NAME

Rinchi::CIGIPP::EnvironmentalConditionsRequest - Perl extension for the Common Image Generator Interface - Environmental Conditions Request data packet. data packet. =head1 SYNOPSIS

  use Rinchi::CIGIPP::EnvironmentalConditionsRequest;
  my $ec_rqst = Rinchi::CIGIPP::EnvironmentalConditionsRequest->new();

  $packet_type = $ec_rqst->packet_type();
  $packet_size = $ec_rqst->packet_size();
  $request_type_ac = $ec_rqst->request_type_ac(0);
  $request_type_wc = $ec_rqst->request_type_wc(1);
  $request_type_tsc = $ec_rqst->request_type_tsc(0);
  $request_type_msc = $ec_rqst->request_type_msc(0);
  $request_ident = $ec_rqst->request_ident(167);
  $latitude = $ec_rqst->latitude(28.347);
  $longitude = $ec_rqst->longitude(82.085);
  $altitude = $ec_rqst->altitude(38.01);

DESCRIPTION

At any given location, it may be impossible for the Host to determine exactly the visibility range, air temperature, or other atmospheric or surface conditions. One factor is that various IG implementations may differ in how they calculate values across transition bands and within overlapping regions. Random phenomena such as winds aloft, scud, and wave activity may also make determining instantaneous conditions at a specific point impossible.

The Environmental Conditions Request packet is used by the Host to request the state of the environment at a specific location. The Request Type attribute determines what data are returned by the IG. Each request type is represented by a power of two (i.e., a unique bit), so request types may be combined by adding or bit-wise ORing the values together.

For a given test point, the IG may respond with no more than one of each of the Maritime Surface Conditions Response and Weather Conditions Response packets. For terrestrial surface conditions requests, the IG should respond with one Terrestrial Surface Conditions Response packet for each surface condition type or attribute present at the test point. If the Request Type attribute specifies that aerosol concentrations should be returned, the IG must send a Weather Conditions Aerosol Response packet for each weather layer that encompasses the test point.

EXPORT

None by default.

#==============================================================================

new $ec_rqst = Rinchi::CIGIPP::EnvironmentalConditionsRequest->new()

Constructor for Rinchi::EnvironmentalConditionsRequest.

sub packet_type()

 $value = $ec_rqst->packet_type();

Data Packet Identifier.

This attribute identifies this data packet as the Environmental Conditions Request packet. The value of this attribute must be 28.

sub packet_size()

 $value = $ec_rqst->packet_size();

Data Packet Size.

This attribute indicates the number of bytes in this data packet. The value of this attribute must be 32.

sub request_type_ac([$newValue])

 $value = $ec_rqst->request_type_ac($newValue);

Request Type.

This attribute specifies the desired response type for the request. The numerical values listed at left may be combined by addition or bit-wise OR. The resulting value may be any combination of the following:

Aerosol Concentrations – The IG will send exactly one Aerosol Concentration Response packet for each weather layer (regardless of scope) that encompasses that location.

sub request_type_wc([$newValue])

 $value = $ec_rqst->request_type_wc($newValue);

Request Type.

This attribute specifies the desired response type for the request. The numerical values listed at left may be combined by addition or bit-wise OR. The resulting value may be any combination of the following:

Weather Conditions – The IG will respond with a Weather Conditions Response packet.

sub request_type_tsc([$newValue])

 $value = $ec_rqst->request_type_tsc($newValue);

Request Type.

This attribute specifies the desired response type for the request. The numerical values listed at left may be combined by addition or bit-wise OR. The resulting value may be any combination of the following:

Terrestrial Surface Conditions – The IG will respond with a Terrestrial Surface Conditions Response packet.

sub request_type_msc([$newValue])

 $value = $ec_rqst->request_type_msc($newValue);

Request Type.

This attribute specifies the desired response type for the request. The numerical values listed at left may be combined by addition or bit-wise OR. The resulting value may be any combination of the following:

Maritime Surface Conditions – The IG will respond with a Maritime Surface Conditions Response packet.

sub request_ident([$newValue])

 $value = $ec_rqst->request_ident($newValue);

Request ID.

This attribute identifies the environmental conditions request. When the IG returns a responds to the request, each response packet(s) will contain this value in its Request ID attribute.

sub latitude([$newValue])

 $value = $ec_rqst->latitude($newValue);

Latitude.

This attribute specifies the geodetic latitude at which the environmental state is requested.

sub longitude([$newValue])

 $value = $ec_rqst->longitude($newValue);

Longitude.

This attribute specifies the geodetic longitude at which the environmental state is requested.

sub altitude([$newValue])

 $value = $ec_rqst->altitude($newValue);

Altitude.

This attribute specifies the geodetic altitude in meters above mean sea level at which the environmental state is requested.

This attribute is used only for weather conditions and aerosol concentrations requests.

sub pack()

 $value = $ec_rqst->pack();

Returns the packed data packet.

sub unpack()

 $value = $ec_rqst->unpack();

Unpacks the packed data packet.

sub byte_swap()

 $obj_name->byte_swap();

Byte swaps the packed data packet.

SEE ALSO

Refer the the Common Image Generator Interface ICD which may be had at this URL: http://cigi.sourceforge.net/specification.php

AUTHOR

Brian M. Ames, <bmames@apk.net>

COPYRIGHT AND LICENSE

Copyright (C) 2009 by Brian M. Ames

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.6 or, at your option, any later version of Perl 5 you may have available.