the minimap mode has been recommended by the pht instrument team in order to obtain accurate photometry of point sources thereby minimizing the cirrus confusion. in addition, the c100 minimap can be used to obtain small images of small extended sources. the original recommendation was to step 1 pixel width (46) in y and z direction in a 3x3 raster with c100. recently, r. laureijs found in his programme that stepping 69 (that is 1.5 pixel width) is very advantageous to obtain high quality high resolution maps of small extended sources. this is due to the improved sampling of 1/2 pixel and the redundancy (overlap) which is good enough to perform accurate flat fielding of the 9 c100 pixels. in order to decide whether a source is extended it is necessary to obtain a map of a known point source, which can be compared with a similar map of an unknown source. for this calibration measurement we observe the calibration star hr6705 at 60 (c_60) and 100 micron (c_100) in order to get an reliable point source template which can also be used for comparison with theoretical predictions. history 28/01/98\t\trjl, initialisation and delivery .tdt\t1776 .ott\t1596 .ott\t
Instrument
PHT22
Temporal Coverage
1998-02-19T15:02:09Z/1998-02-19T15:28:13Z
Version
1.0
Mission Description
The Infrared Space Observatory (ISO) was the world's first true orbiting infrared observatory. Equipped with four highly-sophisticated and versatile scientific instruments, it was launched by Ariane in November 1995 and provided astronomers world-wide with a facility of unprecedented sensitivity and capabilities for a detailed exploration of the Universe at infrared wavelengths.
