This is the User Requirement Document for the UltraDAS Data Acquisition system based on SDSU's new PCI card for CCD control.
The computer platform is a SUN UltraSPARC computer. The user requirements are outlined below

ING requires an interface common to CCD and IR. systems to work with SDSU/IRlabs detector controllers.

ING The Isaac Newton Group of Telescopes.
WHT The William Herschel Telescope.
INT The Isaac Newton Telescope.
JKT The Jacobus Kapteyn Telescope.
SDSU San Diego State University.
DSP Digital Signal Processor.
TCS Telescope Control System.
CCDC (standing for CCD controller) here means any SDSU detector control whether used to drive CCD's or other detectors.
LAL stands for the users Lowest Acceptable Limit for the defined parameter.
HAL stands for the users Highest Acceptable Limit for the defined parameter.
TBD stands for To Be Determined.

The goal of the new UltraDAS project is to install and commission the new SDSU controller as quickly as possible, consistent with good engineering practice.

The following personnel are the intended users for this software.

• visiting astronomers
• ING astronomers/observing assistants
• ING technical staff - operations
• ING technical staff - development

• The interface and the computing system that it is built into have to handle many types of single detector and also current and future mosaics. The largest mosaic currently projected would contain 32 EEV42 CCD's each operating two readout amplifiers.
• On all science CCD's, the computing and communications systems should not limit the readout rates.
• In at least one mode (fast, optical photometry), we need to receive and buffer several CCD readouts per second, so the turn-around time for the commands involved in an exposure and readout must be kept low.
• For the 32 chip mosaic camera, and probably for other mosaics in the near future, the best readout rate allowed by the CCD's exceeds the capacity of the fiber optic downlink. We assume either that we will use the current fibre technology with several fibre sets and interface cards for one camera, or that SUDS will revise the hardware to use faster fibres.
• The interface will be used in a SPARCstation computer running Solaris V2.6.

 

UR01 Incorporate IR. instruments and detectors into the DAS.
 

LAL	IR. Instruments Goal	HAL
Not Incorporated	Incorporated	-


 

UR02 Required CYCLE TIME for the observation.
 

LAL	Cycle Time Goal	HAL
30 Sec.	12 Sec.	5 Sec.

The cycle time is defined by the pixel readout rate for the CCD plus a fixed overhead dependent on the software (memory access / disk acquisition / file transfer / network transfer rates).
The exposure repetition rate is composed of the CYCLE TIME + EXPOSURE TIME.
 
 

UR03 Fast photometric mode with suitable CCD
 

LAL	Fast Mode Time Goal	HAL
5 Sec.	0.2 Sec.	0.1 Sec.

Required for a fast photometric camera.
 
 

UR04 Configuration files
 

LAL	Configuration Files	HAL
Not Implemented	Implemented	-

Required to reconfigure DAS and DSP for different instruments.
 

UR05 Speed

There are separate sets of requirements for optical and IR. instruments. The fastest possible time is required, whereby silicon provides the limit with 30 Seconds being a limiting maximum readout time for any large array (e.g. 32x4kx2k array).
High speed is required for a series of short exposures with each exposure of > 1 sec [WHT2-r1].
The series must be maintained for > 15 mins for 1024 chip with 10 pixel wide strips. [WHT2-r1.1].
 

1. Support for readout speeds
Only 2 speeds are to be supported  FAST and NORMAL.  FAST is high speed and low gain with NORMAL being low speed with high gain.

2. Support of clear speeds
Two clear speeds are required  for IR. use. (IR FAST CLEAR and IR SLOW CLEAR). For optical only one clear speed is required.


 

UR06 Dimension Setup

Normal 2d is supported with options for 3d cubes either as 2d slices or 3d cubes. It would however be useful to allow up to 7d.

LAL	n Dimension Goal	HAL
3D	3D	7D

Note - The (NASA) FITS standard allows a number of dimensions up to 999, but FITS implementations (following) the original FITS papers are thought by JRL to limit it to 7. IRAF also stops at 7 dimensions.
 
 

UR07 Switchable gains

Support is required for gain values of X1,X2 and X4.
 
 

UR08 Windowing
 

1. It is required that up-to n (independent, non overlapping) windows could be defined.

LAL	n Windows Goal	HAL
4	5	10

2. An ability to append windows into one image file to provide a science area plus an over scan area is required.
3. Enable/disable individual windows - nice but not essential.
4. Windows appended.
5. support wide field cameras with different DSP code.

 

UR09 Binning

Required up-to x10 in x and y dimensions, windowing should also be possible.

LAL	Binning Goal	HAL
x10	x10	x10


 

UR10 Exposure types

The required exposure types are:-

1. run  - a numbered science run
2. continuous run - noting number of exposures in the sequence
3. bias
4. flat
5. arc
6. dark
7. glance -  doesn't save in file untill instructed.
8. scratch - save in numbered file but does not archive.
9. sky
10. flash   - dark with preflash for IR.
11. multirun - requires preprocessing for IR.
12. multi continuous run - noting number of exposures in the sequence
13. multi bias
14. multi flat
15. multi arc
16. multi dark
17. multi glance - does't save in file untill instructed. - Movie mode for IR.
18. multi scratch - SAVE IN NUMBERED FILE DOESN'T ARCHIVE - Movie mode for IR.
19. multi sky
20. multi flash
21. abort
22. finish
23. newtime
24. focus_run - capability - via the tcs
25. dither_run - capability required for IR.


Note - For an IR. run sequence:
MNDR:
reset,
n reads (to reduce read noise),
integrate m sec's,
n reads
for multiple MNDR generate a single image file
IR. generates data cubes
For the simple case - 2 planes with post reset read and post int read

The FITS data format needs to be real32 for IR.
Note that OPTICAL is 16BIT Data - and INFRA RED is 32BIT Data.
 
 

UR11 Multiple CCD's and Multiple Readouts
 

1. Support is required for 4 readouts per CCD.
2. Support for readout of individual CCD's in an array of CCD's
3. Ability to select a group of CCD's in a large array.
4. Support 4 CCD's per mimic.


Note - to save disk space throw away unwanted data. address each readout port
insert for current widefield camera - each chip separate
 

UR12 Esoteric

Orthogonal Transfer CCD's - TBD.
 
 

UR13 Telemetry
 

1. An OBSERVERS MIMIC is required (status and control).
2. An ENGINEERING MIMIC is required (full engineering status).

 

UR14 Alarms and CCD Status information
 

1. Anti blooming on/off.
2. Anti blooming settings
3. Diagnostic alarms from user interface
4. Chip ID for current CCD
5. Software version of DSP code.
6. CCD temperature and 2 auxiluary temperatures.
7. CCD temperature alarm and 2 auxilluary temperature alarms.
8. Preflash gain time.
9. The same status information for all CCD's requires a common interface.
10. 6 general purpose alarms.

 

UR15 Aborts
 

1. Exposure Abort
2. Readout Abort

 

UR16 Timing

1. The exposure start time accurate to +/-100 millisec ref [WFC-r22] or 50 millisec for IR ref      [IRSR-r16]

	LAL	Absolute Time	HAL
Optical	100 Millisec	30 Millisec	-
IR.	50 Millisec	30 Millisec	-

2. The exposure length accurate to +/-10 millisec ref [WFC-r22] or 1 millisec for IR. ref [IRSR-r1]

	LAL	Exposure Time	HAL
Optical	10 Millisec	1 Millisec	-
IR.	1 Millisec	1 Millisec	-


 

UR17 Data Saving
 

1. Acquired data to be saved in disk FITS files (FITSREF)
2. Acquired data to be saved on network accessible disks
3. FITS headers in standard format for each observing run.


The specification for the FITS headers at the INT and/or the JKT telescopes are available. (FITS).
 

UR18 Logging

There is a requirement for automatic logging, this may be a separate project.
 
 

UR19 Real time displays

For InfraRed this is required as a standard  - not necessarily needed if files can be accessed via iraf.
NOT ON LINE BUT A FAST/QUICK display.
Pop up images on DAS without user intervention.
 
 

UR20 Misc. Requirements
 

1. An IDENTIFY command to set the observer/programme id in fits headers.
2. Refresh rate button required.

 

UR21 Reliability

A failure rate has been defined which is a percentage of the total observing runs in which no or incorrect data has been acquired.

	LAL	Corruption Rate	HAL
Total	1%	0.5%	-
6 Month Average	1:1500	1:5000	1:10000


 

UR22 Ease of use

Ease of use criterion - a novice user should be able to use the DAS after 1 Hour.

LAL	Time Goal	HAL
2 Hours	1 Hour	-


 

UR23 Documentation

Documentation will be provided for the following levels.

1. technical level
2. expert user level
3. novice level - including fault finding trees
4. faq (frequently asked questions)

 

UR24 Number of controllers supported together

Syncronisation is required for multi controller data acquisition.

LAL	Number of Controllers	HAL
3	4	-


 

UR25 Optional Requirements to save data
 

1. NORTH=UP
2. EAST=LEFT
3. BLUE=????
4. TURN ON/OFF
5. Wavelength Rotation

1. Commonality

The DAS will be the same on each telescope subject to actual differences in telescopes and instruments/detectors.
This may need to be configurable (via add ins for the IR. or 3D cases).

2. User Interface

It is required that commands are accessible via the standard unix shells (e.g. tcsh, csh) to facilitate scripting.