From 70c571272edc7123f6075664a4a41c7615e27fd3 Mon Sep 17 00:00:00 2001
From: Eric Kooistra <kooistra@astron.nl>
Date: Tue, 28 Jun 2022 08:34:32 +0200
Subject: [PATCH] Updates.

---
 .../lofar2/doc/prestudy/lift_lightning.txt       | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/applications/lofar2/doc/prestudy/lift_lightning.txt b/applications/lofar2/doc/prestudy/lift_lightning.txt
index b4104d7002..b62fc976a0 100644
--- a/applications/lofar2/doc/prestudy/lift_lightning.txt
+++ b/applications/lofar2/doc/prestudy/lift_lightning.txt
@@ -1,7 +1,9 @@
 
 
 
-LIFT 27 June 2022 meeting
+1) LIFT 27 June 2022 meeting
+
+a) Transient buffer:
 - only raw, no subband data
 - cosmic ray uses all antennas of one station, lightning ~ 6 antennas but all Dutch stations
   . 6 dual pol antennas per station with long baselines
@@ -9,8 +11,16 @@ LIFT 27 June 2022 meeting
 - cosmic ray is commensal, lightning is dedicated mode
 - cosmic ray 2 ms event, lightning 1 s events
 - individually controlled antenna buffers
-- transient detection based on power after 40 - 80 MHz BPF
-- read out via LCU (with local storage, later TCP to CEP) or directly to CEP (UDP)
+- read out via 10GbE via LCU (with local storage, later TCP to CEP) or directly to CEP (UDP)
+  . one signal input for 1 s takes 200M * 16b = 0.4 GByte = 3.2 Gbit, so 0.3 s
+  . 192 signal inputs for 1 s takes 3.2 Gbit * 192 ~= 0.6 Tbit, so 60 s
 - 2 * 8 GB / (12 * 16b / 8b * 0.2 GHz) =  3.33 s seems enough storage
   . 3.33 * 16b / 14b = 3.81 s
   . header overhead 5 % --> 3.81 * 0.95 = 3.61 s
+
+b) Transient detection:
+- notch filter ?
+- transient detection based on power after 40 - 80 MHz BPF
+- measure power during 10 us to detect pulse, if > threshold then send pulse detection events
+  per signal input via 1GbE
+- e.g. use dead time after a detection to avoid storm of event messages
-- 
GitLab