diff --git a/cxx/mcc_mount_astro_erfa.h b/cxx/mcc_mount_astro_erfa.h
index f920d27..16702fa 100644
--- a/cxx/mcc_mount_astro_erfa.h
+++ b/cxx/mcc_mount_astro_erfa.h
@@ -61,9 +61,9 @@ public:
 
         double wavelength = 0.55;  // observed wavelength in mkm
 
-        MccAngleLAT lat = "00:00:00"_dms;  // site latitude
-        MccAngleLON lon = "00:00:00"_dms;  // site longitude
-        double elev = 0.0;                 // site elevation (in meters)
+        MccAngle lat = "00:00:00"_dms;  // site latitude
+        MccAngle lon = "00:00:00"_dms;  // site longitude
+        double elev = 0.0;              // site elevation (in meters)
 
         mcc::astrom::iers::MccLeapSeconds _leapSeconds{};
         mcc::astrom::iers::MccIersBulletinA _bulletinA{};
@@ -104,7 +104,7 @@ public:
 
     engine_state_t getState() const
     {
-        std::scoped_lock lock{_stateMutex};
+        std::lock_guard lock{_stateMutex};
 
         return _currentState;
     }
@@ -164,7 +164,7 @@ public:
 
         using real_days_t = std::chrono::duration<double, std::ratio<86400>>;
 
-        double ut1, tt = juldate.mjd;
+        double ut1 = juldate.mjd, tt = juldate.mjd;
 
         auto dut1 = _currentState._bulletinA.DUT1(juldate.mjd);
 
@@ -234,6 +234,9 @@ public:
         if (!pol_pos.has_value()) {
             return ERROR_BULLETINA_OUT_OF_RANGE;
         }
+        const auto arcsec2rad = std::numbers::pi / 180 / 3600;
+        pol_pos->x *= arcsec2rad;
+        pol_pos->y *= arcsec2rad;
 
         double oaz, ozd, oha, odec, ora;
 
@@ -298,7 +301,7 @@ public:
 protected:
     engine_state_t _currentState{};
 
-    std::mutex _stateMutex;
+    mutable std::mutex _stateMutex;
 };
 
 }  // namespace mcc::astrom::erfa
diff --git a/cxx/mcc_mount_telemetry.h b/cxx/mcc_mount_telemetry.h
index bff6e9b..038f625 100644
--- a/cxx/mcc_mount_telemetry.h
+++ b/cxx/mcc_mount_telemetry.h
@@ -84,7 +84,7 @@ public:
             // computing ...
 
 
-            std::scoped_lock lock{_updateMutex};
+            std::lock_guard lock{_updateMutex};
 
             _data = current_data;
         };
@@ -102,7 +102,7 @@ public:
     {
         using self_t = decltype(self);
 
-        std::scoped_lock lock{std::forward<self_t>(self)._updateMutex};
+        std::lock_guard lock{std::forward<self_t>(self)._updateMutex};
 
         return std::move(std::forward<self_t>(self)._data);
     }
diff --git a/cxx/tests/astrom_test.cpp b/cxx/tests/astrom_test.cpp
index d5d8899..c1f8339 100644
--- a/cxx/tests/astrom_test.cpp
+++ b/cxx/tests/astrom_test.cpp
@@ -2,30 +2,10 @@
 #include <iostream>
 
 // #include "../mcc_coord.h"
+#include "../mcc_mount_astro_erfa.h"
 #include "../mcc_traits.h"
 #include "../mount_astrom.h"
 
-template <typename T, typename U>
-concept ncr_c =
-    std::is_lvalue_reference_v<T> && !std::is_const_v<T> && std::constructible_from<std::remove_reference_t<T>, U>;
-
-
-template <typename T>
-concept ae_c = requires(T t) {
-    requires mcc::traits::mcc_systime_c<mcc::traits::mcc_func_arg1_t<decltype(&T::greg2jul)>>;
-    requires mcc::traits::mcc_output_arg_c<mcc::traits::mcc_func_argN_t<decltype(&T::greg2jul), 2>>;
-    // requires ncr_c<mcc::traits::mcc_func_argN_t<decltype(&T::greg2jul), 2>, double>;
-    // requires std::constructible_from<mcc::traits::mcc_func_argN_t<decltype(&T::greg2jul), 2>, double>;
-};
-
-
-struct AE {
-    // int greg2jul(mcc::traits::mcc_systime_c auto t, double f) {}
-    int greg2jul(std::chrono::sys_time<std::chrono::nanoseconds> t, double& f)
-    {
-        return 0;
-    }
-};
 
 // BTA coords from maps.yandex.ru: 43.646711, 41.440732
 
@@ -136,8 +116,10 @@ int main(int argc, char* argv[])
     now = std::chrono::system_clock::now();
 
     for (auto& el : mjds) {
-        st = erfa::eraAtco13(1.343523, 0.32352345, 0.0, 0.0, 0.0, 0.0, ERFA_DJM0, el, 0.041, elong, phi, 2100.0, 0.0,
-                             0.0, 700.0, 10.0, 0.8, 0.5, &aob, &zob, &hob, &dob, &rob, &eo);
+        st = mcc::astrom::erfa::eraAtco13(1.343523, 0.32352345, 0.0, 0.0, 0.0, 0.0, ERFA_DJM0, el, 0.041, elong, phi,
+                                          2100.0, 0.0, 0.0, 700.0, 10.0, 0.8, 0.5, &aob, &zob, &hob, &dob, &rob, &eo);
+        // st = erfa::eraAtco13(1.343523, 0.32352345, 0.0, 0.0, 0.0, 0.0, ERFA_DJM0, el, 0.041, elong, phi, 2100.0, 0.0,
+        //                      0.0, 700.0, 10.0, 0.8, 0.5, &aob, &zob, &hob, &dob, &rob, &eo);
     }
     std::cout << std::format(
         "comp time for {} coordinate transf = {}\n", N,
@@ -161,8 +143,32 @@ int main(int argc, char* argv[])
 
     std::cout << ra.sexagesimal(false, 4) << "\n";
 
-    std::cout << "\n\n\n";
-    std::cout << "ae_c = " << std::boolalpha << ae_c<AE> << "\n";
+
+    std::cout << "\n\n\n\n";
+
+    mcc::astrom::erfa::MccMountAstromEngineERFA::engine_state_t state;
+    state.lon = 41.440732_degs;
+    state.lat = 43.646711_degs;
+    state.elev = 2100.0;
+
+    state.meteo = {10.0, 0.5, 1010.0};
+
+
+    mcc::astrom::erfa::MccMountAstromEngineERFA erfa(state);
+    mcc::astrom::erfa::MccMountAstromEngineERFA::juldate_t jd{60861.72};
+
+    now = std::chrono::system_clock::now();
+    erfa.greg2jul(now, jd);
+    std::cout << "MJD(" << now << ") = " << jd.mjd << "\n";
+
+
+    mcc::MccAngle ra1{"10:00:00", mcc::mcc_hms}, dec1{"68:25:10.43"}, ra_o, dec_o, ha1, az1, alt1;
+
+    std::cout << "RA = " << ra1.sexagesimal(true) << ", DEC = " << dec1.sexagesimal() << "\n";
+    auto res = erfa.icrs2obs(ra1, dec1, 0, 0, 0, jd, ra_o, dec_o, ha1, az1, alt1, eo);
+    std::cout << "ret code (icrs2obs) = " << erfa.errorString(res) << "\n";
+    std::cout << "alt = " << alt1.sexagesimal() << "\n";
+    std::cout << "az = " << az1.sexagesimal() << "\n";
 
     return ecode;
 }