*get next batch of exposures requiring pyephem positions*

        **Key Arguments:**
            -  ``concurrentSnapshots`` -- number of concurrent PyEphem snapshots to process

def _get_exposures_requiring_pyephem_positions(
            self,
            concurrentSnapshots=10):
        """*get next batch of exposures requiring pyephem positions*

        **Key Arguments:**
            -  ``concurrentSnapshots`` -- number of concurrent PyEphem snapshots to process
        """
        self.log.info(
            'starting the ``_get_exposures_requiring_pyephem_positions`` method')

        if self.dev_flag == True:
            dev_flag = " and dev_flag = 1"
        else:
            dev_flag = ""

        sqlQuery = u"""
            select distinct pyephem_mjd from atlas_exposures where pyephem_positions = 0 and local_data = 1 %(dev_flag)s order by pyephem_mjd asc
        """ % locals()
        rows = readquery(
            log=self.log,
            sqlQuery=sqlQuery,
            dbConn=self.atlasMoversDBConn,
            quiet=False
        )

        snapshotsRequired = len(rows)

        if snapshotsRequired == 0:
            return [], [], 0

        nextMjds = []
        nextMjds[:] = [r["pyephem_mjd"] for r in rows[:concurrentSnapshots]]

        exposures = []
        for nextMjd in nextMjds:
            sqlQuery = u"""
                select * from atlas_exposures where pyephem_positions = 0 %(dev_flag)s and pyephem_mjd = %(nextMjd)s
            """ % locals()
            theseExps = readquery(
                log=self.log,
                sqlQuery=sqlQuery,
                dbConn=self.atlasMoversDBConn,
                quiet=False
            )
            exposures.append(list(theseExps))

        self.log.info(
            'completed the ``_get_exposures_requiring_pyephem_positions`` method')
        return nextMjds, exposures, snapshotsRequired