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New Control System for the 30m
Specifications
Observing Modes and User Commands

H. Ungerechts
with many contributors

Title: New Control System for the 30m Telescope: Specifications:
Observing Modes and User Commands

Identifier - Master URL:
http://www.iram.es/FutureControl30M/Specifications/Spec_OM
Revision: Spec_Observing_Modes, Section_Preface, v1.0.2
(revision from draft, v0.5 in progress)
Date: 2000-09-18
Author: Hans Ungerechts (mailto:ungerechts@iram.es)
Contributors: during discussions at IRAM, Granada and Grenoble, and MPIfR, Bonn (Granada: WB, UL, RM, GP, JP, AS, HU, WW; Grenoble: DB, DD, MG, MG, SG, BL, RL, DM, RN, AP, KS, CT; Bonn: FG, RG, AJ, KM, JN, JS, RZ, & others)
Audience: astronomers and technical staff; user community
Publisher: IRAM, Granada, Spain
Subject and Keywords: new control system, NCS 30m, requirements, specifications, observing modes, user commands
Description - about this document:
Requirements and specifications for observing modes and user commands for the new control system for the IRAM 30-m telescope (NCS 30m). This document adopts the user's (astronomer's) view of the system.

Any comments and suggestions are very welcome.

This is the ongoing (2000-09-18) revision from draft, v0.5 (1999-December) to v1. It includes changes based on all discussions held and comments received until 2000, July. This is not yet a stable version of this document.

This document in full, including all sections (Postscript):
http://www.iram.es/FutureControl30M/Specifications/Spec_OM/Spec_Observing_Modes.ps

Postscript file with this Section

Contents

HIGHLIGHTS

PREFACE
How to read this document; Overview of Sections; What is described elsewhere; TO DO for this document; Priorities; Typographical conventions

Sections

NOTES:
Sections "General Parameters and Defaults" and "Common Parameters and Options" are not up-to-date relative to the other sections. The Indices are not yet done.

HIGHLIGHTS

(NB: features already in current “OBS” system are in italics)

continuous data taking (fast on-the-fly) as standard observing mode
scanning in more than one coordinate
specification of positions in projections
flexible subscan sequences
positions, offsets, scanning in:
- projection or user-defined “descriptive” system or “basis” system
- apparent hour-angle and declination
- Nasmyth offsets
- horizontal coordinates (astronomical azimuth and elevation)
independent streams for telescope-data (“Headers” and “DAPs” and "Trailers")
and backend data
single consistent command language and user interface
“realtime” data processing software identical to off-line software
interaction --in both directions-- between data acquisition and data processing software by messages = command procedures
systematic handling of status and error messages

PREFACE

How to Read this Document

First time readers may find Sections 1 (Introduction) and 2 (Antenna Control) helpful to put the following sections into the context of the new system. In particular, Section 2 (Antenna Control) gives an overview of coordinates for antenna movements.

Sections 3 to 10 describe the user commands ordered by subject area: 3 frontend; 4 backend; 5 switching modes; 6 basic commands for observing modes, pointing, calibration etc; 7 standard observing modes for target sources; 8 flexible subscan sequences; 9 source and line catalogs; 10 services.

For each command there is a compact summary. Details for the parameters and options of these commands are in tables that follow the command summary. For a quick look at the document, you may want to skip these tables. Also, note that these tables are on purpose redundant: the detailed description of each parameter and option, e.g., STEP dx dy, is identical wherever it appears in these tables. Some subjects covered in these sections are not formalized into user commands, because they provide general information, are comments on how to apply the user commands, or we have not yet decided that a specific user command is needed for the stated purpose.

Section 11 (not yet up-to-date) describes general parameters controlled by a special SET command.

Section 12 (not yet up-to-date) summarizes all parameters and options of all commands from sections 3--10. It is simply for reference and provides no additional information.

Section 13 defines our terminology for (sub-)units of scans and observing sequences. This section should be used for reference for our usage of terms like blanking, phase, cycle, record, segment, track, subscan, scan, CRO-loop.

Section 14 gives specifications for some fundamental parameters for the antenna movements, e.g., for ranges, speeds, accelerations, and accuracy.

Overview of Sections

Introduction
Antenna Control : Overview
Frontend Control

RECEIVER
Backend Control

BACKEND
Switching Modes

TOTAL_POWER
FREQUENCY_SWITCHING
WOBBLER_SWITCHING
BEAM_SWITCHING
SPECIAL_SWITCHING
Observing Modes I: General Commands, Calibration, Pointing, Focus

START
WAIT
HALT_ACTIVE_OBSERVATION
RESUME_ACTIVE_OBSERVATION
KILL_ACTIVE_OBSERVATION
STOP_ACTIVE_OBSERVATION

CALIBRATION
CALIBRATION_SI_RATIO
SIGNAL_GENERATOR
CALIBRATION_OF_PHASE

TIP
POINTING
FOCUS
INCLINOMETER
Observing Modes II: Single Target Positions and Maps

TRACK
ON_OFF
RASTER_MAP
general ON-OFF

OTF_LINE
OTF_CROSS
OTF_MAP
general OTF
WOBBLER_MAP

Array Switching
Special Observing Modes
(Holography, Occultation, Polarimetry, Pulsars, VLBI)
Observing Modes III: Subscans

BEGIN_DEFINE_OBSERVATION
END_DEFINE_OBSERVATION

SUBSCAN CAL_AMBIENT
SUBSCAN CAL_COLD
SUBSCAN CAL_NULL
SUBSCAN CAL_SKY
SUBSCAN CAL_SIGNAL_GENERATOR

SUBSCAN ON
SUBSCAN REFERENCE
SUBSCAN ON_FOCUS
SUBSCAN ON_AIRMASS

SUBSCAN SLEW_AZIMUTH
SUBSCAN SLEW_ELEVATION

SUBSCAN OTF_FOCUS
SUBSCAN OTF_WOBBLER3

SUBSCAN OTF
SEGMENT LINEAR
SEGMENT CIRCLE
SEGMENT CURVE
Catalogs

CATALOG

LINE

SOURCE
OFFSETS
TOPOLOGY
DISPLAY_SYSTEM
Services

HARDCOPY
SOUND

SAVE
General Parameters and Defaults (TBD)

SET
SHOW
Common Parameters and Options (TBD)
Terminology for Subunits of Scans and Observing Sequences
Global Specifications
Indices (TBD)

What is described elsewhere (or is going to be described elsewhere)

This document covers only a limited aspect of the new control system. In particular, it does not cover in any detail the topics of the "Working Groups" for the NCS 30m:
http://www.iram.es/FutureControl30M/Working_Groups/Working_Groups.html
These other topics include: technical implementation details, data formats, data processing, support for guest instruments, (error) messages, monitoring and logging, operations, scheduling, software engineering, (hardware) synchronization, system architecture, antenna control and pointing, and user interface including scripting (command) language.

TO DO for this document

complete revision to version 1

decide open questions
extract list of priorities
extract requirements for Antenna Control Subsystem

update Section 11
decide default values for parameters

update Section 12

check/revise Section 14

create Index

check spelling
check style and grammar
check links

Priorities

All observing modes and user command are assigned a priority:

ESSENTIAL
feature is essential; it should be implemented in the first iteration of the NCS
HIGH
feature gets high priority; it should be implemented in the first iteration of the NCS if this can be achieved with moderate effort; otherwise it should be implemented in the second iteration.
LOW
features gets low priority; it should be implemented in the first iteration of the NCS only if this can be achieved with minimal effort; otherwise it should be implemented in later iterations.

Typographical conventions in this document

The syntax and organization of the description of user commands is modeled on the SIC command language. However, we have not yet made a formal decision which command (scripting) language to use for the NCS. The syntax and keywords, and the exact distinction of parameters, options, optional parameters, defaults etc. will be formalized after we have decided on a scripting language.

"TBD" stands for: to be decided/defined.

Links are underlined (and blue).

Italics are used for emphasis.

COMMAND WORDS ARE ALL CAPITALS.

<TBD: Questions still to be decided are in italics and enclosed in angle brackets like this>.

[optional items are in square brackets]

{alternatives are separated by | and enclosed in curly braces}

In the printed (Postscript) version topics in indented lists (outlines) are flagged with diamonds: the diamonds are filled for topics that have subtopics.
- the diamonds are open for topics without subtopics.

2000-09-18 NCS 30m: Specifications: Observing Modes and User Commands: Preface (HU) § 0