Technical Documents

Licensing terms

Open source technology licensing provides many advantages to the user. NOAO makes MONSOON Technology available through such a license agreement. Please be aware that while you are welcome to browse the technical material in this area, NOAO requires you to agree to the terms and conditions of the license before you begin building things based on the MONSOON designs. This requires you to sign the open source license agreement and return this document to

National Optical Astronomy Observatory,
Attention Dr. David Sprayberry,
950 N. Cherry Ave,
Tucson, Arizona, 85719, USA.

Once you have agreed to the terms of use by returning a signed license agreement to NOAO we can supply you with the source documentation for the information you require.

Document numbering and structure

The documents that describe the MONSOON technology have a structure based on a document numbering system. The numbering system is identical between the Orange and Torrent versions of the technology. The only difference is that the prefix is changed.

MONSOON Orange document numbers start with a MNSN prefix. The Orange document structure graphic is here.

MONSOON Torrent document numbers start with a TRNT prefix. The Torrent document structure graphic is here.

Interface Control Documents

These documents control the function and state of inputs to and outputs from the modules that make up a MONSOON Image Acquisition System. There are four main module interfaces that are required to build a MONSOON system. These are:

DHE to Pixel Acquisition Node (PAN) computer.

The PAN is often generically called the data acquisition computer. This interface is governed by MONSOON Interface Control Document level 6. These interfaces are common to the Orange and Torrent systems.

ICD 6.0 MNSN-AD-01-0004 Generic DHE Interface Description Rev 1.0
ICD 6.1 MNSN-AD-01-0005 DHE Interface Description Rev 1.1

PAN to Instrument Control Computer (ICS).

This is the control and command interface for the image acquisition system. Levels 4 and 5 of the MONSOON Interface Control Documents define this interaction. These interfaces are common to the Orange and Torrent systems.

ICD 4.0 MNSN-AD-01-0004 Generic Pixel Service Communications Command Response and Data Stream Interface Description Rev 1.1
ICD 5.0 MNSN-AD-01-0003 PAN Communications Command Response and Data Stream Interface Description Rev 1.0
ICD 5.1 MNSN-AD-01-0007 PAN Run-time Configuration Setup and Operating Mode Definition Interface Description Rev 1.0

PAN to Data Handling System (DHS).

The interface allows the transport of the pixel data and meta data from the acquisition computer (PAN) to an observatory data handling facility. ICD level 1 governs this interaction (which can be as simple as FITs file generation). These interfaces are common to the Orange and Torrent systems.
ICD 1.0 MNSN-AD-01-0001 Data Handling System Rev 1.0
ICD 1.1 MNSN-AD-01-0012 Data Handling System Interface Status and Data Stream Description Rev 1.0


The manufacturing documents and files available on this site may not reflect the latest optimal configuration of the hardware modules. The documents on this site reflect the configuration of the last production run of the hardware and may not reflect work that was carried out post-production through engineering change orders.

At this point the two versions of the MONSOON Technology (Orange and Torrent) diverge in the way the hardware is used to implement the functionality. The following links will take you to the details of the hardware, software, and mechanical details of each implementation.