Abstract: Numerous ground tests and platform tests were conducted to evaluate platform integration issues and the performance of the POLATOMIC 2000 magnetometer, a laser-pumped helium-4 total magnetic field sensor. These results are compared with those from lamp-pumped helium-4 magnetometers, the AN/ASQ-208 and the AN/ASQ-81 The sensitivity of the digital AN/ASQ-208 magnetometer is 3 PT/square roots of Hz from dc to 216 Hz; and, the analog AN/ASQ-81 has a slightly higher noise floor. The POLATOMIC 2000 noise floor is less than 0.3 pT/ square roots of Hz. For airborne measurements, the sensor noise is not usually the limiting noise. In the magnetic anomaly detection (MAD) band (0.04 Hz to 0.4 Hz), for example, substantial reduction of platform and environmental noise is necessary. Important sources of noise are geology, geomagnetic, platform, gradient, and wave. In order to reduce the effect of these noise sources, ancillary sensors are used in conjunction with noise models. These sensors are fluxgate magnetometers, accelerometers, and a low-noise C-code GPS. The performance of the POLATOMIC 2000 is described, as is the platform integration. Results of ground tests and flight tests are summarized, and the noise models and the effectiveness of the ancillary sensors for ambient and platform noise reduction are discusses.
| Limitations: |
 APPROVED FOR PUBLIC RELEASE |
| Description: |
Professional paper |
| Pages: |
14 |
| Report Date: |
21 MAY 2001 |
| Report Number: |
A733393 |
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