Download the SOFIA Cycle 4 Call for Proposals Document (version 2, June 8, 2015)

SOFIA Observer's Handbook for Cycle 4


For Cycle 4, the following instruments will be available: EXES, FIFI-LS, FLITECAM, FORCAST, FPI+, GREAT, HAWC+, HIPO and the FLITECAM/HIPO combination. The instrument modes available for Cycle 4 observations are listed in the Call for Proposals and described in details in the Observer's Handbook. The instrument properties are summarized on the instrument pages.

Reserved Observations Catalogs (ROCs)

Summary tables containing the reserved observations for each instrument are included as appendices in the Call for Proposals. Generally, these may not be proposed for in Cycle 4. The policies are described in Section 1.7.1 of the Call for Proposals document.

Duplication Checking

Duplications of existing observations, or of observations approved for Cycle 3 but not yet executed, need to be justified explicitly. Proposers should search the SOFIA Science Archive for completed observations and the AOR Search page for approved Cycle 3 observations to check for potential duplications.

We have discovered a few shortcomings in the search results tables, which impact the ability for a complete duplication check for GREAT, EXES and FIFI-LS. These problems will be corrected soon in the next release of the search-tools software, but until then proposers need to take the additional steps described below.

The Science Archive search results tables for the GREAT instrument do not list the exact frequencies observed. Therefore, if proposers find that a target has been observed by GREAT, they should follow up by executing an AOR search for that target for "All Cycles" with GREAT as the selected instrument. The results will include the observed frequencies. The set of frequencies observed may be incomplete for observations in earlier cycles. Please contact us at if you have any questions about possible duplications.

In the case of EXES and FIFI-LS, neither the Science Archive nor the AOR search results table list the central wavelength(s) observed. We have provided four tables, linked below, with the necessary information. Users should first check whether their target of interest has been observed, or is scheduled for observation. If it has, then they should check the wavelength(s) in the appropriate table. In these tables, the column "Processing" indicates what level of data products have been ingested in the archive - blank entries imply that the data are yet to be obtained.

EXES Non-GI Cycles AORs
FIFI-LS Non-GI Cycles AORs

Proposal Tools and Tutorials

SOFIA Proposal Tool (SPT)

All proposals are to be prepared and submitted using the SOFIA Proposal Tool (SPT), which is based on the Astronomer’s Proposal Tool (APT) used for Hubble Space Telescope proposals.

Download SPT (v2_8_1 and higher required for Cycle 4, v2_8_3 required for HAWC+ observing proposals)

All users proposing HAWC+ observations: please check the HAWC+ overhead calculation page.

SPT can be downloaded without registering for a DCS account, and without being logged in to DCS. However, a DCS user account is necessary for submitting a SOFIA Phase I proposal. We recommend that new users register with DCS well before the submission deadline.

Exposure Time Estimation

EXES - exposure times should be obtained from the on-line calculator for EXES observations, maintained by the Instrument PI, Matthew Richter (UC Davis).

FIFI-LS on-line time estimator.

FLITECAM imaging - on-line calculator, SITE.

FLITECAM grism observation calculator.

FORCAST imaging - on-line calculator, SITE.

FORCAST grism observation calculator.

FPI+ - on-line calculator, SITE.

GREAT - exposure times should be calculated using the GREAT on-line time estimator. The calculations are based on the “Guide to observation planning with GREAT”, which also contains detailed information about the instrument. Note that information about upGREAT has not been incorporated into the exposure time estimator yet.

HAWC+ - on-line calculator, SITE.

HIPO - exposure times may be estimated using the information in the Observer's Handbook. Since HIPO and the FLITECAM/HIPO combination are considered special purpose instruments, detailed planning of observations should be carried out in consultation with the Instrument PI, Edward Dunham (Lowell Observatory).

Atmospheric Transmission

The atmospheric transmission as a function of wavelength may be obtained using the on-line tool ATRAN developed and kindly provided to the SOFIA progrm by Steve Lord. The use of ATRAN is necessary for planning SOFIA high-resolution spectroscopic observations.

Target Visibility Tool

The target visibility for SOFIA can be determined using the Visibility Tool (VT), which is now available both as a Java Applet or for download. Note that the use of VT is not a requirement, since detailed flight planning is done by the SMO staff.

Other Supporting Resources

SOFIA Publications

SOFIA Observers' Workshop presentations

Refereed publications using SOFIA data, and about the Observatory and instruments are available on the publications page.

Ringberg Workshop

The "Ringberg Workshop on Spectroscopy with the Stratospheric Observatory for Infrared Astronomy (SOFIA)" was held on March 15-18, 2015. Some presentations from the meeting are available here. Abstracts of all the presentations, and other details may be found on the meeting website.

Instrument Summaries


Cycle 4 Information

Cycle 4: Phase II Information

Contact the SOFIA help-desk