********************************************************************* The Great Palmer Pass Protocol for BP-032 created/sent: John Booth, 3nov99, Palmer Station edited/sent: Sharon Stammerjohn, 9nov99, UCSB edited/sent: John Booth, 12nov99, Palmer Station updated: Karen Baker, 26dec99, UCSD OUTLINE ------- I. BP-032-O (Ray Smith, LTER) has a standing request for "clear" passes of most satellite types to be archived to tape II. BP-032-O (Ray Smith, LTER) has a standing request for weekly 'ice85' images to be ftp'd to UCSB III. BP-032-O (Ray Smith, LTER) requests browse images (e.g. jpeg) to be emailed to ship during LTER cruises that take place in or near the sea ice. **************************************************************** I. BP-032-O (Ray Smith, LTER) has made a standing request for "clear" passes of most satellite types to be archived to tape. They provide separate DDS1 tapes for this task. During the daily check of the accumulated TeraScan imagery, note passes that meet any of the following criteria: 1) The immediate vicinity (within circa 20 km) of Palmer Station is clear. 2) Roughly 1/3 or more of the LTER grid is clear. 3) During an LTER cruise, any area in the LTER grid greater than about 50 km by 50 km is clear. 4) The ice edge to the west of the Antarctic Peninsula, which may be north of the LTER grid in the winter or south of it in the summer, is clearly visible. If one or more of these criteria is met by several passes during a night, pick the best NOAA pass and the best DMSP pass to archive. If different passes of the same telemetry type meet the criteria in different ways, save them all. For example, in the early evening it might be clear over the southern half of the LTER grid, while later in the night it might be clear in the vicinity of Palmer, in which case you would save FOUR passes, the best DMSP and NOAA passes showing each of the relevant clear areas. Additionally, during LTER cruises you should save at least one of each type (NOAA and DMSP) of pass from each night regardless of cloud cover. Generally the highest elevation passes will be the best to save, but be sure to check each pass for dropouts or data gaps. For passes of similar high elevation, err to the west, as the LTER grid lies mostly to Palmer's west, and the "weather" tends to approach from the west. When SeaWiFs telemetry is being collected in encrypted mode, you will, of course, not be able to examine it directly. To decide whether to save SeaWiFs passes, you will need to guess whether you think the encrypted passes for the day met any of the "clear" criteria. To do this, examine the latest DMSP and NOAA passes from the previous night (typically taken circa 10-13 UT) and the earliest DMSP and NOAA passes from the following evening (typically taken circa 19-22 UT), and use your best judgement about whether passes captured circa 13-16 UT were likely to be "clear". In addition, if you know that it was clear at Palmer (ie the sky was blue!) around local noon, it's worth saving the SeaWiFs passes. If you decide that the SeaWiFs passes for a particular day should be archived, save all of them, which will be two or three during most of the summer. Following this protocol you may find that you have several days in a row when you are saving many passes, possibly as many as 6-8 per day (4 or 5 DMSP or NOAA passes and 2 or 3 SeaWiFs passes), but you may also have long periods, up to a week or two, when you are saving NO passes. That's just the way of the weather. Once you know the pass number(s) of the pass(es) you wish to save, use "archive/write" or "archive/mwrite" to save it/them to the appropriate tape. If you use archive/mwrite, be SURE to answer "new_tape"? NO! DMSP and NOAA passes should be saved to one (sequence of) tape(s), labeled "palmer_" (eg palmer99_18), while SeaWiFs passes should go to another, labeled "palmsw_". Most likely you will use /dev/rmt/0n, and in the winter you can just leave the latest palmer_ tape in this drive. In the summer, when SeaWiFs passes are being collected, you will need to swap tapes in and out to save the passes to the correct tape. SeaWiFs tapes should be retrograded at every opportunity, whether or not they are full. DMSP/NOAA tapes may be filled up before they are sent "home". Tapes should be sent to: Ray Smith ICESS 6812 Ellison Hall University of California Santa Barbara, CA 93106-3060 **************************************************************** II. BP-032-O (Ray Smith, LTER) has made a standing request for weekly 'ice85' images, as TDF files, to be ftp'd to UCSB As part of the post-processing routine applied to each pass, ice85 images (in TDF format) are created for a master that covers the LTER grid. Because of the geometry of the satellite orbits, passes from the morning set of DMSP passes will cover the grid more completely. Each Monday, review the ice85 images from the morning set of DMSP passes for the last three nights. Note the most recent pair of consecutive images that do not show excessive cloudiness around any obvious ice and that, in combination, essentially completely cover the "master" area. Copy these images, as TDF files, into the ~/transfer/SSMI directory, run the Unix command "compress" on them, and during the next satellite pass they will be automatically ftp'd to ftp.icess.ucsb.edu and placed in inbox/palmer. **************************************************************** III. BP-032-O (Ray Smith, LTER) requests browse images (e.g. jpeg) to be emailed to ship during LTER cruises that take place in or near the sea ice. Note, this request will rarely apply to the annual Jan-Feb LTER cruises when little sea ice is 'normally' present but should apply to any other LTER cruises that take place during non-summer months (e.g. NBP99-6 sea ice cruise and the scheduled NBP01-x sea ice cruise). This request will also be reiterated in the relevant cruise SIP. Also note that, now that the NBP has its own TeraScan, it should not require this support unless its system is out of service. Daily browse images are emailed to the ship in support of sea ice sampling logistics and navigation: a) An AVHRR (NOAA) or OLS (DMSP) browse image of clouds and/or sea ice conditions of ship's location and planned sampling area. In dark conditions, when IR data is used, if AVHRR is near nadir over this location, then its higher thermal resolution is preferable for discerning sea ice features of interest. If a near nadir AVHRR image is not available, then a cropped image of OLS (to capitalize on its higher spatial resolution) of sampling area is fine. In daylight conditions, if high resolution OLS visible is available, it's preferable. b) An ice85 browse image that includes the ship's location and planned sampling area, and, if possible, the location of the ice edge with respect to the aforementioned sampling area. For almost all cruise conditions, the automatically generated images covering the LTER grid that were mentioned in Section II above will serve well for this purpose. To produce browse images, start with the TDF image that contains the information that you want, then use xvu to "navigate" the image to correct for registration errors and properly align the coastlines, With this done, use TeraVision to annotate the image appropriately and then to export it to a JPEG file. These JPEG files should be mailed as attachments to "admin@lmg.polar.org" or "admin@nbp.polar.org", as these special accounts circumvent the ship email system's message size restrictions. ****************************************************************