View source for Engineering:Humidity Sounder for Brazil

The '''Humidity Sounder for Brazil (HSB)''' was an instrument launched on [[Organization:NASA|NASA]]'s [[Astronomy:Earth Observing System|Earth Observing System]] satellite [[Engineering:Aqua (satellite)|Aqua]] launched in May 2002.  It was a four-channel passive microwave radiometer, with one channel at 150 GHz and three channels at 183 GHz.  It was very similar in design to the AMSU-B instrument, except it lacked the 89 GHz surface sounding channel.  It was intended to study profiles of atmospheric [[Physics:Water vapor|water vapor]] and provide improved input data to the cloud-clearing algorithms in the Unified AIRS Retrieval Suite, but the scan mirror motor failed on February 5, 2003.  It worked with the Atmospheric Infrared Sounder and AMSU-A to form the AIRS Sounding Suite.
HSB was manufactured by [[Company:Matra Marconi Space|Matra Marconi Space]], Limited (MMS), in the United Kingdom under a contract with the Brazilian [[Organization:National Institute for Space Research|National Institute for Space Research]] (INPE).

== Instrument characteristics ==

*Heritage: AMSU-B
*Swath: 1650 km
*Spatial resolution: 13.5 km horizontal at [[Nadir|nadir]]
*Mass: 51 kg
*Duty cycle: 100%
*Power: 56 W
*Data rate: 4.2 kbit/s
*Field of View: ± 49.5 degrees cross-track
*Instrument Instantaneous Field of View: 1.1 degrees circular

'''Table 1: Radiometric characteristics of the HSB'''

{| class="wikitable"
|-
! valign="top" | Channel Number
! valign="top" | AMSU-B<br>
Channel Number
! valign="top" | Frequency<br>
(GHz)<br>
! valign="top" | Bandwidth<br>
(at nadir)<br>
! valign="top" | Instrument Sensitivity <br>
NEDT (K)<br>
|-
| 1
| 16
| 89.9 ± 0.9
| '''DELETED'''
| '''DELETED'''
|-
| 2
| 17
| 150 ± 0.9
| 4000
| 0.68
|-
| 3
| 18
| 183.31 ± 1.00
| 2x500
| 0.57
|-
| 4
| 19
| 183.31 ± 3.00
| 2x1000
| 0.39
|-
| 5
| 20
| 183.31 ± 7.00
| 2x2000
| 0.30
|-
|}

== History ==
HSB stopped scanning suddenly and without warning over the Pacific Ocean February 5, 2003 at 21:39 UTC.  The most likely cause is an electrical failure in the scan electronics.  By design AMSU-B and therefore HSB had very limited hardware redundancy and software update capability.

==External links==
*[http://daac.gsfc.nasa.gov/AIRS/documentation/hsb_instrument_guide.shtml HSB instrument guide]
*[http://daac.gsfc.nasa.gov/AIRS/data_products.shtml HSB data at NASA Goddard]

[[Category:Spacecraft instruments]]
[[Category:Satellite meteorology and remote sensing]]

{{Sourceattribution|Humidity Sounder for Brazil|1}}