11.1 Obtaining ISOPHOT Data

We will illustrate the PHT data retrieval with an example. Suppose one would like to obtain ISOPHOT data from the bright star Altair. Then the following steps should be taken:

• assuming that an internet connection and web browser are available, one should go to the ISO Data Archive (IDA) at:

           http://www.iso.vilspa.esa.es/ $\rightarrow$ Access the Archive

  and start the IDA applet. The `Query Specification' screen will be displayed. To be able to retrieve the data one should be a registered user, and one must login during an IDA session.

• select PHT data products by de-selecting the AOTs of the other instruments. Then type `Altair' and click on `Execute Query'. A `Latest Results' screen will appear containing all ISOPHOT observations related to Altair. Each AOT is accompanied by a postcard created from the auto-analysis results. The postcard provides a first look at the data. The postcard can be enlarged by clicking on it. Multi-filter single pointing observations are displayed in the form of spectral energy discributions. Products of mapping (including nodding) observations have the image of only the first filter in the AOT displayed in the postcard.

• the data products can be retrieved by moving a selected AOT to the shopping basket. Click on `Shopping Basket' to look at what has been selected. In order to download all PHT OLP products of a given AOT including both Derive_SPD and Derive_AAR products, select `All' for `Products Desired' and click on `Submit Request'. An identification number is assigned to the request and the OLP Version 10 data products are transfered to an anonymous ftp area at ftp.iso.vilspa.esa.es^11.1. When the transference of files is finished the system sends an e-mail message to the electronic address of the registered user telling where to get the data from. To leave this screen press `Dismiss'.

• if e.g. a PHT03 multi-filter staring observation was selected (in this case TDT 3001001) then the following files will be placed in the anonymous ftp area:

  
        aocs13001001.fits            pcsh130.fits
        apph130.fits                 pcsv130.fits
        ccsh130.fits                 pisr13001001.fits
        eoha130.fits                 polr13001001.fits
        eohc130.fits                 pp2a13001001.fits
        eohi130.fits                 pp2s13001001.fits
        gehk13001001.fits            ppap13001001.fits
        gshh130.fits                 pper13001001.fits
        iiph13001001.fits            psp13001001.fits
        irph13001001.fits            psta13001001.fits
        lcsh130.fits                 scsh130.fits
  

  For first look purposes, several files are not relevant. Look in Chapter 12 and the subsequent Chapters in this handbook to determine which products can be expected from PHT OLP and to determine the product contents. According to the Table given in Section 12.2 either PPAP or PPAE are the auto analysis products for this PHT03 observation depending whether the observer of the initial proposal has selected `point source' (PPAP) or `extended source' (PPAE).