This function computes the spacecraft clock string corresponding to a given Barycentric Dynamical Time (TDB).

This is the inverse operation of calceph_time_str_spacecraft_clock_to_jd_tdb(). The input Julian Date is provided as two double-precision numbers (jd0_tdb and jdfrac_tdb).

The resulting spacecraft clock string is stored in the character array str.

It is strictly required to load a Spacecraft Clock kernel (usually .tsc) to define the clock partitions and coefficients.

Since this function performs an internal conversion between Barycentric Dynamical Time (TDB) and Terrestrial Time (TT), additional kernels are required depending on the configuration set by calceph_time_set_relationship_tt_tdb():

• If the relationship mode is 0 (default), an Ephemeris kernel (usually .bsp) containing the ntime tranformation TT-TDB must be loaded.

• If the relationship mode is 1, a Leap Seconds kernel (usually .tls) must be loaded.

If the time falls outside the range covered by the SCLK coefficients, then the function returns an error.

The following example converts a TDB date to a spacecraft clock string:

t_calcephbin *peph;
double jd0_tdb = 2459728.0;
double jdfrac_tdb = 0.63395731542095745681;
int target = 28;
t_calcephcharvalue str;
const char *filenames[] = {"example_sclk.tsc", "example_lsk.tls"};

/* open the ephemeris files */
peph = calceph_open_array(2, filenames);

calceph_time_set_relationship_tt_tdb(peph, 1);

if (peph != NULL)
{
    /* Convert TDB to SCLK string */
    if (calceph_time_jd_tdb_to_str_spacecraft_clock(peph, target,
                                                    jd0_tdb, jdfrac_tdb, str) != 0)
    {
        printf("SCLK string: %s\n", str);
    }

    calceph_close(peph);
}