FAQ

Phase 1

• Can I extend the proprietary period for my data? Answer

• What overhead is required to change ACS detectors during an observing sequence? Answer

• Are autoparallel observations allowed for ACS and what is their policy? Answer

• Are there special policies for the use of SBC and parallel observations? Answer

• Is there any target acquisition mode available? Answer

• Are digital versions of the transmission curves available? Answer

Phase 2

• How accurate are the ACS aperture overlays in the VTT? Answer

• What are ACS subarrays? How can I use them? Answer

• What guiding concerns should I have for my ACS observations? Answer

• Why do I get serial buffer dumps in RPS2 and why does it take so long to process? Answer

• How do POS-TARGs and patterns interact? Answer

• Why does adding a WFPC2 coordinated parallel to an existing ACS/WFC result in large changes? Answer

• Will a 9-degree moon avoidance angle gaurantee a zodi-limited background level? Answer

• Is it OK to put a bright star in the gap between the two WFC chips? Answer

• How well do integral pixel dithers in the WFC work? Answer

• What is the offset in the U2 direction that can be taken before a gap appears? Answer

• What aperture should I use for large mosaics? Answer

• Can I add WFPC2 coordinated parallels to my ACS observations? Answer

• What are the current ACS/WFC aperture parameters? Answer

• Dithering for hot pixels Answer

• What are the minimum and maximum length of an exposure with each detector? Answer

• How do I change the configuration from my Phase I submission? Answer

ETCs

• What is the meaning of the 2x2 resolution element in the ACS ETC for an extended source? What do I do if my source is larger than the 2x2 element? Answer

• Are digital versions of the transmission curves available? Answer

• What do "counts" mean in the ACS Instrument Handbook? Answer

• What are N_pix, epsilon_f and epsilon_f(1)? Answer

• What is (epsilon_Nspix)' and how is the spectroscopic S/N calculated? Answer

• How can I maximize SNR when observing a faint diffuse target in the UV with the SBC? Answer

• How do I use the ETC for an emission-line source? Answer

• Will binning be available for the CCDs? Answer

Performance

• What are the maximum allowable SBC count rates? Answer

• What type of compression is available in ACS? Answer

• I just got my ACS data. What are all these files? Answer

• What technique will be used to determine the geometric distortion? Answer

• How bad is the fringing at wavelengths longer than 7500A? Answer

• What strategies can I employ to increase my signal-to-noise? Answer