20190915 updated 20210717

Node Id Event Type Compass (deg) mGa Avg. Ambient mGa Threshold Accel/Pressure Date Time
144 status 192.11 4.5 964.23 30 0.99 2021-07-17 18:20:18
144 status 188.8 7.5 964.23 30 0.99 2021-07-17 18:19:18
144 status 191.88 6 964.23 30 1 2021-07-17 18:18:18
144 status 193.05 6.75 961.69 30 1.01 2021-07-17 18:17:18
144 status 193.06 5.25 961.69 30 1 2021-07-17 18:16:18
144 status 190.14 6.75 961.69 30 1 2021-07-17 18:15:18
144 status 191.79 8.25 961.69 30 1 2021-07-17 18:14:18
144 status 189.76 6 961.69 30 1 2021-07-17 18:13:18

The illustration above is taken from the top of a spreadsheet from Node 144 at Farmington Hills, Michigan. One can see the headings on each column. When a MADAR DataProbe is running properly and not on alert, the word "status" shows up in column 2. Note also that the next three columns give the ambient (normal) readings for the onboard compass (heading) in degrees, the field reading in mGa, followed by the Avg. Ambient (mGa). The threshold is the device's limits setting so that anything at or above that in column 4 will trigger the system. Accel/Pressure is the accelerometer reading now and since May of this year but was the barometric pressure in inches of mercury prior to that. Normal accelerometer reading is 1.0 plus or minus. Date and time are in UTC or Universal Time Code. Node 144 is currently Eastern Daylight Time in this conversion chart at

Before we discuss anomalies and false alerts we need to briefly explain something about the compass and magnetometer features. Normally compasses point north, unless they are too close to metallic objects, have E-M interference, etc. If you held a compass in your hand and the needle was pointing at 180 degrees that means that on your compass the needle is still pointing north, but the compass bezel (outer rim of compass with numbers in degrees) is rotated and shows your heading in degrees. For MADAR, with its amazingly simple plug and play, you just plop it down where you can easily mount it and it will use its onboard computer and program to find out where it is, in other words ...... it will calculate its orientation. That's why you always want to power down before you move it so that you don't confuse its brain and have it disoriented for a while. Disorientation means the blue LED will come on and the alarm will sound and data will be time-stamped every second until the device settles down for three minutes after an "alert". Normal data is time-stamped at one minute intervals and that line is called "status".

Although compass variations have been the source of historic cases in at least 150 instances, the data from the MADAR magnetometer is the most important and the most sensitive to electromagnetic anomalies. Any change in milligaus in any one of the axes from this triple-axis magnetometer is noted in the data. And any change that may trigger the MADAR will probably also result in only a slight (if any) variation in the compass heading, so the magnetometer is the sensor of choice.
Up until June of 2020 we had quite a large number of hits with no appreciable change or improvement in the sighting correlations. We began to look at data for compass heading changes such as derived from solar Coronal Mass Ejections and found that we needed to look for variations at around 3 degrees or more for actual anomalies. When we checked the list of correlations we already had we noticed that they had all passed the 3-degree rule and we started using the MSV or multi-sensor verification system on all candidates. This reduced the number of processed hits down to 10-15 per week or less, which was more reasonable and didn't affect the data at all because any sighting could be checked against the data at any time. 

144 alertStat 200.44 10.12 940.32 30 29.56 2021-03-19 14:10:13
144 alert 201.82 34.12 940.32 30 29.56 2021-03-19 14:10:12
144 alertEnd 201.1 10.12 940.32 30 29.56 2021-03-19 14:10:12
144 alert 200.47 34.12 940.32 30 29.56 2021-03-19 14:10:11
144 alert 199.76 34.12 940.32 30 29.56 2021-03-19 14:10:10
144 alert 201.07 34.12 940.32 30 29.56 2021-03-19 14:10:09
144 alert 198.85 34.12 940.32 30 29.56 2021-03-19 14:10:08
144 alert 202.87 34.88 940.32 30 29.56 2021-03-19 14:10:07
144 alert 201.09 34.88 940.32 30 29.56 2021-03-19 14:10:06
144 alert 202.88 34.88 940.32 30 29.56 2021-03-19 14:10:05
144 alert 203.79 34.88 940.32 30 29.56 2021-03-19 14:10:04
144 alertStart 206.47 34.88 940.32 30 29.56 2021-03-19 14:10:01

The next sample illustrates a genuine alert. Starting from the bottom up, the first line is clocked at 2021-03-19 UTC and shows the alertStart at March 19. This node in March is on EDT so this computes to 10:10 AM. The next line up is the alert data ramped up to once per second, and ending with "alertstat" and AlertEnd near the top. The alertstat at the very top is the beginning of the normal ambient readings or the last line after the anomaly but the MADAR runs an additional 180 seconds in the alert mode (not shown) That is why it is listed as "alertStat" rather than "status". Three minutes later the data-rate drops to one-line-per minute and the word in column two becomes "status".  As you can tell, the compass (col. 3) shows some changes. (More on that coming up) But col. 4 goes from normal of 10.12 to over 34, 4 points over the threshold. This is what the average alert looks like. When the field numbers reach or exceed the threshold, the device is triggered. 

Using these new parameters, the event shown in the spreadsheet above qualifies as an official MADAR anomaly.  With the top line of col. 3 being 200.4 degrees and the normal or "ambient" compass heading, one adds or subtracts 3 degrees to determine what passes MSV. The reading of 206.47 is well over 3 degrees. However, it was the field reading in col. 4 that triggered 144. The compass heading change qualified the hit as MSV, for multi-sensor verification.

There are generally three types of "hits":
a) False alerts.
b) Anomalies
c) Variations

False alerts are indications the device was bumped or some local disturbance was a known cause. In that event the op emails a false alarm or alibi report.

Anomalies are all stored on the server so that any potential sighting of interest can always be checked using our online MADAR Alert Search form. Hits that meet MSV parameters are then checked against sightings listed by NUFORC or MUFON CMS.

Variations are events where field numbers are noted as significant but where the device was not triggered. These are also referred to as "under trigger" anomalies.

Fran Ridge
MADAR Director