maglink-console/capture_raw_ntrip.py

#!/usr/bin/env python3
"""
Capture raw NTRIP stream to binary file - no parsing, just raw bytes.
"""
import base64
import socket
import time
from datetime import datetime


# NTRIP configuration
CASTER_HOST = "truertk.pointonenav.com"
CASTER_PORT = 2101
MOUNTPOINT = "AUTO"
USERNAME = "9t7fwfbm57"
PASSWORD = "96m7bec9g8"

LAT = 36.1140884
LON = -97.0880663
ALT = 390.0


def build_gga(lat: float, lon: float, alt: float) -> bytes:
    """Build NMEA GGA sentence."""
    now_utc = datetime.utcnow().strftime("%H%M%S")
    lat_hemi = "N" if lat >= 0 else "S"
    lat_abs = abs(lat)
    lat_deg = int(lat_abs)
    lat_min = (lat_abs - lat_deg) * 60.0
    lat_str = f"{lat_deg:02d}{lat_min:07.4f}"

    lon_hemi = "E" if lon >= 0 else "W"
    lon_abs = abs(lon)
    lon_deg = int(lon_abs)
    lon_min = (lon_abs - lon_deg) * 60.0
    lon_str = f"{lon_deg:03d}{lon_min:07.4f}"

    fields = ["GPGGA", now_utc, lat_str, lat_hemi, lon_str, lon_hemi, "1", "12", "1.0", f"{alt:.1f}", "M", "", "M", "", ""]
    core = ",".join(fields)
    checksum = 0
    for char in core:
        checksum ^= ord(char)
    return f"${core}*{checksum:02X}\r\n".encode("ascii")


def make_ntrip_request(host: str, port: int, mount: str, user: str, password: str) -> bytes:
    """Create NTRIP v2 HTTP request."""
    auth = base64.b64encode(f"{user}:{password}".encode("utf-8")).decode("ascii")
    req = (
        f"GET /{mount} HTTP/1.1\r\n"
        f"Host: {host}:{port}\r\n"
        f"Ntrip-Version: Ntrip/2.0\r\n"
        f"User-Agent: NTRIP-Raw-Capture/1.0\r\n"
        f"Connection: close\r\n"
        f"Authorization: Basic {auth}\r\n\r\n"
    )
    return req.encode("ascii")


def main():
    timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
    output_file = f"ntrip_raw_{timestamp}.bin"
    log_file = f"ntrip_log_{timestamp}.txt"

    print(f"Raw NTRIP Stream Capture")
    print(f"=" * 80)
    print(f"Caster: {CASTER_HOST}:{CASTER_PORT}/{MOUNTPOINT}")
    print(f"Output: {output_file}")
    print(f"Log:    {log_file}")
    print(f"Duration: 60 seconds")
    print(f"=" * 80)
    print()

    last_gga_time = 0
    start_time = time.monotonic()
    total_bytes = 0

    try:
        # Connect
        print("Connecting...")
        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        sock.settimeout(30)
        sock.connect((CASTER_HOST, CASTER_PORT))
        sock.sendall(make_ntrip_request(CASTER_HOST, CASTER_PORT, MOUNTPOINT, USERNAME, PASSWORD))

        # Read HTTP headers
        header = b""
        while b"\r\n\r\n" not in header:
            chunk = sock.recv(1)
            if not chunk:
                print("ERROR: Connection closed")
                return
            header += chunk

        if "200 OK" not in header.decode("iso-8859-1", errors="replace"):
            print(f"ERROR: Connection failed")
            print(header.decode("iso-8859-1", errors="replace"))
            return

        print("Connected! Capturing raw data stream...\n")

        # Open output files
        with open(output_file, 'wb') as binfile, open(log_file, 'w') as logfile:
            logfile.write(f"# NTRIP Raw Stream Capture Log\n")
            logfile.write(f"# Started: {datetime.now().isoformat()}\n")
            logfile.write(f"# Caster: {CASTER_HOST}:{CASTER_PORT}/{MOUNTPOINT}\n")
            logfile.write(f"#\n")
            logfile.write(f"# timestamp, elapsed_sec, bytes_received, total_bytes\n")

            # Capture loop - just write everything
            while time.monotonic() - start_time < 60:
                now = time.monotonic()
                elapsed = now - start_time

                # Send GGA every 10 seconds
                if now - last_gga_time >= 10:
                    gga = build_gga(LAT, LON, ALT)
                    sock.sendall(gga)
                    ts = datetime.now().isoformat()
                    logfile.write(f"{ts},{elapsed:.1f},GGA_SENT,{total_bytes}\n")
                    logfile.flush()
                    print(f"[{int(elapsed):3d}s] Sent GGA | Captured: {total_bytes:,} bytes")
                    last_gga_time = now

                # Receive raw data
                data = sock.recv(4096)
                if not data:
                    print("Connection closed by caster")
                    break

                # Write raw data to file
                binfile.write(data)
                binfile.flush()

                chunk_len = len(data)
                total_bytes += chunk_len

                # Log this chunk
                ts = datetime.now().isoformat()
                logfile.write(f"{ts},{elapsed:.3f},{chunk_len},{total_bytes}\n")

        elapsed_final = time.monotonic() - start_time
        print(f"\n[{int(elapsed_final):3d}s] Capture complete!")

    except KeyboardInterrupt:
        print("\n\nInterrupted by user")
    except Exception as e:
        print(f"\nERROR: {e}")
        import traceback
        traceback.print_exc()
    finally:
        if 'sock' in locals():
            try:
                sock.close()
            except:
                pass

    print(f"\n{'=' * 80}")
    print(f"CAPTURE COMPLETE")
    print(f"{'=' * 80}")
    print(f"Total bytes: {total_bytes:,}")
    print(f"Output file: {output_file}")
    print(f"Log file:    {log_file}")
    print()
    print("To view the binary file:")
    print(f"  hexdump -C {output_file} | head -100")
    print(f"  xxd {output_file} | head -100")
    print()
    print("To view just the first 1000 bytes:")
    print(f"  head -c 1000 {output_file} | hexdump -C")
    print()
    print("To search for RTCM message 208 (0xD3 header + type 208 = 0x0D0):")
    print("  Look for pattern: D3 ?? ?? 0D 0x")
    print("  where ?? ?? is the length field")


if __name__ == "__main__":
    main()