Tpoint Consulting can offer state-of-the-art expertise in telescope pointing and tracking algorithms and in many other areas of positional-astronomy and astrometry. Any scale of problem can be addressed, from a few hundred lines of code implementing a pointing kernel up to complete telescope control systems. Studies of the pointing characteristics of individual telescopes can also be undertaken.

Endorsed products

• TPOINT: Also known as proTPOINT, this is the analysis tool that takes telescope pointing observations and determines a mathematical model to describe the various systematic errors in the telescope and mount. The application is supplied as an executable (for MS-Windows, Mac OS-X or Linux), together with a 160-page user manual. Each copy is licensed to an individual user and entitles him or her to analyze data from a specified telescope or all the telescopes at an observing site. The license fee depends on the size, type and number of telescopes or antennas.

  It should be understood that TPOINT itself does not control a telescope. It is the responsibility of the user's telescope control system (a) to carry out pointing tests and to log the results in one of the forms that TPOINT accepts, and (b) to implement pointing corrections according to the model that TPOINT finds. The products TCSpk, TPC and CPK (see below) support these aspects.

  In the rare cases where the expense can be justified, TPOINT is also available as ANSI C source code and 235-page manual. The resulting library (TPTLIB) can be used to add TPOINT functionality to the user's applications. SLALIB (see below) is a prerequisite.

• TCSpk: This is a comprehensive and rigorous telescope pointing kernel, aimed at developers of telescope or antenna control systems for professional astronomy and space applications. It provides extremely accurate and sophisticated algorithms for controlling pointing and tracking, including provision for autoguiders, tip-tilt optics and instrument rotators. TCSpk is licensed in ANSI C source code form (just under 100 functions) together with a 300-page programmer's manual. SLALIB is a prerequisite.

• TPC: The telescope pointing corrector library is aimed at those with existing telescope or antenna control systems and wish to add TPOINT pointing and tracking corrections. It is licensed in ANSI C source code form, and comes with an 80-page manual. SLALIB is a prerequisite.

• CPK: The concise pointing kernel library caters for telescope or antenna projects that need a lightweight solution of modest accuracy. It performs the whole transformation from a star's catalog position to the mount pointing demand, and achieves an overall computational accuracy 2 arcseconds while being fast enough to run at servo rates. CPK is licensed in ANSI C source code form, together with a 61-page manual. An introduction to the algorithms used is here.

• SLALIB: This library, which comprises 216 functions, provides the software developer with a wide range of accurate and reliable positional-astronomy functions. SLALIB is used by professional astronomers worldwide, and is at the heart of almost all the control systems for telescopes over 3 meter aperture developed during the past 25 years. It is licensed in ANSI C source code form; the programmer's manual is 385 pages.

• IPHASE: IPHASE is a TPOINT-like package for analyzing optical path-length in 2-telescope interferometers. Given delay-line readings for different stars, the IPHASE package determines the geometry of the interferometer, including the relative locations of the two telescopes or antennae and various runout effects in their mountings. The interferometer control system can use this information to improve the accuracy with which it can set the delay lines, speeding up fringe acquisition, especially for faint objects. IPHASE is a highly specialized tool, of interest to professional observatories which operate, or are developing, interferometer systems. Like TPOINT, a range of versions is available, including executables (for MS-Windows, Mac OS-X and Linux) and source licenses. SLALIB is a prerequisite.

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