ACS-WFC-MOSAIC-BOX
pointing patterns
This is a two-dimensional mosaic pattern, with the following allowable parameter ranges:
Pattern_Number: 1
Pattern_Type: ACS-WFC-MOSAIC-BOX
Pattern_Purpose: MOSAIC
Number_Of_Points: 4
Point_Spacing: 10.0 - 130.0 (arcseconds)
Line_Spacing: 10.0 - 130.0 (arcseconds)
Coordinate_Frame: POS-TARG
Pattern_Orient: 0.0 - 360.0 (degrees)
Angle_Between_Sides: 0.0 - 360.0 (degrees)
Center_Pattern: ? (YES or NO)
Note: When mosaicking in a sparse field, where there may be too few objects in the overlap regions to help register the resulting images, the shifts in the patterns below should be reduced to increase the overlap area. Images taken with the same guide stars will register well just using the WCS, but where a guide star handoff occurs, the WCS will be inadequate for image registration, and the shifts will need to be measured using the relative positions of objects in the overlap regions.
The pattern displayed above has a ~full-FOV shift in x, but only a ~half-FOV shift in y, which covers the interchip gap, and can be done with one guide star pair. This pattern cannot currently be executed with a pattern form due to guide star handoffs needed for the x-shifts (which exceed ~100 arcsec). The POS TARG equivalents must be used for now:
Pattern_Number: 18
Pattern_Type: ACS-WFC-MOSAIC-BOX
Pattern_Purpose: MOSAIC
Number_Of_Points: 4
Point_Spacing: 96.231
Line_Spacing: 192.884
Coordinate_Frame: POS-TARG
Pattern_Orient: 90.0
Angle_Between_Sides: 99.0
Center_Pattern: YES
POS TARG equivalent: -96.108, -55.898
-96.108, 40.334
96.108, 55.898
96.108, -40.334
The full mosaic shift pattern (displayed here) cannot be executed with a pattern form due to guide star handoffs (both the x and y shifts exceed ~100 arcsec). The POS TARG equivalents must be used for now.
Pattern_Number: 17
Pattern_Type: ACS-WFC-MOSAIC-BOX
Pattern_Purpose: MOSAIC
Number_Of_Points: 4
Point_Spacing: 192.215
Line_Spacing: 192.844
Coordinate_Frame: POS-TARG
Pattern_Orient: 90.00
Angle_Between_Sides: 94.63
Center_Pattern: YES
POS TARG equivalent: -96.108, -103.890
-96.083, 88.303
96.108, 103.890
96.108, -88.326