From a99255a36a1f63af96ab5859fdee450107d42f89 Mon Sep 17 00:00:00 2001
From: Corvus Corax <corvuscorax@cybertrench.com>
Date: Sun, 9 Jun 2013 13:57:36 +0200
Subject: [PATCH] allow smaller nonzero variances during runtime

---
 flight/modules/StateEstimation/filterekf.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/flight/modules/StateEstimation/filterekf.c b/flight/modules/StateEstimation/filterekf.c
index 8003c1f13..46b59723b 100644
--- a/flight/modules/StateEstimation/filterekf.c
+++ b/flight/modules/StateEstimation/filterekf.c
@@ -425,7 +425,7 @@ static int32_t filter(stateFilter *self, stateEstimation *state)
     EKFStateVarianceSet(&vardata);
     int t;
     for (t = 0; t < EKFSTATEVARIANCE_P_NUMELEM; t++) {
-        if (invalid_var(vardata.P[t])) {
+        if (!IS_REAL(vardata.P[t]) || vardata.P[t] <= 0.0f) {
             INSResetP(this->ekfConfiguration.P);
             this->init_stage = -1;
             break;