INTRODUCTION ------------ Welcome to the MSI documentation browse page. This browse facility is a website that provides an overview, sequencing information and observational guides to the entire MSI data submission. This site is intended to give the user of the MSI data set an overview of what is available in terms of the raw data set. It answers the questions of why and how we acquired these data through the mission. It does not contain information about multiple calibration sets available for each raw frame. This file, welcome.txt, describes what is available in this web site, how it is organized, AND how to use the web site. Since the data set is so large, a complex organizational scheme was necessary to include all of the supporting information provided here. There is a wealth of information available, but unfortunately, some of the most useful tools are not not obvious by just logging into the front page. For the casual user it may not seem particularly user-friendly. For the serious user, the extra time spent getting to understand the organization will pay off in providing a greater understanding of and thus a greater facility with the data set. There are two sections in this text file: I. ORGANIZATIONAL OVERVIEW - This thoroughly describes what is available and how it is organized. II. HOW TO USE THE WEBSITE - This section contains some notes about how to best use this website. I. ORGANIZATIONAL OVERVIEW -------------------------- Below is an overview of the directory structure and contents. Directories and subdirectories are shown with an underline. Listed below each directory are the unique files, each with a brief description, as well as file 'types' and descriptions. This top level directory has two subdirectories: 1) pre_eros, and 2) eros. The major subdivision into 'eros' and 'pre-eros' directories was a logical one, but also reflects the transition to using SEQGEN for sequence building. All sequences in the 'pre-eros' section were built by hand using STOL; everything after was done with SEQGEN and these are contained in the 'eros' subdirectory. Organization of the ancillary files is thus different for each subdirectory. In the pre-eros subdirectory, there are just four subdirectories as shown that represent the major observational events. In the eros section, the files are organized by 'sequence week'. Throughout this period we built one sequence per week and the name of the sequence was the last two digits of the year, plus the day of year. In the 'eros' subdirectory there is an additional subdirectory called 'descript'. Here you will find sorted subsets of the main spreadsheet for the different observation types. Additional information which will help with interpretation of the following files can be found in the /eros/eros_seq_archive.txt and /pre_eros_seq_archive.txt files. sequence -------- msibrowse.htm - main page of website; contains tables with links to the spreadsheets, and other text information files. welcome.txt - this file; explains what is available in the sequence directory and how to use it observation_overview.txt - text description of all MSI activities throughout the mission, linked from all spreadsheets. sequserguide.pdf - this files contains details about how these data were sequenced; useful if user wants to interpret the sequence files provided pre-eros -------- pre_eros_obsv_guide.xls - spreadsheet with description of observations; covers time period 1996/051 to 1998/026. pre_eros_obsv_guide.htm - spreadsheet in HTML format, linked from front page, contains links to plots and text files that explain the observations. pre_eros_columns.txt - describes columns in the above spreadsheet, linked from pre_eros spreadsheet pre_eros_seq_archive.txt - describes in more detail what ancillary sequence files are available and how they are organized; also describes how to interpret the files. This file is linked from the main page, and from the spreadsheet. cruisecals_1 ----------- mathilde -------- cruisecals_2 ------------ earthmoon_flyby --------------- >>>>>> The above four directories may contain some or all of the following types of files: obsv_seq.txt - text description and STOL sequence script; linked from the spreadsheet Sequence column; referenced from the observation_overview.txt file obsv_name.gif - some sequence design plots are available; linked from spreadsheet in Predict column obsv_name.txt - a few description files are available, linked from spreadsheet Detailed Description column and referenced individually from the observation_overview.txt obsv_imagelist.txt - several imagelists are available, referenced from observation_overview.txt event_orbital_info.txt - trajectory information files eros ---- The spreadsheets and html files: a_appr_orbinsert_trns.xls......1998/210 to 2000/063 a_appr_orbinsert_trns.htm b_200km_100km_north.xls...........2000/063 to 2000/121 b_200km_100km_north.htm c_50kma.xls.......................2000/121 to 2000/185 c_50kma.htm d_35kma_50kmb.xls.................2000/185 to 2000/234 d_35kma_50kmb.htm e_100kmsouth_lowalt1.xls..........2000/234 to 2000/297 e_100kmsouth_lowalt1.htm f_200kmsouth.xls..................2000/300 to 2000/348 f_200kmsouth.htm g_35kmbc_lowalt2_land.xls......2000/348 to 2001/043 g_35kmbc_lowalt2_land.htm Other files: eros_columns.txt - describes columns in the spreadsheets, linked from spreadsheets eros_seq_archive.txt - describes what ancillary sequence files are available, how they are organized and how to interpret them; linked from main page, and from the spreadsheets msi_seqid_log.txt - log of when MSI sequence definitions were changed starting on 1998/309; linked from spreadsheets eros_orbital_info.txt - text file that gives information about spacecraft range and viewing to Eros through the orbital mission; linked from main page descript -------- This is an important subdirectory of ../eros that contains description files for observation sub-types, and companion spreadsheets that contain a sorted listing of just those observations. This subdirectory is NOT linked from anywhere in the spreadsheets. However an overview file (observation_key.txt) which lists the files is linked from front page. In addition most of the .txt files ARE linked from the individual observations in the Detailed Description column of the spreadsheets. The .xls files are not linked from anywhere and must be downloaded for use. observation_key.txt - this is a useful file for getting an overview the various observation types available; gives a brief description of the sorted files listed below. approachmovies.xls .txt lightcurves.xls .txt canopuscals.xls .txt rastertests.txt mirrorgeom.txt mirrorplane.txt satsearches.txt misc_cals.xls global.xls .txt globalmovies.xls .txt featuretracks.xls .txt flyover.xls .txt lonscans.xls .txt lowrobitopnavs.xls --> high orbit opnavs are listed in global.xls opnav.txt --> description for high and low orbit opnavs xreqs.xls .txt color200.xls .txt color100.xls .txt color50km.xls .txt color35km.xls .txt colorflyovers.xls only /traj This subdirectory contains trajectory plots for the orbital phases of the mission. There are three types of files, listed below. trajectory_plots.txt - describes the files contained in this subdirectory. traj_xxxxxxx_rtc.txt - range to center vs. time traj_xxxxxxx_lat.txt - sub-s/c latitude vs. time traj_xxxxxxx_rts.txt - range to surface vs. time /loworbit This subdirectory contains maps of the low orbit coverage loworbit_maps.txt - this file lists the maps available with brief description. xreqs_xxxxx.gif - example of a map >>>> The following subdirectories of /eros ARE linked from the Sequence column in the 7 major Eros spreadsheets. The link will take you to the directory itself where the files can be accessed. Only the .gif files are linked directly from the spreadsheets (in the Predict columns). 99201 ----- -- through -- 01036 ----- >>>>> The above subdirectories may contain some or all of the following file types: yydoy_final_sasf.txt - sequence file for sequencing week 'yydoy' yydoy.msi - command expansion of the above sequence for msi with pointing yydoy.nis - command expansion of the above sequence for nis with pointing (the above two files are not available for some of the early sequence weeks) yydoy.imagelist - One line for each image, gives summary info about each image. Only available for 98357 and all weeks after week 99340. obsv_name.gif - One or more plots exists for most of the observations. Some observations have none. These ARE linked from the 'Predict' columns in the spreadsheets. See ../eros/eros_columns.txt for explanation. I. HOW TO USE THIS WEB PAGE ---------------------------- The main portion of the front page of this website is dedicated to the 8 spreadsheets that collectively list each observation acquired through the mission. Links are available directly from those spreadsheets which can take you to description files and plots as well as the subdirectories containing sequence files and imagelists. These will be an invaluable resource for the user that has an overall understanding of what is available. Unfortunately, I have found them difficult to work with on the web page because they are so wide and also because they take too much time to reload after looking at the linked files. In fact, the primary reason we broke them into the eight separate files was because some commonly available web browsers (Netscape, for example) were incapable of loading the full spreadsheet. I would suggest downloading the Excel versions of the spreadsheets to your local computer. To access the the associated files (gif plots, imagelists and so forth) from the web page, it is easiest to go to the appropriate subdirectory and click on the files to open them up directly. The files pop up and down more quickly this way. Manuevering through the directories is much faster as well. The other problem is that there is just so much data contained in the spreadsheets that they are not a good way to get an overview of what is available. How to get the overview: 1) The observation_overview.txt file (linked from the main page, and also from the top of each spreadsheet) contains a descriptive overview of why and how all of these data were acquired. This file is also somewhat cumbersome, but it is well organized. This file is divided into chapters that progressively move through each time period in the mission. Chapter 1 contains the directory contents, and lists what time period is covered by each chapter. It also has a guide to supporting files available. You can proceed to the chapter containing the part of the mission of interest to you. Each chapter has a sub-section that describes historical context, and one that describes sequence design. In the sequence design section you will find description of observation TYPES for that orbital phase. Take a little time to scan through through the observation_overview.txt, at least enough to get a feel for what was done during the different orbital phases of the mission. This will provide a important context for understanding what data was acquired and why. Because the viewing geometry changed so dramatically as a function of orbital phase, the science goals as well as observation designs varied correspondingly. There simply was no quick way to summarize this information without being vague and misleading. ***>>> Chapter 11 is a nice overview of the orbital mission. That is a good place to start if you are just interested in the Eros orbital data. 2) The second most useful way to get an overview is go to the /eros/descript/ subdirectory and look at the file called observation_key.txt. This file describes the contents of this subdirectory which basically contains a set of excel spreadsheets are are subsets of the larger spreadsheets. I have sorted out all observations for specific catagories and put them in these separate spreadsheets (e.g., color100.xls, approachmovies.txt, lightcurves.txt, etc.). These .xls files are not directly linked from anyplace on the main 7 eros spreadsheets. They must be downloaded for use. Also, html versions are not available. For almost all of the spreadsheets in this directory, a companion .txt file exists that provides a descriptive summary of the observations. This gives a little more information about the observations than was possible in the Brief Description column of the spreadsheets. Most of these .txt files ARE actually LINKED from the Detailed Description column in the 7 main eros spreadsheets for each observation. I expect that these will be very useful for people working with specific data sub-types. Good luck!