OPNAV DESCRIPTION FILE Please also refer to the sequserguide.pdf. There is a nice section on OPNAVS. There are two excel files which list opnavs. 1) global.xls - this includes opnavs that were taken at high altitudes using a global mosaic pattern (approach, post orbit insertion, and 200km orbits mainly). 2) loworbitopnavs.xls - all the rest, including opnavs at 100km and below. This file contains three sections - I. OVERVIEW OF OPNAV DESIGN - general naming guidelines II. EXAMPLES FROM MISSION SECTIONS - detailed examples from major mission orbital periods III. OPNAV DESCRIPTIONS BY LETTER - detailed description of letter types and mosaic shapes I. OVERVIEW OF OPNAV DESIGN A few overall guidelines: 1) LETTER SCHEME - Most opnavs have in them one of the following letters: D,F,H,L,M,N,Q. This indicates the mosaic shape. A = 1x1 (except has a small slew over 2x2 pixel region) B = 1x1 ('1x1' means a single position) C = 1x1 + 2x2 (one frame in middle, followed by 2x2) D = 2x2 F = 2x3 H = 3x3 L = 3x4 M = 4x3 N = 4x4 Q = 3x5 2) The use of the letter K in opnav naming does NOT signify a mosaic shape. This was a sequencing shorthand that means we used a special type of Opnav CAS that allowed the flexibility to make any type of mosaic shape. Ignore the letter K. 3) NUMBERING SCHEME: In the opnav names, there is often a number between 1 and 4 that immediately follows the letter describing mosaic shape. This number describes the corner of the mosaic where the first frame of the mosaic is taken. The example given below is for a 3x3 mosaic and shows the associated slewing patterns. This can be applied to any mosaic type (letters D through Q). H1 H2 H3 H4 (1) | ^---->| <-----^ |(2) ^ <----^ ^----> ^ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | \/--->| \/ \/ <----\/ <----\/ |(3) (4)| \/---> 4) All opnavs are monochrome, filter 4, except for Opnav A and BP and a few multi-color opnavs taken in the later part of the mission (the word 'color' is in the name of these opnavs); one image is taken at each position in the mosaic. II. EXAMPLES FROM MISSION SECTIONS Cruise and Approach: the following opnav types were numbered (eg, Opnav_A1, Opnav_A3) ------------------- Opnav_A - (see OPNAV DESCRIPTIONS BY LETTER, below) Opnav_B - (see OPNAV DESCRIPTIONS BY LETTER, below) Opnav_BP - (see OPNAV DESCRIPTIONS BY LETTER, below) Opnav_C - (see OPNAV DESCRIPTIONS BY LETTER, below) Opnav_CA - simple concatenation of Opnavs C and A. Post Orbit Insertion and High Orbits: ------------------------------------ OPH_3 - The letter H designates mosaic type, 3x3 (colxrow) These early opnavs were numbered. for example, this was the third Opnav H executed. (all opnavs after orbit insertion up to doy 53 were OPH's) OPN_53a_KF - From this one on, doy is given in the name. The lowercase 'a' means it was the first opnav of doy 53. The letter F designates the mosaic type, 2x3 (colxrow). Ignore the K. OPN_063d_KL1 - Again, doy year given, 'd' means that it was the 4th opnav on day 63. The letter L describes the mosaic shape (3x4). The number '1' tells you what corner the mosaic started in (in this case upper left corner) (1 = first frame is upper left, 2 = first frame upper right, 3 = first frame lower right, 4 = first frame lower left; slewing proceeds in column direction first, except for a few noted cases. Ignore the letter K.) OPN_68c_M3 - This was 3rd opnav of doy 69 ('c'). It is a 3x4 (colxrow), starts in lower right (goes up first, then left, then down, the left etc) OPN_60a_H - This is a 3x3 mosaic taken on doy 60, first opnav of the day ('a'). No number this time. OPN_113cPostBrnKL3A - The post-burn opnavs often had queer names. Usually there was some indication of the mosaic type. This one was an L3 (3x4, starts in lower right corner). 'A' means it was the first opnav after the burn. There were usually two opnavs taken after each burn. 'A' will be taken at about 30 min to 1 hour after. 'B' will be taken at about + 4 hours. Sometimes, instead of A and B, there will be a 1, or 2 (eg, OPN_BRN1_KH) that signifies first and second opnavs after the burn. OPK_OIM1_3x4 - Sometimes there is an indication of which burn these opnavs followed. This was the first opnav after orbit insertion. In this case the mosaic starts in lower left but it is not labelled. 100 km North and 50kmA orbits: ----------------------------- ****==> Starting on doy 94 we began to execute two small mosaics for each 'Opnav' set. We describe this double set of mosaics with only ONE observation name. This is a change. Before we generally only took one mosaic per Opnav observation. Examples: OPN_94c_KD - In this Opnav, two D (2x2) mosaics are taken on day 97, 3rd mosaic set of the day ('c'). The only way to tell it's a double is because the number of frames is 8. OPN_136d_KF - Here is another 'double' opnav that executes two 2x3 mosaics (total number of frames is 12). *****==> During week 00129, a new kind of Opnav CAS became available called the 'Double K' which allowed us to design and execute these two different small mosaics in the same Opnav CAS. There is NO DIFFERENCE in the result. We still execute two small mosaics in the same Opnav period, but it simplified the sequencing. For most of these you will see a designation like 'DKD' or 'DKF'. The 'DK' part means 'Double K'. The D or F, or what not, that follows is the mosaic type (2x2, or 2x3, etc). Example: OPN_133c_DKD - Here is a 'Double K' which takes two 2x2 mosaics. NOTE: Looking through these I've noticed we were not always consistent. 100km South: ------------ ****> On doy 241 starting with OPN_241c_DKD, we began using new type of OPN_XXX_DKD. Instead of two single 2x2 mosaics, we now take two repeating 2x2 mosaics. Only one repeat for each, that is, we go around the 2x2 pattern twice for each mosiac. Each contains 8 frames. Examples: OPN_241C_DKD - Two repeating 2x2 mosaics. Eight frames per mosaic. OPN_O17A_KHKD - Here's a good one. The O17A stands for OCM-17, A is first opnav after the burn. The KHKD means we took two mosaics, an H (3x3), followed by a D (2x2). 200km South: ------------ Back up to 200km, we started using the single, tailored global mosaics again. Example: OPN_304D_KL - This is a single 3x4 mosaic taken as the 4th opnav observation on day 304. Check the number of frames, which is 12. Since there is no number after the L, probably means it starts in upper left (a '1'). 35km BC: -------- ***>> During this orbit we changed the DKD design yet again (starting with OPN_362B_DKD) to be two zig-zag 2x4 mosaics (instead of the two 2x2 repeating mosaics). Still 8 frames per mosaic, but the zig-zag design helped prevent pull-apart. By zig-zag I mean this: 1 2 3 4 5 6 7 8 Clearly, we should have removed the designation 'D' from these opnavs, but at that point in the mission we were very tired and had other things to worry about. Example: OPN_362B_DKD - Two zig-zag 2x4 mosaics. III. OPNAV DESCRIPTIONS BY LETTER: --------------------------------- Summary: Opnav A - 16 frames slewing across 2x2 pix Opnav B - 8 frames still Opnav C - 1x1 followed by 2x2, 1 image at each position Opnav D - 2x2, 1 image at each position for this and all below Opnav F - 2x3 Opnav G - 3x2 Opnav H - 3x3 Opnav I - 1x2 Opnav J - 2x1 Opnav L - 3x4 Opnav M - 4x3 Opnav N - 4x4 Opnav O - 4x5 Opnav P - 5x4 Opnav Q - 3x5 Opnav R - 2x4 Detailed Descriptions and Diagrams: Opnav A - Used during cruise or on approach when Eros is subpixel. It slews the MSI FOV to nadir then takes 16 pics (2 sec apart) while scanning slowly across the diagonal of a 2x2 pixel rectangle. The images are taken through clear filter, 999m manual exposure, no compression. Opnav B and BP - Takes 8 frames with Eros nadir in center of frame. These were used between the time when Eros is approximately equal to one pixel through some time when it is less than one FOV. ____________________ | | | | | | | E | | | | | |____________________| Opnav_B - The 8 frames include: 3 clear filter, 999ms manual exposure (exposed for stars) 5 clear filter autoexposure frames (exposed for Eros) This one only used once on (98-324). After that we used Opnav_BP exclusively. Opnav_BP - (for B Prime): This is Opnav B slightly redesigned to convert 2 of the autoexposures to two short manual exposure images as a backup for Eros imaging in case autoexposure did not work properly. Opnav_BP was used in this form until mid-way through final approach to Eros when Bill Owen discovered that he was having trouble seeing stars due to scattered light. The content of the MSI Seq Defs were modified to ameliorate this problem. See /eros/00031/NOTES.00031 for a full explanation. Below is a summary of changes to Seq Defs used by Opnav_BP. Summary of opnav_bp changes: pre-00031 rtc 00031 rtc 00033 and after seq 29 1 man clr 999ms 1 man filt4 150ms 1 man filt4 150ms seq 8 3 auto clr 3 auto filt4 3 auto filt4 seq 9 4 man clr 4 man filt4 4 man clr (4,60,999,999ms) (all 999ms) (all 999ms) Opnav_BP_3-7 (98-348) OPNAV_BP_112 OPNAV_BP_113 to 140 Opnav_BP_N1-N5 (98-363 to 99-007 OPNAV_BP_100-111 (00-14 to 42) Opnav C - In this opnav we take a single image centered on Eros, followed by a 2x2 mosaic also centered on Eros. One image at each position. Only used in 1998 and 1999, just after the Eros Flyby when navigation uncertainty was large. Opnav_C_N1-N5 (98-363 to 99-007) Opnav_CA_1 - 9 (99-19 to 99-42) ... an Opnav A was also performed with the Opnav C ___________________________________ | | | | | 2 | | 5 | | ________|_|_______ | | | | | | | | | 1 | | | | |_______|________|_|_______|________| |_______|________|_|_______|________| | | | | | | | | | | | | | |________|_|______ | | | | | 4 | | 3 | | | |________________|_|________________| Opnav D - 2x2 mosaic This mosaic type was used extensively in the low orbits ( 50 km and 35 km orbits) ___________________________________ | | | | | | | | | | | | | 1 | | 4 | | | | | |________________|_|________________| |________________|_|________________| | | | | | | | | | 2 | | 3 | | | | | | | | | |________________|_|________________| Opnav E1 through E4 - Never used. There were single pot-shots, or concatenations of single pot-shots. Opnav F - 2x3 Mosaic First used during post orbit insertion transition period. NOTE!!!!!! the slewing pattern for these was different than for later uses of this opnav. For OPN_053a_KF through OPN_059c_KF the slewing pattern was as follows: 1 2 3 4 5 6 Used quite a bit during 50km orbits. **NOTE ABOUT SLEWING: The scan from position 1 to 3 does not stop at position 2. Slewing pattern was more normal for Same thing for the scan from position 4 to 6, does not stop at 5. The column slews in these see below (and note >>>>>) this and all mosaics to follow are performed at slow controlled rates, designed to keep smear less than .5 pixel for the images taken while the slew is happening. ___________________________________ | | | | | | | | | | | | | 1 | | 6 | | | | | |________________|_|________________| |________________|_|________________| | | | | | | | | | 2 | | 5 | | | | | |________________|_|________________| |________________|_|________________| | | | | | | | | | 3 | | 4 | | | | | | | | | |________________|_|________________| Opnav G - 3x2 Rarely, if ever used. ___________________________________________________ | | | | | | | | | | | | | | | | | | | 6 | | 5 | | 4 | | | | | | | |________________|_|______________|_|_______________| |________________|_|______________|_|_______________| | | | | | | | | | | | | | 1 | | 2 | | 3 | | | | | | | | | | | | | |________________|_|______________|_|_______________| Opnav H - 3x3 mosaic Used right after orbit insertion, also in the high orbits (200 and 100km), and also extensively during the first 50km orbit. ____________________________________________________ | | | | | | | | | | | | | | | | | | | 1 | | 6 | | 7 | | | | | | | |________________|_|______________|_|________________| |________________|_|______________|_|________________| | | | | | | | | | | | | | 2 | | 5 | | 8 | | | | | | | | | | | | | |________________|_|______________|_|________________| |________________|_|______________|_|________________| | | | | | | | | | | | | | 3 | | 4 | | 9 | | | | | | | | | | | | | |________________|_|______________|_|________________| Opnav I - 2x1 (never used) Opnav J - 1x2 (never used) Opnav L - 3x4 Often used following orbit correction maneuvers, and in the 200km orbits. ____________________________________________________ | | | | | | | | | | | | | | | | | | | 1 | | 8 | | 9 | | | | | | | |________________|_|______________|_|________________| |________________|_|______________|_|________________| | | | | | | | | | | | | | 2 | | 7 | | 10 | | | | | | | | | | | | | |________________|_|______________|_|________________| |________________|_|______________|_|________________| | | | | | | | | | | | | | 3 | | 6 | | 11 | | | | | | | | | | | | | |________________|_|______________|_|________________| |________________|_|______________|_|________________| | | | | | | | | | | | | | 4 | | 5 | | 12 | | | | | | | | | | | | | |________________|_|______________|_|________________| Opnav M - 4x3 Used in 200km orbits. ________________________________________________________________________ | | | | | | | | | | | | | | | | | | | | | | | | | 1 | | 6 | | 7 | | 12 | | | | | | | | | |________________|_|_______________|_|________________|_|________________| |________________|_|_______________|_|________________|_|________________| | | | | | | | | | | | | | | | | | 2 | | 5 | | 8 | | 11 | | | | | | | | | | | | | | | | | |________________|_|_______________|_|________________|_|________________| |________________|_|_______________|_|________________|_|________________| | | | | | | | | | | | | | | | | | 3 | | 4 | | 9 | | 10 | | | | | | | | | | | | | | | | | |________________|_|_______________|_|________________|_|________________| Opnav N - 4x4 Used extensively in 200km and 100km orbits. ________________________________________________________________________ | | | | | | | | | | | | | | | | | | | | | | | | | 1 | | 8 | | 9 | | 16 | | | | | | | | | |________________|_|_______________|_|________________|_|________________| |________________|_|_______________|_|________________|_|________________| | | | | | | | | | | | | | | | | | 2 | | 7 | | 10 | | 15 | | | | | | | | | | | | | | | | | |________________|_|_______________|_|________________|_|________________| |________________|_|_______________|_|________________|_|________________| | | | | | | | | | | | | | | | | | 3 | | 6 | | 11 | | 14 | | | | | | | | | | | | | | | | | |________________|_|_______________|_|________________|_|________________| |________________|_|_______________|_|________________|_|________________| | | | | | | | | | | | | | | | | | 4 | | 5 | | 12 | | 13 | | | | | | | | | | | | | | | | | |________________|_|_______________|_|________________|_|________________| Opnav O - 4x5 Opnav P - 5x4 Opnav Q - 3x5 Used in 200km orbits. ____________________________________________________ | | | | | | | | | | | | | | | | | | | 1 | | 10 | | 11 | | | | | | | |________________|_|______________|_|________________| |________________|_|______________|_|________________| | | | | | | | | | | | | | 2 | | 9 | | 12 | | | | | | | | | | | | | |________________|_|______________|_|________________| |________________|_|______________|_|________________| | | | | | | | | | | | | | 3 | | 8 | | 13 | | | | | | | | | | | | | |________________|_|______________|_|________________| |________________|_|______________|_|________________| | | | | | | | | | | | | | 4 | | 7 | | 14 | | | | | | | | | | | | | |________________|_|______________|_|________________| |________________|_|______________|_|________________| | | | | | | | | | | | | | 5 | | 6 | | 15 | | | | | | | | | | | | | |________________|_|______________|_|________________|