add LST

G4:G431/CORDIC/astro.h

@@ -0,0 +1,32 @@
+/*
+ * This file is part of the cordic project.
+ * Copyright 2026 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <stdint.h>
+
+void set_sincos(int iscordic);
+int get_sincos();
+float MJD_from_unix(uint32_t t);
+//float LST_from_mjd(float mjd);
+float LST_from_unix(uint32_t t);
+float ha_to_ra(float ha, float lst);
+float ra_to_ha(float ra, float lst);
+void altaz_to_hadec(float alt_deg, float az_deg, float *ha_deg, float *dec_deg);
+void hadec_to_altaz(float ha_deg, float dec_deg, float *alt_deg, float *az_deg);
+float refraction(float phpa, float tc, float rh, float Z_rad);