SC-30 roll/pitch motion compensation

[Anonymous]

I am working with a SC-30 sat compass. I am using a rate table to verify measurements of heading, pitch and roll. I would expect to see a change in roll by pitching the sensor 15 degrees and performing an azimuth rotation about its center. This should manifest a change in the roll component, unless this motion is already compensated for by the sensor. When I perform this test, I see only a very small change in roll - much less than anticipated. Does anyone know if the sensor compensates for roll based on pitch and for pitch based on roll?

 

[Anonymous]

Hello,
I would believe that the data is not raw data, but processed data dampened by the rate sensors. I do not know the answer to your question, but I will find out and let you know.

What are you using the SC30 for?

Regards,
Birdman.

 

[Anonymous]

The SC30 is used as a motion reference for another system. I notice that its data output lags; I measure approximately a 2 second latency between motion and sensor response - I presume it is the effect of numerical low pass filtering or something similar. Is there any way to tune the sensor for better response?

 

[Anonymous]

Hello,
Sorry about the time it took to get back to you on this.

SC-30 has a mechanical head and calculates heading, pitch and roll based on that. If you pitch it 15 degrees and rotate it 90 degrees horizontally for example, the roll value against the original heading position is 15 degrees. However, there is no change in the roll value against the mechanical head and thus it does not show any roll. This is not related to the compensation.
The SC30 always points to the direction of ship's heading and Pitch, Roll, and Heading are calculated based on that direction. Therefore Roll value does not change with the combination of pitching and heading (yawing). If you pitch and rotate the SC30 only, then it seems like the SC30 is rolling against the boat's heading, but the SC30 itself is not rolling (just pitching and rotating).

How are you using the SC30? Are you using the NMEA2000 data, or are you converting it using an NMEA2000 to 0183 converter or IF-NMEASC box?

Again I'm sorry about the late response,
Birdman