int i;
+    for (i = 0; i < 4; i++) {
+        if (buff[(pos+i)%4] != str[i]) break;
+    }
+    return i;
+}
+
+int read_wav_header(FILE *fp) {
+    char txt[4+1] = "\0\0\0\0";
+    unsigned char dat[4];
+    int byte, p=0;
+
+    if (fread(txt, 1, 4, fp) < 4) return -1;
+    if (strncmp(txt, "RIFF", 4)) return -1;
+    if (fread(txt, 1, 4, fp) < 4) return -1;
+    // pos_WAVE = 8L
+    if (fread(txt, 1, 4, fp) < 4) return -1;
+    if (strncmp(txt, "WAVE", 4)) return -1;
+    // pos_fmt = 12L
+    for ( ; ; ) {
+        if ( (byte=fgetc(fp)) == EOF ) return -1;
+        txt[p % 4] = byte;
+        p++; if (p==4) p=0;
+        if (findstr(txt, "fmt ", p) == 4) break;
+    }
+    if (fread(dat, 1, 4, fp) < 4) return -1;
+    if (fread(dat, 1, 2, fp) < 2) return -1;
+
+    if (fread(dat, 1, 2, fp) < 2) return -1;
+    channels = dat[0] + (dat[1] << 8);
+
+    if (fread(dat, 1, 4, fp) < 4) return -1;
+    memcpy(&sample_rate, dat, 4); //sample_rate = dat[0]|(dat[1]<<8)|(dat[2]<<16)|(dat[3]<<24);
+
+    if (fread(dat, 1, 4, fp) < 4) return -1;
+    if (fread(dat, 1, 2, fp) < 2) return -1;
+    //byte = dat[0] + (dat[1] << 8);
+
+    if (fread(dat, 1, 2, fp) < 2) return -1;
+    bits_sample = dat[0] + (dat[1] << 8);
+
+    // pos_dat = 36L + info
+    for ( ; ; ) {
+        if ( (byte=fgetc(fp)) == EOF ) return -1;
+        txt[p % 4] = byte;
+        p++; if (p==4) p=0;
+        if (findstr(txt, "data", p) == 4) break;
+    }
+    if (fread(dat, 1, 4, fp) < 4) return -1;
+
+
+    fprintf(stderr, "sample_rate: %d\n", sample_rate);
+    fprintf(stderr, "bits       : %d\n", bits_sample);
+    fprintf(stderr, "channels   : %d\n", channels);
+
+    if ((bits_sample != 8) && (bits_sample != 16)) return -1;
+
+    samples_per_bit = sample_rate/(float)BAUD_RATE;
+
+    fprintf(stderr, "samples/bit: %.2f\n", samples_per_bit);
+
+    return 0;
+}
+
+
+#define EOF_INT  0x1000000
+
+int read_signed_sample(FILE *fp) {  // int = i32_t
+    int byte, i, ret;         //  EOF -> 0x1000000
+
+    for (i = 0; i < channels; i++) {
+                           // i = 0: links bzw. mono
+        byte = fgetc(fp);
+        if (byte == EOF) return EOF_INT;
+        if (i == 0) ret = byte;
+    
+        if (bits_sample == 16) {
+            byte = fgetc(fp);
+            if (byte == EOF) return EOF_INT;
+            if (i == 0) ret +=  byte << 8;
+        }
+
+    }
+
+    if (bits_sample ==  8) return ret-128;   // 8bit: 00..FF, centerpoint 0x80=128
+    if (bits_sample == 16) return (short)ret;
+
+    return ret;
+}
+
+int par=1, par_alt=1;
+unsigned long sample_count = 0;
+
+int read_bits_fsk(FILE *fp, int *bit, int *len) {
+    int n, sample, y0;
+    float l, x1;
+    static float x0;
+
+    n = 0;
+    do{
+        y0 = sample;
+        sample = read_signed_sample(fp);
+        if (sample == EOF_INT) return EOF;
+        sample_count++;
+        par_alt = par;
+        par =  (sample > 0) ? 1 : -1;
+        n++;
+    } while (par*par_alt > 0);
+
+    if (!option_res) l = (float)n / samples_per_bit;
+    else {                                 // genauere Bitlaengen-Messung
+        x1 = sample/(float)(sample-y0);    // hilft bei niedriger sample rate
+        l = (n+x0-x1) / samples_per_bit;   // meist mehr frames (nicht immer)
+        x0 = x1;
+    }
+
+    *len = (int)(l+0.5);
+
+    if (!option_inv) *bit = (1+par_alt)/2;  // oben 1, unten -1
+    else             *bit = (1-par_alt)/2;  // sdr#<rev1381?, invers: unten 1, oben -1
+
+    /* Y-offset ? */
+
+    return 0;
+}
+
+/* ------------------------------------------------------------------------------------ */
+
+#define BITFRAME_LEN    1200
+#define RAWBITFRAME_LEN (BITFRAME_LEN*2)
+
+char frame_rawbits[RAWBITFRAME_LEN+10];  // braucht eigentlich nur 1/4
+char frame_bits[BITFRAME_LEN+10];
+
+#define HEADLEN 24
+#define RAWHEADLEN (2*HEADLEN)
+
+char header0x049DCE[] =                             // 0x049DCE =
+"101010101011010100101011001101001100101011001101"; // 00000100 10011101 11001110
+char header0x049DCEbits[] = "000001001001110111001110";
+                           //111110110110001000110000
+char header0xFB6230[] =                             // 0xFB6230 =
+"110011001101001101001101010100101010110010101010"; // 11111011 01100010 00110000
+char header0xFB6230bits[] = "111110110110001000110000";
+                                                    // 0x049DCE ^ 0xFB6230 = 0xFFFFFE
+
+char buf[RAWHEADLEN+1] = "xxxxxxxxxx\0";
+int  bufpos = 0;
+
+/* -------------------------------------------------------------------------- */
+
+void inc_bufpos() {
+  bufpos = (bufpos+1) % RAWHEADLEN;
+}
+
+
+char cb_inv(char c) {
+    if (c == '0') return '1';
+    if (c == '1') return '0';
+    return c;
+}
+
+int compare_subheader() {
+    int i, j;
+
+    i = 0;
+    j = bufpos;
+    while (i < RAWHEADLEN) {
+        if (j < 0) j = RAWHEADLEN-1;
+        if (buf[j] != header0x049DCE[RAWHEADLEN-1-i]) break;
+        j--;
+        i++;
+    }
+    if (i == RAWHEADLEN) return 1;
+
+    i = 0;
+    j = bufpos;
+    while (i < RAWHEADLEN) {
+        if (j < 0) j = RAWHEADLEN-1;
+        if (buf[j] != cb_inv(header0x049DCE[RAWHEADLEN-1-i])) break;
+        j--;
+        i++;
+    }
+    if (i == RAWHEADLEN) return 3;
+
+    i = 0;
+    j = bufpos;
+    while (i < RAWHEADLEN) {
+        if (j < 0) j = RAWHEADLEN-1;
+        if (buf[j] != header0xFB6230[RAWHEADLEN-1-i]) break;
+        j--;
+        i++;
+    }
+    if (i == RAWHEADLEN) return 2;
+
+    i = 0;
+    j = bufpos;
+    while (i < RAWHEADLEN) {
+        if (j < 0) j = RAWHEADLEN-1;
+        if (buf[j] != cb_inv(header0xFB6230[RAWHEADLEN-1-i])) break;
+        j--;
+        i++;
+    }
+    if (i == RAWHEADLEN) return 4;
+
+    return 0;
+
+}
+
+
+
+/* -------------------------------------------------------------------------- */
+
+
+int biphi_s0(char* frame_rawbits, char *frame_bits) {
+    int j = 0;
+    int byt, bytes[2];
+    int c = 0;
+
+    j = 0;
+    while (byt = frame_rawbits[j]) {
+        if ((byt >= 0x30) && (byt <= 0x31)) {
+            bytes[c] = byt;
+            c = !c;
+
+            if ((j > 0) && (c == 0)) {
+                if ( bytes[0] == bytes[1] ) { byt = '1'; }
+                else
+                if ( bytes[0] != bytes[1] ) { byt = '0'; }
+
+                frame_bits[j/2] = byt;
+            }
+            j++;
+
+        }
+    }
+    frame_bits[j/2] = '\0';
+    return j/2;
+}
+
+int biphi_s(char* frame_rawbits, char *frame_bits) {
+    int j = 0;
+    int byt;
+
+    j = 0;
+    while (byt = frame_rawbits[j]) {
+        if ((byt < 0x30) || (byt > 0x31)) break;
+
+        if ( frame_rawbits[2*j] == frame_rawbits[2*j+1] ) { byt = '1'; }
+        else                                              { byt = '0'; }
+
+        frame_bits[j] = byt;
+        j++;
+
+    }
+    frame_bits[j] = '\0';
+    return j;
+}
+
+/* -------------------------------------------------------------------------- */
+
+ui32_t bitstr2val(char *bits, int len) {
+    int j;
+    ui8_t bit;
+    ui32_t val;
+    if ((len < 0) || (len > 32)) return -1;
+    val = 0;
+    for (j = 0; j < len; j++) {
+                bit = bits[j] - 0x30;
+                val |= (bit << (len-1-j)); // big endian
+                //val |= (bit << j);      // little endian
+    }
+    return val;
+}
+
+/* -------------------------------------------------------------------------- */
+
+
+int main(int argc, char **argv) {
+
+    FILE *fp;
+    char *fpname;
+    int i, j;
+    int bit_count = 0,
+        header_found = 0,
+        bit, len;
+
+    int counter;
+    ui32_t val;
+    ui32_t dat2;
+    int lat, lat1, lat2,
+        lon, lon1, lon2,
+        alt, alt1, alt2;
+    int latdeg,londeg;
+    double latmin, lonmin;
+    ui32_t t1, t2, ms, min, std, tt, mm, jj;
+
+
+#ifdef WIN
+    _setmode(fileno(stdin), _O_BINARY);  // _setmode(_fileno(stdin), _O_BINARY);
+    setbuf(stdout, NULL);
+#endif
+
+    fpname = argv[0];
+    ++argv;
+    while ((*argv) && (!wavloaded)) {
+        if      ( (strcmp(*argv, "-h") == 0) || (strcmp(*argv, "--help") == 0) ) {
+        help_out:
+            fprintf(stderr, "%s <-n> [options] audio.wav\n", fpname);
+            fprintf(stderr, "  n=1,2\n");
+            fprintf(stderr, "  options:\n");
+            //fprintf(stderr, "       -v, --verbose\n");
+            fprintf(stderr, "       -r, --raw\n");
+            return 0;
+        }
+/*
+        else if ( (strcmp(*argv, "-v") == 0) || (strcmp(*argv, "--verbose") == 0) ) {
+            option_verbose = 1;
+        }
+*/
+        else if ( (strcmp(*argv, "-r") == 0) || (strcmp(*argv, "--raw") == 0) ) {
+            option_raw = 1;
+        }
+        else if   (strcmp(*argv, "--res") == 0) { option_res = 1; }
+        else if ( (strcmp(*argv, "-i") == 0) || (strcmp(*argv, "--invert") == 0) ) {
+            option_inv = 1;  // nicht noetig
+        }
+        else if ( (strcmp(*argv, "-2") == 0) ) {
+            option2 = 1;
+        }
+        else if ( (strcmp(*argv, "-1") == 0) ) {
+            option1 = 1;
+        }
+        else {
+            if ((option1 == 1  && option2 == 1) || (!option_raw && option1 == 0  && option2 == 0)) goto help_out;
+            fp = fopen(*argv, "rb");
+            if (fp == NULL) {
+                fprintf(stderr, "%s konnte nicht geoeffnet werden\n", *argv);
+                return -1;
+            }
+            wavloaded = 1;
+        }
+        ++argv;
+    }
+    if (!wavloaded) fp = stdin;
+
+
+    i = read_wav_header(fp);
+    if (i) {
+        fclose(fp);
+        return -1;
+    }
+
+
+    bufpos = 0;
+    bit_count = 0;
+
+    while (!read_bits_fsk(fp, &bit, &len)) {
+
+        if (len == 0) { // reset_frame();
+/*
+            if (byte_count > FRAME_LEN-20) {
+                print_frame(byte_count);
+                bit_count = 0;
+                byte_count = FRAMESTART;
+                header_found = 0;
+            }
+*/
+            //inc_bufpos();
+            //buf[bufpos] = 'x';
+            continue;   // ...
+        }
+
+        for (i = 0; i < len; i++) {
+
+            inc_bufpos();
+            buf[bufpos] = 0x30 + bit;  // Ascii
+
+            if (!header_found) {
+                header_found = compare_subheader();
+                if (header_found) {
+                    bit_count = 0;
+                    for (j = 0; j < HEADLEN; j++) {
+                        if (header_found % 2 == 1) frame_bits[j] = header0x049DCEbits[j];
+                        else                       frame_bits[j] = header0xFB6230bits[j];
+                    }
+                }
+            }
+            else {
+                frame_rawbits[bit_count] = 0x30 + bit;
+                bit_count++;
+            
+                if (bit_count >= RAWBITFRAME_LEN/4-RAWHEADLEN) {  // 600-48
+                    frame_rawbits[bit_count] = '\0';
+
+                    biphi_s(frame_rawbits, frame_bits+HEADLEN);
+
+                    if (!option2 && !option_raw) {
+
+                        if (header_found % 2 == 1) {
+                            val = bitstr2val(frame_bits+HEADLEN, 16);
+                            counter = val & 0xFFFF;
+                            if (counter % 2 == 0) printf("\n");
+                            //printf("[0x%04X = %d] ", counter, counter);
+                            printf("[%d] ", counter);
+
+                            if (counter % 2 == 1) {
+                                t2 = bitstr2val(frame_bits+HEADLEN+5*46  , 8);  // LSB
+                                t1 = bitstr2val(frame_bits+HEADLEN+5*46+8, 8);
+                                ms = (t1 << 8) | t2;
+                                std = bitstr2val(frame_bits+HEADLEN+5*46+17, 8);
+                                min = bitstr2val(frame_bits+HEADLEN+5*46+25, 8);
+                                printf("  ");    
+                                printf("%02d:%02d:%06.3f ", std, min, (double)ms/1000.0);
+                                printf("  ");
+
+                                //printf("\n");
+                            }
+                        }
+
+                        if (header_found % 2 == 0) {
+                            val = bitstr2val(frame_bits+HEADLEN, 16);
+                            //printf("%04x ", val & 0xFFFF);
+                            if ((counter % 2 == 0))  { //  (val & 0xFFFF) > 0)  {// == 0x8080
+                                //offset=24+16+1;
+
+                                lat1 = bitstr2val(frame_bits+HEADLEN+17, 16);
+                                lat2 = bitstr2val(frame_bits+HEADLEN+46, 16);
+                                lon1 = bitstr2val(frame_bits+HEADLEN+46+17, 16);
+                                lon2 = bitstr2val(frame_bits+HEADLEN+46+46, 16);
+                                alt1 = bitstr2val(frame_bits+HEADLEN+46+46+17, 16);
+                                alt2 = bitstr2val(frame_bits+HEADLEN+46+46+46, 16);
+
+                                lat = (lat1 << 16) | lat2;
+                                lon = (lon1 << 16) | lon2;
+                                alt = (alt1 << 16) | alt2;
+                                //printf("%08X %08X %08X :  ", lat, lon, alt);
+                                printf("  ");
+                                printf("%.6f  %.6f  %.2f", (double)lat/1e7, (double)lon/1e7, (double)alt/1e2);
+                                printf("  ");
+
+                                jj = bitstr2val(frame_bits+HEADLEN+5*46+ 8, 8) + 0x0700;
+                                mm = bitstr2val(frame_bits+HEADLEN+5*46+17, 8);
+                                tt = bitstr2val(frame_bits+HEADLEN+5*46+25, 8);
+                                printf("  ");
+                                printf("%4d-%02d-%02d ", jj, mm, tt);
+                                printf("  ");
+
+                                //printf("\n");
+                            }
+                        }
+
+                    }
+                    else if (option2 && !option_raw) {
+
+                        if (header_found % 2 == 1) {
+                            val = bitstr2val(frame_bits+HEADLEN, 16);
+                            counter = val & 0xFFFF;
+                            if (counter % 2 == 0) printf("\n");
+                            //printf("[0x%04X = %d] ", counter, counter);
+                            printf("[%d] ", counter);
+
+                            if (counter % 2 == 0) {
+                                t1 = bitstr2val(frame_bits+HEADLEN+5*46  , 8);  // MSB
+                                t2 = bitstr2val(frame_bits+HEADLEN+5*46+8, 8);
+                                ms = (t1 << 8) | t2;
+                                std = bitstr2val(frame_bits+HEADLEN+5*46+17, 8);
+                                min = bitstr2val(frame_bits+HEADLEN+5*46+25, 8);
+                                printf("  ");    
+                                printf("%02d:%02d:%06.3f ", std, min, (double)ms/1000.0);
+                                printf("  ");
+                            }
+                        }
+
+                        if (header_found % 2 == 0) {
+                            val = bitstr2val(frame_bits+HEADLEN, 16);
+                            //printf("%04x ", val & 0xFFFF);
+                            if ((counter % 2 == 0))  { //  (val & 0xFFFF) > 0)  {// == 0x2390
+                                //offset=24+16+1;
+
+                                dat2 = bitstr2val(frame_bits+HEADLEN, 16);
+                                printf("%05u (?%02d-%02d-%02d) ", dat2, dat2/1000,(dat2/10)%100, (dat2%10)+10);
+
+                                lat1 = bitstr2val(frame_bits+HEADLEN+17, 16);
+                                lat2 = bitstr2val(frame_bits+HEADLEN+46, 16);
+                                lon1 = bitstr2val(frame_bits+HEADLEN+46+17, 16);
+                                lon2 = bitstr2val(frame_bits+HEADLEN+46+46, 16);
+                                alt1 = bitstr2val(frame_bits+HEADLEN+46+46+17, 16);
+                                alt2 = bitstr2val(frame_bits+HEADLEN+46+46+46,  8);
+
+                                lat = (lat1 << 16) | lat2;
+                                lon = (lon1 << 16) | lon2;
+                                alt = (alt1 <<  8) | alt2;
+                                latdeg = (int)lat / 1e6;
+                                latmin = (double)(lat/1e6-latdeg)*100/60.0;
+                                londeg = (int)lon / 1e6;
+                                lonmin = (double)(lon/1e6-londeg)*100/60.0;
+                                //printf("%08X %08X %08X :  ", lat, lon, alt);
+                                printf("  ");
+                                printf("%.6f  %.6f  %.2f", (double)latdeg+latmin, (double)londeg+lonmin, (double)alt/1e2);
+                                printf("  ");
+                            }
+                            //else { printf("\n"); }
+                        }
+
+                    }
+                    else { // raw
+
+                        val = bitstr2val(frame_bits, HEADLEN);
+                        printf("%06X ", val & 0xFFFFFF);
+                        printf("  ");
+                        for (i = 0; i < 6; i++) {
+
+                            val = bitstr2val(frame_bits+HEADLEN+46*i   , 16);
+                            printf("%04X ", val & 0xFFFF);
+
+                            val = bitstr2val(frame_bits+HEADLEN+46*i+17, 16);
+                            printf("%04X ", val & 0xFFFF);
+
+                            val = bitstr2val(frame_bits+HEADLEN+46*i+34, 12);
+                            //printf("%03X ", val & 0xFFF);
+                            //printf(" ");
+                        }
+                        printf("\n");
+                    }
+
+                    bit_count = 0;
+                    header_found = 0;
+                }
+            }
+        }
+    }
+
+    printf("\n");
+
+    fclose(fp);
+
+    return 0;
+}
+