mrtk_station.c

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/*------------------------------------------------------------------------------
 * mrtk_station.c : station position and BLQ functions
 *
 * Copyright (C) 2026 H.SHIONO (MRTKLIB Project)
 * Copyright (C) 2023-2025 Cabinet Office, Japan
 * Copyright (C) 2024-2025 Lighthouse Technology & Consulting Co. Ltd.
 * Copyright (C) 2023-2025 Japan Aerospace Exploration Agency
 * Copyright (C) 2023-2025 TOSHIBA ELECTRONIC TECHNOLOGIES CORPORATION
 * Copyright (C) 2015- Mitsubishi Electric Corp.
 * Copyright (C) 2014 Geospatial Information Authority of Japan
 * Copyright (C) 2014 T.SUZUKI
 * Copyright (C) 2007-2023 T.TAKASU
 *
 * SPDX-License-Identifier: BSD-2-Clause
 *----------------------------------------------------------------------------*/
/**
 * @file mrtk_station.c
 * @brief MRTKLIB Station Module — Implementation.
 *
 * All functions and static data in this file are cut-and-paste extractions
 * from the legacy rtkcmn.c with zero algorithmic changes.
 */
 
#include "mrtklib/mrtk_station.h"
 
#include <ctype.h>
#include <math.h>
#include <stdio.h>
#include <string.h>
 
#include "mrtklib/mrtk_trace.h"
 
/*============================================================================
 * Forward Declarations (resolved at link time)
 *===========================================================================*/
 
/*============================================================================
 * Private Constants
 *===========================================================================*/
 
#define PI 3.1415926535897932 /* pi */
#define D2R (PI / 180.0)      /* deg to rad */
 
/*============================================================================
 * Private Functions
 *===========================================================================*/
 
/* read blq record -----------------------------------------------------------*/
extern int readblqrecord(FILE* fp, double* odisp) {
    double v[11];
    char buff[256];
    int i, n = 0;
 
    while (fgets(buff, sizeof(buff), fp)) {
        if (!strncmp(buff, "$$", 2)) {
            continue;
        }
        if (sscanf(buff, "%lf %lf %lf %lf %lf %lf %lf %lf %lf %lf %lf", v, v + 1, v + 2, v + 3, v + 4, v + 5, v + 6,
                   v + 7, v + 8, v + 9, v + 10) < 11) {
            continue;
        }
        for (i = 0; i < 11; i++) {
            odisp[n + i * 6] = v[i];
        }
        if (++n == 6) {
            return 1;
        }
    }
    return 0;
}
 
/*============================================================================
 * Public Functions
 *===========================================================================*/
 
/* read elevation mask file ----------------------------------------------------
 * read elevation mask file
 * args   : char   *file     I   elevation mask file
 *          int16_t *elmask  O   elevation mask vector (360 x 1) (0.1 deg)
 *                                 elmask[i]: elevation mask at azimuth i (deg)
 * return : status (1:ok,0:file open error)
 * notes  : text format of the elevation mask file
 *            AZ1  EL1
 *            AZ2  EL2
 *            ...
 *          (1) EL{i} defines the elevation mask (deg) at the azimuth angle az
 *              (AZ{i} <= az (deg) < AZ{i+1}, AZ1 < AZ2 < ... < AZ{n}, n <= 360)
 *          (2) text after % or # is treated as comments
 *-----------------------------------------------------------------------------*/
extern int readelmask(const char* file, int16_t* elmask) {
    FILE* fp;
    double az[360], el[360], mask = 0.0;
    char buff[256], *p;
    int i, j = 0, n = 0;
 
    trace(NULL, 3, "readelmask: file=%s\n", file);
 
    for (i = 0; i < 360; i++) {
        elmask[i] = 0;
    }
    if (!(fp = fopen(file, "r"))) {
        fprintf(stderr, "elevation mask file open error : %s\n", file);
        return 0;
    }
    while (fgets(buff, sizeof(buff), fp) && n < 360) {
        if ((p = strchr(buff, '%'))) {
            *p = '\0';
        }
        if ((p = strchr(buff, '#'))) {
            *p = '\0';
        }
        if (sscanf(buff, "%lf %lf", az + n, el + n) == 2) {
            n++;
        }
    }
    fclose(fp);
 
    for (i = 0; i < 360; i++) {
        if (j < n && i >= (int)az[j]) {
            mask = el[j++];
        }
        elmask[i] = (int16_t)(mask / 0.1);
    }
    return 1;
}
/* read station positions ------------------------------------------------------
 * read positions from station position file
 * args   : char  *file      I   station position file containing
 *                               lat(deg) lon(deg) height(m) name in a line
 *          char  *rcvs      I   station name
 *          double *pos      O   station position {lat,lon,h} (rad/m)
 *                               (all 0 if search error)
 * return : none
 *-----------------------------------------------------------------------------*/
extern void readpos(const char* file, const char* rcv, double* pos) {
    static double poss[2048][3];
    static char stas[2048][16];
    FILE* fp;
    int i, j, len, np = 0;
    char buff[256], str[256];
 
    trace(NULL, 3, "readpos: file=%s\n", file);
 
    if (!(fp = fopen(file, "r"))) {
        fprintf(stderr, "reference position file open error : %s\n", file);
        return;
    }
    while (np < 2048 && fgets(buff, sizeof(buff), fp)) {
        if (buff[0] == '%' || buff[0] == '#') {
            continue;
        }
        if (sscanf(buff, "%lf %lf %lf %s", &poss[np][0], &poss[np][1], &poss[np][2], str) < 4) {
            continue;
        }
        sprintf(stas[np++], "%.15s", str);
    }
    fclose(fp);
    len = (int)strlen(rcv);
    for (i = 0; i < np; i++) {
        if (strncmp(stas[i], rcv, len)) {
            continue;
        }
        for (j = 0; j < 3; j++) {
            pos[j] = poss[i][j];
        }
        pos[0] *= D2R;
        pos[1] *= D2R;
        return;
    }
    pos[0] = pos[1] = pos[2] = 0.0;
}
/* read blq ocean tide loading parameters --------------------------------------
 * read blq ocean tide loading parameters
 * args   : char   *file       I   BLQ ocean tide loading parameter file
 *          char   *sta        I   station name
 *          double *odisp      O   ocean tide loading parameters
 * return : status (1:ok,0:file open error)
 *-----------------------------------------------------------------------------*/
extern int readblq(const char* file, const char* sta, double* odisp) {
    FILE* fp;
    char buff[256], staname[32] = "", name[32], *p;
 
    /* station name to upper case */
    sscanf(sta, "%16s", staname);
    for (p = staname; (*p = (char)toupper((int)(*p))); p++) {
        /* convert in-place via loop header */
    }
 
    if (!(fp = fopen(file, "r"))) {
        trace(NULL, 2, "blq file open error: file=%s\n", file);
        return 0;
    }
    while (fgets(buff, sizeof(buff), fp)) {
        if (!strncmp(buff, "$$", 2) || strlen(buff) < 2) {
            continue;
        }
 
        if (sscanf(buff + 2, "%16s", name) < 1) {
            continue;
        }
        for (p = name; (*p = (char)toupper((int)(*p))); p++) {
            /* convert in-place via loop header */
        }
        if (strcmp(name, staname)) {
            continue;
        }
 
        /* read blq record */
        if (readblqrecord(fp, odisp)) {
            fclose(fp);
            return 1;
        }
    }
    fclose(fp);
    trace(NULL, 2, "no otl parameters: sta=%s file=%s\n", sta, file);
    return 0;
}