10.1	Phase I Proposing

10.1.1 Phase I Orbit Allocation Examples

At this point you should have assembled all the information you need to submit your Phase I HST observing proposal. During the course of this process you should review the items listed below.

For All Proposals:

•	Check the catalog of previously executed and accepted programs to search for any duplications, and if present, provide a justification for duplicate observations.

•	Justify any special requirements (e.g., SHADOW, interactive acquisition, CVZ, target-of-opportunity, time critical scheduling, or the re-use target capability).

•	Consider any special calibrations (e.g., unusually accurate wavelength determination requiring additional (non-automatic) wavecal exposures, fringe flats, or slitless spectroscopy), and account for their time in your request.

•	Check your exposure times and configurations to ensure they are sufficient to provide the desired signal-to-noise ratios and accuracies, without saturation.

•	Check that no visit is longer than 5 orbits.

•	Allocate time for a target acquisition with appropriate centering accuracy. If a pre-acquisition image is needed, include the necessary extra orbit in the total orbit time request.

•	Consider the need for, and benefit of, obtaining coordinated parallel exposures with other instruments. Take into account any applicable data volume restrictions.

•	Include all applicable overheads so that in Phase II you will have enough orbits available to successfully implement your observations.

•	Make sure that all configurations used in your proposal are included in the summary table.

•	If applicable, justify the use of any available-but-unsupported modes, and explain how you plan to deal with calibration issues.

For CCD Observations:

•	Check that you are not exceeding the CCD full well counts/pix limit for pixels (emission lines or objects) of interest.

•	Allow time for CR-SPLIT observations and dithering, as needed.

For MAMA Observations:

•	Check that your source does not exceed the absolute bright object count rate limits for MAMA exposures. For target-of-opportunity programs, explain how you plan to show that the target does not exceed the bright object limits.

•	Check that you are not exceeding the MAMA 65,536 counts/pix buffer imposed limit over pixels (emission lines or objects) of interest.

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Check that your proposal does not violate the policy that restricts the mixing of CCD and MAMA observations in the same visit, (see Section 2.6). Be sure that you are requesting sufficient orbits to allow the MAMA and CCD observations to be done in separate visits. Provide a justification if the scientific needs of your program require violating this policy.

•	If early acquisition images in support of MAMA bright object checking are necessary, they must be included in the Phase I orbit request.

•	Remember that MAMA pure parallels are not allowed (see Section 2.7).

•	Be aware of the limits on the number of targets for STIS/MAMA and COS snapshot and survey programs (see Section 2.8).

10.1.1 Phase I Orbit Allocation Examples

Phase I orbit allocation examples are presented in the HST Primer. Additional examples of Phase I orbit estimations are worked through in this Handbook (see Section 1.2.2, Section 6.8, and Section 9.3).