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# LV1b IMU Calibration Page

Here's our best guess to the linear calibration constants for the LV1b IMU:

<div>
  <table>
    <tbody>
      <tr>
        <td style="background-color: #E0E0FF; text-align: center">
          <p><strong>Sensor</strong></p>
        </td>
        <td style="background-color: #E0E0FF; text-align: center">
          <p><strong>Calibration Equation</strong></p>
        </td>
      </tr>
      <tr>
        <td style="background-color: #E0E0FF; text-align: center">
          <p><strong>X</strong></p>
        </td>
        <td>
          <p><tt>g&#39;s = (raw ADC) / (0.624 V/g * (6.025 V / 5 V) * (4096 counts/5 V))</tt></p>
        </td>
      </tr>
      <tr>
        <td style="background-color: #E0E0FF; text-align: center">
          <p><strong>Y</strong></p>
        </td>
        <td>
          <p><tt>g&#39;s = (raw ADC) / (0.624 V/g * (6.025 V / 5 V) * (4096 counts/5 V))</tt></p>
        </td>
      </tr>
      <tr>
        <td style="background-color: #E0E0FF; text-align: center">
          <p><strong>Z</strong></p>
        </td>
        <td>
          <p><tt>g&#39;s = (raw ADC) / (0.038 V/g * (6.025 V / 5 V) * (4096 counts/5 V))</tt></p>
        </td>
      </tr>
      <tr>
        <td style="background-color: #E0E0FF; text-align: center">
          <p><strong>Q</strong></p>
        </td>
        <td>
          <p><tt>g&#39;s = (raw ADC) / (0.038 V/g * (6.025 V / 5 V) * (4096 counts/5 V))</tt></p>
        </td>
      </tr>
      <tr>
        <td style="background-color: #E0E0FF; text-align: center">
          <p><strong>Roll</strong></p>
        </td>
        <td>
          <p><tt>&amp;amp;deg;/s = (raw ADC) / (5 * 1.1628)</tt></p>
        </td>
      </tr>
      <tr>
        <td style="background-color: #E0E0FF; text-align: center">
          <p><strong>Pitch</strong></p>
        </td>
        <td>
          <p>Same as roll?</p>
        </td>
      </tr>
      <tr>
        <td style="background-color: #E0E0FF; text-align: center">
          <p><strong>Yaw</strong></p>
        </td>
        <td>
          <p>Same as roll?</p>
        </td>
      </tr>
    </tbody>
  </table>
</div>

- Note that the (6.025 V / 5V) is for the fact that we ran the ratiometric sensors at 6.025V, but the ADC was expecting them to be running at 5V
- It's a 12bit ADC, thus 4096 counts over the single sided 5V supply

----

\*OLD OLD OLD:\*

So, we built this IMU and it's cool... but what does it do? To find out, we did a calibration run on October 5, 2000 (prior to the 10/07/2000) launch. Although lacking in many ways, the analysis of the calibration data should be able to tell us:

- Linear models of the linear accelerometers (X, Y, Z and "Q")
  - By fitting a line to three points of acceleration values (+1g, 0g, -1g).
    - Note that the X accelerometer data was corrupted.
- Models of the rate gyroscopes (roll, pitch and yaw)
  - By fitting a line to two points of rotational values (0rad/s,?rad/s)

Attached (see below) are the raw data and processed calibration data files.


[[Static Data|ImuCalibrationLV1b/static-raw.tgz]]
[[Spin Data|ImuCalibrationLV1b/spin-raw.tgz]]