adding in sd dector tests

kat_test/physics/filter_cavity.kat

+sq sq1 0 10 0 nfc1
+
+m1 mfc1 70u 0 0 nfc1 nfc2
+s  sfc1 16 nfc2 nfc3
+m1 mfc2 0 20u -0.001 nfc3 nfc4
+
+sd  sd1 0 nfc1
+sd* sd2 0 nfc1
+
+fsig sig1 sq1 amp 1 0 1
+
+xaxis sig1 f log 1 10k 1000
+
+yaxis abs:deg
+maxtem off
+gnuterm no
+
+
+# bs1 mfc1 70u 0 0 0 nfc1 nfc2 nfc3 nfc4
+# s sfc1 16 nfc3 nfc5
+# s sfc2 16 nfc6 nfc4
+# bs1 mfc2 0 20u -0.001 0 nfc5 nfc6 nfc7 nfc8
\ No newline at end of file

kat_test/physics/homodyne_sd_a.kat

+sq sq1 0 10 0 nd
+l l1 1 0 0 na
+bs bs1 0.5 0.5 0 0 na nb nc nd
+
+sd sdc 0 nc
+sd sdb 0 nb
+
+qnoised qnc 1 $fs nc
+scale PSD_HF qnc
+scale 2 qnc
+
+qnoised qnb 1 $fs nb
+scale PSD_HF qnb
+scale 2 qnb
+
+fsig noise 1
+
+xaxis bs1 phi lin -90 90 180
+#xaxis sq1 angle lin -180 180 180
+#xaxis l1 phase lin -180 180 180
+yaxis abs:deg
+gnuterm no
\ No newline at end of file

kat_test/physics/homodyne_sd_b.kat

+sq sq1 0 10 0 nd
+l l1 1 0 0 na
+bs bs1 0.5 0.5 0 0 na nb nc nd
+
+sd sdc 0 nc
+sd sdb 0 nb
+
+qnoised qnc 1 $fs nc
+scale PSD_HF qnc
+scale 2 qnc
+
+qnoised qnb 1 $fs nb
+scale PSD_HF qnb
+scale 2 qnb
+
+fsig noise 1
+
+#xaxis bs1 phi lin -90 90 180
+xaxis sq1 angle lin -180 180 180
+#xaxis l1 phase lin -180 180 180
+yaxis abs:deg
+gnuterm no
\ No newline at end of file

kat_test/physics/homodyne_sd_c.kat

+sq sq1 0 10 0 nd
+l l1 1 0 0 na
+bs bs1 0.5 0.5 0 0 na nb nc nd
+
+sd sdc 0 nc
+sd sdb 0 nb
+
+qnoised qnc 1 $fs nc
+scale PSD_HF qnc
+scale 2 qnc
+
+qnoised qnb 1 $fs nb
+scale PSD_HF qnb
+scale 2 qnb
+
+fsig noise 1
+
+#xaxis bs1 phi lin -90 90 180
+#xaxis sq1 angle lin -180 180 180
+xaxis l1 phase lin -180 180 180
+yaxis abs:deg
+gnuterm no
\ No newline at end of file