Add check to confirm telescope reached position

pyproject.toml

@@ -34,6 +34,7 @@ typing-extensions = "^4.5.0"
 httpx = "^0.24.1"
 tqdm = "^4.65.0"
 kubernetes = "^26.1.0"
+astropy = "^5.3.1"
 
 [tool.poetry.group.dev.dependencies]
 ipython = ">=8.0.0"

src/gort/telescope.py

@@ -9,13 +9,15 @@
 from __future__ import annotations
 
 import asyncio
+import inspect
+from inspect import currentframe, getouterframes
 
 from typing import TYPE_CHECKING
 
 from gort import config
 from gort.exceptions import GortTelescopeError
 from gort.gort import GortDevice, GortDeviceSet
-from gort.tools import get_calibrators, get_next_tile_id
+from gort.tools import angular_separation, get_calibrators, get_next_tile_id
 
 
 if TYPE_CHECKING:
@@ -367,6 +369,19 @@ async def goto_coordinates(
             self.write_to_log(f"Moving to ra={ra:.6f} dec={dec:.6f}.", level="info")
             await self.pwi.commands.gotoRaDecJ2000(ra / 15.0, dec)
 
+            # Check that we reached the position.
+            status = await self.status()
+            ra_status = status["ra_j2000_hours"] * 15
+            dec_status = status["dec_j2000_degs"]
+            separation = angular_separation(ra, dec, ra_status, dec_status)
+            if separation > 0.1:
+                await self.actor.commands.setEnabled(False)
+                raise GortTelescopeError(
+                    "Telescope failed to reach desired position. "
+                    "The axes have been disabled for safety. "
+                    "Try re-homing the telescope."
+                )
+
         elif alt is not None and az is not None:
             is_altaz = alt is not None and az is not None and not ra and not dec
             assert is_altaz, "Invalid input parameters"
@@ -378,6 +393,10 @@ async def goto_coordinates(
             if altaz_tracking:
                 await self.pwi.commands.setTracking(enable=True)
 
+            status = await self.status()
+            ra_status = status["altitude_degs"] * 15
+            dec_status = status["azimuth_degs"] * 15
+
         if kmirror_task is not None and not kmirror_task.done():
             await kmirror_task
 

src/gort/tools.py

@@ -15,6 +15,8 @@
 from typing import TYPE_CHECKING, Callable, Coroutine
 
 import httpx
+from astropy import units as uu
+from astropy.coordinates import angular_separation as astropy_angular_separation
 
 from gort import config
 
@@ -40,6 +42,7 @@
     "get_ccd_frame_path",
     "move_mask_interval",
     "radec_sexagesimal_to_decimal",
+    "angular_separation",
 ]
 
 CAMERAS = [
@@ -443,3 +446,21 @@ def radec_sexagesimal_to_decimal(ra: str, dec: str, ra_is_hours: bool = True):
         dec_deg -= float(dec_groups[1]) / 60 - float(dec_groups[2]) / 3600
 
     return ra_deg, dec_deg
+
+
+def angular_separation(lon1: float, lat1: float, lon2: float, lat2: float):
+    """A wrapper around astropy's ``angular_separation``.
+
+    Returns the separation between two sets of coordinates. All units must
+    be degrees and the returned values is also the separation in degrees.
+
+    """
+
+    separation = astropy_angular_separation(
+        lon1 * uu.degree,  # type: ignore
+        lat1 * uu.degree,  # type: ignore
+        lon2 * uu.degree,  # type: ignore
+        lat2 * uu.degree,  # type: ignore
+    )
+
+    return separation.to("deg").value

typings/astropy/__init__.pyi

@@ -0,0 +1,3 @@
+from typing import Any
+
+def __getattr__(name: str) -> Any: ...

typings/astropy/coordinates/__init__.pyi

@@ -0,0 +1,3 @@
+from typing import Any
+
+def __getattr__(name: str) -> Any: ...

typings/astropy/io/__init__.pyi

@@ -0,0 +1,3 @@
+from typing import Any
+
+def __getattr__(name: str) -> Any: ...

typings/astropy/io/fits/__init__.pyi

@@ -0,0 +1,3 @@
+from typing import Any
+
+def __getattr__(name: str) -> Any: ...

typings/astropy/units/__init__.pyi

@@ -0,0 +1,3 @@
+from typing import Any
+
+def __getattr__(name: str) -> Any: ...

typings/astropy/wcs/__init__.pyi

@@ -0,0 +1,3 @@
+from typing import Any
+
+def __getattr__(name: str) -> Any: ...